// Copyright 2011 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.
// -----------------------------------------------------------------------------
//
// Read APIs for mux.
//
// Authors: Urvang (urvang@google.com)
// Vikas (vikasa@google.com)
#include <assert.h>
#include "src/mux/muxi.h"
#include "src/utils/utils.h"
//------------------------------------------------------------------------------
// Helper method(s).
// Handy MACRO.
#define SWITCH_ID_LIST(INDEX, LIST) \
if (idx == (INDEX)) { \
const WebPChunk* const chunk = ChunkSearchList((LIST), nth, \
kChunks[(INDEX)].tag); \
if (chunk) { \
*data = chunk->data_; \
return WEBP_MUX_OK; \
} else { \
return WEBP_MUX_NOT_FOUND; \
} \
}
static WebPMuxError MuxGet(const WebPMux* const mux, CHUNK_INDEX idx,
uint32_t nth, WebPData* const data) {
assert(mux != NULL);
assert(!IsWPI(kChunks[idx].id));
WebPDataInit(data);
SWITCH_ID_LIST(IDX_VP8X, mux->vp8x_);
SWITCH_ID_LIST(IDX_ICCP, mux->iccp_);
SWITCH_ID_LIST(IDX_ANIM, mux->anim_);
SWITCH_ID_LIST(IDX_EXIF, mux->exif_);
SWITCH_ID_LIST(IDX_XMP, mux->xmp_);
assert(idx != IDX_UNKNOWN);
return WEBP_MUX_NOT_FOUND;
}
#undef SWITCH_ID_LIST
// Fill the chunk with the given data (includes chunk header bytes), after some
// verifications.
static WebPMuxError ChunkVerifyAndAssign(WebPChunk* chunk,
const uint8_t* data, size_t data_size,
size_t riff_size, int copy_data) {
uint32_t chunk_size;
WebPData chunk_data;
// Sanity checks.
if (data_size < CHUNK_HEADER_SIZE) return WEBP_MUX_NOT_ENOUGH_DATA;
chunk_size = GetLE32(data + TAG_SIZE);
{
const size_t chunk_disk_size = SizeWithPadding(chunk_size);
if (chunk_disk_size > riff_size) return WEBP_MUX_BAD_DATA;
if (chunk_disk_size > data_size) return WEBP_MUX_NOT_ENOUGH_DATA;
}
// Data assignment.
chunk_data.bytes = data + CHUNK_HEADER_SIZE;
chunk_data.size = chunk_size;
return ChunkAssignData(chunk, &chunk_data, copy_data, GetLE32(data + 0));
}
int MuxImageFinalize(WebPMuxImage* const wpi) {
const WebPChunk* const img = wpi->img_;
const WebPData* const image = &img->data_;
const int is_lossless = (img->tag_ == kChunks[IDX_VP8L].tag);
int w, h;
int vp8l_has_alpha = 0;
const int ok = is_lossless ?
VP8LGetInfo(image->bytes, image->size, &w, &h, &vp8l_has_alpha) :
VP8GetInfo(image->bytes, image->size, image->size, &w, &h);
assert(img != NULL);
if (ok) {
// Ignore ALPH chunk accompanying VP8L.
if (is_lossless && (wpi->alpha_ != NULL)) {
ChunkDelete(wpi->alpha_);
wpi->alpha_ = NULL;
}
wpi->width_ = w;
wpi->height_ = h;
wpi->has_alpha_ = vp8l_has_alpha || (wpi->alpha_ != NULL);
}
return ok;
}
static int MuxImageParse(const WebPChunk* const chunk, int copy_data,
WebPMuxImage* const wpi) {
const uint8_t* bytes = chunk->data_.bytes;
size_t size = chunk->data_.size;
const uint8_t* const last = bytes + size;
WebPChunk subchunk;
size_t subchunk_size;
ChunkInit(&subchunk);
assert(chunk->tag_ == kChunks[IDX_ANMF].tag);
assert(!wpi->is_partial_);
// ANMF.
{
const size_t hdr_size = ANMF_CHUNK_SIZE;
const WebPData temp = { bytes, hdr_size };
// Each of ANMF chunk contain a header at the beginning. So, its size should
// be at least 'hdr_size'.
if (size < hdr_size) goto Fail;
ChunkAssignData(&subchunk, &temp, copy_data, chunk->tag_);
}
ChunkSetNth(&subchunk, &wpi->header_, 1);
wpi->is_partial_ = 1; // Waiting for ALPH and/or VP8/VP8L chunks.
// Rest of the chunks.
subchunk_size = ChunkDiskSize(&subchunk) - CHUNK_HEADER_SIZE;
bytes += subchunk_size;
size -= subchunk_size;
while (bytes != last) {
ChunkInit(&subchunk);
if (ChunkVerifyAndAssign(&subchunk, bytes, size, size,
copy_data) != WEBP_MUX_OK) {
goto Fail;
}
switch (ChunkGetIdFromTag(subchunk.tag_)) {
case WEBP_CHUNK_ALPHA:
if (wpi->alpha_ != NULL) goto Fail; // Consecutive ALPH chunks.
if (ChunkSetNth(&subchunk, &wpi->alpha_, 1) != WEBP_MUX_OK) goto Fail;
wpi->is_partial_ = 1; // Waiting for a VP8 chunk.
break;
case WEBP_CHUNK_IMAGE:
if (ChunkSetNth(&subchunk, &wpi->img_, 1) != WEBP_MUX_OK) goto Fail;
if (!MuxImageFinalize(wpi)) goto Fail;
wpi->is_partial_ = 0; // wpi is completely filled.
break;
case WEBP_CHUNK_UNKNOWN:
if (wpi->is_partial_) goto Fail; // Encountered an unknown chunk
// before some image chunks.
if (ChunkSetNth(&subchunk, &wpi->unknown_, 0) != WEBP_MUX_OK) goto Fail;
break;
default:
goto Fail;
break;
}
subchunk_size = ChunkDiskSize(&subchunk);
bytes += subchunk_size;
size -= subchunk_size;
}
if (wpi->is_partial_) goto Fail;
return 1;
Fail:
ChunkRelease(&subchunk);
return 0;
}
//------------------------------------------------------------------------------
// Create a mux object from WebP-RIFF data.
WebPMux* WebPMuxCreateInternal(const WebPData* bitstream, int copy_data,
int version) {
size_t riff_size;
uint32_t tag;
const uint8_t* end;
WebPMux* mux = NULL;
WebPMuxImage* wpi = NULL;
const uint8_t* data;
size_t size;
WebPChunk chunk;
ChunkInit(&chunk);
// Sanity checks.
if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_MUX_ABI_VERSION)) {
return NULL; // version mismatch
}
if (bitstream == NULL) return NULL;
data = bitstream->bytes;
size = bitstream->size;
if (data == NULL) return NULL;
if (size < RIFF_HEADER_SIZE) return NULL;
if (GetLE32(data + 0) != MKFOURCC('R', 'I', 'F', 'F') ||
GetLE32(data + CHUNK_HEADER_SIZE) != MKFOURCC('W', 'E', 'B', 'P')) {
return NULL;
}
mux = WebPMuxNew();
if (mux == NULL) return NULL;
if (size < RIFF_HEADER_SIZE + TAG_SIZE) goto Err;
tag = GetLE32(data + RIFF_HEADER_SIZE);
if (tag != kChunks[IDX_VP8].tag &&
tag != kChunks[IDX_VP8L].tag &&
tag != kChunks[IDX_VP8X].tag) {
goto Err; // First chunk should be VP8, VP8L or VP8X.
}
riff_size = SizeWithPadding(GetLE32(data + TAG_SIZE));
if (riff_size > MAX_CHUNK_PAYLOAD || riff_size > size) {
goto Err;
} else {
if (riff_size < size) { // Redundant data after last chunk.
size = riff_size; // To make sure we don't read any data beyond mux_size.
}
}
end = data + size;
data += RIFF_HEADER_SIZE;
size -= RIFF_HEADER_SIZE;
wpi = (WebPMuxImage*)WebPSafeMalloc(1ULL, sizeof(*wpi));
if (wpi == NULL) goto Err;
MuxImageInit(wpi);
// Loop over chunks.
while (data != end) {
size_t data_size;
WebPChunkId id;
WebPChunk** chunk_list;
if (ChunkVerifyAndAssign(&chunk, data, size, riff_size,
copy_data) != WEBP_MUX_OK) {
goto Err;
}
data_size = ChunkDiskSize(&chunk);
id = ChunkGetIdFromTag(chunk.tag_);
switch (id) {
case WEBP_CHUNK_ALPHA:
if (wpi->alpha_ != NULL) goto Err; // Consecutive ALPH chunks.
if (ChunkSetNth(&chunk, &wpi->alpha_, 1) != WEBP_MUX_OK) goto Err;
wpi->is_partial_ = 1; // Waiting for a VP8 chunk.
break;
case WEBP_CHUNK_IMAGE:
if (ChunkSetNth(&chunk, &wpi->img_, 1) != WEBP_MUX_OK) goto Err;
if (!MuxImageFinalize(wpi)) goto Err;
wpi->is_partial_ = 0; // wpi is completely filled.
PushImage:
// Add this to mux->images_ list.
if (MuxImagePush(wpi, &mux->images_) != WEBP_MUX_OK) goto Err;
MuxImageInit(wpi); // Reset for reading next image.
break;
case WEBP_CHUNK_ANMF:
if (wpi->is_partial_) goto Err; // Previous wpi is still incomplete.
if (!MuxImageParse(&chunk, copy_data, wpi)) goto Err;
ChunkRelease(&chunk);
goto PushImage;
break;
default: // A non-image chunk.
if (wpi->is_partial_) goto Err; // Encountered a non-image chunk before
// getting all chunks of an image.
chunk_list = MuxGetChunkListFromId(mux, id); // List to add this chunk.
if (ChunkSetNth(&chunk, chunk_list, 0) != WEBP_MUX_OK) goto Err;
if (id == WEBP_CHUNK_VP8X) { // grab global specs
mux->canvas_width_ = GetLE24(data + 12) + 1;
mux->canvas_height_ = GetLE24(data + 15) + 1;
}
break;
}
data += data_size;
size -= data_size;
ChunkInit(&chunk);
}
// Incomplete image.
if (wpi->is_partial_) goto Err;
// Validate mux if complete.
if (MuxValidate(mux) != WEBP_MUX_OK) goto Err;
MuxImageDelete(wpi);
return mux; // All OK;
Err: // Something bad happened.
ChunkRelease(&chunk);
MuxImageDelete(wpi);
WebPMuxDelete(mux);
return NULL;
}
//------------------------------------------------------------------------------
// Get API(s).
// Validates that the given mux has a single image.
static WebPMuxError ValidateForSingleImage(const WebPMux* const mux) {
const int num_images = MuxImageCount(mux->images_, WEBP_CHUNK_IMAGE);
const int num_frames = MuxImageCount(mux->images_, WEBP_CHUNK_ANMF);
if (num_images == 0) {
// No images in mux.
return WEBP_MUX_NOT_FOUND;
} else if (num_images == 1 && num_frames == 0) {
// Valid case (single image).
return WEBP_MUX_OK;
} else {
// Frame case OR an invalid mux.
return WEBP_MUX_INVALID_ARGUMENT;
}
}
// Get the canvas width, height and flags after validating that VP8X/VP8/VP8L
// chunk and canvas size are valid.
static WebPMuxError MuxGetCanvasInfo(const WebPMux* const mux,
int* width, int* height, uint32_t* flags) {
int w, h;
uint32_t f = 0;
WebPData data;
assert(mux != NULL);
// Check if VP8X chunk is present.
if (MuxGet(mux, IDX_VP8X, 1, &data) == WEBP_MUX_OK) {
if (data.size < VP8X_CHUNK_SIZE) return WEBP_MUX_BAD_DATA;
f = GetLE32(data.bytes + 0);
w = GetLE24(data.bytes + 4) + 1;
h = GetLE24(data.bytes + 7) + 1;
} else {
const WebPMuxImage* const wpi = mux->images_;
// Grab user-forced canvas size as default.
w = mux->canvas_width_;
h = mux->canvas_height_;
if (w == 0 && h == 0 && ValidateForSingleImage(mux) == WEBP_MUX_OK) {
// single image and not forced canvas size => use dimension of first frame
assert(wpi != NULL);
w = wpi->width_;
h = wpi->height_;
}
if (wpi != NULL) {
if (wpi->has_alpha_) f |= ALPHA_FLAG;
}
}
if (w * (uint64_t)h >= MAX_IMAGE_AREA) return WEBP_MUX_BAD_DATA;
if (width != NULL) *width = w;
if (height != NULL) *height = h;
if (flags != NULL) *flags = f;
return WEBP_MUX_OK;
}
WebPMuxError WebPMuxGetCanvasSize(const WebPMux* mux, int* width, int* height) {
if (mux == NULL || width == NULL || height == NULL) {
return WEBP_MUX_INVALID_ARGUMENT;
}
return MuxGetCanvasInfo(mux, width, height, NULL);
}
WebPMuxError WebPMuxGetFeatures(const WebPMux* mux, uint32_t* flags) {
if (mux == NULL || flags == NULL) return WEBP_MUX_INVALID_ARGUMENT;
return MuxGetCanvasInfo(mux, NULL, NULL, flags);
}
static uint8_t* EmitVP8XChunk(uint8_t* const dst, int width,
int height, uint32_t flags) {
const size_t vp8x_size = CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE;
assert(width >= 1 && height >= 1);
assert(width <= MAX_CANVAS_SIZE && height <= MAX_CANVAS_SIZE);
assert(width * (uint64_t)height < MAX_IMAGE_AREA);
PutLE32(dst, MKFOURCC('V', 'P', '8', 'X'));
PutLE32(dst + TAG_SIZE, VP8X_CHUNK_SIZE);
PutLE32(dst + CHUNK_HEADER_SIZE, flags);
PutLE24(dst + CHUNK_HEADER_SIZE + 4, width - 1);
PutLE24(dst + CHUNK_HEADER_SIZE + 7, height - 1);
return dst + vp8x_size;
}
// Assemble a single image WebP bitstream from 'wpi'.
static WebPMuxError SynthesizeBitstream(const WebPMuxImage* const wpi,
WebPData* const bitstream) {
uint8_t* dst;
// Allocate data.
const int need_vp8x = (wpi->alpha_ != NULL);
const size_t vp8x_size = need_vp8x ? CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE : 0;
const size_t alpha_size = need_vp8x ? ChunkDiskSize(wpi->alpha_) : 0;
// Note: No need to output ANMF chunk for a single image.
const size_t size = RIFF_HEADER_SIZE + vp8x_size + alpha_size +
ChunkDiskSize(wpi->img_);
uint8_t* const data = (uint8_t*)WebPSafeMalloc(1ULL, size);
if (data == NULL) return WEBP_MUX_MEMORY_ERROR;
// Main RIFF header.
dst = MuxEmitRiffHeader(data, size);
if (need_vp8x) {
dst = EmitVP8XChunk(dst, wpi->width_, wpi->height_, ALPHA_FLAG); // VP8X.
dst = ChunkListEmit(wpi->alpha_, dst); // ALPH.
}
// Bitstream.
dst = ChunkListEmit(wpi->img_, dst);
assert(dst == data + size);
// Output.
bitstream->bytes = data;
bitstream->size = size;
return WEBP_MUX_OK;
}
WebPMuxError WebPMuxGetChunk(const WebPMux* mux, const char fourcc[4],
WebPData* chunk_data) {
CHUNK_INDEX idx;
if (mux == NULL || fourcc == NULL || chunk_data == NULL) {
return WEBP_MUX_INVALID_ARGUMENT;
}
idx = ChunkGetIndexFromFourCC(fourcc);
if (IsWPI(kChunks[idx].id)) { // An image chunk.
return WEBP_MUX_INVALID_ARGUMENT;
} else if (idx != IDX_UNKNOWN) { // A known chunk type.
return MuxGet(mux, idx, 1, chunk_data);
} else { // An unknown chunk type.
const WebPChunk* const chunk =
ChunkSearchList(mux->unknown_, 1, ChunkGetTagFromFourCC(fourcc));
if (chunk == NULL) return WEBP_MUX_NOT_FOUND;
*chunk_data = chunk->data_;
return WEBP_MUX_OK;
}
}
static WebPMuxError MuxGetImageInternal(const WebPMuxImage* const wpi,
WebPMuxFrameInfo* const info) {
// Set some defaults for unrelated fields.
info->x_offset = 0;
info->y_offset = 0;
info->duration = 1;
info->dispose_method = WEBP_MUX_DISPOSE_NONE;
info->blend_method = WEBP_MUX_BLEND;
// Extract data for related fields.
info->id = ChunkGetIdFromTag(wpi->img_->tag_);
return SynthesizeBitstream(wpi, &info->bitstream);
}
static WebPMuxError MuxGetFrameInternal(const WebPMuxImage* const wpi,
WebPMuxFrameInfo* const frame) {
const int is_frame = (wpi->header_->tag_ == kChunks[IDX_ANMF].tag);
const WebPData* frame_data;
if (!is_frame) return WEBP_MUX_INVALID_ARGUMENT;
assert(wpi->header_ != NULL); // Already checked by WebPMuxGetFrame().
// Get frame chunk.
frame_data = &wpi->header_->data_;
if (frame_data->size < kChunks[IDX_ANMF].size) return WEBP_MUX_BAD_DATA;
// Extract info.
frame->x_offset = 2 * GetLE24(frame_data->bytes + 0);
frame->y_offset = 2 * GetLE24(frame_data->bytes + 3);
{
const uint8_t bits = frame_data->bytes[15];
frame->duration = GetLE24(frame_data->bytes + 12);
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;
}
frame->id = ChunkGetIdFromTag(wpi->header_->tag_);
return SynthesizeBitstream(wpi, &frame->bitstream);
}
WebPMuxError WebPMuxGetFrame(
const WebPMux* mux, uint32_t nth, WebPMuxFrameInfo* frame) {
WebPMuxError err;
WebPMuxImage* wpi;
// Sanity checks.
if (mux == NULL || frame == NULL) {
return WEBP_MUX_INVALID_ARGUMENT;
}
// Get the nth WebPMuxImage.
err = MuxImageGetNth((const WebPMuxImage**)&mux->images_, nth, &wpi);
if (err != WEBP_MUX_OK) return err;
// Get frame info.
if (wpi->header_ == NULL) {
return MuxGetImageInternal(wpi, frame);
} else {
return MuxGetFrameInternal(wpi, frame);
}
}
WebPMuxError WebPMuxGetAnimationParams(const WebPMux* mux,
WebPMuxAnimParams* params) {
WebPData anim;
WebPMuxError err;
if (mux == NULL || params == NULL) return WEBP_MUX_INVALID_ARGUMENT;
err = MuxGet(mux, IDX_ANIM, 1, &anim);
if (err != WEBP_MUX_OK) return err;
if (anim.size < kChunks[WEBP_CHUNK_ANIM].size) return WEBP_MUX_BAD_DATA;
params->bgcolor = GetLE32(anim.bytes);
params->loop_count = GetLE16(anim.bytes + 4);
return WEBP_MUX_OK;
}
// Get chunk index from chunk id. Returns IDX_NIL if not found.
static CHUNK_INDEX ChunkGetIndexFromId(WebPChunkId id) {
int i;
for (i = 0; kChunks[i].id != WEBP_CHUNK_NIL; ++i) {
if (id == kChunks[i].id) return (CHUNK_INDEX)i;
}
return IDX_NIL;
}
// Count number of chunks matching 'tag' in the 'chunk_list'.
// If tag == NIL_TAG, any tag will be matched.
static int CountChunks(const WebPChunk* const chunk_list, uint32_t tag) {
int count = 0;
const WebPChunk* current;
for (current = chunk_list; current != NULL; current = current->next_) {
if (tag == NIL_TAG || current->tag_ == tag) {
count++; // Count chunks whose tags match.
}
}
return count;
}
WebPMuxError WebPMuxNumChunks(const WebPMux* mux,
WebPChunkId id, int* num_elements) {
if (mux == NULL || num_elements == NULL) {
return WEBP_MUX_INVALID_ARGUMENT;
}
if (IsWPI(id)) {
*num_elements = MuxImageCount(mux->images_, id);
} else {
WebPChunk* const* chunk_list = MuxGetChunkListFromId(mux, id);
const CHUNK_INDEX idx = ChunkGetIndexFromId(id);
*num_elements = CountChunks(*chunk_list, kChunks[idx].tag);
}
return WEBP_MUX_OK;
}
//------------------------------------------------------------------------------