diff options
Diffstat (limited to 'drivers/webp/demux/demux.c')
| -rw-r--r-- | drivers/webp/demux/demux.c | 966 |
1 files changed, 0 insertions, 966 deletions
diff --git a/drivers/webp/demux/demux.c b/drivers/webp/demux/demux.c deleted file mode 100644 index df93c5b379..0000000000 --- a/drivers/webp/demux/demux.c +++ /dev/null @@ -1,966 +0,0 @@ -// Copyright 2012 Google Inc. All Rights Reserved. -// -// Use of this source code is governed by a BSD-style license -// that can be found in the COPYING file in the root of the source -// tree. An additional intellectual property rights grant can be found -// in the file PATENTS. All contributing project authors may -// be found in the AUTHORS file in the root of the source tree. -// ----------------------------------------------------------------------------- -// -// WebP container demux. -// - -#ifdef HAVE_CONFIG_H -#include "webp/config.h" -#endif - -#include <assert.h> -#include <stdlib.h> -#include <string.h> - -#include "../utils/utils.h" -#include "webp/decode.h" // WebPGetFeatures -#include "webp/demux.h" -#include "webp/format_constants.h" - -#define DMUX_MAJ_VERSION 0 -#define DMUX_MIN_VERSION 3 -#define DMUX_REV_VERSION 0 - -typedef struct { - size_t start_; // start location of the data - size_t end_; // end location - size_t riff_end_; // riff chunk end location, can be > end_. - size_t buf_size_; // size of the buffer - const uint8_t* buf_; -} MemBuffer; - -typedef struct { - size_t offset_; - size_t size_; -} ChunkData; - -typedef struct Frame { - int x_offset_, y_offset_; - int width_, height_; - int has_alpha_; - int duration_; - WebPMuxAnimDispose dispose_method_; - WebPMuxAnimBlend blend_method_; - int frame_num_; - int complete_; // img_components_ contains a full image. - ChunkData img_components_[2]; // 0=VP8{,L} 1=ALPH - struct Frame* next_; -} Frame; - -typedef struct Chunk { - ChunkData data_; - struct Chunk* next_; -} Chunk; - -struct WebPDemuxer { - MemBuffer mem_; - WebPDemuxState state_; - int is_ext_format_; - uint32_t feature_flags_; - int canvas_width_, canvas_height_; - int loop_count_; - uint32_t bgcolor_; - int num_frames_; - Frame* frames_; - Frame** frames_tail_; - Chunk* chunks_; // non-image chunks - Chunk** chunks_tail_; -}; - -typedef enum { - PARSE_OK, - PARSE_NEED_MORE_DATA, - PARSE_ERROR -} ParseStatus; - -typedef struct ChunkParser { - uint8_t id[4]; - ParseStatus (*parse)(WebPDemuxer* const dmux); - int (*valid)(const WebPDemuxer* const dmux); -} ChunkParser; - -static ParseStatus ParseSingleImage(WebPDemuxer* const dmux); -static ParseStatus ParseVP8X(WebPDemuxer* const dmux); -static int IsValidSimpleFormat(const WebPDemuxer* const dmux); -static int IsValidExtendedFormat(const WebPDemuxer* const dmux); - -static const ChunkParser kMasterChunks[] = { - { { 'V', 'P', '8', ' ' }, ParseSingleImage, IsValidSimpleFormat }, - { { 'V', 'P', '8', 'L' }, ParseSingleImage, IsValidSimpleFormat }, - { { 'V', 'P', '8', 'X' }, ParseVP8X, IsValidExtendedFormat }, - { { '0', '0', '0', '0' }, NULL, NULL }, -}; - -//------------------------------------------------------------------------------ - -int WebPGetDemuxVersion(void) { - return (DMUX_MAJ_VERSION << 16) | (DMUX_MIN_VERSION << 8) | DMUX_REV_VERSION; -} - -// ----------------------------------------------------------------------------- -// MemBuffer - -static int RemapMemBuffer(MemBuffer* const mem, - const uint8_t* data, size_t size) { - if (size < mem->buf_size_) return 0; // can't remap to a shorter buffer! - - mem->buf_ = data; - mem->end_ = mem->buf_size_ = size; - return 1; -} - -static int InitMemBuffer(MemBuffer* const mem, - const uint8_t* data, size_t size) { - memset(mem, 0, sizeof(*mem)); - return RemapMemBuffer(mem, data, size); -} - -// Return the remaining data size available in 'mem'. -static WEBP_INLINE size_t MemDataSize(const MemBuffer* const mem) { - return (mem->end_ - mem->start_); -} - -// Return true if 'size' exceeds the end of the RIFF chunk. -static WEBP_INLINE int SizeIsInvalid(const MemBuffer* const mem, size_t size) { - return (size > mem->riff_end_ - mem->start_); -} - -static WEBP_INLINE void Skip(MemBuffer* const mem, size_t size) { - mem->start_ += size; -} - -static WEBP_INLINE void Rewind(MemBuffer* const mem, size_t size) { - mem->start_ -= size; -} - -static WEBP_INLINE const uint8_t* GetBuffer(MemBuffer* const mem) { - return mem->buf_ + mem->start_; -} - -// Read from 'mem' and skip the read bytes. -static WEBP_INLINE uint8_t ReadByte(MemBuffer* const mem) { - const uint8_t byte = mem->buf_[mem->start_]; - Skip(mem, 1); - return byte; -} - -static WEBP_INLINE int ReadLE16s(MemBuffer* const mem) { - const uint8_t* const data = mem->buf_ + mem->start_; - const int val = GetLE16(data); - Skip(mem, 2); - return val; -} - -static WEBP_INLINE int ReadLE24s(MemBuffer* const mem) { - const uint8_t* const data = mem->buf_ + mem->start_; - const int val = GetLE24(data); - Skip(mem, 3); - return val; -} - -static WEBP_INLINE uint32_t ReadLE32(MemBuffer* const mem) { - const uint8_t* const data = mem->buf_ + mem->start_; - const uint32_t val = GetLE32(data); - Skip(mem, 4); - return val; -} - -// ----------------------------------------------------------------------------- -// Secondary chunk parsing - -static void AddChunk(WebPDemuxer* const dmux, Chunk* const chunk) { - *dmux->chunks_tail_ = chunk; - chunk->next_ = NULL; - dmux->chunks_tail_ = &chunk->next_; -} - -// Add a frame to the end of the list, ensuring the last frame is complete. -// Returns true on success, false otherwise. -static int AddFrame(WebPDemuxer* const dmux, Frame* const frame) { - const Frame* const last_frame = *dmux->frames_tail_; - if (last_frame != NULL && !last_frame->complete_) return 0; - - *dmux->frames_tail_ = frame; - frame->next_ = NULL; - dmux->frames_tail_ = &frame->next_; - return 1; -} - -static void SetFrameInfo(size_t start_offset, size_t size, - int frame_num, int complete, - const WebPBitstreamFeatures* const features, - Frame* const frame) { - frame->img_components_[0].offset_ = start_offset; - frame->img_components_[0].size_ = size; - frame->width_ = features->width; - frame->height_ = features->height; - frame->has_alpha_ |= features->has_alpha; - frame->frame_num_ = frame_num; - frame->complete_ = complete; -} - -// Store image bearing chunks to 'frame'. -static ParseStatus StoreFrame(int frame_num, uint32_t min_size, - MemBuffer* const mem, Frame* const frame) { - int alpha_chunks = 0; - int image_chunks = 0; - int done = (MemDataSize(mem) < min_size); - ParseStatus status = PARSE_OK; - - if (done) return PARSE_NEED_MORE_DATA; - - do { - const size_t chunk_start_offset = mem->start_; - const uint32_t fourcc = ReadLE32(mem); - const uint32_t payload_size = ReadLE32(mem); - const uint32_t payload_size_padded = payload_size + (payload_size & 1); - const size_t payload_available = (payload_size_padded > MemDataSize(mem)) - ? MemDataSize(mem) : payload_size_padded; - const size_t chunk_size = CHUNK_HEADER_SIZE + payload_available; - - if (payload_size > MAX_CHUNK_PAYLOAD) return PARSE_ERROR; - if (SizeIsInvalid(mem, payload_size_padded)) return PARSE_ERROR; - if (payload_size_padded > MemDataSize(mem)) status = PARSE_NEED_MORE_DATA; - - switch (fourcc) { - case MKFOURCC('A', 'L', 'P', 'H'): - if (alpha_chunks == 0) { - ++alpha_chunks; - frame->img_components_[1].offset_ = chunk_start_offset; - frame->img_components_[1].size_ = chunk_size; - frame->has_alpha_ = 1; - frame->frame_num_ = frame_num; - Skip(mem, payload_available); - } else { - goto Done; - } - break; - case MKFOURCC('V', 'P', '8', 'L'): - if (alpha_chunks > 0) return PARSE_ERROR; // VP8L has its own alpha - // fall through - case MKFOURCC('V', 'P', '8', ' '): - if (image_chunks == 0) { - // Extract the bitstream features, tolerating failures when the data - // is incomplete. - WebPBitstreamFeatures features; - const VP8StatusCode vp8_status = - WebPGetFeatures(mem->buf_ + chunk_start_offset, chunk_size, - &features); - if (status == PARSE_NEED_MORE_DATA && - vp8_status == VP8_STATUS_NOT_ENOUGH_DATA) { - return PARSE_NEED_MORE_DATA; - } else if (vp8_status != VP8_STATUS_OK) { - // We have enough data, and yet WebPGetFeatures() failed. - return PARSE_ERROR; - } - ++image_chunks; - SetFrameInfo(chunk_start_offset, chunk_size, frame_num, - status == PARSE_OK, &features, frame); - Skip(mem, payload_available); - } else { - goto Done; - } - break; - Done: - default: - // Restore fourcc/size when moving up one level in parsing. - Rewind(mem, CHUNK_HEADER_SIZE); - done = 1; - break; - } - - if (mem->start_ == mem->riff_end_) { - done = 1; - } else if (MemDataSize(mem) < CHUNK_HEADER_SIZE) { - status = PARSE_NEED_MORE_DATA; - } - } while (!done && status == PARSE_OK); - - return status; -} - -// Creates a new Frame if 'actual_size' is within bounds and 'mem' contains -// enough data ('min_size') to parse the payload. -// Returns PARSE_OK on success with *frame pointing to the new Frame. -// Returns PARSE_NEED_MORE_DATA with insufficient data, PARSE_ERROR otherwise. -static ParseStatus NewFrame(const MemBuffer* const mem, - uint32_t min_size, uint32_t actual_size, - Frame** frame) { - if (SizeIsInvalid(mem, min_size)) return PARSE_ERROR; - if (actual_size < min_size) return PARSE_ERROR; - if (MemDataSize(mem) < min_size) return PARSE_NEED_MORE_DATA; - - *frame = (Frame*)WebPSafeCalloc(1ULL, sizeof(**frame)); - return (*frame == NULL) ? PARSE_ERROR : PARSE_OK; -} - -// Parse a 'ANMF' chunk and any image bearing chunks that immediately follow. -// 'frame_chunk_size' is the previously validated, padded chunk size. -static ParseStatus ParseAnimationFrame( - WebPDemuxer* const dmux, uint32_t frame_chunk_size) { - const int is_animation = !!(dmux->feature_flags_ & ANIMATION_FLAG); - const uint32_t anmf_payload_size = frame_chunk_size - ANMF_CHUNK_SIZE; - int added_frame = 0; - int bits; - MemBuffer* const mem = &dmux->mem_; - Frame* frame; - ParseStatus status = - NewFrame(mem, ANMF_CHUNK_SIZE, frame_chunk_size, &frame); - if (status != PARSE_OK) return status; - - frame->x_offset_ = 2 * ReadLE24s(mem); - frame->y_offset_ = 2 * ReadLE24s(mem); - frame->width_ = 1 + ReadLE24s(mem); - frame->height_ = 1 + ReadLE24s(mem); - frame->duration_ = ReadLE24s(mem); - bits = ReadByte(mem); - frame->dispose_method_ = - (bits & 1) ? WEBP_MUX_DISPOSE_BACKGROUND : WEBP_MUX_DISPOSE_NONE; - frame->blend_method_ = (bits & 2) ? WEBP_MUX_NO_BLEND : WEBP_MUX_BLEND; - if (frame->width_ * (uint64_t)frame->height_ >= MAX_IMAGE_AREA) { - WebPSafeFree(frame); - return PARSE_ERROR; - } - - // Store a frame only if the animation flag is set there is some data for - // this frame is available. - status = StoreFrame(dmux->num_frames_ + 1, anmf_payload_size, mem, frame); - if (status != PARSE_ERROR && is_animation && frame->frame_num_ > 0) { - added_frame = AddFrame(dmux, frame); - if (added_frame) { - ++dmux->num_frames_; - } else { - status = PARSE_ERROR; - } - } - - if (!added_frame) WebPSafeFree(frame); - return status; -} - -// General chunk storage, starting with the header at 'start_offset', allowing -// the user to request the payload via a fourcc string. 'size' includes the -// header and the unpadded payload size. -// Returns true on success, false otherwise. -static int StoreChunk(WebPDemuxer* const dmux, - size_t start_offset, uint32_t size) { - Chunk* const chunk = (Chunk*)WebPSafeCalloc(1ULL, sizeof(*chunk)); - if (chunk == NULL) return 0; - - chunk->data_.offset_ = start_offset; - chunk->data_.size_ = size; - AddChunk(dmux, chunk); - return 1; -} - -// ----------------------------------------------------------------------------- -// Primary chunk parsing - -static ParseStatus ReadHeader(MemBuffer* const mem) { - const size_t min_size = RIFF_HEADER_SIZE + CHUNK_HEADER_SIZE; - uint32_t riff_size; - - // Basic file level validation. - if (MemDataSize(mem) < min_size) return PARSE_NEED_MORE_DATA; - if (memcmp(GetBuffer(mem), "RIFF", CHUNK_SIZE_BYTES) || - memcmp(GetBuffer(mem) + CHUNK_HEADER_SIZE, "WEBP", CHUNK_SIZE_BYTES)) { - return PARSE_ERROR; - } - - riff_size = GetLE32(GetBuffer(mem) + TAG_SIZE); - if (riff_size < CHUNK_HEADER_SIZE) return PARSE_ERROR; - if (riff_size > MAX_CHUNK_PAYLOAD) return PARSE_ERROR; - - // There's no point in reading past the end of the RIFF chunk - mem->riff_end_ = riff_size + CHUNK_HEADER_SIZE; - if (mem->buf_size_ > mem->riff_end_) { - mem->buf_size_ = mem->end_ = mem->riff_end_; - } - - Skip(mem, RIFF_HEADER_SIZE); - return PARSE_OK; -} - -static ParseStatus ParseSingleImage(WebPDemuxer* const dmux) { - const size_t min_size = CHUNK_HEADER_SIZE; - MemBuffer* const mem = &dmux->mem_; - Frame* frame; - ParseStatus status; - int image_added = 0; - - if (dmux->frames_ != NULL) return PARSE_ERROR; - if (SizeIsInvalid(mem, min_size)) return PARSE_ERROR; - if (MemDataSize(mem) < min_size) return PARSE_NEED_MORE_DATA; - - frame = (Frame*)WebPSafeCalloc(1ULL, sizeof(*frame)); - if (frame == NULL) return PARSE_ERROR; - - // For the single image case we allow parsing of a partial frame, but we need - // at least CHUNK_HEADER_SIZE for parsing. - status = StoreFrame(1, CHUNK_HEADER_SIZE, &dmux->mem_, frame); - if (status != PARSE_ERROR) { - const int has_alpha = !!(dmux->feature_flags_ & ALPHA_FLAG); - // Clear any alpha when the alpha flag is missing. - if (!has_alpha && frame->img_components_[1].size_ > 0) { - frame->img_components_[1].offset_ = 0; - frame->img_components_[1].size_ = 0; - frame->has_alpha_ = 0; - } - - // Use the frame width/height as the canvas values for non-vp8x files. - // Also, set ALPHA_FLAG if this is a lossless image with alpha. - if (!dmux->is_ext_format_ && frame->width_ > 0 && frame->height_ > 0) { - dmux->state_ = WEBP_DEMUX_PARSED_HEADER; - dmux->canvas_width_ = frame->width_; - dmux->canvas_height_ = frame->height_; - dmux->feature_flags_ |= frame->has_alpha_ ? ALPHA_FLAG : 0; - } - if (!AddFrame(dmux, frame)) { - status = PARSE_ERROR; // last frame was left incomplete - } else { - image_added = 1; - dmux->num_frames_ = 1; - } - } - - if (!image_added) WebPSafeFree(frame); - return status; -} - -static ParseStatus ParseVP8XChunks(WebPDemuxer* const dmux) { - const int is_animation = !!(dmux->feature_flags_ & ANIMATION_FLAG); - MemBuffer* const mem = &dmux->mem_; - int anim_chunks = 0; - ParseStatus status = PARSE_OK; - - do { - int store_chunk = 1; - const size_t chunk_start_offset = mem->start_; - const uint32_t fourcc = ReadLE32(mem); - const uint32_t chunk_size = ReadLE32(mem); - const uint32_t chunk_size_padded = chunk_size + (chunk_size & 1); - - if (chunk_size > MAX_CHUNK_PAYLOAD) return PARSE_ERROR; - if (SizeIsInvalid(mem, chunk_size_padded)) return PARSE_ERROR; - - switch (fourcc) { - case MKFOURCC('V', 'P', '8', 'X'): { - return PARSE_ERROR; - } - case MKFOURCC('A', 'L', 'P', 'H'): - case MKFOURCC('V', 'P', '8', ' '): - case MKFOURCC('V', 'P', '8', 'L'): { - // check that this isn't an animation (all frames should be in an ANMF). - if (anim_chunks > 0 || is_animation) return PARSE_ERROR; - - Rewind(mem, CHUNK_HEADER_SIZE); - status = ParseSingleImage(dmux); - break; - } - case MKFOURCC('A', 'N', 'I', 'M'): { - if (chunk_size_padded < ANIM_CHUNK_SIZE) return PARSE_ERROR; - - if (MemDataSize(mem) < chunk_size_padded) { - status = PARSE_NEED_MORE_DATA; - } else if (anim_chunks == 0) { - ++anim_chunks; - dmux->bgcolor_ = ReadLE32(mem); - dmux->loop_count_ = ReadLE16s(mem); - Skip(mem, chunk_size_padded - ANIM_CHUNK_SIZE); - } else { - store_chunk = 0; - goto Skip; - } - break; - } - case MKFOURCC('A', 'N', 'M', 'F'): { - if (anim_chunks == 0) return PARSE_ERROR; // 'ANIM' precedes frames. - status = ParseAnimationFrame(dmux, chunk_size_padded); - break; - } - case MKFOURCC('I', 'C', 'C', 'P'): { - store_chunk = !!(dmux->feature_flags_ & ICCP_FLAG); - goto Skip; - } - case MKFOURCC('E', 'X', 'I', 'F'): { - store_chunk = !!(dmux->feature_flags_ & EXIF_FLAG); - goto Skip; - } - case MKFOURCC('X', 'M', 'P', ' '): { - store_chunk = !!(dmux->feature_flags_ & XMP_FLAG); - goto Skip; - } - Skip: - default: { - if (chunk_size_padded <= MemDataSize(mem)) { - if (store_chunk) { - // Store only the chunk header and unpadded size as only the payload - // will be returned to the user. - if (!StoreChunk(dmux, chunk_start_offset, - CHUNK_HEADER_SIZE + chunk_size)) { - return PARSE_ERROR; - } - } - Skip(mem, chunk_size_padded); - } else { - status = PARSE_NEED_MORE_DATA; - } - } - } - - if (mem->start_ == mem->riff_end_) { - break; - } else if (MemDataSize(mem) < CHUNK_HEADER_SIZE) { - status = PARSE_NEED_MORE_DATA; - } - } while (status == PARSE_OK); - - return status; -} - -static ParseStatus ParseVP8X(WebPDemuxer* const dmux) { - MemBuffer* const mem = &dmux->mem_; - uint32_t vp8x_size; - - if (MemDataSize(mem) < CHUNK_HEADER_SIZE) return PARSE_NEED_MORE_DATA; - - dmux->is_ext_format_ = 1; - Skip(mem, TAG_SIZE); // VP8X - vp8x_size = ReadLE32(mem); - if (vp8x_size > MAX_CHUNK_PAYLOAD) return PARSE_ERROR; - if (vp8x_size < VP8X_CHUNK_SIZE) return PARSE_ERROR; - vp8x_size += vp8x_size & 1; - if (SizeIsInvalid(mem, vp8x_size)) return PARSE_ERROR; - if (MemDataSize(mem) < vp8x_size) return PARSE_NEED_MORE_DATA; - - dmux->feature_flags_ = ReadByte(mem); - Skip(mem, 3); // Reserved. - dmux->canvas_width_ = 1 + ReadLE24s(mem); - dmux->canvas_height_ = 1 + ReadLE24s(mem); - if (dmux->canvas_width_ * (uint64_t)dmux->canvas_height_ >= MAX_IMAGE_AREA) { - return PARSE_ERROR; // image final dimension is too large - } - Skip(mem, vp8x_size - VP8X_CHUNK_SIZE); // skip any trailing data. - dmux->state_ = WEBP_DEMUX_PARSED_HEADER; - - if (SizeIsInvalid(mem, CHUNK_HEADER_SIZE)) return PARSE_ERROR; - if (MemDataSize(mem) < CHUNK_HEADER_SIZE) return PARSE_NEED_MORE_DATA; - - return ParseVP8XChunks(dmux); -} - -// ----------------------------------------------------------------------------- -// Format validation - -static int IsValidSimpleFormat(const WebPDemuxer* const dmux) { - const Frame* const frame = dmux->frames_; - if (dmux->state_ == WEBP_DEMUX_PARSING_HEADER) return 1; - - if (dmux->canvas_width_ <= 0 || dmux->canvas_height_ <= 0) return 0; - if (dmux->state_ == WEBP_DEMUX_DONE && frame == NULL) return 0; - - if (frame->width_ <= 0 || frame->height_ <= 0) return 0; - return 1; -} - -// If 'exact' is true, check that the image resolution matches the canvas. -// If 'exact' is false, check that the x/y offsets do not exceed the canvas. -static int CheckFrameBounds(const Frame* const frame, int exact, - int canvas_width, int canvas_height) { - if (exact) { - if (frame->x_offset_ != 0 || frame->y_offset_ != 0) { - return 0; - } - if (frame->width_ != canvas_width || frame->height_ != canvas_height) { - return 0; - } - } else { - if (frame->x_offset_ < 0 || frame->y_offset_ < 0) return 0; - if (frame->width_ + frame->x_offset_ > canvas_width) return 0; - if (frame->height_ + frame->y_offset_ > canvas_height) return 0; - } - return 1; -} - -static int IsValidExtendedFormat(const WebPDemuxer* const dmux) { - const int is_animation = !!(dmux->feature_flags_ & ANIMATION_FLAG); - const int is_fragmented = !!(dmux->feature_flags_ & FRAGMENTS_FLAG); - const Frame* f = dmux->frames_; - - if (dmux->state_ == WEBP_DEMUX_PARSING_HEADER) return 1; - - if (dmux->canvas_width_ <= 0 || dmux->canvas_height_ <= 0) return 0; - if (dmux->loop_count_ < 0) return 0; - if (dmux->state_ == WEBP_DEMUX_DONE && dmux->frames_ == NULL) return 0; - if (is_fragmented) return 0; - - while (f != NULL) { - const int cur_frame_set = f->frame_num_; - int frame_count = 0; - - // Check frame properties. - for (; f != NULL && f->frame_num_ == cur_frame_set; f = f->next_) { - const ChunkData* const image = f->img_components_; - const ChunkData* const alpha = f->img_components_ + 1; - - if (!is_animation && f->frame_num_ > 1) return 0; - - if (f->complete_) { - if (alpha->size_ == 0 && image->size_ == 0) return 0; - // Ensure alpha precedes image bitstream. - if (alpha->size_ > 0 && alpha->offset_ > image->offset_) { - return 0; - } - - if (f->width_ <= 0 || f->height_ <= 0) return 0; - } else { - // There shouldn't be a partial frame in a complete file. - if (dmux->state_ == WEBP_DEMUX_DONE) return 0; - - // Ensure alpha precedes image bitstream. - if (alpha->size_ > 0 && image->size_ > 0 && - alpha->offset_ > image->offset_) { - return 0; - } - // There shouldn't be any frames after an incomplete one. - if (f->next_ != NULL) return 0; - } - - if (f->width_ > 0 && f->height_ > 0 && - !CheckFrameBounds(f, !is_animation, - dmux->canvas_width_, dmux->canvas_height_)) { - return 0; - } - - ++frame_count; - } - } - return 1; -} - -// ----------------------------------------------------------------------------- -// WebPDemuxer object - -static void InitDemux(WebPDemuxer* const dmux, const MemBuffer* const mem) { - dmux->state_ = WEBP_DEMUX_PARSING_HEADER; - dmux->loop_count_ = 1; - dmux->bgcolor_ = 0xFFFFFFFF; // White background by default. - dmux->canvas_width_ = -1; - dmux->canvas_height_ = -1; - dmux->frames_tail_ = &dmux->frames_; - dmux->chunks_tail_ = &dmux->chunks_; - dmux->mem_ = *mem; -} - -static ParseStatus CreateRawImageDemuxer(MemBuffer* const mem, - WebPDemuxer** demuxer) { - WebPBitstreamFeatures features; - const VP8StatusCode status = - WebPGetFeatures(mem->buf_, mem->buf_size_, &features); - *demuxer = NULL; - if (status != VP8_STATUS_OK) { - return (status == VP8_STATUS_NOT_ENOUGH_DATA) ? PARSE_NEED_MORE_DATA - : PARSE_ERROR; - } - - { - WebPDemuxer* const dmux = (WebPDemuxer*)WebPSafeCalloc(1ULL, sizeof(*dmux)); - Frame* const frame = (Frame*)WebPSafeCalloc(1ULL, sizeof(*frame)); - if (dmux == NULL || frame == NULL) goto Error; - InitDemux(dmux, mem); - SetFrameInfo(0, mem->buf_size_, 1 /*frame_num*/, 1 /*complete*/, &features, - frame); - if (!AddFrame(dmux, frame)) goto Error; - dmux->state_ = WEBP_DEMUX_DONE; - dmux->canvas_width_ = frame->width_; - dmux->canvas_height_ = frame->height_; - dmux->feature_flags_ |= frame->has_alpha_ ? ALPHA_FLAG : 0; - dmux->num_frames_ = 1; - assert(IsValidSimpleFormat(dmux)); - *demuxer = dmux; - return PARSE_OK; - - Error: - WebPSafeFree(dmux); - WebPSafeFree(frame); - return PARSE_ERROR; - } -} - -WebPDemuxer* WebPDemuxInternal(const WebPData* data, int allow_partial, - WebPDemuxState* state, int version) { - const ChunkParser* parser; - int partial; - ParseStatus status = PARSE_ERROR; - MemBuffer mem; - WebPDemuxer* dmux; - - if (state != NULL) *state = WEBP_DEMUX_PARSE_ERROR; - - if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DEMUX_ABI_VERSION)) return NULL; - if (data == NULL || data->bytes == NULL || data->size == 0) return NULL; - - if (!InitMemBuffer(&mem, data->bytes, data->size)) return NULL; - status = ReadHeader(&mem); - if (status != PARSE_OK) { - // If parsing of the webp file header fails attempt to handle a raw - // VP8/VP8L frame. Note 'allow_partial' is ignored in this case. - if (status == PARSE_ERROR) { - status = CreateRawImageDemuxer(&mem, &dmux); - if (status == PARSE_OK) { - if (state != NULL) *state = WEBP_DEMUX_DONE; - return dmux; - } - } - if (state != NULL) { - *state = (status == PARSE_NEED_MORE_DATA) ? WEBP_DEMUX_PARSING_HEADER - : WEBP_DEMUX_PARSE_ERROR; - } - return NULL; - } - - partial = (mem.buf_size_ < mem.riff_end_); - if (!allow_partial && partial) return NULL; - - dmux = (WebPDemuxer*)WebPSafeCalloc(1ULL, sizeof(*dmux)); - if (dmux == NULL) return NULL; - InitDemux(dmux, &mem); - - status = PARSE_ERROR; - for (parser = kMasterChunks; parser->parse != NULL; ++parser) { - if (!memcmp(parser->id, GetBuffer(&dmux->mem_), TAG_SIZE)) { - status = parser->parse(dmux); - if (status == PARSE_OK) dmux->state_ = WEBP_DEMUX_DONE; - if (status == PARSE_NEED_MORE_DATA && !partial) status = PARSE_ERROR; - if (status != PARSE_ERROR && !parser->valid(dmux)) status = PARSE_ERROR; - if (status == PARSE_ERROR) dmux->state_ = WEBP_DEMUX_PARSE_ERROR; - break; - } - } - if (state != NULL) *state = dmux->state_; - - if (status == PARSE_ERROR) { - WebPDemuxDelete(dmux); - return NULL; - } - return dmux; -} - -void WebPDemuxDelete(WebPDemuxer* dmux) { - Chunk* c; - Frame* f; - if (dmux == NULL) return; - - for (f = dmux->frames_; f != NULL;) { - Frame* const cur_frame = f; - f = f->next_; - WebPSafeFree(cur_frame); - } - for (c = dmux->chunks_; c != NULL;) { - Chunk* const cur_chunk = c; - c = c->next_; - WebPSafeFree(cur_chunk); - } - WebPSafeFree(dmux); -} - -// ----------------------------------------------------------------------------- - -uint32_t WebPDemuxGetI(const WebPDemuxer* dmux, WebPFormatFeature feature) { - if (dmux == NULL) return 0; - - switch (feature) { - case WEBP_FF_FORMAT_FLAGS: return dmux->feature_flags_; - case WEBP_FF_CANVAS_WIDTH: return (uint32_t)dmux->canvas_width_; - case WEBP_FF_CANVAS_HEIGHT: return (uint32_t)dmux->canvas_height_; - case WEBP_FF_LOOP_COUNT: return (uint32_t)dmux->loop_count_; - case WEBP_FF_BACKGROUND_COLOR: return dmux->bgcolor_; - case WEBP_FF_FRAME_COUNT: return (uint32_t)dmux->num_frames_; - } - return 0; -} - -// ----------------------------------------------------------------------------- -// Frame iteration - -static const Frame* GetFrame(const WebPDemuxer* const dmux, int frame_num) { - const Frame* f; - for (f = dmux->frames_; f != NULL; f = f->next_) { - if (frame_num == f->frame_num_) break; - } - return f; -} - -static const uint8_t* GetFramePayload(const uint8_t* const mem_buf, - const Frame* const frame, - size_t* const data_size) { - *data_size = 0; - if (frame != NULL) { - const ChunkData* const image = frame->img_components_; - const ChunkData* const alpha = frame->img_components_ + 1; - size_t start_offset = image->offset_; - *data_size = image->size_; - - // if alpha exists it precedes image, update the size allowing for - // intervening chunks. - if (alpha->size_ > 0) { - const size_t inter_size = (image->offset_ > 0) - ? image->offset_ - (alpha->offset_ + alpha->size_) - : 0; - start_offset = alpha->offset_; - *data_size += alpha->size_ + inter_size; - } - return mem_buf + start_offset; - } - return NULL; -} - -// Create a whole 'frame' from VP8 (+ alpha) or lossless. -static int SynthesizeFrame(const WebPDemuxer* const dmux, - const Frame* const frame, - WebPIterator* const iter) { - const uint8_t* const mem_buf = dmux->mem_.buf_; - size_t payload_size = 0; - const uint8_t* const payload = GetFramePayload(mem_buf, frame, &payload_size); - if (payload == NULL) return 0; - assert(frame != NULL); - - iter->frame_num = frame->frame_num_; - iter->num_frames = dmux->num_frames_; - iter->x_offset = frame->x_offset_; - iter->y_offset = frame->y_offset_; - iter->width = frame->width_; - iter->height = frame->height_; - iter->has_alpha = frame->has_alpha_; - iter->duration = frame->duration_; - iter->dispose_method = frame->dispose_method_; - iter->blend_method = frame->blend_method_; - iter->complete = frame->complete_; - iter->fragment.bytes = payload; - iter->fragment.size = payload_size; - return 1; -} - -static int SetFrame(int frame_num, WebPIterator* const iter) { - const Frame* frame; - const WebPDemuxer* const dmux = (WebPDemuxer*)iter->private_; - if (dmux == NULL || frame_num < 0) return 0; - if (frame_num > dmux->num_frames_) return 0; - if (frame_num == 0) frame_num = dmux->num_frames_; - - frame = GetFrame(dmux, frame_num); - if (frame == NULL) return 0; - - return SynthesizeFrame(dmux, frame, iter); -} - -int WebPDemuxGetFrame(const WebPDemuxer* dmux, int frame, WebPIterator* iter) { - if (iter == NULL) return 0; - - memset(iter, 0, sizeof(*iter)); - iter->private_ = (void*)dmux; - return SetFrame(frame, iter); -} - -int WebPDemuxNextFrame(WebPIterator* iter) { - if (iter == NULL) return 0; - return SetFrame(iter->frame_num + 1, iter); -} - -int WebPDemuxPrevFrame(WebPIterator* iter) { - if (iter == NULL) return 0; - if (iter->frame_num <= 1) return 0; - return SetFrame(iter->frame_num - 1, iter); -} - -void WebPDemuxReleaseIterator(WebPIterator* iter) { - (void)iter; -} - -// ----------------------------------------------------------------------------- -// Chunk iteration - -static int ChunkCount(const WebPDemuxer* const dmux, const char fourcc[4]) { - const uint8_t* const mem_buf = dmux->mem_.buf_; - const Chunk* c; - int count = 0; - for (c = dmux->chunks_; c != NULL; c = c->next_) { - const uint8_t* const header = mem_buf + c->data_.offset_; - if (!memcmp(header, fourcc, TAG_SIZE)) ++count; - } - return count; -} - -static const Chunk* GetChunk(const WebPDemuxer* const dmux, - const char fourcc[4], int chunk_num) { - const uint8_t* const mem_buf = dmux->mem_.buf_; - const Chunk* c; - int count = 0; - for (c = dmux->chunks_; c != NULL; c = c->next_) { - const uint8_t* const header = mem_buf + c->data_.offset_; - if (!memcmp(header, fourcc, TAG_SIZE)) ++count; - if (count == chunk_num) break; - } - return c; -} - -static int SetChunk(const char fourcc[4], int chunk_num, - WebPChunkIterator* const iter) { - const WebPDemuxer* const dmux = (WebPDemuxer*)iter->private_; - int count; - - if (dmux == NULL || fourcc == NULL || chunk_num < 0) return 0; - count = ChunkCount(dmux, fourcc); - if (count == 0) return 0; - if (chunk_num == 0) chunk_num = count; - - if (chunk_num <= count) { - const uint8_t* const mem_buf = dmux->mem_.buf_; - const Chunk* const chunk = GetChunk(dmux, fourcc, chunk_num); - iter->chunk.bytes = mem_buf + chunk->data_.offset_ + CHUNK_HEADER_SIZE; - iter->chunk.size = chunk->data_.size_ - CHUNK_HEADER_SIZE; - iter->num_chunks = count; - iter->chunk_num = chunk_num; - return 1; - } - return 0; -} - -int WebPDemuxGetChunk(const WebPDemuxer* dmux, - const char fourcc[4], int chunk_num, - WebPChunkIterator* iter) { - if (iter == NULL) return 0; - - memset(iter, 0, sizeof(*iter)); - iter->private_ = (void*)dmux; - return SetChunk(fourcc, chunk_num, iter); -} - -int WebPDemuxNextChunk(WebPChunkIterator* iter) { - if (iter != NULL) { - const char* const fourcc = - (const char*)iter->chunk.bytes - CHUNK_HEADER_SIZE; - return SetChunk(fourcc, iter->chunk_num + 1, iter); - } - return 0; -} - -int WebPDemuxPrevChunk(WebPChunkIterator* iter) { - if (iter != NULL && iter->chunk_num > 1) { - const char* const fourcc = - (const char*)iter->chunk.bytes - CHUNK_HEADER_SIZE; - return SetChunk(fourcc, iter->chunk_num - 1, iter); - } - return 0; -} - -void WebPDemuxReleaseChunkIterator(WebPChunkIterator* iter) { - (void)iter; -} - |