diff options
Diffstat (limited to 'drivers/opus/opusfile.c')
| -rw-r--r-- | drivers/opus/opusfile.c | 3158 |
1 files changed, 3158 insertions, 0 deletions
diff --git a/drivers/opus/opusfile.c b/drivers/opus/opusfile.c new file mode 100644 index 0000000000..1e7497f6cd --- /dev/null +++ b/drivers/opus/opusfile.c @@ -0,0 +1,3158 @@ +/******************************************************************** + * * + * 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 $ + + ********************************************************************/ +#ifdef OPUS_HAVE_CONFIG_H +#include "opus_config.h" +#endif + +#include "internal.h" +#include <stdio.h> +#include <stdlib.h> +#include <errno.h> +#include <limits.h> +#include <string.h> +#include <math.h> + +#include "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-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; + 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{ + opus_int64 llret; + llret=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(llret<0)){ + /*Fail if there was a read error.*/ + if(llret<OP_FALSE)return (int)llret; + /*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; + 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_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; + } + /*Fall through.*/ + 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(OPUS_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 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; + 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->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; + 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_pos,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_pos=op_get_next_page(_of,&og,_of->end); + /*EOF: Leave uninitialized.*/ + if(_page_pos<0)return _page_pos<OP_FALSE?(int)_page_pos: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_pos<=links[cur_link].data_offset){ + _of->prev_packet_gp=links[cur_link].pcm_start; + _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. + 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->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; +} + +/*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 page_offset; + opus_int64 d0; + opus_int64 d1; + opus_int64 d2; + int force_bisect; + 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=begin=link->data_offset; + page_offset=-1; + /*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; + } + } + 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->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); + /*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){ + page_offset=-1; + ret=op_seek_helper(_of,bisect); + if(OP_UNLIKELY(ret<0))return ret; + } + chunk_size=OP_CHUNK_SIZE; + next_boundary=boundary; + 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.*/ + 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; + /*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; + gp=ogg_page_granulepos(&og); + if(gp==-1)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=begin; + 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. + Seek to the end of it and update prev_packet_gp. + Our caller will set cur_discard_count. + This is an easier case than op_raw_seek(), as we don't need to keep any + packets from the page we found.*/ + /*Seek, if necessary.*/ + if(best!=page_offset){ + page_offset=-1; + ret=op_seek_helper(_of,best); + if(OP_UNLIKELY(ret<0))return ret; + } + OP_ASSERT(op_granpos_cmp(best_gp,pcm_start)>=0); + _of->cur_link=_li; + _of->ready_state=OP_STREAMSET; + _of->prev_packet_gp=best_gp; + ogg_stream_reset_serialno(&_of->os,serialno); + 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; + } + 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_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(OPUS_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(OPUS_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(OPUS_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(OPUS_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(OPUS_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 |