diff options
Diffstat (limited to 'drivers/opus/opusfile.c')
| -rw-r--r-- | drivers/opus/opusfile.c | 3275 |
1 files changed, 0 insertions, 3275 deletions
diff --git a/drivers/opus/opusfile.c b/drivers/opus/opusfile.c deleted file mode 100644 index a9d6cc4d63..0000000000 --- a/drivers/opus/opusfile.c +++ /dev/null @@ -1,3275 +0,0 @@ -/******************************************************************** - * * - * THIS FILE IS PART OF THE libopusfile SOFTWARE CODEC SOURCE CODE. * - * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS * - * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE * - * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. * - * * - * THE libopusfile SOURCE CODE IS (C) COPYRIGHT 1994-2012 * - * by the Xiph.Org Foundation and contributors http://www.xiph.org/ * - * * - ******************************************************************** - - function: stdio-based convenience library for opening/seeking/decoding - last mod: $Id: vorbisfile.c 17573 2010-10-27 14:53:59Z xiphmont $ - - ********************************************************************/ -#include "opus/opus_config.h" - -#include "opus/internal.h" -#include <stdio.h> -#include <stdlib.h> -#include <errno.h> -#include <limits.h> -#include <string.h> -#include <math.h> - -#include "opus/opusfile.h" - -/*This implementation is largely based off of libvorbisfile. - All of the Ogg bits work roughly the same, though I have made some - "improvements" that have not been folded back there, yet.*/ - -/*A 'chained bitstream' is an Ogg Opus bitstream that contains more than one - logical bitstream arranged end to end (the only form of Ogg multiplexing - supported by this library. - Grouping (parallel multiplexing) is not supported, except to the extent that - if there are multiple logical Ogg streams in a single link of the chain, we - will ignore all but the first Opus stream we find.*/ - -/*An Ogg Opus file can be played beginning to end (streamed) without worrying - ahead of time about chaining (see opusdec from the opus-tools package). - If we have the whole file, however, and want random access - (seeking/scrubbing) or desire to know the total length/time of a file, we - need to account for the possibility of chaining.*/ - -/*We can handle things a number of ways. - We can determine the entire bitstream structure right off the bat, or find - pieces on demand. - This library determines and caches structure for the entire bitstream, but - builds a virtual decoder on the fly when moving between links in the chain.*/ - -/*There are also different ways to implement seeking. - Enough information exists in an Ogg bitstream to seek to sample-granularity - positions in the output. - Or, one can seek by picking some portion of the stream roughly in the desired - area if we only want coarse navigation through the stream. - We implement and expose both strategies.*/ - -/*The maximum number of bytes in a page (including the page headers).*/ -#define OP_PAGE_SIZE_MAX (65307) -/*The default amount to seek backwards per step when trying to find the - previous page. - This must be at least as large as the maximum size of a page.*/ -#define OP_CHUNK_SIZE (65536) -/*The maximum amount to seek backwards per step when trying to find the - previous page.*/ -#define OP_CHUNK_SIZE_MAX (1024*(opus_int32)1024) -/*A smaller read size is needed for low-rate streaming.*/ -#define OP_READ_SIZE (2048) - -int op_test(OpusHead *_head, - const unsigned char *_initial_data,size_t _initial_bytes){ - ogg_sync_state oy; - char *data; - int err; - /*The first page of a normal Opus file will be at most 57 bytes (27 Ogg - page header bytes + 1 lacing value + 21 Opus header bytes + 8 channel - mapping bytes). - It will be at least 47 bytes (27 Ogg page header bytes + 1 lacing value + - 19 Opus header bytes using channel mapping family 0). - If we don't have at least that much data, give up now.*/ - if(_initial_bytes<47)return OP_FALSE; - /*Only proceed if we start with the magic OggS string. - This is to prevent us spending a lot of time allocating memory and looking - for Ogg pages in non-Ogg files.*/ - if(memcmp(_initial_data,"OggS",4)!=0)return OP_ENOTFORMAT; - ogg_sync_init(&oy); - data=ogg_sync_buffer(&oy,_initial_bytes); - if(data!=NULL){ - ogg_stream_state os; - ogg_page og; - int ret; - memcpy(data,_initial_data,_initial_bytes); - ogg_sync_wrote(&oy,_initial_bytes); - ogg_stream_init(&os,-1); - err=OP_FALSE; - do{ - ogg_packet op; - ret=ogg_sync_pageout(&oy,&og); - /*Ignore holes.*/ - if(ret<0)continue; - /*Stop if we run out of data.*/ - if(!ret)break; - ogg_stream_reset_serialno(&os,ogg_page_serialno(&og)); - ogg_stream_pagein(&os,&og); - /*Only process the first packet on this page (if it's a BOS packet, - it's required to be the only one).*/ - if(ogg_stream_packetout(&os,&op)==1){ - if(op.b_o_s){ - ret=opus_head_parse(_head,op.packet,op.bytes); - /*If this didn't look like Opus, keep going.*/ - if(ret==OP_ENOTFORMAT)continue; - /*Otherwise we're done, one way or another.*/ - err=ret; - } - /*We finished parsing the headers. - There is no Opus to be found.*/ - else err=OP_ENOTFORMAT; - } - } - while(err==OP_FALSE); - ogg_stream_clear(&os); - } - else err=OP_EFAULT; - ogg_sync_clear(&oy); - return err; -} - -/*Many, many internal helpers. - The intention is not to be confusing. - Rampant duplication and monolithic function implementation (though we do have - some large, omnibus functions still) would be harder to understand anyway. - The high level functions are last. - Begin grokking near the end of the file if you prefer to read things - top-down.*/ - -/*The read/seek functions track absolute position within the stream.*/ - -/*Read a little more data from the file/pipe into the ogg_sync framer. - _nbytes: The maximum number of bytes to read. - Return: A positive number of bytes read on success, 0 on end-of-file, or a - negative value on failure.*/ -static int op_get_data(OggOpusFile *_of,int _nbytes){ - unsigned char *buffer; - int nbytes; - OP_ASSERT(_nbytes>0); - buffer=(unsigned char *)ogg_sync_buffer(&_of->oy,_nbytes); - nbytes=(int)(*_of->callbacks.read)(_of->source,buffer,_nbytes); - OP_ASSERT(nbytes<=_nbytes); - if(OP_LIKELY(nbytes>0))ogg_sync_wrote(&_of->oy,nbytes); - return nbytes; -} - -/*Save a tiny smidge of verbosity to make the code more readable.*/ -static int op_seek_helper(OggOpusFile *_of,opus_int64 _offset){ - if(_offset==_of->offset)return 0; - if(_of->callbacks.seek==NULL - ||(*_of->callbacks.seek)(_of->source,_offset,SEEK_SET)){ - return OP_EREAD; - } - _of->offset=_offset; - ogg_sync_reset(&_of->oy); - return 0; -} - -/*Get the current position indicator of the underlying source. - This should be the same as the value reported by tell().*/ -static opus_int64 op_position(const OggOpusFile *_of){ - /*The current position indicator is _not_ simply offset. - We may also have unprocessed, buffered data in the sync state.*/ - return _of->offset+_of->oy.fill-_of->oy.returned; -} - -/*From the head of the stream, get the next page. - _boundary specifies if the function is allowed to fetch more data from the - stream (and how much) or only use internally buffered data. - _boundary: -1: Unbounded search. - 0: Read no additional data. - Use only cached data. - n: Search for the start of a new page up to file position n. - Return: n>=0: Found a page at absolute offset n. - OP_FALSE: Hit the _boundary limit. - OP_EREAD: An underlying read operation failed. - OP_BADLINK: We hit end-of-file before reaching _boundary.*/ -static opus_int64 op_get_next_page(OggOpusFile *_of,ogg_page *_og, - opus_int64 _boundary){ - while(_boundary<=0||_of->offset<_boundary){ - int more; - more=ogg_sync_pageseek(&_of->oy,_og); - /*Skipped (-more) bytes.*/ - if(OP_UNLIKELY(more<0))_of->offset-=more; - else if(more==0){ - int read_nbytes; - int ret; - /*Send more paramedics.*/ - if(!_boundary)return OP_FALSE; - if(_boundary<0)read_nbytes=OP_READ_SIZE; - else{ - opus_int64 position; - position=op_position(_of); - if(position>=_boundary)return OP_FALSE; - read_nbytes=(int)OP_MIN(_boundary-position,OP_READ_SIZE); - } - ret=op_get_data(_of,read_nbytes); - if(OP_UNLIKELY(ret<0))return OP_EREAD; - if(OP_UNLIKELY(ret==0)){ - /*Only fail cleanly on EOF if we didn't have a known boundary. - Otherwise, we should have been able to reach that boundary, and this - is a fatal error.*/ - return OP_UNLIKELY(_boundary<0)?OP_FALSE:OP_EBADLINK; - } - } - else{ - /*Got a page. - Return the page start offset and advance the internal offset past the - page end.*/ - opus_int64 page_offset; - page_offset=_of->offset; - _of->offset+=more; - OP_ASSERT(page_offset>=0); - return page_offset; - } - } - return OP_FALSE; -} - -static int op_add_serialno(const ogg_page *_og, - ogg_uint32_t **_serialnos,int *_nserialnos,int *_cserialnos){ - ogg_uint32_t *serialnos; - int nserialnos; - int cserialnos; - ogg_uint32_t s; - s=ogg_page_serialno(_og); - serialnos=*_serialnos; - nserialnos=*_nserialnos; - cserialnos=*_cserialnos; - if(OP_UNLIKELY(nserialnos>=cserialnos)){ - if(OP_UNLIKELY(cserialnos>INT_MAX/(int)sizeof(*serialnos)-1>>1)){ - return OP_EFAULT; - } - cserialnos=2*cserialnos+1; - OP_ASSERT(nserialnos<cserialnos); - serialnos=(ogg_uint32_t *)_ogg_realloc(serialnos, - sizeof(*serialnos)*cserialnos); - if(OP_UNLIKELY(serialnos==NULL))return OP_EFAULT; - } - serialnos[nserialnos++]=s; - *_serialnos=serialnos; - *_nserialnos=nserialnos; - *_cserialnos=cserialnos; - return 0; -} - -/*Returns nonzero if found.*/ -static int op_lookup_serialno(ogg_uint32_t _s, - const ogg_uint32_t *_serialnos,int _nserialnos){ - int i; - for(i=0;i<_nserialnos&&_serialnos[i]!=_s;i++); - return i<_nserialnos; -} - -static int op_lookup_page_serialno(const ogg_page *_og, - const ogg_uint32_t *_serialnos,int _nserialnos){ - return op_lookup_serialno(ogg_page_serialno(_og),_serialnos,_nserialnos); -} - -typedef struct OpusSeekRecord OpusSeekRecord; - -/*We use this to remember the pages we found while enumerating the links of a - chained stream. - We keep track of the starting and ending offsets, as well as the point we - started searching from, so we know where to bisect. - We also keep the serial number, so we can tell if the page belonged to the - current link or not, as well as the granule position, to aid in estimating - the start of the link.*/ -struct OpusSeekRecord{ - /*The earliest byte we know of such that reading forward from it causes - capture to be regained at this page.*/ - opus_int64 search_start; - /*The offset of this page.*/ - opus_int64 offset; - /*The size of this page.*/ - opus_int32 size; - /*The serial number of this page.*/ - ogg_uint32_t serialno; - /*The granule position of this page.*/ - ogg_int64_t gp; -}; - -/*Find the last page beginning before _offset with a valid granule position. - There is no '_boundary' parameter as it will always have to read more data. - This is much dirtier than the above, as Ogg doesn't have any backward search - linkage. - This search prefers pages of the specified serial number. - If a page of the specified serial number is spotted during the - seek-back-and-read-forward, it will return the info of last page of the - matching serial number, instead of the very last page, unless the very last - page belongs to a different link than preferred serial number. - If no page of the specified serial number is seen, it will return the info of - the last page. - [out] _sr: Returns information about the page that was found on success. - _offset: The _offset before which to find a page. - Any page returned will consist of data entirely before _offset. - _serialno: The preferred serial number. - If a page with this serial number is found, it will be returned - even if another page in the same link is found closer to - _offset. - This is purely opportunistic: there is no guarantee such a page - will be found if it exists. - _serialnos: The list of serial numbers in the link that contains the - preferred serial number. - _nserialnos: The number of serial numbers in the current link. - Return: 0 on success, or a negative value on failure. - OP_EREAD: Failed to read more data (error or EOF). - OP_EBADLINK: We couldn't find a page even after seeking back to the - start of the stream.*/ -static int op_get_prev_page_serial(OggOpusFile *_of,OpusSeekRecord *_sr, - opus_int64 _offset,ogg_uint32_t _serialno, - const ogg_uint32_t *_serialnos,int _nserialnos){ - OpusSeekRecord preferred_sr; - ogg_page og; - opus_int64 begin; - opus_int64 end; - opus_int64 original_end; - opus_int32 chunk_size; - int preferred_found; - original_end=end=begin=_offset; - preferred_found=0; - _offset=-1; - chunk_size=OP_CHUNK_SIZE; - do{ - opus_int64 search_start; - int ret; - OP_ASSERT(chunk_size>=OP_PAGE_SIZE_MAX); - begin=OP_MAX(begin-chunk_size,0); - ret=op_seek_helper(_of,begin); - if(OP_UNLIKELY(ret<0))return ret; - search_start=begin; - while(_of->offset<end){ - opus_int64 llret; - ogg_uint32_t serialno; - llret=op_get_next_page(_of,&og,end); - if(OP_UNLIKELY(llret<OP_FALSE))return (int)llret; - else if(llret==OP_FALSE)break; - serialno=ogg_page_serialno(&og); - /*Save the information for this page. - We're not interested in the page itself... just the serial number, byte - offset, page size, and granule position.*/ - _sr->search_start=search_start; - _sr->offset=_offset=llret; - _sr->serialno=serialno; - OP_ASSERT(_of->offset-_offset>=0); - OP_ASSERT(_of->offset-_offset<=OP_PAGE_SIZE_MAX); - _sr->size=(opus_int32)(_of->offset-_offset); - _sr->gp=ogg_page_granulepos(&og); - /*If this page is from the stream we're looking for, remember it.*/ - if(serialno==_serialno){ - preferred_found=1; - *&preferred_sr=*_sr; - } - if(!op_lookup_serialno(serialno,_serialnos,_nserialnos)){ - /*We fell off the end of the link, which means we seeked back too far - and shouldn't have been looking in that link to begin with. - If we found the preferred serial number, forget that we saw it.*/ - preferred_found=0; - } - search_start=llret+1; - } - /*We started from the beginning of the stream and found nothing. - This should be impossible unless the contents of the source changed out - from under us after we read from it.*/ - if(OP_UNLIKELY(!begin)&&OP_UNLIKELY(_offset<0))return OP_EBADLINK; - /*Bump up the chunk size. - This is mildly helpful when seeks are very expensive (http).*/ - chunk_size=OP_MIN(2*chunk_size,OP_CHUNK_SIZE_MAX); - /*Avoid quadratic complexity if we hit an invalid patch of the file.*/ - end=OP_MIN(begin+OP_PAGE_SIZE_MAX-1,original_end); - } - while(_offset<0); - if(preferred_found)*_sr=*&preferred_sr; - return 0; -} - -/*Find the last page beginning before _offset with the given serial number and - a valid granule position. - Unlike the above search, this continues until it finds such a page, but does - not stray outside the current link. - We could implement it (inefficiently) by calling op_get_prev_page_serial() - repeatedly until it returned a page that had both our preferred serial - number and a valid granule position, but doing it with a separate function - allows us to avoid repeatedly re-scanning valid pages from other streams as - we seek-back-and-read-forward. - [out] _gp: Returns the granule position of the page that was found on - success. - _offset: The _offset before which to find a page. - Any page returned will consist of data entirely before _offset. - _serialno: The target serial number. - _serialnos: The list of serial numbers in the link that contains the - preferred serial number. - _nserialnos: The number of serial numbers in the current link. - Return: The offset of the page on success, or a negative value on failure. - OP_EREAD: Failed to read more data (error or EOF). - OP_EBADLINK: We couldn't find a page even after seeking back past the - beginning of the link.*/ -static opus_int64 op_get_last_page(OggOpusFile *_of,ogg_int64_t *_gp, - opus_int64 _offset,ogg_uint32_t _serialno, - const ogg_uint32_t *_serialnos,int _nserialnos){ - ogg_page og; - ogg_int64_t gp; - opus_int64 begin; - opus_int64 end; - opus_int64 original_end; - opus_int32 chunk_size; - /*The target serial number must belong to the current link.*/ - OP_ASSERT(op_lookup_serialno(_serialno,_serialnos,_nserialnos)); - original_end=end=begin=_offset; - _offset=-1; - /*We shouldn't have to initialize gp, but gcc is too dumb to figure out that - ret>=0 implies we entered the if(page_gp!=-1) block at least once.*/ - gp=-1; - chunk_size=OP_CHUNK_SIZE; - do{ - int left_link; - int ret; - OP_ASSERT(chunk_size>=OP_PAGE_SIZE_MAX); - begin=OP_MAX(begin-chunk_size,0); - ret=op_seek_helper(_of,begin); - if(OP_UNLIKELY(ret<0))return ret; - left_link=0; - while(_of->offset<end){ - opus_int64 llret; - ogg_uint32_t serialno; - llret=op_get_next_page(_of,&og,end); - if(OP_UNLIKELY(llret<OP_FALSE))return llret; - else if(llret==OP_FALSE)break; - serialno=ogg_page_serialno(&og); - if(serialno==_serialno){ - ogg_int64_t page_gp; - /*The page is from the right stream...*/ - page_gp=ogg_page_granulepos(&og); - if(page_gp!=-1){ - /*And has a valid granule position. - Let's remember it.*/ - _offset=llret; - gp=page_gp; - } - } - else if(OP_UNLIKELY(!op_lookup_serialno(serialno, - _serialnos,_nserialnos))){ - /*We fell off the start of the link, which means we don't need to keep - seeking any farther back.*/ - left_link=1; - } - } - /*We started from at or before the beginning of the link and found nothing. - This should be impossible unless the contents of the source changed out - from under us after we read from it.*/ - if((OP_UNLIKELY(left_link)||OP_UNLIKELY(!begin))&&OP_UNLIKELY(_offset<0)){ - return OP_EBADLINK; - } - /*Bump up the chunk size. - This is mildly helpful when seeks are very expensive (http).*/ - chunk_size=OP_MIN(2*chunk_size,OP_CHUNK_SIZE_MAX); - /*Avoid quadratic complexity if we hit an invalid patch of the file.*/ - end=OP_MIN(begin+OP_PAGE_SIZE_MAX-1,original_end); - } - while(_offset<0); - *_gp=gp; - return _offset; -} - -/*Uses the local ogg_stream storage in _of. - This is important for non-streaming input sources.*/ -static int op_fetch_headers_impl(OggOpusFile *_of,OpusHead *_head, - OpusTags *_tags,ogg_uint32_t **_serialnos,int *_nserialnos, - int *_cserialnos,ogg_page *_og){ - ogg_packet op; - int ret; - if(_serialnos!=NULL)*_nserialnos=0; - /*Extract the serialnos of all BOS pages plus the first set of Opus headers - we see in the link.*/ - while(ogg_page_bos(_og)){ - if(_serialnos!=NULL){ - if(OP_UNLIKELY(op_lookup_page_serialno(_og,*_serialnos,*_nserialnos))){ - /*A dupe serialnumber in an initial header packet set==invalid stream.*/ - return OP_EBADHEADER; - } - ret=op_add_serialno(_og,_serialnos,_nserialnos,_cserialnos); - if(OP_UNLIKELY(ret<0))return ret; - } - if(_of->ready_state<OP_STREAMSET){ - /*We don't have an Opus stream in this link yet, so begin prospective - stream setup. - We need a stream to get packets.*/ - ogg_stream_reset_serialno(&_of->os,ogg_page_serialno(_og)); - ogg_stream_pagein(&_of->os,_og); - if(OP_LIKELY(ogg_stream_packetout(&_of->os,&op)>0)){ - ret=opus_head_parse(_head,op.packet,op.bytes); - /*Found a valid Opus header. - Continue setup.*/ - if(OP_LIKELY(ret>=0))_of->ready_state=OP_STREAMSET; - /*If it's just a stream type we don't recognize, ignore it. - Everything else is fatal.*/ - else if(ret!=OP_ENOTFORMAT)return ret; - } - } - /*Get the next page. - No need to clamp the boundary offset against _of->end, as all errors - become OP_ENOTFORMAT or OP_EBADHEADER.*/ - if(OP_UNLIKELY(op_get_next_page(_of,_og, - OP_ADV_OFFSET(_of->offset,OP_CHUNK_SIZE))<0)){ - return _of->ready_state<OP_STREAMSET?OP_ENOTFORMAT:OP_EBADHEADER; - } - } - if(OP_UNLIKELY(_of->ready_state!=OP_STREAMSET))return OP_ENOTFORMAT; - /*If the first non-header page belonged to our Opus stream, submit it.*/ - if(_of->os.serialno==ogg_page_serialno(_og))ogg_stream_pagein(&_of->os,_og); - /*Loop getting packets.*/ - for(;;){ - switch(ogg_stream_packetout(&_of->os,&op)){ - case 0:{ - /*Loop getting pages.*/ - for(;;){ - /*No need to clamp the boundary offset against _of->end, as all - errors become OP_EBADHEADER.*/ - if(OP_UNLIKELY(op_get_next_page(_of,_og, - OP_ADV_OFFSET(_of->offset,OP_CHUNK_SIZE))<0)){ - return OP_EBADHEADER; - } - /*If this page belongs to the correct stream, go parse it.*/ - if(_of->os.serialno==ogg_page_serialno(_og)){ - ogg_stream_pagein(&_of->os,_og); - break; - } - /*If the link ends before we see the Opus comment header, abort.*/ - if(OP_UNLIKELY(ogg_page_bos(_og)))return OP_EBADHEADER; - /*Otherwise, keep looking.*/ - } - }break; - /*We shouldn't get a hole in the headers!*/ - case -1:return OP_EBADHEADER; - default:{ - /*Got a packet. - It should be the comment header.*/ - ret=opus_tags_parse(_tags,op.packet,op.bytes); - if(OP_UNLIKELY(ret<0))return ret; - /*Make sure the page terminated at the end of the comment header. - If there is another packet on the page, or part of a packet, then - reject the stream. - Otherwise seekable sources won't be able to seek back to the start - properly.*/ - ret=ogg_stream_packetout(&_of->os,&op); - if(OP_UNLIKELY(ret!=0) - ||OP_UNLIKELY(_og->header[_og->header_len-1]==255)){ - /*If we fail, the caller assumes our tags are uninitialized.*/ - opus_tags_clear(_tags); - return OP_EBADHEADER; - } - return 0; - } - } - } -} - -static int op_fetch_headers(OggOpusFile *_of,OpusHead *_head, - OpusTags *_tags,ogg_uint32_t **_serialnos,int *_nserialnos, - int *_cserialnos,ogg_page *_og){ - ogg_page og; - int ret; - if(!_og){ - /*No need to clamp the boundary offset against _of->end, as all errors - become OP_ENOTFORMAT.*/ - if(OP_UNLIKELY(op_get_next_page(_of,&og, - OP_ADV_OFFSET(_of->offset,OP_CHUNK_SIZE))<0)){ - return OP_ENOTFORMAT; - } - _og=&og; - } - _of->ready_state=OP_OPENED; - ret=op_fetch_headers_impl(_of,_head,_tags,_serialnos,_nserialnos, - _cserialnos,_og); - /*Revert back from OP_STREAMSET to OP_OPENED on failure, to prevent - double-free of the tags in an unseekable stream.*/ - if(OP_UNLIKELY(ret<0))_of->ready_state=OP_OPENED; - return ret; -} - -/*Granule position manipulation routines. - A granule position is defined to be an unsigned 64-bit integer, with the - special value -1 in two's complement indicating an unset or invalid granule - position. - We are not guaranteed to have an unsigned 64-bit type, so we construct the - following routines that - a) Properly order negative numbers as larger than positive numbers, and - b) Check for underflow or overflow past the special -1 value. - This lets us operate on the full, valid range of granule positions in a - consistent and safe manner. - This full range is organized into distinct regions: - [ -1 (invalid) ][ 0 ... OP_INT64_MAX ][ OP_INT64_MIN ... -2 ][-1 (invalid) ] - - No one should actually use granule positions so large that they're negative, - even if they are technically valid, as very little software handles them - correctly (including most of Xiph.Org's). - This library also refuses to support durations so large they won't fit in a - signed 64-bit integer (to avoid exposing this mess to the application, and - to simplify a good deal of internal arithmetic), so the only way to use them - successfully is if pcm_start is very large. - This means there isn't anything you can do with negative granule positions - that you couldn't have done with purely non-negative ones. - The main purpose of these routines is to allow us to think very explicitly - about the possible failure cases of all granule position manipulations.*/ - -/*Safely adds a small signed integer to a valid (not -1) granule position. - The result can use the full 64-bit range of values (both positive and - negative), but will fail on overflow (wrapping past -1; wrapping past - OP_INT64_MAX is explicitly okay). - [out] _dst_gp: The resulting granule position. - Only modified on success. - _src_gp: The granule position to add to. - This must not be -1. - _delta: The amount to add. - This is allowed to be up to 32 bits to support the maximum - duration of a single Ogg page (255 packets * 120 ms per - packet == 1,468,800 samples at 48 kHz). - Return: 0 on success, or OP_EINVAL if the result would wrap around past -1.*/ -static int op_granpos_add(ogg_int64_t *_dst_gp,ogg_int64_t _src_gp, - opus_int32 _delta){ - /*The code below handles this case correctly, but there's no reason we - should ever be called with these values, so make sure we aren't.*/ - OP_ASSERT(_src_gp!=-1); - if(_delta>0){ - /*Adding this amount to the granule position would overflow its 64-bit - range.*/ - if(OP_UNLIKELY(_src_gp<0)&&OP_UNLIKELY(_src_gp>=-1-_delta))return OP_EINVAL; - if(OP_UNLIKELY(_src_gp>OP_INT64_MAX-_delta)){ - /*Adding this amount to the granule position would overflow the positive - half of its 64-bit range. - Since signed overflow is undefined in C, do it in a way the compiler - isn't allowed to screw up.*/ - _delta-=(opus_int32)(OP_INT64_MAX-_src_gp)+1; - _src_gp=OP_INT64_MIN; - } - } - else if(_delta<0){ - /*Subtracting this amount from the granule position would underflow its - 64-bit range.*/ - if(_src_gp>=0&&OP_UNLIKELY(_src_gp<-_delta))return OP_EINVAL; - if(OP_UNLIKELY(_src_gp<OP_INT64_MIN-_delta)){ - /*Subtracting this amount from the granule position would underflow the - negative half of its 64-bit range. - Since signed underflow is undefined in C, do it in a way the compiler - isn't allowed to screw up.*/ - _delta+=(opus_int32)(_src_gp-OP_INT64_MIN)+1; - _src_gp=OP_INT64_MAX; - } - } - *_dst_gp=_src_gp+_delta; - return 0; -} - -/*Safely computes the difference between two granule positions. - The difference must fit in a signed 64-bit integer, or the function fails. - It correctly handles the case where the granule position has wrapped around - from positive values to negative ones. - [out] _delta: The difference between the granule positions. - Only modified on success. - _gp_a: The granule position to subtract from. - This must not be -1. - _gp_b: The granule position to subtract. - This must not be -1. - Return: 0 on success, or OP_EINVAL if the result would not fit in a signed - 64-bit integer.*/ -static int op_granpos_diff(ogg_int64_t *_delta, - ogg_int64_t _gp_a,ogg_int64_t _gp_b){ - int gp_a_negative; - int gp_b_negative; - /*The code below handles these cases correctly, but there's no reason we - should ever be called with these values, so make sure we aren't.*/ - OP_ASSERT(_gp_a!=-1); - OP_ASSERT(_gp_b!=-1); - gp_a_negative=OP_UNLIKELY(_gp_a<0); - gp_b_negative=OP_UNLIKELY(_gp_b<0); - if(OP_UNLIKELY(gp_a_negative^gp_b_negative)){ - ogg_int64_t da; - ogg_int64_t db; - if(gp_a_negative){ - /*_gp_a has wrapped to a negative value but _gp_b hasn't: the difference - should be positive.*/ - /*Step 1: Handle wrapping.*/ - /*_gp_a < 0 => da < 0.*/ - da=(OP_INT64_MIN-_gp_a)-1; - /*_gp_b >= 0 => db >= 0.*/ - db=OP_INT64_MAX-_gp_b; - /*Step 2: Check for overflow.*/ - if(OP_UNLIKELY(OP_INT64_MAX+da<db))return OP_EINVAL; - *_delta=db-da; - } - else{ - /*_gp_b has wrapped to a negative value but _gp_a hasn't: the difference - should be negative.*/ - /*Step 1: Handle wrapping.*/ - /*_gp_a >= 0 => da <= 0*/ - da=_gp_a+OP_INT64_MIN; - /*_gp_b < 0 => db <= 0*/ - db=OP_INT64_MIN-_gp_b; - /*Step 2: Check for overflow.*/ - if(OP_UNLIKELY(da<OP_INT64_MIN-db))return OP_EINVAL; - *_delta=da+db; - } - } - else *_delta=_gp_a-_gp_b; - return 0; -} - -static int op_granpos_cmp(ogg_int64_t _gp_a,ogg_int64_t _gp_b){ - /*The invalid granule position -1 should behave like NaN: neither greater - than nor less than any other granule position, nor equal to any other - granule position, including itself. - However, that means there isn't anything we could sensibly return from this - function for it.*/ - OP_ASSERT(_gp_a!=-1); - OP_ASSERT(_gp_b!=-1); - /*Handle the wrapping cases.*/ - if(OP_UNLIKELY(_gp_a<0)){ - if(_gp_b>=0)return 1; - /*Else fall through.*/ - } - else if(OP_UNLIKELY(_gp_b<0))return -1; - /*No wrapping case.*/ - return (_gp_a>_gp_b)-(_gp_b>_gp_a); -} - -/*Returns the duration of the packet (in samples at 48 kHz), or a negative - value on error.*/ -static int op_get_packet_duration(const unsigned char *_data,int _len){ - int nframes; - int frame_size; - int nsamples; - nframes=opus_packet_get_nb_frames(_data,_len); - if(OP_UNLIKELY(nframes<0))return OP_EBADPACKET; - frame_size=opus_packet_get_samples_per_frame(_data,48000); - nsamples=nframes*frame_size; - if(OP_UNLIKELY(nsamples>120*48))return OP_EBADPACKET; - return nsamples; -} - -/*This function more properly belongs in info.c, but we define it here to allow - the static granule position manipulation functions to remain static.*/ -ogg_int64_t opus_granule_sample(const OpusHead *_head,ogg_int64_t _gp){ - opus_int32 pre_skip; - pre_skip=_head->pre_skip; - if(_gp!=-1&&op_granpos_add(&_gp,_gp,-pre_skip))_gp=-1; - return _gp; -} - -/*Grab all the packets currently in the stream state, and compute their - durations. - _of->op_count is set to the number of packets collected. - [out] _durations: Returns the durations of the individual packets. - Return: The total duration of all packets, or OP_HOLE if there was a hole.*/ -static opus_int32 op_collect_audio_packets(OggOpusFile *_of, - int _durations[255]){ - opus_int32 total_duration; - int op_count; - /*Count the durations of all packets in the page.*/ - op_count=0; - total_duration=0; - for(;;){ - int ret; - /*This takes advantage of undocumented libogg behavior that returned - ogg_packet buffers are valid at least until the next page is - submitted. - Relying on this is not too terrible, as _none_ of the Ogg memory - ownership/lifetime rules are well-documented. - But I can read its code and know this will work.*/ - ret=ogg_stream_packetout(&_of->os,_of->op+op_count); - if(!ret)break; - if(OP_UNLIKELY(ret<0)){ - /*We shouldn't get holes in the middle of pages.*/ - OP_ASSERT(op_count==0); - /*Set the return value and break out of the loop. - We want to make sure op_count gets set to 0, because we've ingested a - page, so any previously loaded packets are now invalid.*/ - total_duration=OP_HOLE; - break; - } - /*Unless libogg is broken, we can't get more than 255 packets from a - single page.*/ - OP_ASSERT(op_count<255); - _durations[op_count]=op_get_packet_duration(_of->op[op_count].packet, - _of->op[op_count].bytes); - if(OP_LIKELY(_durations[op_count]>0)){ - /*With at most 255 packets on a page, this can't overflow.*/ - total_duration+=_durations[op_count++]; - } - /*Ignore packets with an invalid TOC sequence.*/ - else if(op_count>0){ - /*But save the granule position, if there was one.*/ - _of->op[op_count-1].granulepos=_of->op[op_count].granulepos; - } - } - _of->op_pos=0; - _of->op_count=op_count; - return total_duration; -} - -/*Starting from current cursor position, get the initial PCM offset of the next - page. - This also validates the granule position on the first page with a completed - audio data packet, as required by the spec. - If this link is completely empty (no pages with completed packets), then this - function sets pcm_start=pcm_end=0 and returns the BOS page of the next link - (if any). - In the seekable case, we initialize pcm_end=-1 before calling this function, - so that later we can detect that the link was empty before calling - op_find_final_pcm_offset(). - [inout] _link: The link for which to find pcm_start. - [out] _og: Returns the BOS page of the next link if this link was empty. - In the unseekable case, we can then feed this to - op_fetch_headers() to start the next link. - The caller may pass NULL (e.g., for seekable streams), in - which case this page will be discarded. - Return: 0 on success, 1 if there is a buffered BOS page available, or a - negative value on unrecoverable error.*/ -static int op_find_initial_pcm_offset(OggOpusFile *_of, - OggOpusLink *_link,ogg_page *_og){ - ogg_page og; - opus_int64 page_offset; - ogg_int64_t pcm_start; - ogg_int64_t prev_packet_gp; - ogg_int64_t cur_page_gp; - ogg_uint32_t serialno; - opus_int32 total_duration; - int durations[255]; - int cur_page_eos; - int op_count; - int pi; - if(_og==NULL)_og=&og; - serialno=_of->os.serialno; - op_count=0; - /*We shouldn't have to initialize total_duration, but gcc is too dumb to - figure out that op_count>0 implies we've been through the whole loop at - least once.*/ - total_duration=0; - do{ - page_offset=op_get_next_page(_of,_og,_of->end); - /*We should get a page unless the file is truncated or mangled. - Otherwise there are no audio data packets in the whole logical stream.*/ - if(OP_UNLIKELY(page_offset<0)){ - /*Fail if there was a read error.*/ - if(page_offset<OP_FALSE)return (int)page_offset; - /*Fail if the pre-skip is non-zero, since it's asking us to skip more - samples than exist.*/ - if(_link->head.pre_skip>0)return OP_EBADTIMESTAMP; - /*Set pcm_end and end_offset so we can skip the call to - op_find_final_pcm_offset().*/ - _link->pcm_start=_link->pcm_end=0; - _link->end_offset=_link->data_offset; - return 0; - } - /*Similarly, if we hit the next link in the chain, we've gone too far.*/ - if(OP_UNLIKELY(ogg_page_bos(_og))){ - if(_link->head.pre_skip>0)return OP_EBADTIMESTAMP; - /*Set pcm_end and end_offset so we can skip the call to - op_find_final_pcm_offset().*/ - _link->pcm_end=_link->pcm_start=0; - _link->end_offset=_link->data_offset; - /*Tell the caller we've got a buffered page for them.*/ - return 1; - } - /*Ignore pages from other streams (not strictly necessary, because of the - checks in ogg_stream_pagein(), but saves some work).*/ - if(serialno!=(ogg_uint32_t)ogg_page_serialno(_og))continue; - ogg_stream_pagein(&_of->os,_og); - /*Bitrate tracking: add the header's bytes here. - The body bytes are counted when we consume the packets.*/ - _of->bytes_tracked+=_og->header_len; - /*Count the durations of all packets in the page.*/ - do total_duration=op_collect_audio_packets(_of,durations); - /*Ignore holes.*/ - while(OP_UNLIKELY(total_duration<0)); - op_count=_of->op_count; - } - while(op_count<=0); - /*We found the first page with a completed audio data packet: actually look - at the granule position. - RFC 3533 says, "A special value of -1 (in two's complement) indicates that - no packets finish on this page," which does not say that a granule - position that is NOT -1 indicates that some packets DO finish on that page - (even though this was the intention, libogg itself violated this intention - for years before we fixed it). - The Ogg Opus specification only imposes its start-time requirements - on the granule position of the first page with completed packets, - so we ignore any set granule positions until then.*/ - cur_page_gp=_of->op[op_count-1].granulepos; - /*But getting a packet without a valid granule position on the page is not - okay.*/ - if(cur_page_gp==-1)return OP_EBADTIMESTAMP; - cur_page_eos=_of->op[op_count-1].e_o_s; - if(OP_LIKELY(!cur_page_eos)){ - /*The EOS flag wasn't set. - Work backwards from the provided granule position to get the starting PCM - offset.*/ - if(OP_UNLIKELY(op_granpos_add(&pcm_start,cur_page_gp,-total_duration)<0)){ - /*The starting granule position MUST not be smaller than the amount of - audio on the first page with completed packets.*/ - return OP_EBADTIMESTAMP; - } - } - else{ - /*The first page with completed packets was also the last.*/ - if(OP_LIKELY(op_granpos_add(&pcm_start,cur_page_gp,-total_duration)<0)){ - /*If there's less audio on the page than indicated by the granule - position, then we're doing end-trimming, and the starting PCM offset - is zero by spec mandate.*/ - pcm_start=0; - /*However, the end-trimming MUST not ask us to trim more samples than - exist after applying the pre-skip.*/ - if(OP_UNLIKELY(op_granpos_cmp(cur_page_gp,_link->head.pre_skip)<0)){ - return OP_EBADTIMESTAMP; - } - } - } - /*Timestamp the individual packets.*/ - prev_packet_gp=pcm_start; - for(pi=0;pi<op_count;pi++){ - if(cur_page_eos){ - ogg_int64_t diff; - OP_ALWAYS_TRUE(!op_granpos_diff(&diff,cur_page_gp,prev_packet_gp)); - diff=durations[pi]-diff; - /*If we have samples to trim...*/ - if(diff>0){ - /*If we trimmed the entire packet, stop (the spec says encoders - shouldn't do this, but we support it anyway).*/ - if(OP_UNLIKELY(diff>durations[pi]))break; - _of->op[pi].granulepos=prev_packet_gp=cur_page_gp; - /*Move the EOS flag to this packet, if necessary, so we'll trim the - samples.*/ - _of->op[pi].e_o_s=1; - continue; - } - } - /*Update the granule position as normal.*/ - OP_ALWAYS_TRUE(!op_granpos_add(&_of->op[pi].granulepos, - prev_packet_gp,durations[pi])); - prev_packet_gp=_of->op[pi].granulepos; - } - /*Update the packet count after end-trimming.*/ - _of->op_count=pi; - _of->cur_discard_count=_link->head.pre_skip; - _of->prev_packet_gp=_link->pcm_start=pcm_start; - _of->prev_page_offset=page_offset; - return 0; -} - -/*Starting from current cursor position, get the final PCM offset of the - previous page. - This also validates the duration of the link, which, while not strictly - required by the spec, we need to ensure duration calculations don't - overflow. - This is only done for seekable sources. - We must validate that op_find_initial_pcm_offset() succeeded for this link - before calling this function, otherwise it will scan the entire stream - backwards until it reaches the start, and then fail.*/ -static int op_find_final_pcm_offset(OggOpusFile *_of, - const ogg_uint32_t *_serialnos,int _nserialnos,OggOpusLink *_link, - opus_int64 _offset,ogg_uint32_t _end_serialno,ogg_int64_t _end_gp, - ogg_int64_t *_total_duration){ - ogg_int64_t total_duration; - ogg_int64_t duration; - ogg_uint32_t cur_serialno; - /*For the time being, fetch end PCM offset the simple way.*/ - cur_serialno=_link->serialno; - if(_end_serialno!=cur_serialno||_end_gp==-1){ - _offset=op_get_last_page(_of,&_end_gp,_offset, - cur_serialno,_serialnos,_nserialnos); - if(OP_UNLIKELY(_offset<0))return (int)_offset; - } - /*At worst we should have found the first page with completed packets.*/ - if(OP_UNLIKELY(_offset<_link->data_offset))return OP_EBADLINK; - /*This implementation requires that the difference between the first and last - granule positions in each link be representable in a signed, 64-bit - number, and that each link also have at least as many samples as the - pre-skip requires.*/ - if(OP_UNLIKELY(op_granpos_diff(&duration,_end_gp,_link->pcm_start)<0) - ||OP_UNLIKELY(duration<_link->head.pre_skip)){ - return OP_EBADTIMESTAMP; - } - /*We also require that the total duration be representable in a signed, - 64-bit number.*/ - duration-=_link->head.pre_skip; - total_duration=*_total_duration; - if(OP_UNLIKELY(OP_INT64_MAX-duration<total_duration))return OP_EBADTIMESTAMP; - *_total_duration=total_duration+duration; - _link->pcm_end=_end_gp; - _link->end_offset=_offset; - return 0; -} - -/*Rescale the number _x from the range [0,_from] to [0,_to]. - _from and _to must be positive.*/ -static opus_int64 op_rescale64(opus_int64 _x,opus_int64 _from,opus_int64 _to){ - opus_int64 frac; - opus_int64 ret; - int i; - if(_x>=_from)return _to; - if(_x<=0)return 0; - frac=0; - for(i=0;i<63;i++){ - frac<<=1; - OP_ASSERT(_x<=_from); - if(_x>=_from>>1){ - _x-=_from-_x; - frac|=1; - } - else _x<<=1; - } - ret=0; - for(i=0;i<63;i++){ - if(frac&1)ret=(ret&_to&1)+(ret>>1)+(_to>>1); - else ret>>=1; - frac>>=1; - } - return ret; -} - -/*The minimum granule position spacing allowed for making predictions. - This corresponds to about 1 second of audio at 48 kHz for both Opus and - Vorbis, or one keyframe interval in Theora with the default keyframe spacing - of 256.*/ -#define OP_GP_SPACING_MIN (48000) - -/*Try to estimate the location of the next link using the current seek - records, assuming the initial granule position of any streams we've found is - 0.*/ -static opus_int64 op_predict_link_start(const OpusSeekRecord *_sr,int _nsr, - opus_int64 _searched,opus_int64 _end_searched,opus_int32 _bias){ - opus_int64 bisect; - int sri; - int srj; - /*Require that we be at least OP_CHUNK_SIZE from the end. - We don't require that we be at least OP_CHUNK_SIZE from the beginning, - because if we are we'll just scan forward without seeking.*/ - _end_searched-=OP_CHUNK_SIZE; - if(_searched>=_end_searched)return -1; - bisect=_end_searched; - for(sri=0;sri<_nsr;sri++){ - ogg_int64_t gp1; - ogg_int64_t gp2_min; - ogg_uint32_t serialno1; - opus_int64 offset1; - /*If the granule position is negative, either it's invalid or we'd cause - overflow.*/ - gp1=_sr[sri].gp; - if(gp1<0)continue; - /*We require some minimum distance between granule positions to make an - estimate. - We don't actually know what granule position scheme is being used, - because we have no idea what kind of stream these came from. - Therefore we require a minimum spacing between them, with the - expectation that while bitrates and granule position increments might - vary locally in quite complex ways, they are globally smooth.*/ - if(OP_UNLIKELY(op_granpos_add(&gp2_min,gp1,OP_GP_SPACING_MIN)<0)){ - /*No granule position would satisfy us.*/ - continue; - } - offset1=_sr[sri].offset; - serialno1=_sr[sri].serialno; - for(srj=sri;srj-->0;){ - ogg_int64_t gp2; - opus_int64 offset2; - opus_int64 num; - ogg_int64_t den; - ogg_int64_t ipart; - gp2=_sr[srj].gp; - if(gp2<gp2_min)continue; - /*Oh, and also make sure these came from the same stream.*/ - if(_sr[srj].serialno!=serialno1)continue; - offset2=_sr[srj].offset; - /*For once, we can subtract with impunity.*/ - den=gp2-gp1; - ipart=gp2/den; - num=offset2-offset1; - OP_ASSERT(num>0); - if(ipart>0&&(offset2-_searched)/ipart<num)continue; - offset2-=ipart*num; - gp2-=ipart*den; - offset2-=op_rescale64(gp2,den,num)-_bias; - if(offset2<_searched)continue; - bisect=OP_MIN(bisect,offset2); - break; - } - } - return bisect>=_end_searched?-1:bisect; -} - -/*Finds each bitstream link, one at a time, using a bisection search. - This has to begin by knowing the offset of the first link's initial page.*/ -static int op_bisect_forward_serialno(OggOpusFile *_of, - opus_int64 _searched,OpusSeekRecord *_sr,int _csr, - ogg_uint32_t **_serialnos,int *_nserialnos,int *_cserialnos){ - ogg_page og; - OggOpusLink *links; - int nlinks; - int clinks; - ogg_uint32_t *serialnos; - int nserialnos; - ogg_int64_t total_duration; - int nsr; - int ret; - links=_of->links; - nlinks=clinks=_of->nlinks; - total_duration=0; - /*We start with one seek record, for the last page in the file. - We build up a list of records for places we seek to during link - enumeration. - This list is kept sorted in reverse order. - We only care about seek locations that were _not_ in the current link, - therefore we can add them one at a time to the end of the list as we - improve the lower bound on the location where the next link starts.*/ - nsr=1; - for(;;){ - opus_int64 end_searched; - opus_int64 bisect; - opus_int64 next; - opus_int64 last; - ogg_int64_t end_offset; - ogg_int64_t end_gp; - int sri; - serialnos=*_serialnos; - nserialnos=*_nserialnos; - if(OP_UNLIKELY(nlinks>=clinks)){ - if(OP_UNLIKELY(clinks>INT_MAX-1>>1))return OP_EFAULT; - clinks=2*clinks+1; - OP_ASSERT(nlinks<clinks); - links=(OggOpusLink *)_ogg_realloc(links,sizeof(*links)*clinks); - if(OP_UNLIKELY(links==NULL))return OP_EFAULT; - _of->links=links; - } - /*Invariants: - We have the headers and serial numbers for the link beginning at 'begin'. - We have the offset and granule position of the last page in the file - (potentially not a page we care about).*/ - /*Scan the seek records we already have to save us some bisection.*/ - for(sri=0;sri<nsr;sri++){ - if(op_lookup_serialno(_sr[sri].serialno,serialnos,nserialnos))break; - } - /*Is the last page in our current list of serial numbers?*/ - if(sri<=0)break; - /*Last page wasn't found. - We have at least one more link.*/ - last=-1; - end_searched=_sr[sri-1].search_start; - next=_sr[sri-1].offset; - end_gp=-1; - if(sri<nsr){ - _searched=_sr[sri].offset+_sr[sri].size; - if(_sr[sri].serialno==links[nlinks-1].serialno){ - end_gp=_sr[sri].gp; - end_offset=_sr[sri].offset; - } - } - nsr=sri; - bisect=-1; - /*If we've already found the end of at least one link, try to pick the - first bisection point at twice the average link size. - This is a good choice for files with lots of links that are all about the - same size.*/ - if(nlinks>1){ - opus_int64 last_offset; - opus_int64 avg_link_size; - opus_int64 upper_limit; - last_offset=links[nlinks-1].offset; - avg_link_size=last_offset/(nlinks-1); - upper_limit=end_searched-OP_CHUNK_SIZE-avg_link_size; - if(OP_LIKELY(last_offset>_searched-avg_link_size) - &&OP_LIKELY(last_offset<upper_limit)){ - bisect=last_offset+avg_link_size; - if(OP_LIKELY(bisect<upper_limit))bisect+=avg_link_size; - } - } - /*We guard against garbage separating the last and first pages of two - links below.*/ - while(_searched<end_searched){ - opus_int32 next_bias; - /*If we don't have a better estimate, use simple bisection.*/ - if(bisect==-1)bisect=_searched+(end_searched-_searched>>1); - /*If we're within OP_CHUNK_SIZE of the start, scan forward.*/ - if(bisect-_searched<OP_CHUNK_SIZE)bisect=_searched; - /*Otherwise we're skipping data. - Forget the end page, if we saw one, as we might miss a later one.*/ - else end_gp=-1; - ret=op_seek_helper(_of,bisect); - if(OP_UNLIKELY(ret<0))return ret; - last=op_get_next_page(_of,&og,_sr[nsr-1].offset); - if(OP_UNLIKELY(last<OP_FALSE))return (int)last; - next_bias=0; - if(last==OP_FALSE)end_searched=bisect; - else{ - ogg_uint32_t serialno; - ogg_int64_t gp; - serialno=ogg_page_serialno(&og); - gp=ogg_page_granulepos(&og); - if(!op_lookup_serialno(serialno,serialnos,nserialnos)){ - end_searched=bisect; - next=last; - /*In reality we should always have enough room, but be paranoid.*/ - if(OP_LIKELY(nsr<_csr)){ - _sr[nsr].search_start=bisect; - _sr[nsr].offset=last; - OP_ASSERT(_of->offset-last>=0); - OP_ASSERT(_of->offset-last<=OP_PAGE_SIZE_MAX); - _sr[nsr].size=(opus_int32)(_of->offset-last); - _sr[nsr].serialno=serialno; - _sr[nsr].gp=gp; - nsr++; - } - } - else{ - _searched=_of->offset; - next_bias=OP_CHUNK_SIZE; - if(serialno==links[nlinks-1].serialno){ - /*This page was from the stream we want, remember it. - If it's the last such page in the link, we won't have to go back - looking for it later.*/ - end_gp=gp; - end_offset=last; - } - } - } - bisect=op_predict_link_start(_sr,nsr,_searched,end_searched,next_bias); - } - /*Bisection point found. - Get the final granule position of the previous link, assuming - op_find_initial_pcm_offset() didn't already determine the link was - empty.*/ - if(OP_LIKELY(links[nlinks-1].pcm_end==-1)){ - if(end_gp==-1){ - /*If we don't know where the end page is, we'll have to seek back and - look for it, starting from the end of the link.*/ - end_offset=next; - /*Also forget the last page we read. - It won't be available after the seek.*/ - last=-1; - } - ret=op_find_final_pcm_offset(_of,serialnos,nserialnos, - links+nlinks-1,end_offset,links[nlinks-1].serialno,end_gp, - &total_duration); - if(OP_UNLIKELY(ret<0))return ret; - } - if(last!=next){ - /*The last page we read was not the first page the next link. - Move the cursor position to the offset of that first page. - This only performs an actual seek if the first page of the next link - does not start at the end of the last page from the current Opus - stream with a valid granule position.*/ - ret=op_seek_helper(_of,next); - if(OP_UNLIKELY(ret<0))return ret; - } - ret=op_fetch_headers(_of,&links[nlinks].head,&links[nlinks].tags, - _serialnos,_nserialnos,_cserialnos,last!=next?NULL:&og); - if(OP_UNLIKELY(ret<0))return ret; - links[nlinks].offset=next; - links[nlinks].data_offset=_of->offset; - links[nlinks].serialno=_of->os.serialno; - links[nlinks].pcm_end=-1; - /*This might consume a page from the next link, however the next bisection - always starts with a seek.*/ - ret=op_find_initial_pcm_offset(_of,links+nlinks,NULL); - if(OP_UNLIKELY(ret<0))return ret; - _searched=_of->offset; - /*Mark the current link count so it can be cleaned up on error.*/ - _of->nlinks=++nlinks; - } - /*Last page is in the starting serialno list, so we've reached the last link. - Now find the last granule position for it (if we didn't the first time we - looked at the end of the stream, and if op_find_initial_pcm_offset() - didn't already determine the link was empty).*/ - if(OP_LIKELY(links[nlinks-1].pcm_end==-1)){ - ret=op_find_final_pcm_offset(_of,serialnos,nserialnos, - links+nlinks-1,_sr[0].offset,_sr[0].serialno,_sr[0].gp,&total_duration); - if(OP_UNLIKELY(ret<0))return ret; - } - /*Trim back the links array if necessary.*/ - links=(OggOpusLink *)_ogg_realloc(links,sizeof(*links)*nlinks); - if(OP_LIKELY(links!=NULL))_of->links=links; - /*We also don't need these anymore.*/ - _ogg_free(*_serialnos); - *_serialnos=NULL; - *_cserialnos=*_nserialnos=0; - return 0; -} - -static void op_update_gain(OggOpusFile *_of){ - OpusHead *head; - opus_int32 gain_q8; - int li; - /*If decode isn't ready, then we'll apply the gain when we initialize the - decoder.*/ - if(_of->ready_state<OP_INITSET)return; - gain_q8=_of->gain_offset_q8; - li=_of->seekable?_of->cur_link:0; - head=&_of->links[li].head; - /*We don't have to worry about overflow here because the header gain and - track gain must lie in the range [-32768,32767], and the user-supplied - offset has been pre-clamped to [-98302,98303].*/ - switch(_of->gain_type){ - case OP_ALBUM_GAIN:{ - int album_gain_q8; - album_gain_q8=0; - opus_tags_get_album_gain(&_of->links[li].tags,&album_gain_q8); - gain_q8+=album_gain_q8; - gain_q8+=head->output_gain; - }break; - case OP_TRACK_GAIN:{ - int track_gain_q8; - track_gain_q8=0; - opus_tags_get_track_gain(&_of->links[li].tags,&track_gain_q8); - gain_q8+=track_gain_q8; - gain_q8+=head->output_gain; - }break; - case OP_HEADER_GAIN:gain_q8+=head->output_gain;break; - case OP_ABSOLUTE_GAIN:break; - default:OP_ASSERT(0); - } - gain_q8=OP_CLAMP(-32768,gain_q8,32767); - OP_ASSERT(_of->od!=NULL); -#if defined(OPUS_SET_GAIN) - opus_multistream_decoder_ctl(_of->od,OPUS_SET_GAIN(gain_q8)); -#else -/*A fallback that works with both float and fixed-point is a bunch of work, - so just force people to use a sufficiently new version. - This is deployed well enough at this point that this shouldn't be a burden.*/ -# error "libopus 1.0.1 or later required" -#endif -} - -static int op_make_decode_ready(OggOpusFile *_of){ - const OpusHead *head; - int li; - int stream_count; - int coupled_count; - int channel_count; - if(_of->ready_state>OP_STREAMSET)return 0; - if(OP_UNLIKELY(_of->ready_state<OP_STREAMSET))return OP_EFAULT; - li=_of->seekable?_of->cur_link:0; - head=&_of->links[li].head; - stream_count=head->stream_count; - coupled_count=head->coupled_count; - channel_count=head->channel_count; - /*Check to see if the current decoder is compatible with the current link.*/ - if(_of->od!=NULL&&_of->od_stream_count==stream_count - &&_of->od_coupled_count==coupled_count&&_of->od_channel_count==channel_count - &&memcmp(_of->od_mapping,head->mapping, - sizeof(*head->mapping)*channel_count)==0){ - opus_multistream_decoder_ctl(_of->od,OPUS_RESET_STATE); - } - else{ - int err; - opus_multistream_decoder_destroy(_of->od); - _of->od=opus_multistream_decoder_create(48000,channel_count, - stream_count,coupled_count,head->mapping,&err); - if(_of->od==NULL)return OP_EFAULT; - _of->od_stream_count=stream_count; - _of->od_coupled_count=coupled_count; - _of->od_channel_count=channel_count; - memcpy(_of->od_mapping,head->mapping,sizeof(*head->mapping)*channel_count); - } - _of->ready_state=OP_INITSET; - _of->bytes_tracked=0; - _of->samples_tracked=0; -#if !defined(OP_FIXED_POINT) - _of->state_channel_count=0; - /*Use the serial number for the PRNG seed to get repeatable output for - straight play-throughs.*/ - _of->dither_seed=_of->links[li].serialno; -#endif - op_update_gain(_of); - return 0; -} - -static int op_open_seekable2_impl(OggOpusFile *_of){ - /*64 seek records should be enough for anybody. - Actually, with a bisection search in a 63-bit range down to OP_CHUNK_SIZE - granularity, much more than enough.*/ - OpusSeekRecord sr[64]; - opus_int64 data_offset; - int ret; - /*We can seek, so set out learning all about this file.*/ - (*_of->callbacks.seek)(_of->source,0,SEEK_END); - _of->offset=_of->end=(*_of->callbacks.tell)(_of->source); - if(OP_UNLIKELY(_of->end<0))return OP_EREAD; - data_offset=_of->links[0].data_offset; - if(OP_UNLIKELY(_of->end<data_offset))return OP_EBADLINK; - /*Get the offset of the last page of the physical bitstream, or, if we're - lucky, the last Opus page of the first link, as most Ogg Opus files will - contain a single logical bitstream.*/ - ret=op_get_prev_page_serial(_of,sr,_of->end, - _of->links[0].serialno,_of->serialnos,_of->nserialnos); - if(OP_UNLIKELY(ret<0))return ret; - /*If there's any trailing junk, forget about it.*/ - _of->end=sr[0].offset+sr[0].size; - if(OP_UNLIKELY(_of->end<data_offset))return OP_EBADLINK; - /*Now enumerate the bitstream structure.*/ - return op_bisect_forward_serialno(_of,data_offset,sr,sizeof(sr)/sizeof(*sr), - &_of->serialnos,&_of->nserialnos,&_of->cserialnos); -} - -static int op_open_seekable2(OggOpusFile *_of){ - ogg_sync_state oy_start; - ogg_stream_state os_start; - ogg_packet *op_start; - opus_int64 prev_page_offset; - opus_int64 start_offset; - int start_op_count; - int ret; - /*We're partially open and have a first link header state in storage in _of. - Save off that stream state so we can come back to it. - It would be simpler to just dump all this state and seek back to - links[0].data_offset when we're done. - But we do the extra work to allow us to seek back to _exactly_ the same - stream position we're at now. - This allows, e.g., the HTTP backend to continue reading from the original - connection (if it's still available), instead of opening a new one. - This means we can open and start playing a normal Opus file with a single - link and reasonable packet sizes using only two HTTP requests.*/ - start_op_count=_of->op_count; - /*This is a bit too large to put on the stack unconditionally.*/ - op_start=(ogg_packet *)_ogg_malloc(sizeof(*op_start)*start_op_count); - if(op_start==NULL)return OP_EFAULT; - *&oy_start=_of->oy; - *&os_start=_of->os; - prev_page_offset=_of->prev_page_offset; - start_offset=_of->offset; - memcpy(op_start,_of->op,sizeof(*op_start)*start_op_count); - OP_ASSERT((*_of->callbacks.tell)(_of->source)==op_position(_of)); - ogg_sync_init(&_of->oy); - ogg_stream_init(&_of->os,-1); - ret=op_open_seekable2_impl(_of); - /*Restore the old stream state.*/ - ogg_stream_clear(&_of->os); - ogg_sync_clear(&_of->oy); - *&_of->oy=*&oy_start; - *&_of->os=*&os_start; - _of->offset=start_offset; - _of->op_count=start_op_count; - memcpy(_of->op,op_start,sizeof(*_of->op)*start_op_count); - _ogg_free(op_start); - _of->prev_packet_gp=_of->links[0].pcm_start; - _of->prev_page_offset=prev_page_offset; - _of->cur_discard_count=_of->links[0].head.pre_skip; - if(OP_UNLIKELY(ret<0))return ret; - /*And restore the position indicator.*/ - ret=(*_of->callbacks.seek)(_of->source,op_position(_of),SEEK_SET); - return OP_UNLIKELY(ret<0)?OP_EREAD:0; -} - -/*Clear out the current logical bitstream decoder.*/ -static void op_decode_clear(OggOpusFile *_of){ - /*We don't actually free the decoder. - We might be able to re-use it for the next link.*/ - _of->op_count=0; - _of->od_buffer_size=0; - _of->prev_packet_gp=-1; - _of->prev_page_offset=-1; - if(!_of->seekable){ - OP_ASSERT(_of->ready_state>=OP_INITSET); - opus_tags_clear(&_of->links[0].tags); - } - _of->ready_state=OP_OPENED; -} - -static void op_clear(OggOpusFile *_of){ - OggOpusLink *links; - _ogg_free(_of->od_buffer); - if(_of->od!=NULL)opus_multistream_decoder_destroy(_of->od); - links=_of->links; - if(!_of->seekable){ - if(_of->ready_state>OP_OPENED||_of->ready_state==OP_PARTOPEN){ - opus_tags_clear(&links[0].tags); - } - } - else if(OP_LIKELY(links!=NULL)){ - int nlinks; - int link; - nlinks=_of->nlinks; - for(link=0;link<nlinks;link++)opus_tags_clear(&links[link].tags); - } - _ogg_free(links); - _ogg_free(_of->serialnos); - ogg_stream_clear(&_of->os); - ogg_sync_clear(&_of->oy); - if(_of->callbacks.close!=NULL)(*_of->callbacks.close)(_of->source); -} - -static int op_open1(OggOpusFile *_of, - void *_source,const OpusFileCallbacks *_cb, - const unsigned char *_initial_data,size_t _initial_bytes){ - ogg_page og; - ogg_page *pog; - int seekable; - int ret; - memset(_of,0,sizeof(*_of)); - _of->end=-1; - _of->source=_source; - *&_of->callbacks=*_cb; - /*At a minimum, we need to be able to read data.*/ - if(OP_UNLIKELY(_of->callbacks.read==NULL))return OP_EREAD; - /*Initialize the framing state.*/ - ogg_sync_init(&_of->oy); - /*Perhaps some data was previously read into a buffer for testing against - other stream types. - Allow initialization from this previously read data (especially as we may - be reading from a non-seekable stream). - This requires copying it into a buffer allocated by ogg_sync_buffer() and - doesn't support seeking, so this is not a good mechanism to use for - decoding entire files from RAM.*/ - if(_initial_bytes>0){ - char *buffer; - buffer=ogg_sync_buffer(&_of->oy,_initial_bytes); - memcpy(buffer,_initial_data,_initial_bytes*sizeof(*buffer)); - ogg_sync_wrote(&_of->oy,_initial_bytes); - } - /*Can we seek? - Stevens suggests the seek test is portable.*/ - seekable=_cb->seek!=NULL&&(*_cb->seek)(_source,0,SEEK_CUR)!=-1; - /*If seek is implemented, tell must also be implemented.*/ - if(seekable){ - opus_int64 pos; - if(OP_UNLIKELY(_of->callbacks.tell==NULL))return OP_EINVAL; - pos=(*_of->callbacks.tell)(_of->source); - /*If the current position is not equal to the initial bytes consumed, - absolute seeking will not work.*/ - if(OP_UNLIKELY(pos!=(opus_int64)_initial_bytes))return OP_EINVAL; - } - _of->seekable=seekable; - /*Don't seek yet. - Set up a 'single' (current) logical bitstream entry for partial open.*/ - _of->links=(OggOpusLink *)_ogg_malloc(sizeof(*_of->links)); - /*The serialno gets filled in later by op_fetch_headers().*/ - ogg_stream_init(&_of->os,-1); - pog=NULL; - for(;;){ - /*Fetch all BOS pages, store the Opus header and all seen serial numbers, - and load subsequent Opus setup headers.*/ - ret=op_fetch_headers(_of,&_of->links[0].head,&_of->links[0].tags, - &_of->serialnos,&_of->nserialnos,&_of->cserialnos,pog); - if(OP_UNLIKELY(ret<0))break; - _of->nlinks=1; - _of->links[0].offset=0; - _of->links[0].data_offset=_of->offset; - _of->links[0].pcm_end=-1; - _of->links[0].serialno=_of->os.serialno; - /*Fetch the initial PCM offset.*/ - ret=op_find_initial_pcm_offset(_of,_of->links,&og); - if(seekable||OP_LIKELY(ret<=0))break; - /*This link was empty, but we already have the BOS page for the next one in - og. - We can't seek, so start processing the next link right now.*/ - opus_tags_clear(&_of->links[0].tags); - _of->nlinks=0; - if(!seekable)_of->cur_link++; - pog=&og; - } - if(OP_LIKELY(ret>=0))_of->ready_state=OP_PARTOPEN; - return ret; -} - -static int op_open2(OggOpusFile *_of){ - int ret; - OP_ASSERT(_of->ready_state==OP_PARTOPEN); - if(_of->seekable){ - _of->ready_state=OP_OPENED; - ret=op_open_seekable2(_of); - } - else ret=0; - if(OP_LIKELY(ret>=0)){ - /*We have buffered packets from op_find_initial_pcm_offset(). - Move to OP_INITSET so we can use them.*/ - _of->ready_state=OP_STREAMSET; - ret=op_make_decode_ready(_of); - if(OP_LIKELY(ret>=0))return 0; - } - /*Don't auto-close the stream on failure.*/ - _of->callbacks.close=NULL; - op_clear(_of); - return ret; -} - -OggOpusFile *op_test_callbacks(void *_source,const OpusFileCallbacks *_cb, - const unsigned char *_initial_data,size_t _initial_bytes,int *_error){ - OggOpusFile *of; - int ret; - of=(OggOpusFile *)_ogg_malloc(sizeof(*of)); - ret=OP_EFAULT; - if(OP_LIKELY(of!=NULL)){ - ret=op_open1(of,_source,_cb,_initial_data,_initial_bytes); - if(OP_LIKELY(ret>=0)){ - if(_error!=NULL)*_error=0; - return of; - } - /*Don't auto-close the stream on failure.*/ - of->callbacks.close=NULL; - op_clear(of); - _ogg_free(of); - } - if(_error!=NULL)*_error=ret; - return NULL; -} - -OggOpusFile *op_open_callbacks(void *_source,const OpusFileCallbacks *_cb, - const unsigned char *_initial_data,size_t _initial_bytes,int *_error){ - OggOpusFile *of; - of=op_test_callbacks(_source,_cb,_initial_data,_initial_bytes,_error); - if(OP_LIKELY(of!=NULL)){ - int ret; - ret=op_open2(of); - if(OP_LIKELY(ret>=0))return of; - if(_error!=NULL)*_error=ret; - _ogg_free(of); - } - return NULL; -} - -/*Convenience routine to clean up from failure for the open functions that - create their own streams.*/ -static OggOpusFile *op_open_close_on_failure(void *_source, - const OpusFileCallbacks *_cb,int *_error){ - OggOpusFile *of; - if(OP_UNLIKELY(_source==NULL)){ - if(_error!=NULL)*_error=OP_EFAULT; - return NULL; - } - of=op_open_callbacks(_source,_cb,NULL,0,_error); - if(OP_UNLIKELY(of==NULL))(*_cb->close)(_source); - return of; -} - -OggOpusFile *op_open_file(const char *_path,int *_error){ - OpusFileCallbacks cb; - return op_open_close_on_failure(op_fopen(&cb,_path,"rb"),&cb,_error); -} - -OggOpusFile *op_open_memory(const unsigned char *_data,size_t _size, - int *_error){ - OpusFileCallbacks cb; - return op_open_close_on_failure(op_mem_stream_create(&cb,_data,_size),&cb, - _error); -} - -/*Convenience routine to clean up from failure for the open functions that - create their own streams.*/ -static OggOpusFile *op_test_close_on_failure(void *_source, - const OpusFileCallbacks *_cb,int *_error){ - OggOpusFile *of; - if(OP_UNLIKELY(_source==NULL)){ - if(_error!=NULL)*_error=OP_EFAULT; - return NULL; - } - of=op_test_callbacks(_source,_cb,NULL,0,_error); - if(OP_UNLIKELY(of==NULL))(*_cb->close)(_source); - return of; -} - -OggOpusFile *op_test_file(const char *_path,int *_error){ - OpusFileCallbacks cb; - return op_test_close_on_failure(op_fopen(&cb,_path,"rb"),&cb,_error); -} - -OggOpusFile *op_test_memory(const unsigned char *_data,size_t _size, - int *_error){ - OpusFileCallbacks cb; - return op_test_close_on_failure(op_mem_stream_create(&cb,_data,_size),&cb, - _error); -} - -int op_test_open(OggOpusFile *_of){ - int ret; - if(OP_UNLIKELY(_of->ready_state!=OP_PARTOPEN))return OP_EINVAL; - ret=op_open2(_of); - /*op_open2() will clear this structure on failure. - Reset its contents to prevent double-frees in op_free().*/ - if(OP_UNLIKELY(ret<0))memset(_of,0,sizeof(*_of)); - return ret; -} - -void op_free(OggOpusFile *_of){ - if(OP_LIKELY(_of!=NULL)){ - op_clear(_of); - _ogg_free(_of); - } -} - -int op_seekable(const OggOpusFile *_of){ - return _of->seekable; -} - -int op_link_count(const OggOpusFile *_of){ - return _of->nlinks; -} - -ogg_uint32_t op_serialno(const OggOpusFile *_of,int _li){ - if(OP_UNLIKELY(_li>=_of->nlinks))_li=_of->nlinks-1; - if(!_of->seekable)_li=0; - return _of->links[_li<0?_of->cur_link:_li].serialno; -} - -int op_channel_count(const OggOpusFile *_of,int _li){ - return op_head(_of,_li)->channel_count; -} - -opus_int64 op_raw_total(const OggOpusFile *_of,int _li){ - if(OP_UNLIKELY(_of->ready_state<OP_OPENED) - ||OP_UNLIKELY(!_of->seekable) - ||OP_UNLIKELY(_li>=_of->nlinks)){ - return OP_EINVAL; - } - if(_li<0)return _of->end-_of->links[0].offset; - return (_li+1>=_of->nlinks?_of->end:_of->links[_li+1].offset) - -_of->links[_li].offset; -} - -ogg_int64_t op_pcm_total(const OggOpusFile *_of,int _li){ - OggOpusLink *links; - ogg_int64_t diff; - int nlinks; - nlinks=_of->nlinks; - if(OP_UNLIKELY(_of->ready_state<OP_OPENED) - ||OP_UNLIKELY(!_of->seekable) - ||OP_UNLIKELY(_li>=nlinks)){ - return OP_EINVAL; - } - links=_of->links; - /*We verify that the granule position differences are larger than the - pre-skip and that the total duration does not overflow during link - enumeration, so we don't have to check here.*/ - if(_li<0){ - ogg_int64_t pcm_total; - int li; - pcm_total=0; - for(li=0;li<nlinks;li++){ - OP_ALWAYS_TRUE(!op_granpos_diff(&diff, - links[li].pcm_end,links[li].pcm_start)); - pcm_total+=diff-links[li].head.pre_skip; - } - return pcm_total; - } - OP_ALWAYS_TRUE(!op_granpos_diff(&diff, - links[_li].pcm_end,links[_li].pcm_start)); - return diff-links[_li].head.pre_skip; -} - -const OpusHead *op_head(const OggOpusFile *_of,int _li){ - if(OP_UNLIKELY(_li>=_of->nlinks))_li=_of->nlinks-1; - if(!_of->seekable)_li=0; - return &_of->links[_li<0?_of->cur_link:_li].head; -} - -const OpusTags *op_tags(const OggOpusFile *_of,int _li){ - if(OP_UNLIKELY(_li>=_of->nlinks))_li=_of->nlinks-1; - if(!_of->seekable){ - if(_of->ready_state<OP_STREAMSET&&_of->ready_state!=OP_PARTOPEN){ - return NULL; - } - _li=0; - } - else if(_li<0)_li=_of->ready_state>=OP_STREAMSET?_of->cur_link:0; - return &_of->links[_li].tags; -} - -int op_current_link(const OggOpusFile *_of){ - if(OP_UNLIKELY(_of->ready_state<OP_OPENED))return OP_EINVAL; - return _of->cur_link; -} - -/*Compute an average bitrate given a byte and sample count. - Return: The bitrate in bits per second.*/ -static opus_int32 op_calc_bitrate(opus_int64 _bytes,ogg_int64_t _samples){ - /*These rates are absurd, but let's handle them anyway.*/ - if(OP_UNLIKELY(_bytes>(OP_INT64_MAX-(_samples>>1))/(48000*8))){ - ogg_int64_t den; - if(OP_UNLIKELY(_bytes/(OP_INT32_MAX/(48000*8))>=_samples)){ - return OP_INT32_MAX; - } - den=_samples/(48000*8); - return (opus_int32)((_bytes+(den>>1))/den); - } - if(OP_UNLIKELY(_samples<=0))return OP_INT32_MAX; - /*This can't actually overflow in normal operation: even with a pre-skip of - 545 2.5 ms frames with 8 streams running at 1282*8+1 bytes per packet - (1275 byte frames + Opus framing overhead + Ogg lacing values), that all - produce a single sample of decoded output, we still don't top 45 Mbps. - The only way to get bitrates larger than that is with excessive Opus - padding, more encoded streams than output channels, or lots and lots of - Ogg pages with no packets on them.*/ - return (opus_int32)OP_MIN((_bytes*48000*8+(_samples>>1))/_samples, - OP_INT32_MAX); -} - -opus_int32 op_bitrate(const OggOpusFile *_of,int _li){ - if(OP_UNLIKELY(_of->ready_state<OP_OPENED)||OP_UNLIKELY(!_of->seekable) - ||OP_UNLIKELY(_li>=_of->nlinks)){ - return OP_EINVAL; - } - return op_calc_bitrate(op_raw_total(_of,_li),op_pcm_total(_of,_li)); -} - -opus_int32 op_bitrate_instant(OggOpusFile *_of){ - ogg_int64_t samples_tracked; - opus_int32 ret; - if(OP_UNLIKELY(_of->ready_state<OP_OPENED))return OP_EINVAL; - samples_tracked=_of->samples_tracked; - if(OP_UNLIKELY(samples_tracked==0))return OP_FALSE; - ret=op_calc_bitrate(_of->bytes_tracked,samples_tracked); - _of->bytes_tracked=0; - _of->samples_tracked=0; - return ret; -} - -/*Fetch and process a page. - This handles the case where we're at a bitstream boundary and dumps the - decoding machine. - If the decoding machine is unloaded, it loads it. - It also keeps prev_packet_gp up to date (seek and read both use this; seek - uses a special hack with _readp). - Return: <0) Error, OP_HOLE (lost packet), or OP_EOF. - 0) Need more data (only if _readp==0). - 1) Got at least one audio data packet.*/ -static int op_fetch_and_process_page(OggOpusFile *_of, - ogg_page *_og,opus_int64 _page_offset, - int _readp,int _spanp,int _ignore_holes){ - OggOpusLink *links; - ogg_uint32_t cur_serialno; - int seekable; - int cur_link; - int ret; - /*We shouldn't get here if we have unprocessed packets.*/ - OP_ASSERT(_of->ready_state<OP_INITSET||_of->op_pos>=_of->op_count); - if(!_readp)return 0; - seekable=_of->seekable; - links=_of->links; - cur_link=seekable?_of->cur_link:0; - cur_serialno=links[cur_link].serialno; - /*Handle one page.*/ - for(;;){ - ogg_page og; - OP_ASSERT(_of->ready_state>=OP_OPENED); - /*This loop is not strictly necessary, but there's no sense in doing the - extra checks of the larger loop for the common case in a multiplexed - bistream where the page is simply part of a different logical - bitstream.*/ - do{ - /*If we were given a page to use, use it.*/ - if(_og!=NULL){ - *&og=*_og; - _og=NULL; - } - /*Keep reading until we get a page with the correct serialno.*/ - else _page_offset=op_get_next_page(_of,&og,_of->end); - /*EOF: Leave uninitialized.*/ - if(_page_offset<0)return _page_offset<OP_FALSE?(int)_page_offset:OP_EOF; - if(OP_LIKELY(_of->ready_state>=OP_STREAMSET)){ - if(cur_serialno!=(ogg_uint32_t)ogg_page_serialno(&og)){ - /*Two possibilities: - 1) Another stream is multiplexed into this logical section, or*/ - if(OP_LIKELY(!ogg_page_bos(&og)))continue; - /* 2) Our decoding just traversed a bitstream boundary.*/ - if(!_spanp)return OP_EOF; - if(OP_LIKELY(_of->ready_state>=OP_INITSET))op_decode_clear(_of); - break; - } - } - /*Bitrate tracking: add the header's bytes here. - The body bytes are counted when we consume the packets.*/ - _of->bytes_tracked+=og.header_len; - } - while(0); - /*Do we need to load a new machine before submitting the page? - This is different in the seekable and non-seekable cases. - In the seekable case, we already have all the header information loaded - and cached. - We just initialize the machine with it and continue on our merry way. - In the non-seekable (streaming) case, we'll only be at a boundary if we - just left the previous logical bitstream, and we're now nominally at the - header of the next bitstream.*/ - if(OP_UNLIKELY(_of->ready_state<OP_STREAMSET)){ - if(seekable){ - ogg_uint32_t serialno; - int nlinks; - int li; - serialno=ogg_page_serialno(&og); - /*Match the serialno to bitstream section. - We use this rather than offset positions to avoid problems near - logical bitstream boundaries.*/ - nlinks=_of->nlinks; - for(li=0;li<nlinks&&links[li].serialno!=serialno;li++); - /*Not a desired Opus bitstream section. - Keep trying.*/ - if(li>=nlinks)continue; - cur_serialno=serialno; - _of->cur_link=cur_link=li; - ogg_stream_reset_serialno(&_of->os,serialno); - _of->ready_state=OP_STREAMSET; - /*If we're at the start of this link, initialize the granule position - and pre-skip tracking.*/ - if(_page_offset<=links[cur_link].data_offset){ - _of->prev_packet_gp=links[cur_link].pcm_start; - _of->prev_page_offset=-1; - _of->cur_discard_count=links[cur_link].head.pre_skip; - /*Ignore a hole at the start of a new link (this is common for - streams joined in the middle) or after seeking.*/ - _ignore_holes=1; - } - } - else{ - do{ - /*We're streaming. - Fetch the two header packets, build the info struct.*/ - ret=op_fetch_headers(_of,&links[0].head,&links[0].tags, - NULL,NULL,NULL,&og); - if(OP_UNLIKELY(ret<0))return ret; - /*op_find_initial_pcm_offset() will suppress any initial hole for us, - so no need to set _ignore_holes.*/ - ret=op_find_initial_pcm_offset(_of,links,&og); - if(OP_UNLIKELY(ret<0))return ret; - _of->links[0].serialno=cur_serialno=_of->os.serialno; - _of->cur_link++; - } - /*If the link was empty, keep going, because we already have the - BOS page of the next one in og.*/ - while(OP_UNLIKELY(ret>0)); - /*If we didn't get any packets out of op_find_initial_pcm_offset(), - keep going (this is possible if end-trimming trimmed them all).*/ - if(_of->op_count<=0)continue; - /*Otherwise, we're done.*/ - ret=op_make_decode_ready(_of); - if(OP_UNLIKELY(ret<0))return ret; - return 1; - } - } - /*The buffered page is the data we want, and we're ready for it. - Add it to the stream state.*/ - if(OP_UNLIKELY(_of->ready_state==OP_STREAMSET)){ - ret=op_make_decode_ready(_of); - if(OP_UNLIKELY(ret<0))return ret; - } - /*Extract all the packets from the current page.*/ - ogg_stream_pagein(&_of->os,&og); - if(OP_LIKELY(_of->ready_state>=OP_INITSET)){ - opus_int32 total_duration; - int durations[255]; - int op_count; - total_duration=op_collect_audio_packets(_of,durations); - if(OP_UNLIKELY(total_duration<0)){ - /*Drain the packets from the page anyway.*/ - total_duration=op_collect_audio_packets(_of,durations); - OP_ASSERT(total_duration>=0); - /*Report holes to the caller.*/ - if(!_ignore_holes)return OP_HOLE; - } - op_count=_of->op_count; - /*If we found at least one audio data packet, compute per-packet granule - positions for them.*/ - if(op_count>0){ - ogg_int64_t diff; - ogg_int64_t prev_packet_gp; - ogg_int64_t cur_packet_gp; - ogg_int64_t cur_page_gp; - int cur_page_eos; - int pi; - cur_page_gp=_of->op[op_count-1].granulepos; - cur_page_eos=_of->op[op_count-1].e_o_s; - prev_packet_gp=_of->prev_packet_gp; - if(OP_UNLIKELY(prev_packet_gp==-1)){ - opus_int32 cur_discard_count; - /*This is the first call after a raw seek. - Try to reconstruct prev_packet_gp from scratch.*/ - OP_ASSERT(seekable); - if(OP_UNLIKELY(cur_page_eos)){ - /*If the first page we hit after our seek was the EOS page, and - we didn't start from data_offset or before, we don't have - enough information to do end-trimming. - Proceed to the next link, rather than risk playing back some - samples that shouldn't have been played.*/ - _of->op_count=0; - continue; - } - /*By default discard 80 ms of data after a seek, unless we seek - into the pre-skip region.*/ - cur_discard_count=80*48; - cur_page_gp=_of->op[op_count-1].granulepos; - /*Try to initialize prev_packet_gp. - If the current page had packets but didn't have a granule - position, or the granule position it had was too small (both - illegal), just use the starting granule position for the link.*/ - prev_packet_gp=links[cur_link].pcm_start; - if(OP_LIKELY(cur_page_gp!=-1)){ - op_granpos_add(&prev_packet_gp,cur_page_gp,-total_duration); - } - if(OP_LIKELY(!op_granpos_diff(&diff, - prev_packet_gp,links[cur_link].pcm_start))){ - opus_int32 pre_skip; - /*If we start at the beginning of the pre-skip region, or we're - at least 80 ms from the end of the pre-skip region, we discard - to the end of the pre-skip region. - Otherwise, we still use the 80 ms default, which will discard - past the end of the pre-skip region.*/ - pre_skip=links[cur_link].head.pre_skip; - if(diff>=0&&diff<=OP_MAX(0,pre_skip-80*48)){ - cur_discard_count=pre_skip-(int)diff; - } - } - _of->cur_discard_count=cur_discard_count; - } - if(OP_UNLIKELY(cur_page_gp==-1)){ - /*This page had completed packets but didn't have a valid granule - position. - This is illegal, but we'll try to handle it by continuing to count - forwards from the previous page.*/ - if(op_granpos_add(&cur_page_gp,prev_packet_gp,total_duration)<0){ - /*The timestamp for this page overflowed.*/ - cur_page_gp=links[cur_link].pcm_end; - } - } - /*If we hit the last page, handle end-trimming.*/ - if(OP_UNLIKELY(cur_page_eos) - &&OP_LIKELY(!op_granpos_diff(&diff,cur_page_gp,prev_packet_gp)) - &&OP_LIKELY(diff<total_duration)){ - cur_packet_gp=prev_packet_gp; - for(pi=0;pi<op_count;pi++){ - diff=durations[pi]-diff; - /*If we have samples to trim...*/ - if(diff>0){ - /*If we trimmed the entire packet, stop (the spec says encoders - shouldn't do this, but we support it anyway).*/ - if(OP_UNLIKELY(diff>durations[pi]))break; - cur_packet_gp=cur_page_gp; - /*Move the EOS flag to this packet, if necessary, so we'll trim - the samples during decode.*/ - _of->op[pi].e_o_s=1; - } - else{ - /*Update the granule position as normal.*/ - OP_ALWAYS_TRUE(!op_granpos_add(&cur_packet_gp, - cur_packet_gp,durations[pi])); - } - _of->op[pi].granulepos=cur_packet_gp; - OP_ALWAYS_TRUE(!op_granpos_diff(&diff,cur_page_gp,cur_packet_gp)); - } - } - else{ - /*Propagate timestamps to earlier packets. - op_granpos_add(&prev_packet_gp,prev_packet_gp,total_duration) - should succeed and give prev_packet_gp==cur_page_gp. - But we don't bother to check that, as there isn't much we can do - if it's not true, and it actually will not be true on the first - page after a seek, if there was a continued packet. - The only thing we guarantee is that the start and end granule - positions of the packets are valid, and that they are monotonic - within a page. - They might be completely out of range for this link (we'll check - that elsewhere), or non-monotonic between pages.*/ - if(OP_UNLIKELY(op_granpos_add(&prev_packet_gp, - cur_page_gp,-total_duration)<0)){ - /*The starting timestamp for the first packet on this page - underflowed. - This is illegal, but we ignore it.*/ - prev_packet_gp=0; - } - for(pi=0;pi<op_count;pi++){ - if(OP_UNLIKELY(op_granpos_add(&cur_packet_gp, - cur_page_gp,-total_duration)<0)){ - /*The start timestamp for this packet underflowed. - This is illegal, but we ignore it.*/ - cur_packet_gp=0; - } - total_duration-=durations[pi]; - OP_ASSERT(total_duration>=0); - OP_ALWAYS_TRUE(!op_granpos_add(&cur_packet_gp, - cur_packet_gp,durations[pi])); - _of->op[pi].granulepos=cur_packet_gp; - } - OP_ASSERT(total_duration==0); - } - _of->prev_packet_gp=prev_packet_gp; - _of->prev_page_offset=_page_offset; - _of->op_count=pi; - /*If end-trimming didn't trim all the packets, we're done.*/ - if(OP_LIKELY(pi>0))return 1; - } - } - } -} - -int op_raw_seek(OggOpusFile *_of,opus_int64 _pos){ - int ret; - if(OP_UNLIKELY(_of->ready_state<OP_OPENED))return OP_EINVAL; - /*Don't dump the decoder state if we can't seek.*/ - if(OP_UNLIKELY(!_of->seekable))return OP_ENOSEEK; - if(OP_UNLIKELY(_pos<0)||OP_UNLIKELY(_pos>_of->end))return OP_EINVAL; - /*Clear out any buffered, decoded data.*/ - op_decode_clear(_of); - _of->bytes_tracked=0; - _of->samples_tracked=0; - ret=op_seek_helper(_of,_pos); - if(OP_UNLIKELY(ret<0))return OP_EREAD; - ret=op_fetch_and_process_page(_of,NULL,-1,1,1,1); - /*If we hit EOF, op_fetch_and_process_page() leaves us uninitialized. - Instead, jump to the end.*/ - if(ret==OP_EOF){ - int cur_link; - op_decode_clear(_of); - cur_link=_of->nlinks-1; - _of->cur_link=cur_link; - _of->prev_packet_gp=_of->links[cur_link].pcm_end; - _of->cur_discard_count=0; - ret=0; - } - else if(ret>0)ret=0; - return ret; -} - -/*Convert a PCM offset relative to the start of the whole stream to a granule - position in an individual link.*/ -static ogg_int64_t op_get_granulepos(const OggOpusFile *_of, - ogg_int64_t _pcm_offset,int *_li){ - const OggOpusLink *links; - ogg_int64_t duration; - int nlinks; - int li; - OP_ASSERT(_pcm_offset>=0); - nlinks=_of->nlinks; - links=_of->links; - for(li=0;OP_LIKELY(li<nlinks);li++){ - ogg_int64_t pcm_start; - opus_int32 pre_skip; - pcm_start=links[li].pcm_start; - pre_skip=links[li].head.pre_skip; - OP_ALWAYS_TRUE(!op_granpos_diff(&duration,links[li].pcm_end,pcm_start)); - duration-=pre_skip; - if(_pcm_offset<duration){ - _pcm_offset+=pre_skip; - if(OP_UNLIKELY(pcm_start>OP_INT64_MAX-_pcm_offset)){ - /*Adding this amount to the granule position would overflow the positive - half of its 64-bit range. - Since signed overflow is undefined in C, do it in a way the compiler - isn't allowed to screw up.*/ - _pcm_offset-=OP_INT64_MAX-pcm_start+1; - pcm_start=OP_INT64_MIN; - } - pcm_start+=_pcm_offset; - *_li=li; - return pcm_start; - } - _pcm_offset-=duration; - } - return -1; -} - -/*A small helper to determine if an Ogg page contains data that continues onto - a subsequent page.*/ -static int op_page_continues(const ogg_page *_og){ - int nlacing; - OP_ASSERT(_og->header_len>=27); - nlacing=_og->header[26]; - OP_ASSERT(_og->header_len>=27+nlacing); - /*This also correctly handles the (unlikely) case of nlacing==0, because - 0!=255.*/ - return _og->header[27+nlacing-1]==255; -} - -/*A small helper to buffer the continued packet data from a page.*/ -static void op_buffer_continued_data(OggOpusFile *_of,ogg_page *_og){ - ogg_packet op; - ogg_stream_pagein(&_of->os,_og); - /*Drain any packets that did end on this page (and ignore holes). - We only care about the continued packet data.*/ - while(ogg_stream_packetout(&_of->os,&op)); -} - -/*This controls how close the target has to be to use the current stream - position to subdivide the initial range. - Two minutes seems to be a good default.*/ -#define OP_CUR_TIME_THRESH (120*48*(opus_int32)1000) - -/*Note: The OP_SMALL_FOOTPRINT #define doesn't (currently) save much code size, - but it's meant to serve as documentation for portions of the seeking - algorithm that are purely optional, to aid others learning from/porting this - code to other contexts.*/ -/*#define OP_SMALL_FOOTPRINT (1)*/ - -/*Search within link _li for the page with the highest granule position - preceding (or equal to) _target_gp. - There is a danger here: missing pages or incorrect frame number information - in the bitstream could make our task impossible. - Account for that (and report it as an error condition).*/ -static int op_pcm_seek_page(OggOpusFile *_of, - ogg_int64_t _target_gp,int _li){ - const OggOpusLink *link; - ogg_page og; - ogg_int64_t pcm_pre_skip; - ogg_int64_t pcm_start; - ogg_int64_t pcm_end; - ogg_int64_t best_gp; - ogg_int64_t diff; - ogg_uint32_t serialno; - opus_int32 pre_skip; - opus_int64 begin; - opus_int64 end; - opus_int64 boundary; - opus_int64 best; - opus_int64 best_start; - opus_int64 page_offset; - opus_int64 d0; - opus_int64 d1; - opus_int64 d2; - int force_bisect; - int buffering; - int ret; - _of->bytes_tracked=0; - _of->samples_tracked=0; - link=_of->links+_li; - best_gp=pcm_start=link->pcm_start; - pcm_end=link->pcm_end; - serialno=link->serialno; - best=best_start=begin=link->data_offset; - page_offset=-1; - buffering=0; - /*We discard the first 80 ms of data after a seek, so seek back that much - farther. - If we can't, simply seek to the beginning of the link.*/ - if(OP_UNLIKELY(op_granpos_add(&_target_gp,_target_gp,-80*48)<0) - ||OP_UNLIKELY(op_granpos_cmp(_target_gp,pcm_start)<0)){ - _target_gp=pcm_start; - } - /*Special case seeking to the start of the link.*/ - pre_skip=link->head.pre_skip; - OP_ALWAYS_TRUE(!op_granpos_add(&pcm_pre_skip,pcm_start,pre_skip)); - if(op_granpos_cmp(_target_gp,pcm_pre_skip)<0)end=boundary=begin; - else{ - end=boundary=link->end_offset; -#if !defined(OP_SMALL_FOOTPRINT) - /*If we were decoding from this link, we can narrow the range a bit.*/ - if(_li==_of->cur_link&&_of->ready_state>=OP_INITSET){ - opus_int64 offset; - int op_count; - op_count=_of->op_count; - /*The only way the offset can be invalid _and_ we can fail the granule - position checks below is if someone changed the contents of the last - page since we read it. - We'd be within our rights to just return OP_EBADLINK in that case, but - we'll simply ignore the current position instead.*/ - offset=_of->offset; - if(op_count>0&&OP_LIKELY(offset<=end)){ - ogg_int64_t gp; - /*Make sure the timestamp is valid. - The granule position might be -1 if we collected the packets from a - page without a granule position after reporting a hole.*/ - gp=_of->op[op_count-1].granulepos; - if(OP_LIKELY(gp!=-1)&&OP_LIKELY(op_granpos_cmp(pcm_start,gp)<0) - &&OP_LIKELY(op_granpos_cmp(pcm_end,gp)>0)){ - OP_ALWAYS_TRUE(!op_granpos_diff(&diff,gp,_target_gp)); - /*We only actually use the current time if either - a) We can cut off at least half the range, or - b) We're seeking sufficiently close to the current position that - it's likely to be informative. - Otherwise it appears using the whole link range to estimate the - first seek location gives better results, on average.*/ - if(diff<0){ - OP_ASSERT(offset>=begin); - if(offset-begin>=end-begin>>1||diff>-OP_CUR_TIME_THRESH){ - best=begin=offset; - best_gp=pcm_start=gp; - /*If we have buffered data from a continued packet, remember the - offset of the previous page's start, so that if we do wind up - having to seek back here later, we can prime the stream with - the continued packet data. - With no continued packet, we remember the end of the page.*/ - best_start=_of->os.body_returned<_of->os.body_fill? - _of->prev_page_offset:best; - /*If there's completed packets and data in the stream state, - prev_page_offset should always be set.*/ - OP_ASSERT(best_start>=0); - /*Buffer any continued packet data starting from here.*/ - buffering=1; - } - } - else{ - ogg_int64_t prev_page_gp; - /*We might get lucky and already have the packet with the target - buffered. - Worth checking. - For very small files (with all of the data in a single page, - generally 1 second or less), we can loop them continuously - without seeking at all.*/ - OP_ALWAYS_TRUE(!op_granpos_add(&prev_page_gp,_of->op[0].granulepos, - -op_get_packet_duration(_of->op[0].packet,_of->op[0].bytes))); - if(op_granpos_cmp(prev_page_gp,_target_gp)<=0){ - /*Don't call op_decode_clear(), because it will dump our - packets.*/ - _of->op_pos=0; - _of->od_buffer_size=0; - _of->prev_packet_gp=prev_page_gp; - /*_of->prev_page_offset already points to the right place.*/ - _of->ready_state=OP_STREAMSET; - return op_make_decode_ready(_of); - } - /*No such luck. - Check if we can cut off at least half the range, though.*/ - if(offset-begin<=end-begin>>1||diff<OP_CUR_TIME_THRESH){ - /*We really want the page start here, but this will do.*/ - end=boundary=offset; - pcm_end=gp; - } - } - } - } - } -#endif - } - /*This code was originally based on the "new search algorithm by HB (Nicholas - Vinen)" from libvorbisfile. - It has been modified substantially since.*/ - op_decode_clear(_of); - if(!buffering)ogg_stream_reset_serialno(&_of->os,serialno); - _of->cur_link=_li; - _of->ready_state=OP_STREAMSET; - /*Initialize the interval size history.*/ - d2=d1=d0=end-begin; - force_bisect=0; - while(begin<end){ - opus_int64 bisect; - opus_int64 next_boundary; - opus_int32 chunk_size; - if(end-begin<OP_CHUNK_SIZE)bisect=begin; - else{ - /*Update the interval size history.*/ - d0=d1>>1; - d1=d2>>1; - d2=end-begin>>1; - if(force_bisect)bisect=begin+(end-begin>>1); - else{ - ogg_int64_t diff2; - OP_ALWAYS_TRUE(!op_granpos_diff(&diff,_target_gp,pcm_start)); - OP_ALWAYS_TRUE(!op_granpos_diff(&diff2,pcm_end,pcm_start)); - /*Take a (pretty decent) guess.*/ - bisect=begin+op_rescale64(diff,diff2,end-begin)-OP_CHUNK_SIZE; - } - if(bisect-OP_CHUNK_SIZE<begin)bisect=begin; - force_bisect=0; - } - if(bisect!=_of->offset){ - /*Discard any buffered continued packet data.*/ - if(buffering)ogg_stream_reset(&_of->os); - buffering=0; - page_offset=-1; - ret=op_seek_helper(_of,bisect); - if(OP_UNLIKELY(ret<0))return ret; - } - chunk_size=OP_CHUNK_SIZE; - next_boundary=boundary; - /*Now scan forward and figure out where we landed. - In the ideal case, we will see a page with a granule position at or - before our target, followed by a page with a granule position after our - target (or the end of the search interval). - Then we can just drop out and will have all of the data we need with no - additional seeking. - If we landed too far before, or after, we'll break out and do another - bisection.*/ - while(begin<end){ - page_offset=op_get_next_page(_of,&og,boundary); - if(page_offset<0){ - if(page_offset<OP_FALSE)return (int)page_offset; - /*There are no more pages in our interval from our stream with a valid - timestamp that start at position bisect or later.*/ - /*If we scanned the whole interval, we're done.*/ - if(bisect<=begin+1)end=begin; - else{ - /*Otherwise, back up one chunk. - First, discard any data from a continued packet.*/ - if(buffering)ogg_stream_reset(&_of->os); - buffering=0; - bisect=OP_MAX(bisect-chunk_size,begin); - ret=op_seek_helper(_of,bisect); - if(OP_UNLIKELY(ret<0))return ret; - /*Bump up the chunk size.*/ - chunk_size=OP_MIN(2*chunk_size,OP_CHUNK_SIZE_MAX); - /*If we did find a page from another stream or without a timestamp, - don't read past it.*/ - boundary=next_boundary; - } - } - else{ - ogg_int64_t gp; - int has_packets; - /*Save the offset of the first page we found after the seek, regardless - of the stream it came from or whether or not it has a timestamp.*/ - next_boundary=OP_MIN(page_offset,next_boundary); - if(serialno!=(ogg_uint32_t)ogg_page_serialno(&og))continue; - has_packets=ogg_page_packets(&og)>0; - /*Force the gp to -1 (as it should be per spec) if no packets end on - this page. - Otherwise we might get confused when we try to pull out a packet - with that timestamp and can't find it.*/ - gp=has_packets?ogg_page_granulepos(&og):-1; - if(gp==-1){ - if(buffering){ - if(OP_LIKELY(!has_packets))ogg_stream_pagein(&_of->os,&og); - else{ - /*If packets did end on this page, but we still didn't have a - valid granule position (in violation of the spec!), stop - buffering continued packet data. - Otherwise we might continue past the packet we actually - wanted.*/ - ogg_stream_reset(&_of->os); - buffering=0; - } - } - continue; - } - if(op_granpos_cmp(gp,_target_gp)<0){ - /*We found a page that ends before our target. - Advance to the raw offset of the next page.*/ - begin=_of->offset; - if(OP_UNLIKELY(op_granpos_cmp(pcm_start,gp)>0) - ||OP_UNLIKELY(op_granpos_cmp(pcm_end,gp)<0)){ - /*Don't let pcm_start get out of range! - That could happen with an invalid timestamp.*/ - break; - } - /*Save the byte offset of the end of the page with this granule - position.*/ - best=best_start=begin; - /*Buffer any data from a continued packet, if necessary. - This avoids the need to seek back here if the next timestamp we - encounter while scanning forward lies after our target.*/ - if(buffering)ogg_stream_reset(&_of->os); - if(op_page_continues(&og)){ - op_buffer_continued_data(_of,&og); - /*If we have a continued packet, remember the offset of this - page's start, so that if we do wind up having to seek back here - later, we can prime the stream with the continued packet data. - With no continued packet, we remember the end of the page.*/ - best_start=page_offset; - } - /*Then force buffering on, so that if a packet starts (but does not - end) on the next page, we still avoid the extra seek back.*/ - buffering=1; - best_gp=pcm_start=gp; - OP_ALWAYS_TRUE(!op_granpos_diff(&diff,_target_gp,pcm_start)); - /*If we're more than a second away from our target, break out and - do another bisection.*/ - if(diff>48000)break; - /*Otherwise, keep scanning forward (do NOT use begin+1).*/ - bisect=begin; - } - else{ - /*We found a page that ends after our target.*/ - /*If we scanned the whole interval before we found it, we're done.*/ - if(bisect<=begin+1)end=begin; - else{ - end=bisect; - /*In later iterations, don't read past the first page we found.*/ - boundary=next_boundary; - /*If we're not making much progress shrinking the interval size, - start forcing straight bisection to limit the worst case.*/ - force_bisect=end-begin>d0*2; - /*Don't let pcm_end get out of range! - That could happen with an invalid timestamp.*/ - if(OP_LIKELY(op_granpos_cmp(pcm_end,gp)>0) - &&OP_LIKELY(op_granpos_cmp(pcm_start,gp)<=0)){ - pcm_end=gp; - } - break; - } - } - } - } - } - /*Found our page.*/ - OP_ASSERT(op_granpos_cmp(best_gp,pcm_start)>=0); - /*Seek, if necessary. - If we were buffering data from a continued packet, we should be able to - continue to scan forward to get the rest of the data (even if - page_offset==-1). - Otherwise, we need to seek back to best_start.*/ - if(!buffering){ - if(best_start!=page_offset){ - page_offset=-1; - ret=op_seek_helper(_of,best_start); - if(OP_UNLIKELY(ret<0))return ret; - } - if(best_start<best){ - /*Retrieve the page at best_start, if we do not already have it.*/ - if(page_offset<0){ - page_offset=op_get_next_page(_of,&og,link->end_offset); - if(OP_UNLIKELY(page_offset<OP_FALSE))return (int)page_offset; - if(OP_UNLIKELY(page_offset!=best_start))return OP_EBADLINK; - } - op_buffer_continued_data(_of,&og); - page_offset=-1; - } - } - /*Update prev_packet_gp to allow per-packet granule position assignment.*/ - _of->prev_packet_gp=best_gp; - _of->prev_page_offset=best_start; - ret=op_fetch_and_process_page(_of,page_offset<0?NULL:&og,page_offset,1,0,1); - if(OP_UNLIKELY(ret<=0))return OP_EBADLINK; - /*Verify result.*/ - if(OP_UNLIKELY(op_granpos_cmp(_of->prev_packet_gp,_target_gp)>0)){ - return OP_EBADLINK; - } - /*Our caller will set cur_discard_count to handle pre-roll.*/ - return 0; -} - -int op_pcm_seek(OggOpusFile *_of,ogg_int64_t _pcm_offset){ - const OggOpusLink *link; - ogg_int64_t pcm_start; - ogg_int64_t target_gp; - ogg_int64_t prev_packet_gp; - ogg_int64_t skip; - ogg_int64_t diff; - int op_count; - int op_pos; - int ret; - int li; - if(OP_UNLIKELY(_of->ready_state<OP_OPENED))return OP_EINVAL; - if(OP_UNLIKELY(!_of->seekable))return OP_ENOSEEK; - if(OP_UNLIKELY(_pcm_offset<0))return OP_EINVAL; - target_gp=op_get_granulepos(_of,_pcm_offset,&li); - if(OP_UNLIKELY(target_gp==-1))return OP_EINVAL; - link=_of->links+li; - pcm_start=link->pcm_start; - OP_ALWAYS_TRUE(!op_granpos_diff(&_pcm_offset,target_gp,pcm_start)); -#if !defined(OP_SMALL_FOOTPRINT) - /*For small (90 ms or less) forward seeks within the same link, just decode - forward. - This also optimizes the case of seeking to the current position.*/ - if(li==_of->cur_link&&_of->ready_state>=OP_INITSET){ - ogg_int64_t gp; - gp=_of->prev_packet_gp; - if(OP_LIKELY(gp!=-1)){ - int nbuffered; - nbuffered=OP_MAX(_of->od_buffer_size-_of->od_buffer_pos,0); - OP_ALWAYS_TRUE(!op_granpos_add(&gp,gp,-nbuffered)); - /*We do _not_ add cur_discard_count to gp. - Otherwise the total amount to discard could grow without bound, and it - would be better just to do a full seek.*/ - if(OP_LIKELY(!op_granpos_diff(&diff,gp,pcm_start))){ - ogg_int64_t discard_count; - discard_count=_pcm_offset-diff; - /*We use a threshold of 90 ms instead of 80, since 80 ms is the - _minimum_ we would have discarded after a full seek. - Assuming 20 ms frames (the default), we'd discard 90 ms on average.*/ - if(discard_count>=0&&OP_UNLIKELY(discard_count<90*48)){ - _of->cur_discard_count=(opus_int32)discard_count; - return 0; - } - } - } - } -#endif - ret=op_pcm_seek_page(_of,target_gp,li); - if(OP_UNLIKELY(ret<0))return ret; - /*Now skip samples until we actually get to our target.*/ - /*Figure out where we should skip to.*/ - if(_pcm_offset<=link->head.pre_skip)skip=0; - else skip=OP_MAX(_pcm_offset-80*48,0); - OP_ASSERT(_pcm_offset-skip>=0); - OP_ASSERT(_pcm_offset-skip<OP_INT32_MAX-120*48); - /*Skip packets until we find one with samples past our skip target.*/ - for(;;){ - op_count=_of->op_count; - prev_packet_gp=_of->prev_packet_gp; - for(op_pos=_of->op_pos;op_pos<op_count;op_pos++){ - ogg_int64_t cur_packet_gp; - cur_packet_gp=_of->op[op_pos].granulepos; - if(OP_LIKELY(!op_granpos_diff(&diff,cur_packet_gp,pcm_start)) - &&diff>skip){ - break; - } - prev_packet_gp=cur_packet_gp; - } - _of->prev_packet_gp=prev_packet_gp; - _of->op_pos=op_pos; - if(op_pos<op_count)break; - /*We skipped all the packets on this page. - Fetch another.*/ - ret=op_fetch_and_process_page(_of,NULL,-1,1,0,1); - if(OP_UNLIKELY(ret<=0))return OP_EBADLINK; - } - OP_ALWAYS_TRUE(!op_granpos_diff(&diff,prev_packet_gp,pcm_start)); - /*We skipped too far. - Either the timestamps were illegal or there was a hole in the data.*/ - if(diff>skip)return OP_EBADLINK; - OP_ASSERT(_pcm_offset-diff<OP_INT32_MAX); - /*TODO: If there are further holes/illegal timestamps, we still won't decode - to the correct sample. - However, at least op_pcm_tell() will report the correct value immediately - after returning.*/ - _of->cur_discard_count=(opus_int32)(_pcm_offset-diff); - return 0; -} - -opus_int64 op_raw_tell(const OggOpusFile *_of){ - if(OP_UNLIKELY(_of->ready_state<OP_OPENED))return OP_EINVAL; - return _of->offset; -} - -/*Convert a granule position from a given link to a PCM offset relative to the - start of the whole stream. - For unseekable sources, this gets reset to 0 at the beginning of each link.*/ -static ogg_int64_t op_get_pcm_offset(const OggOpusFile *_of, - ogg_int64_t _gp,int _li){ - const OggOpusLink *links; - ogg_int64_t pcm_offset; - ogg_int64_t delta; - int li; - links=_of->links; - pcm_offset=0; - OP_ASSERT(_li<_of->nlinks); - for(li=0;li<_li;li++){ - OP_ALWAYS_TRUE(!op_granpos_diff(&delta, - links[li].pcm_end,links[li].pcm_start)); - delta-=links[li].head.pre_skip; - pcm_offset+=delta; - } - OP_ASSERT(_li>=0); - if(_of->seekable&&OP_UNLIKELY(op_granpos_cmp(_gp,links[_li].pcm_end)>0)){ - _gp=links[_li].pcm_end; - } - if(OP_LIKELY(op_granpos_cmp(_gp,links[_li].pcm_start)>0)){ - if(OP_UNLIKELY(op_granpos_diff(&delta,_gp,links[_li].pcm_start)<0)){ - /*This means an unseekable stream claimed to have a page from more than - 2 billion days after we joined.*/ - OP_ASSERT(!_of->seekable); - return OP_INT64_MAX; - } - if(delta<links[_li].head.pre_skip)delta=0; - else delta-=links[_li].head.pre_skip; - /*In the seekable case, _gp was limited by pcm_end. - In the unseekable case, pcm_offset should be 0.*/ - OP_ASSERT(pcm_offset<=OP_INT64_MAX-delta); - pcm_offset+=delta; - } - return pcm_offset; -} - -ogg_int64_t op_pcm_tell(const OggOpusFile *_of){ - ogg_int64_t gp; - int nbuffered; - int li; - if(OP_UNLIKELY(_of->ready_state<OP_OPENED))return OP_EINVAL; - gp=_of->prev_packet_gp; - if(gp==-1)return 0; - nbuffered=OP_MAX(_of->od_buffer_size-_of->od_buffer_pos,0); - OP_ALWAYS_TRUE(!op_granpos_add(&gp,gp,-nbuffered)); - li=_of->seekable?_of->cur_link:0; - if(op_granpos_add(&gp,gp,_of->cur_discard_count)<0){ - gp=_of->links[li].pcm_end; - } - return op_get_pcm_offset(_of,gp,li); -} - -void op_set_decode_callback(OggOpusFile *_of, - op_decode_cb_func _decode_cb,void *_ctx){ - _of->decode_cb=_decode_cb; - _of->decode_cb_ctx=_ctx; -} - -int op_set_gain_offset(OggOpusFile *_of, - int _gain_type,opus_int32 _gain_offset_q8){ - if(_gain_type!=OP_HEADER_GAIN&&_gain_type!=OP_ALBUM_GAIN - &&_gain_type!=OP_TRACK_GAIN&&_gain_type!=OP_ABSOLUTE_GAIN){ - return OP_EINVAL; - } - _of->gain_type=_gain_type; - /*The sum of header gain and track gain lies in the range [-65536,65534]. - These bounds allow the offset to set the final value to anywhere in the - range [-32768,32767], which is what we'll clamp it to before applying.*/ - _of->gain_offset_q8=OP_CLAMP(-98302,_gain_offset_q8,98303); - op_update_gain(_of); - return 0; -} - -void op_set_dither_enabled(OggOpusFile *_of,int _enabled){ -#if !defined(OP_FIXED_POINT) - _of->dither_disabled=!_enabled; - if(!_enabled)_of->dither_mute=65; -#endif -} - -/*Allocate the decoder scratch buffer. - This is done lazily, since if the user provides large enough buffers, we'll - never need it.*/ -static int op_init_buffer(OggOpusFile *_of){ - int nchannels_max; - if(_of->seekable){ - const OggOpusLink *links; - int nlinks; - int li; - links=_of->links; - nlinks=_of->nlinks; - nchannels_max=1; - for(li=0;li<nlinks;li++){ - nchannels_max=OP_MAX(nchannels_max,links[li].head.channel_count); - } - } - else nchannels_max=OP_NCHANNELS_MAX; - _of->od_buffer=(op_sample *)_ogg_malloc( - sizeof(*_of->od_buffer)*nchannels_max*120*48); - if(_of->od_buffer==NULL)return OP_EFAULT; - return 0; -} - -/*Decode a single packet into the target buffer.*/ -static int op_decode(OggOpusFile *_of,op_sample *_pcm, - const ogg_packet *_op,int _nsamples,int _nchannels){ - int ret; - /*First we try using the application-provided decode callback.*/ - if(_of->decode_cb!=NULL){ -#if defined(OP_FIXED_POINT) - ret=(*_of->decode_cb)(_of->decode_cb_ctx,_of->od,_pcm,_op, - _nsamples,_nchannels,OP_DEC_FORMAT_SHORT,_of->cur_link); -#else - ret=(*_of->decode_cb)(_of->decode_cb_ctx,_of->od,_pcm,_op, - _nsamples,_nchannels,OP_DEC_FORMAT_FLOAT,_of->cur_link); -#endif - } - else ret=OP_DEC_USE_DEFAULT; - /*If the application didn't want to handle decoding, do it ourselves.*/ - if(ret==OP_DEC_USE_DEFAULT){ -#if defined(OP_FIXED_POINT) - ret=opus_multistream_decode(_of->od, - _op->packet,_op->bytes,_pcm,_nsamples,0); -#else - ret=opus_multistream_decode_float(_of->od, - _op->packet,_op->bytes,_pcm,_nsamples,0); -#endif - OP_ASSERT(ret<0||ret==_nsamples); - } - /*If the application returned a positive value other than 0 or - OP_DEC_USE_DEFAULT, fail.*/ - else if(OP_UNLIKELY(ret>0))return OP_EBADPACKET; - if(OP_UNLIKELY(ret<0))return OP_EBADPACKET; - return ret; -} - -/*Read more samples from the stream, using the same API as op_read() or - op_read_float().*/ -static int op_read_native(OggOpusFile *_of, - op_sample *_pcm,int _buf_size,int *_li){ - if(OP_UNLIKELY(_of->ready_state<OP_OPENED))return OP_EINVAL; - for(;;){ - int ret; - if(OP_LIKELY(_of->ready_state>=OP_INITSET)){ - int nchannels; - int od_buffer_pos; - int nsamples; - int op_pos; - nchannels=_of->links[_of->seekable?_of->cur_link:0].head.channel_count; - od_buffer_pos=_of->od_buffer_pos; - nsamples=_of->od_buffer_size-od_buffer_pos; - /*If we have buffered samples, return them.*/ - if(nsamples>0){ - if(nsamples*nchannels>_buf_size)nsamples=_buf_size/nchannels; - memcpy(_pcm,_of->od_buffer+nchannels*od_buffer_pos, - sizeof(*_pcm)*nchannels*nsamples); - od_buffer_pos+=nsamples; - _of->od_buffer_pos=od_buffer_pos; - if(_li!=NULL)*_li=_of->cur_link; - return nsamples; - } - /*If we have buffered packets, decode one.*/ - op_pos=_of->op_pos; - if(OP_LIKELY(op_pos<_of->op_count)){ - const ogg_packet *pop; - ogg_int64_t diff; - opus_int32 cur_discard_count; - int duration; - int trimmed_duration; - pop=_of->op+op_pos++; - _of->op_pos=op_pos; - cur_discard_count=_of->cur_discard_count; - duration=op_get_packet_duration(pop->packet,pop->bytes); - /*We don't buffer packets with an invalid TOC sequence.*/ - OP_ASSERT(duration>0); - trimmed_duration=duration; - /*Perform end-trimming.*/ - if(OP_UNLIKELY(pop->e_o_s)){ - if(OP_UNLIKELY(op_granpos_cmp(pop->granulepos, - _of->prev_packet_gp)<=0)){ - trimmed_duration=0; - } - else if(OP_LIKELY(!op_granpos_diff(&diff, - pop->granulepos,_of->prev_packet_gp))){ - trimmed_duration=(int)OP_MIN(diff,trimmed_duration); - } - } - _of->prev_packet_gp=pop->granulepos; - if(OP_UNLIKELY(duration*nchannels>_buf_size)){ - op_sample *buf; - /*If the user's buffer is too small, decode into a scratch buffer.*/ - buf=_of->od_buffer; - if(OP_UNLIKELY(buf==NULL)){ - ret=op_init_buffer(_of); - if(OP_UNLIKELY(ret<0))return ret; - buf=_of->od_buffer; - } - ret=op_decode(_of,buf,pop,duration,nchannels); - if(OP_UNLIKELY(ret<0))return ret; - /*Perform pre-skip/pre-roll.*/ - od_buffer_pos=(int)OP_MIN(trimmed_duration,cur_discard_count); - cur_discard_count-=od_buffer_pos; - _of->cur_discard_count=cur_discard_count; - _of->od_buffer_pos=od_buffer_pos; - _of->od_buffer_size=trimmed_duration; - /*Update bitrate tracking based on the actual samples we used from - what was decoded.*/ - _of->bytes_tracked+=pop->bytes; - _of->samples_tracked+=trimmed_duration-od_buffer_pos; - } - else{ - /*Otherwise decode directly into the user's buffer.*/ - ret=op_decode(_of,_pcm,pop,duration,nchannels); - if(OP_UNLIKELY(ret<0))return ret; - if(OP_LIKELY(trimmed_duration>0)){ - /*Perform pre-skip/pre-roll.*/ - od_buffer_pos=(int)OP_MIN(trimmed_duration,cur_discard_count); - cur_discard_count-=od_buffer_pos; - _of->cur_discard_count=cur_discard_count; - trimmed_duration-=od_buffer_pos; - if(OP_LIKELY(trimmed_duration>0) - &&OP_UNLIKELY(od_buffer_pos>0)){ - memmove(_pcm,_pcm+od_buffer_pos*nchannels, - sizeof(*_pcm)*trimmed_duration*nchannels); - } - /*Update bitrate tracking based on the actual samples we used from - what was decoded.*/ - _of->bytes_tracked+=pop->bytes; - _of->samples_tracked+=trimmed_duration; - if(OP_LIKELY(trimmed_duration>0)){ - if(_li!=NULL)*_li=_of->cur_link; - return trimmed_duration; - } - } - } - /*Don't grab another page yet. - This one might have more packets, or might have buffered data now.*/ - continue; - } - } - /*Suck in another page.*/ - ret=op_fetch_and_process_page(_of,NULL,-1,1,1,0); - if(OP_UNLIKELY(ret==OP_EOF)){ - if(_li!=NULL)*_li=_of->cur_link; - return 0; - } - if(OP_UNLIKELY(ret<0))return ret; - } -} - -/*A generic filter to apply to the decoded audio data. - _src is non-const because we will destructively modify the contents of the - source buffer that we consume in some cases.*/ -typedef int (*op_read_filter_func)(OggOpusFile *_of,void *_dst,int _dst_sz, - op_sample *_src,int _nsamples,int _nchannels); - -/*Decode some samples and then apply a custom filter to them. - This is used to convert to different output formats.*/ -static int op_filter_read_native(OggOpusFile *_of,void *_dst,int _dst_sz, - op_read_filter_func _filter,int *_li){ - int ret; - /*Ensure we have some decoded samples in our buffer.*/ - ret=op_read_native(_of,NULL,0,_li); - /*Now apply the filter to them.*/ - if(OP_LIKELY(ret>=0)&&OP_LIKELY(_of->ready_state>=OP_INITSET)){ - int od_buffer_pos; - od_buffer_pos=_of->od_buffer_pos; - ret=_of->od_buffer_size-od_buffer_pos; - if(OP_LIKELY(ret>0)){ - int nchannels; - nchannels=_of->links[_of->seekable?_of->cur_link:0].head.channel_count; - ret=(*_filter)(_of,_dst,_dst_sz, - _of->od_buffer+nchannels*od_buffer_pos,ret,nchannels); - OP_ASSERT(ret>=0); - OP_ASSERT(ret<=_of->od_buffer_size-od_buffer_pos); - od_buffer_pos+=ret; - _of->od_buffer_pos=od_buffer_pos; - } - } - return ret; -} - -#if !defined(OP_FIXED_POINT)||!defined(OP_DISABLE_FLOAT_API) - -/*Matrices for downmixing from the supported channel counts to stereo. - The matrices with 5 or more channels are normalized to a total volume of 2.0, - since most mixes sound too quiet if normalized to 1.0 (as there is generally - little volume in the side/rear channels).*/ -static const float OP_STEREO_DOWNMIX[OP_NCHANNELS_MAX-2][OP_NCHANNELS_MAX][2]={ - /*3.0*/ - { - {0.5858F,0.0F},{0.4142F,0.4142F},{0.0F,0.5858F} - }, - /*quadrophonic*/ - { - {0.4226F,0.0F},{0.0F,0.4226F},{0.366F,0.2114F},{0.2114F,0.336F} - }, - /*5.0*/ - { - {0.651F,0.0F},{0.46F,0.46F},{0.0F,0.651F},{0.5636F,0.3254F}, - {0.3254F,0.5636F} - }, - /*5.1*/ - { - {0.529F,0.0F},{0.3741F,0.3741F},{0.0F,0.529F},{0.4582F,0.2645F}, - {0.2645F,0.4582F},{0.3741F,0.3741F} - }, - /*6.1*/ - { - {0.4553F,0.0F},{0.322F,0.322F},{0.0F,0.4553F},{0.3943F,0.2277F}, - {0.2277F,0.3943F},{0.2788F,0.2788F},{0.322F,0.322F} - }, - /*7.1*/ - { - {0.3886F,0.0F},{0.2748F,0.2748F},{0.0F,0.3886F},{0.3366F,0.1943F}, - {0.1943F,0.3366F},{0.3366F,0.1943F},{0.1943F,0.3366F},{0.2748F,0.2748F} - } -}; - -#endif - -#if defined(OP_FIXED_POINT) - -/*Matrices for downmixing from the supported channel counts to stereo. - The matrices with 5 or more channels are normalized to a total volume of 2.0, - since most mixes sound too quiet if normalized to 1.0 (as there is generally - little volume in the side/rear channels). - Hence we keep the coefficients in Q14, so the downmix values won't overflow a - 32-bit number.*/ -static const opus_int16 OP_STEREO_DOWNMIX_Q14 - [OP_NCHANNELS_MAX-2][OP_NCHANNELS_MAX][2]={ - /*3.0*/ - { - {9598,0},{6786,6786},{0,9598} - }, - /*quadrophonic*/ - { - {6924,0},{0,6924},{5996,3464},{3464,5996} - }, - /*5.0*/ - { - {10666,0},{7537,7537},{0,10666},{9234,5331},{5331,9234} - }, - /*5.1*/ - { - {8668,0},{6129,6129},{0,8668},{7507,4335},{4335,7507},{6129,6129} - }, - /*6.1*/ - { - {7459,0},{5275,5275},{0,7459},{6460,3731},{3731,6460},{4568,4568}, - {5275,5275} - }, - /*7.1*/ - { - {6368,0},{4502,4502},{0,6368},{5515,3183},{3183,5515},{5515,3183}, - {3183,5515},{4502,4502} - } -}; - -int op_read(OggOpusFile *_of,opus_int16 *_pcm,int _buf_size,int *_li){ - return op_read_native(_of,_pcm,_buf_size,_li); -} - -static int op_stereo_filter(OggOpusFile *_of,void *_dst,int _dst_sz, - op_sample *_src,int _nsamples,int _nchannels){ - (void)_of; - _nsamples=OP_MIN(_nsamples,_dst_sz>>1); - if(_nchannels==2)memcpy(_dst,_src,_nsamples*2*sizeof(*_src)); - else{ - opus_int16 *dst; - int i; - dst=(opus_int16 *)_dst; - if(_nchannels==1){ - for(i=0;i<_nsamples;i++)dst[2*i+0]=dst[2*i+1]=_src[i]; - } - else{ - for(i=0;i<_nsamples;i++){ - opus_int32 l; - opus_int32 r; - int ci; - l=r=0; - for(ci=0;ci<_nchannels;ci++){ - opus_int32 s; - s=_src[_nchannels*i+ci]; - l+=OP_STEREO_DOWNMIX_Q14[_nchannels-3][ci][0]*s; - r+=OP_STEREO_DOWNMIX_Q14[_nchannels-3][ci][1]*s; - } - /*TODO: For 5 or more channels, we should do soft clipping here.*/ - dst[2*i+0]=(opus_int16)OP_CLAMP(-32768,l+8192>>14,32767); - dst[2*i+1]=(opus_int16)OP_CLAMP(-32768,r+8192>>14,32767); - } - } - } - return _nsamples; -} - -int op_read_stereo(OggOpusFile *_of,opus_int16 *_pcm,int _buf_size){ - return op_filter_read_native(_of,_pcm,_buf_size,op_stereo_filter,NULL); -} - -# if !defined(OP_DISABLE_FLOAT_API) - -static int op_short2float_filter(OggOpusFile *_of,void *_dst,int _dst_sz, - op_sample *_src,int _nsamples,int _nchannels){ - float *dst; - int i; - (void)_of; - dst=(float *)_dst; - if(OP_UNLIKELY(_nsamples*_nchannels>_dst_sz))_nsamples=_dst_sz/_nchannels; - _dst_sz=_nsamples*_nchannels; - for(i=0;i<_dst_sz;i++)dst[i]=(1.0F/32768)*_src[i]; - return _nsamples; -} - -int op_read_float(OggOpusFile *_of,float *_pcm,int _buf_size,int *_li){ - return op_filter_read_native(_of,_pcm,_buf_size,op_short2float_filter,_li); -} - -static int op_short2float_stereo_filter(OggOpusFile *_of, - void *_dst,int _dst_sz,op_sample *_src,int _nsamples,int _nchannels){ - float *dst; - int i; - dst=(float *)_dst; - _nsamples=OP_MIN(_nsamples,_dst_sz>>1); - if(_nchannels==1){ - _nsamples=op_short2float_filter(_of,dst,_nsamples,_src,_nsamples,1); - for(i=_nsamples;i-->0;)dst[2*i+0]=dst[2*i+1]=dst[i]; - } - else if(_nchannels<5){ - /*For 3 or 4 channels, we can downmix in fixed point without risk of - clipping.*/ - if(_nchannels>2){ - _nsamples=op_stereo_filter(_of,_src,_nsamples*2, - _src,_nsamples,_nchannels); - } - return op_short2float_filter(_of,dst,_dst_sz,_src,_nsamples,2); - } - else{ - /*For 5 or more channels, we convert to floats and then downmix (so that we - don't risk clipping).*/ - for(i=0;i<_nsamples;i++){ - float l; - float r; - int ci; - l=r=0; - for(ci=0;ci<_nchannels;ci++){ - float s; - s=(1.0F/32768)*_src[_nchannels*i+ci]; - l+=OP_STEREO_DOWNMIX[_nchannels-3][ci][0]*s; - r+=OP_STEREO_DOWNMIX[_nchannels-3][ci][1]*s; - } - dst[2*i+0]=l; - dst[2*i+1]=r; - } - } - return _nsamples; -} - -int op_read_float_stereo(OggOpusFile *_of,float *_pcm,int _buf_size){ - return op_filter_read_native(_of,_pcm,_buf_size, - op_short2float_stereo_filter,NULL); -} - -# endif - -#else - -# if defined(OP_HAVE_LRINTF) -# include <math.h> -# define op_float2int(_x) (lrintf(_x)) -# else -# define op_float2int(_x) ((int)((_x)+((_x)<0?-0.5F:0.5F))) -# endif - -/*The dithering code here is adapted from opusdec, part of opus-tools. - It was originally written by Greg Maxwell.*/ - -static opus_uint32 op_rand(opus_uint32 _seed){ - return _seed*96314165+907633515&0xFFFFFFFFU; -} - -/*This implements 16-bit quantization with full triangular dither and IIR noise - shaping. - The noise shaping filters were designed by Sebastian Gesemann, and are based - on the LAME ATH curves with flattening to limit their peak gain to 20 dB. - Everyone else's noise shaping filters are mildly crazy. - The 48 kHz version of this filter is just a warped version of the 44.1 kHz - filter and probably could be improved by shifting the HF shelf up in - frequency a little bit, since 48 kHz has a bit more room and being more - conservative against bat-ears is probably more important than more noise - suppression. - This process can increase the peak level of the signal (in theory by the peak - error of 1.5 +20 dB, though that is unobservably rare). - To avoid clipping, the signal is attenuated by a couple thousandths of a dB. - Initially, the approach taken here was to only attenuate by the 99.9th - percentile, making clipping rare but not impossible (like SoX), but the - limited gain of the filter means that the worst case was only two - thousandths of a dB more, so this just uses the worst case. - The attenuation is probably also helpful to prevent clipping in the DAC - reconstruction filters or downstream resampling, in any case.*/ - -# define OP_GAIN (32753.0F) - -# define OP_PRNG_GAIN (1.0F/0xFFFFFFFF) - -/*48 kHz noise shaping filter, sd=2.34.*/ - -static const float OP_FCOEF_B[4]={ - 2.2374F,-0.7339F,-0.1251F,-0.6033F -}; - -static const float OP_FCOEF_A[4]={ - 0.9030F,0.0116F,-0.5853F,-0.2571F -}; - -static int op_float2short_filter(OggOpusFile *_of,void *_dst,int _dst_sz, - float *_src,int _nsamples,int _nchannels){ - opus_int16 *dst; - int ci; - int i; - dst=(opus_int16 *)_dst; - if(OP_UNLIKELY(_nsamples*_nchannels>_dst_sz))_nsamples=_dst_sz/_nchannels; -# if defined(OP_SOFT_CLIP) - if(_of->state_channel_count!=_nchannels){ - for(ci=0;ci<_nchannels;ci++)_of->clip_state[ci]=0; - } - opus_pcm_soft_clip(_src,_nsamples,_nchannels,_of->clip_state); -# endif - if(_of->dither_disabled){ - for(i=0;i<_nchannels*_nsamples;i++){ - dst[i]=op_float2int(OP_CLAMP(-32768,32768.0F*_src[i],32767)); - } - } - else{ - opus_uint32 seed; - int mute; - seed=_of->dither_seed; - mute=_of->dither_mute; - if(_of->state_channel_count!=_nchannels)mute=65; - /*In order to avoid replacing digital silence with quiet dither noise, we - mute if the output has been silent for a while.*/ - if(mute>64)memset(_of->dither_a,0,sizeof(*_of->dither_a)*4*_nchannels); - for(i=0;i<_nsamples;i++){ - int silent; - silent=1; - for(ci=0;ci<_nchannels;ci++){ - float r; - float s; - float err; - int si; - int j; - s=_src[_nchannels*i+ci]; - silent&=s==0; - s*=OP_GAIN; - err=0; - for(j=0;j<4;j++){ - err+=OP_FCOEF_B[j]*_of->dither_b[ci*4+j] - -OP_FCOEF_A[j]*_of->dither_a[ci*4+j]; - } - for(j=3;j-->0;)_of->dither_a[ci*4+j+1]=_of->dither_a[ci*4+j]; - for(j=3;j-->0;)_of->dither_b[ci*4+j+1]=_of->dither_b[ci*4+j]; - _of->dither_a[ci*4]=err; - s-=err; - if(mute>16)r=0; - else{ - seed=op_rand(seed); - r=seed*OP_PRNG_GAIN; - seed=op_rand(seed); - r-=seed*OP_PRNG_GAIN; - } - /*Clamp in float out of paranoia that the input will be > 96 dBFS and - wrap if the integer is clamped.*/ - si=op_float2int(OP_CLAMP(-32768,s+r,32767)); - dst[_nchannels*i+ci]=(opus_int16)si; - /*Including clipping in the noise shaping is generally disastrous: the - futile effort to restore the clipped energy results in more clipping. - However, small amounts---at the level which could normally be created - by dither and rounding---are harmless and can even reduce clipping - somewhat due to the clipping sometimes reducing the dither + rounding - error.*/ - _of->dither_b[ci*4]=mute>16?0:OP_CLAMP(-1.5F,si-s,1.5F); - } - mute++; - if(!silent)mute=0; - } - _of->dither_mute=OP_MIN(mute,65); - _of->dither_seed=seed; - } - _of->state_channel_count=_nchannels; - return _nsamples; -} - -int op_read(OggOpusFile *_of,opus_int16 *_pcm,int _buf_size,int *_li){ - return op_filter_read_native(_of,_pcm,_buf_size,op_float2short_filter,_li); -} - -int op_read_float(OggOpusFile *_of,float *_pcm,int _buf_size,int *_li){ - _of->state_channel_count=0; - return op_read_native(_of,_pcm,_buf_size,_li); -} - -static int op_stereo_filter(OggOpusFile *_of,void *_dst,int _dst_sz, - op_sample *_src,int _nsamples,int _nchannels){ - (void)_of; - _nsamples=OP_MIN(_nsamples,_dst_sz>>1); - if(_nchannels==2)memcpy(_dst,_src,_nsamples*2*sizeof(*_src)); - else{ - float *dst; - int i; - dst=(float *)_dst; - if(_nchannels==1){ - for(i=0;i<_nsamples;i++)dst[2*i+0]=dst[2*i+1]=_src[i]; - } - else{ - for(i=0;i<_nsamples;i++){ - float l; - float r; - int ci; - l=r=0; - for(ci=0;ci<_nchannels;ci++){ - l+=OP_STEREO_DOWNMIX[_nchannels-3][ci][0]*_src[_nchannels*i+ci]; - r+=OP_STEREO_DOWNMIX[_nchannels-3][ci][1]*_src[_nchannels*i+ci]; - } - dst[2*i+0]=l; - dst[2*i+1]=r; - } - } - } - return _nsamples; -} - -static int op_float2short_stereo_filter(OggOpusFile *_of, - void *_dst,int _dst_sz,op_sample *_src,int _nsamples,int _nchannels){ - opus_int16 *dst; - dst=(opus_int16 *)_dst; - if(_nchannels==1){ - int i; - _nsamples=op_float2short_filter(_of,dst,_dst_sz>>1,_src,_nsamples,1); - for(i=_nsamples;i-->0;)dst[2*i+0]=dst[2*i+1]=dst[i]; - } - else{ - if(_nchannels>2){ - _nsamples=OP_MIN(_nsamples,_dst_sz>>1); - _nsamples=op_stereo_filter(_of,_src,_nsamples*2, - _src,_nsamples,_nchannels); - } - _nsamples=op_float2short_filter(_of,dst,_dst_sz,_src,_nsamples,2); - } - return _nsamples; -} - -int op_read_stereo(OggOpusFile *_of,opus_int16 *_pcm,int _buf_size){ - return op_filter_read_native(_of,_pcm,_buf_size, - op_float2short_stereo_filter,NULL); -} - -int op_read_float_stereo(OggOpusFile *_of,float *_pcm,int _buf_size){ - _of->state_channel_count=0; - return op_filter_read_native(_of,_pcm,_buf_size,op_stereo_filter,NULL); -} - -#endif |