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// Copyright 2012 Google Inc. All Rights Reserved.
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//
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// Use of this source code is governed by a BSD-style license
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// that can be found in the COPYING file in the root of the source
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// tree. An additional intellectual property rights grant can be found
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// in the file PATENTS. All contributing project authors may
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// be found in the AUTHORS file in the root of the source tree.
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// -----------------------------------------------------------------------------
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//
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// WebP container demux.
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//
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#ifdef HAVE_CONFIG_H
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#include "../webp/config.h"
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#endif
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#include <assert.h>
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#include <stdlib.h>
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#include <string.h>
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#include "../utils/utils.h"
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#include "../webp/decode.h" // WebPGetFeatures
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#include "../webp/demux.h"
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#include "../webp/format_constants.h"
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#define DMUX_MAJ_VERSION 0
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#define DMUX_MIN_VERSION 3
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#define DMUX_REV_VERSION 2
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typedef struct {
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size_t start_; // start location of the data
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size_t end_; // end location
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size_t riff_end_; // riff chunk end location, can be > end_.
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size_t buf_size_; // size of the buffer
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const uint8_t* buf_;
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} MemBuffer;
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typedef struct {
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size_t offset_;
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size_t size_;
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} ChunkData;
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typedef struct Frame {
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int x_offset_, y_offset_;
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int width_, height_;
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int has_alpha_;
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int duration_;
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WebPMuxAnimDispose dispose_method_;
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WebPMuxAnimBlend blend_method_;
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int frame_num_;
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int complete_; // img_components_ contains a full image.
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ChunkData img_components_[2]; // 0=VP8{,L} 1=ALPH
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struct Frame* next_;
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} Frame;
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typedef struct Chunk {
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ChunkData data_;
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struct Chunk* next_;
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} Chunk;
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struct WebPDemuxer {
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MemBuffer mem_;
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WebPDemuxState state_;
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int is_ext_format_;
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uint32_t feature_flags_;
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int canvas_width_, canvas_height_;
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int loop_count_;
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uint32_t bgcolor_;
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int num_frames_;
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Frame* frames_;
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Frame** frames_tail_;
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Chunk* chunks_; // non-image chunks
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Chunk** chunks_tail_;
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};
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typedef enum {
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PARSE_OK,
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PARSE_NEED_MORE_DATA,
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PARSE_ERROR
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} ParseStatus;
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typedef struct ChunkParser {
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uint8_t id[4];
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ParseStatus (*parse)(WebPDemuxer* const dmux);
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int (*valid)(const WebPDemuxer* const dmux);
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} ChunkParser;
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static ParseStatus ParseSingleImage(WebPDemuxer* const dmux);
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static ParseStatus ParseVP8X(WebPDemuxer* const dmux);
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static int IsValidSimpleFormat(const WebPDemuxer* const dmux);
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static int IsValidExtendedFormat(const WebPDemuxer* const dmux);
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static const ChunkParser kMasterChunks[] = {
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{ { 'V', 'P', '8', ' ' }, ParseSingleImage, IsValidSimpleFormat },
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{ { 'V', 'P', '8', 'L' }, ParseSingleImage, IsValidSimpleFormat },
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{ { 'V', 'P', '8', 'X' }, ParseVP8X, IsValidExtendedFormat },
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{ { '0', '0', '0', '0' }, NULL, NULL },
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};
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//------------------------------------------------------------------------------
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int WebPGetDemuxVersion(void) {
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return (DMUX_MAJ_VERSION << 16) | (DMUX_MIN_VERSION << 8) | DMUX_REV_VERSION;
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}
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// -----------------------------------------------------------------------------
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// MemBuffer
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static int RemapMemBuffer(MemBuffer* const mem,
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const uint8_t* data, size_t size) {
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if (size < mem->buf_size_) return 0; // can't remap to a shorter buffer!
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mem->buf_ = data;
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mem->end_ = mem->buf_size_ = size;
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return 1;
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}
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static int InitMemBuffer(MemBuffer* const mem,
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const uint8_t* data, size_t size) {
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memset(mem, 0, sizeof(*mem));
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return RemapMemBuffer(mem, data, size);
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}
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// Return the remaining data size available in 'mem'.
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static WEBP_INLINE size_t MemDataSize(const MemBuffer* const mem) {
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return (mem->end_ - mem->start_);
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}
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// Return true if 'size' exceeds the end of the RIFF chunk.
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static WEBP_INLINE int SizeIsInvalid(const MemBuffer* const mem, size_t size) {
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return (size > mem->riff_end_ - mem->start_);
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}
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static WEBP_INLINE void Skip(MemBuffer* const mem, size_t size) {
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mem->start_ += size;
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}
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static WEBP_INLINE void Rewind(MemBuffer* const mem, size_t size) {
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mem->start_ -= size;
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}
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static WEBP_INLINE const uint8_t* GetBuffer(MemBuffer* const mem) {
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return mem->buf_ + mem->start_;
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}
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// Read from 'mem' and skip the read bytes.
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static WEBP_INLINE uint8_t ReadByte(MemBuffer* const mem) {
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const uint8_t byte = mem->buf_[mem->start_];
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Skip(mem, 1);
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return byte;
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}
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static WEBP_INLINE int ReadLE16s(MemBuffer* const mem) {
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const uint8_t* const data = mem->buf_ + mem->start_;
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const int val = GetLE16(data);
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Skip(mem, 2);
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return val;
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}
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static WEBP_INLINE int ReadLE24s(MemBuffer* const mem) {
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const uint8_t* const data = mem->buf_ + mem->start_;
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const int val = GetLE24(data);
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Skip(mem, 3);
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return val;
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}
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static WEBP_INLINE uint32_t ReadLE32(MemBuffer* const mem) {
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const uint8_t* const data = mem->buf_ + mem->start_;
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const uint32_t val = GetLE32(data);
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Skip(mem, 4);
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return val;
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}
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// -----------------------------------------------------------------------------
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// Secondary chunk parsing
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static void AddChunk(WebPDemuxer* const dmux, Chunk* const chunk) {
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*dmux->chunks_tail_ = chunk;
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chunk->next_ = NULL;
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dmux->chunks_tail_ = &chunk->next_;
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}
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// Add a frame to the end of the list, ensuring the last frame is complete.
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// Returns true on success, false otherwise.
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static int AddFrame(WebPDemuxer* const dmux, Frame* const frame) {
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const Frame* const last_frame = *dmux->frames_tail_;
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if (last_frame != NULL && !last_frame->complete_) return 0;
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*dmux->frames_tail_ = frame;
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frame->next_ = NULL;
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dmux->frames_tail_ = &frame->next_;
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return 1;
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}
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static void SetFrameInfo(size_t start_offset, size_t size,
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int frame_num, int complete,
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const WebPBitstreamFeatures* const features,
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Frame* const frame) {
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frame->img_components_[0].offset_ = start_offset;
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frame->img_components_[0].size_ = size;
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frame->width_ = features->width;
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frame->height_ = features->height;
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frame->has_alpha_ |= features->has_alpha;
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frame->frame_num_ = frame_num;
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frame->complete_ = complete;
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}
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// Store image bearing chunks to 'frame'.
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static ParseStatus StoreFrame(int frame_num, uint32_t min_size,
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MemBuffer* const mem, Frame* const frame) {
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int alpha_chunks = 0;
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int image_chunks = 0;
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int done = (MemDataSize(mem) < min_size);
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ParseStatus status = PARSE_OK;
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if (done) return PARSE_NEED_MORE_DATA;
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do {
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const size_t chunk_start_offset = mem->start_;
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const uint32_t fourcc = ReadLE32(mem);
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const uint32_t payload_size = ReadLE32(mem);
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const uint32_t payload_size_padded = payload_size + (payload_size & 1);
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const size_t payload_available = (payload_size_padded > MemDataSize(mem))
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? MemDataSize(mem) : payload_size_padded;
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const size_t chunk_size = CHUNK_HEADER_SIZE + payload_available;
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if (payload_size > MAX_CHUNK_PAYLOAD) return PARSE_ERROR;
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if (SizeIsInvalid(mem, payload_size_padded)) return PARSE_ERROR;
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if (payload_size_padded > MemDataSize(mem)) status = PARSE_NEED_MORE_DATA;
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switch (fourcc) {
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case MKFOURCC('A', 'L', 'P', 'H'):
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if (alpha_chunks == 0) {
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++alpha_chunks;
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frame->img_components_[1].offset_ = chunk_start_offset;
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frame->img_components_[1].size_ = chunk_size;
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frame->has_alpha_ = 1;
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frame->frame_num_ = frame_num;
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Skip(mem, payload_available);
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} else {
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goto Done;
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}
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break;
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case MKFOURCC('V', 'P', '8', 'L'):
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if (alpha_chunks > 0) return PARSE_ERROR; // VP8L has its own alpha
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// fall through
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case MKFOURCC('V', 'P', '8', ' '):
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if (image_chunks == 0) {
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// Extract the bitstream features, tolerating failures when the data
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// is incomplete.
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WebPBitstreamFeatures features;
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const VP8StatusCode vp8_status =
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WebPGetFeatures(mem->buf_ + chunk_start_offset, chunk_size,
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&features);
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if (status == PARSE_NEED_MORE_DATA &&
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vp8_status == VP8_STATUS_NOT_ENOUGH_DATA) {
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return PARSE_NEED_MORE_DATA;
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} else if (vp8_status != VP8_STATUS_OK) {
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// We have enough data, and yet WebPGetFeatures() failed.
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return PARSE_ERROR;
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}
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++image_chunks;
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SetFrameInfo(chunk_start_offset, chunk_size, frame_num,
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status == PARSE_OK, &features, frame);
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Skip(mem, payload_available);
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} else {
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goto Done;
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}
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break;
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Done:
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default:
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// Restore fourcc/size when moving up one level in parsing.
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Rewind(mem, CHUNK_HEADER_SIZE);
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done = 1;
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break;
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}
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if (mem->start_ == mem->riff_end_) {
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done = 1;
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} else if (MemDataSize(mem) < CHUNK_HEADER_SIZE) {
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status = PARSE_NEED_MORE_DATA;
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}
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} while (!done && status == PARSE_OK);
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return status;
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}
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// Creates a new Frame if 'actual_size' is within bounds and 'mem' contains
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// enough data ('min_size') to parse the payload.
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// Returns PARSE_OK on success with *frame pointing to the new Frame.
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// Returns PARSE_NEED_MORE_DATA with insufficient data, PARSE_ERROR otherwise.
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static ParseStatus NewFrame(const MemBuffer* const mem,
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uint32_t min_size, uint32_t actual_size,
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Frame** frame) {
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if (SizeIsInvalid(mem, min_size)) return PARSE_ERROR;
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if (actual_size < min_size) return PARSE_ERROR;
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if (MemDataSize(mem) < min_size) return PARSE_NEED_MORE_DATA;
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*frame = (Frame*)WebPSafeCalloc(1ULL, sizeof(**frame));
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return (*frame == NULL) ? PARSE_ERROR : PARSE_OK;
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}
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// Parse a 'ANMF' chunk and any image bearing chunks that immediately follow.
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// 'frame_chunk_size' is the previously validated, padded chunk size.
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static ParseStatus ParseAnimationFrame(
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WebPDemuxer* const dmux, uint32_t frame_chunk_size) {
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const int is_animation = !!(dmux->feature_flags_ & ANIMATION_FLAG);
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const uint32_t anmf_payload_size = frame_chunk_size - ANMF_CHUNK_SIZE;
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int added_frame = 0;
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int bits;
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MemBuffer* const mem = &dmux->mem_;
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Frame* frame;
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ParseStatus status =
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NewFrame(mem, ANMF_CHUNK_SIZE, frame_chunk_size, &frame);
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if (status != PARSE_OK) return status;
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frame->x_offset_ = 2 * ReadLE24s(mem);
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frame->y_offset_ = 2 * ReadLE24s(mem);
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frame->width_ = 1 + ReadLE24s(mem);
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frame->height_ = 1 + ReadLE24s(mem);
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frame->duration_ = ReadLE24s(mem);
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bits = ReadByte(mem);
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frame->dispose_method_ =
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(bits & 1) ? WEBP_MUX_DISPOSE_BACKGROUND : WEBP_MUX_DISPOSE_NONE;
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frame->blend_method_ = (bits & 2) ? WEBP_MUX_NO_BLEND : WEBP_MUX_BLEND;
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if (frame->width_ * (uint64_t)frame->height_ >= MAX_IMAGE_AREA) {
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WebPSafeFree(frame);
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return PARSE_ERROR;
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}
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// Store a frame only if the animation flag is set there is some data for
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// this frame is available.
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status = StoreFrame(dmux->num_frames_ + 1, anmf_payload_size, mem, frame);
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if (status != PARSE_ERROR && is_animation && frame->frame_num_ > 0) {
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added_frame = AddFrame(dmux, frame);
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if (added_frame) {
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++dmux->num_frames_;
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} else {
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status = PARSE_ERROR;
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}
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}
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if (!added_frame) WebPSafeFree(frame);
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return status;
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}
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// General chunk storage, starting with the header at 'start_offset', allowing
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// the user to request the payload via a fourcc string. 'size' includes the
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// header and the unpadded payload size.
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// Returns true on success, false otherwise.
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static int StoreChunk(WebPDemuxer* const dmux,
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size_t start_offset, uint32_t size) {
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Chunk* const chunk = (Chunk*)WebPSafeCalloc(1ULL, sizeof(*chunk));
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if (chunk == NULL) return 0;
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chunk->data_.offset_ = start_offset;
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chunk->data_.size_ = size;
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AddChunk(dmux, chunk);
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return 1;
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}
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|
|
|
|
|
// -----------------------------------------------------------------------------
|
|
|
|
// 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 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 (dmux->feature_flags_ & ~ALL_VALID_FLAGS) return 0; // invalid bitstream
|
|
|
|
|
|
|
|
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;
|
|
|
|
}
|
|
|
|
|