// 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. // ----------------------------------------------------------------------------- // // Incremental decoding // // Author: somnath@google.com (Somnath Banerjee) #include <assert.h> #include <string.h> #include <stdlib.h> #include "./alphai.h" #include "./webpi.h" #include "./vp8i.h" #include "../utils/utils.h" // In append mode, buffer allocations increase as multiples of this value. // Needs to be a power of 2. #define CHUNK_SIZE 4096 #define MAX_MB_SIZE 4096 //------------------------------------------------------------------------------ // Data structures for memory and states // Decoding states. State normally flows as: // WEBP_HEADER->VP8_HEADER->VP8_PARTS0->VP8_DATA->DONE for a lossy image, and // WEBP_HEADER->VP8L_HEADER->VP8L_DATA->DONE for a lossless image. // If there is any error the decoder goes into state ERROR. typedef enum { STATE_WEBP_HEADER, // All the data before that of the VP8/VP8L chunk. STATE_VP8_HEADER, // The VP8 Frame header (within the VP8 chunk). STATE_VP8_PARTS0, STATE_VP8_DATA, STATE_VP8L_HEADER, STATE_VP8L_DATA, STATE_DONE, STATE_ERROR } DecState; // Operating state for the MemBuffer typedef enum { MEM_MODE_NONE = 0, MEM_MODE_APPEND, MEM_MODE_MAP } MemBufferMode; // storage for partition #0 and partial data (in a rolling fashion) typedef struct { MemBufferMode mode_; // Operation mode size_t start_; // start location of the data to be decoded size_t end_; // end location size_t buf_size_; // size of the allocated buffer uint8_t* buf_; // We don't own this buffer in case WebPIUpdate() size_t part0_size_; // size of partition #0 const uint8_t* part0_buf_; // buffer to store partition #0 } MemBuffer; struct WebPIDecoder { DecState state_; // current decoding state WebPDecParams params_; // Params to store output info int is_lossless_; // for down-casting 'dec_'. void* dec_; // either a VP8Decoder or a VP8LDecoder instance VP8Io io_; MemBuffer mem_; // input memory buffer. WebPDecBuffer output_; // output buffer (when no external one is supplied) size_t chunk_size_; // Compressed VP8/VP8L size extracted from Header. int last_mb_y_; // last row reached for intra-mode decoding }; // MB context to restore in case VP8DecodeMB() fails typedef struct { VP8MB left_; VP8MB info_; VP8BitReader token_br_; } MBContext; //------------------------------------------------------------------------------ // MemBuffer: incoming data handling static WEBP_INLINE size_t MemDataSize(const MemBuffer* mem) { return (mem->end_ - mem->start_); } // Check if we need to preserve the compressed alpha data, as it may not have // been decoded yet. static int NeedCompressedAlpha(const WebPIDecoder* const idec) { if (idec->state_ == STATE_WEBP_HEADER) { // We haven't parsed the headers yet, so we don't know whether the image is // lossy or lossless. This also means that we haven't parsed the ALPH chunk. return 0; } if (idec->is_lossless_) { return 0; // ALPH chunk is not present for lossless images. } else { const VP8Decoder* const dec = (VP8Decoder*)idec->dec_; assert(dec != NULL); // Must be true as idec->state_ != STATE_WEBP_HEADER. return (dec->alpha_data_ != NULL) && !dec->is_alpha_decoded_; } } static void DoRemap(WebPIDecoder* const idec, ptrdiff_t offset) { MemBuffer* const mem = &idec->mem_; const uint8_t* const new_base = mem->buf_ + mem->start_; // note: for VP8, setting up idec->io_ is only really needed at the beginning // of the decoding, till partition #0 is complete. idec->io_.data = new_base; idec->io_.data_size = MemDataSize(mem); if (idec->dec_ != NULL) { if (!idec->is_lossless_) { VP8Decoder* const dec = (VP8Decoder*)idec->dec_; const int last_part = dec->num_parts_ - 1; if (offset != 0) { int p; for (p = 0; p <= last_part; ++p) { VP8RemapBitReader(dec->parts_ + p, offset); } // Remap partition #0 data pointer to new offset, but only in MAP // mode (in APPEND mode, partition #0 is copied into a fixed memory). if (mem->mode_ == MEM_MODE_MAP) { VP8RemapBitReader(&dec->br_, offset); } } assert(last_part >= 0); dec->parts_[last_part].buf_end_ = mem->buf_ + mem->end_; if (NeedCompressedAlpha(idec)) { ALPHDecoder* const alph_dec = dec->alph_dec_; dec->alpha_data_ += offset; if (alph_dec != NULL) { if (alph_dec->method_ == ALPHA_LOSSLESS_COMPRESSION) { VP8LDecoder* const alph_vp8l_dec = alph_dec->vp8l_dec_; assert(alph_vp8l_dec != NULL); assert(dec->alpha_data_size_ >= ALPHA_HEADER_LEN); VP8LBitReaderSetBuffer(&alph_vp8l_dec->br_, dec->alpha_data_ + ALPHA_HEADER_LEN, dec->alpha_data_size_ - ALPHA_HEADER_LEN); } else { // alph_dec->method_ == ALPHA_NO_COMPRESSION // Nothing special to do in this case. } } } } else { // Resize lossless bitreader VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; VP8LBitReaderSetBuffer(&dec->br_, new_base, MemDataSize(mem)); } } } // Appends data to the end of MemBuffer->buf_. It expands the allocated memory // size if required and also updates VP8BitReader's if new memory is allocated. static int AppendToMemBuffer(WebPIDecoder* const idec, const uint8_t* const data, size_t data_size) { VP8Decoder* const dec = (VP8Decoder*)idec->dec_; MemBuffer* const mem = &idec->mem_; const int need_compressed_alpha = NeedCompressedAlpha(idec); const uint8_t* const old_start = mem->buf_ + mem->start_; const uint8_t* const old_base = need_compressed_alpha ? dec->alpha_data_ : old_start; assert(mem->mode_ == MEM_MODE_APPEND); if (data_size > MAX_CHUNK_PAYLOAD) { // security safeguard: trying to allocate more than what the format // allows for a chunk should be considered a smoke smell. return 0; } if (mem->end_ + data_size > mem->buf_size_) { // Need some free memory const size_t new_mem_start = old_start - old_base; const size_t current_size = MemDataSize(mem) + new_mem_start; const uint64_t new_size = (uint64_t)current_size + data_size; const uint64_t extra_size = (new_size + CHUNK_SIZE - 1) & ~(CHUNK_SIZE - 1); uint8_t* const new_buf = (uint8_t*)WebPSafeMalloc(extra_size, sizeof(*new_buf)); if (new_buf == NULL) return 0; memcpy(new_buf, old_base, current_size); WebPSafeFree(mem->buf_); mem->buf_ = new_buf; mem->buf_size_ = (size_t)extra_size; mem->start_ = new_mem_start; mem->end_ = current_size; } memcpy(mem->buf_ + mem->end_, data, data_size); mem->end_ += data_size; assert(mem->end_ <= mem->buf_size_); DoRemap(idec, mem->buf_ + mem->start_ - old_start); return 1; } static int RemapMemBuffer(WebPIDecoder* const idec, const uint8_t* const data, size_t data_size) { MemBuffer* const mem = &idec->mem_; const uint8_t* const old_buf = mem->buf_; const uint8_t* const old_start = old_buf + mem->start_; assert(mem->mode_ == MEM_MODE_MAP); if (data_size < mem->buf_size_) return 0; // can't remap to a shorter buffer! mem->buf_ = (uint8_t*)data; mem->end_ = mem->buf_size_ = data_size; DoRemap(idec, mem->buf_ + mem->start_ - old_start); return 1; } static void InitMemBuffer(MemBuffer* const mem) { mem->mode_ = MEM_MODE_NONE; mem->buf_ = NULL; mem->buf_size_ = 0; mem->part0_buf_ = NULL; mem->part0_size_ = 0; } static void ClearMemBuffer(MemBuffer* const mem) { assert(mem); if (mem->mode_ == MEM_MODE_APPEND) { WebPSafeFree(mem->buf_); WebPSafeFree((void*)mem->part0_buf_); } } static int CheckMemBufferMode(MemBuffer* const mem, MemBufferMode expected) { if (mem->mode_ == MEM_MODE_NONE) { mem->mode_ = expected; // switch to the expected mode } else if (mem->mode_ != expected) { return 0; // we mixed the modes => error } assert(mem->mode_ == expected); // mode is ok return 1; } // To be called last. static VP8StatusCode FinishDecoding(WebPIDecoder* const idec) { #if WEBP_DECODER_ABI_VERSION > 0x0203 const WebPDecoderOptions* const options = idec->params_.options; WebPDecBuffer* const output = idec->params_.output; idec->state_ = STATE_DONE; if (options != NULL && options->flip) { return WebPFlipBuffer(output); } #endif idec->state_ = STATE_DONE; return VP8_STATUS_OK; } //------------------------------------------------------------------------------ // Macroblock-decoding contexts static void SaveContext(const VP8Decoder* dec, const VP8BitReader* token_br, MBContext* const context) { context->left_ = dec->mb_info_[-1]; context->info_ = dec->mb_info_[dec->mb_x_]; context->token_br_ = *token_br; } static void RestoreContext(const MBContext* context, VP8Decoder* const dec, VP8BitReader* const token_br) { dec->mb_info_[-1] = context->left_; dec->mb_info_[dec->mb_x_] = context->info_; *token_br = context->token_br_; } //------------------------------------------------------------------------------ static VP8StatusCode IDecError(WebPIDecoder* const idec, VP8StatusCode error) { if (idec->state_ == STATE_VP8_DATA) { VP8Io* const io = &idec->io_; if (io->teardown != NULL) { io->teardown(io); } } idec->state_ = STATE_ERROR; return error; } static void ChangeState(WebPIDecoder* const idec, DecState new_state, size_t consumed_bytes) { MemBuffer* const mem = &idec->mem_; idec->state_ = new_state; mem->start_ += consumed_bytes; assert(mem->start_ <= mem->end_); idec->io_.data = mem->buf_ + mem->start_; idec->io_.data_size = MemDataSize(mem); } // Headers static VP8StatusCode DecodeWebPHeaders(WebPIDecoder* const idec) { MemBuffer* const mem = &idec->mem_; const uint8_t* data = mem->buf_ + mem->start_; size_t curr_size = MemDataSize(mem); VP8StatusCode status; WebPHeaderStructure headers; headers.data = data; headers.data_size = curr_size; headers.have_all_data = 0; status = WebPParseHeaders(&headers); if (status == VP8_STATUS_NOT_ENOUGH_DATA) { return VP8_STATUS_SUSPENDED; // We haven't found a VP8 chunk yet. } else if (status != VP8_STATUS_OK) { return IDecError(idec, status); } idec->chunk_size_ = headers.compressed_size; idec->is_lossless_ = headers.is_lossless; if (!idec->is_lossless_) { VP8Decoder* const dec = VP8New(); if (dec == NULL) { return VP8_STATUS_OUT_OF_MEMORY; } idec->dec_ = dec; dec->alpha_data_ = headers.alpha_data; dec->alpha_data_size_ = headers.alpha_data_size; ChangeState(idec, STATE_VP8_HEADER, headers.offset); } else { VP8LDecoder* const dec = VP8LNew(); if (dec == NULL) { return VP8_STATUS_OUT_OF_MEMORY; } idec->dec_ = dec; ChangeState(idec, STATE_VP8L_HEADER, headers.offset); } return VP8_STATUS_OK; } static VP8StatusCode DecodeVP8FrameHeader(WebPIDecoder* const idec) { const uint8_t* data = idec->mem_.buf_ + idec->mem_.start_; const size_t curr_size = MemDataSize(&idec->mem_); int width, height; uint32_t bits; if (curr_size < VP8_FRAME_HEADER_SIZE) { // Not enough data bytes to extract VP8 Frame Header. return VP8_STATUS_SUSPENDED; } if (!VP8GetInfo(data, curr_size, idec->chunk_size_, &width, &height)) { return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); } bits = data[0] | (data[1] << 8) | (data[2] << 16); idec->mem_.part0_size_ = (bits >> 5) + VP8_FRAME_HEADER_SIZE; idec->io_.data = data; idec->io_.data_size = curr_size; idec->state_ = STATE_VP8_PARTS0; return VP8_STATUS_OK; } // Partition #0 static VP8StatusCode CopyParts0Data(WebPIDecoder* const idec) { VP8Decoder* const dec = (VP8Decoder*)idec->dec_; VP8BitReader* const br = &dec->br_; const size_t part_size = br->buf_end_ - br->buf_; MemBuffer* const mem = &idec->mem_; assert(!idec->is_lossless_); assert(mem->part0_buf_ == NULL); // the following is a format limitation, no need for runtime check: assert(part_size <= mem->part0_size_); if (part_size == 0) { // can't have zero-size partition #0 return VP8_STATUS_BITSTREAM_ERROR; } if (mem->mode_ == MEM_MODE_APPEND) { // We copy and grab ownership of the partition #0 data. uint8_t* const part0_buf = (uint8_t*)WebPSafeMalloc(1ULL, part_size); if (part0_buf == NULL) { return VP8_STATUS_OUT_OF_MEMORY; } memcpy(part0_buf, br->buf_, part_size); mem->part0_buf_ = part0_buf; br->buf_ = part0_buf; br->buf_end_ = part0_buf + part_size; } else { // Else: just keep pointers to the partition #0's data in dec_->br_. } mem->start_ += part_size; return VP8_STATUS_OK; } static VP8StatusCode DecodePartition0(WebPIDecoder* const idec) { VP8Decoder* const dec = (VP8Decoder*)idec->dec_; VP8Io* const io = &idec->io_; const WebPDecParams* const params = &idec->params_; WebPDecBuffer* const output = params->output; // Wait till we have enough data for the whole partition #0 if (MemDataSize(&idec->mem_) < idec->mem_.part0_size_) { return VP8_STATUS_SUSPENDED; } if (!VP8GetHeaders(dec, io)) { const VP8StatusCode status = dec->status_; if (status == VP8_STATUS_SUSPENDED || status == VP8_STATUS_NOT_ENOUGH_DATA) { // treating NOT_ENOUGH_DATA as SUSPENDED state return VP8_STATUS_SUSPENDED; } return IDecError(idec, status); } // Allocate/Verify output buffer now dec->status_ = WebPAllocateDecBuffer(io->width, io->height, params->options, output); if (dec->status_ != VP8_STATUS_OK) { return IDecError(idec, dec->status_); } // This change must be done before calling VP8InitFrame() dec->mt_method_ = VP8GetThreadMethod(params->options, NULL, io->width, io->height); VP8InitDithering(params->options, dec); dec->status_ = CopyParts0Data(idec); if (dec->status_ != VP8_STATUS_OK) { return IDecError(idec, dec->status_); } // Finish setting up the decoding parameters. Will call io->setup(). if (VP8EnterCritical(dec, io) != VP8_STATUS_OK) { return IDecError(idec, dec->status_); } // Note: past this point, teardown() must always be called // in case of error. idec->state_ = STATE_VP8_DATA; // Allocate memory and prepare everything. if (!VP8InitFrame(dec, io)) { return IDecError(idec, dec->status_); } return VP8_STATUS_OK; } // Remaining partitions static VP8StatusCode DecodeRemaining(WebPIDecoder* const idec) { VP8Decoder* const dec = (VP8Decoder*)idec->dec_; VP8Io* const io = &idec->io_; assert(dec->ready_); for (; dec->mb_y_ < dec->mb_h_; ++dec->mb_y_) { if (idec->last_mb_y_ != dec->mb_y_) { if (!VP8ParseIntraModeRow(&dec->br_, dec)) { // note: normally, error shouldn't occur since we already have the whole // partition0 available here in DecodeRemaining(). Reaching EOF while // reading intra modes really means a BITSTREAM_ERROR. return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); } idec->last_mb_y_ = dec->mb_y_; } for (; dec->mb_x_ < dec->mb_w_; ++dec->mb_x_) { VP8BitReader* const token_br = &dec->parts_[dec->mb_y_ & (dec->num_parts_ - 1)]; MBContext context; SaveContext(dec, token_br, &context); if (!VP8DecodeMB(dec, token_br)) { // We shouldn't fail when MAX_MB data was available if (dec->num_parts_ == 1 && MemDataSize(&idec->mem_) > MAX_MB_SIZE) { return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); } RestoreContext(&context, dec, token_br); return VP8_STATUS_SUSPENDED; } // Release buffer only if there is only one partition if (dec->num_parts_ == 1) { idec->mem_.start_ = token_br->buf_ - idec->mem_.buf_; assert(idec->mem_.start_ <= idec->mem_.end_); } } VP8InitScanline(dec); // Prepare for next scanline // Reconstruct, filter and emit the row. if (!VP8ProcessRow(dec, io)) { return IDecError(idec, VP8_STATUS_USER_ABORT); } } // Synchronize the thread and check for errors. if (!VP8ExitCritical(dec, io)) { return IDecError(idec, VP8_STATUS_USER_ABORT); } dec->ready_ = 0; return FinishDecoding(idec); } static VP8StatusCode ErrorStatusLossless(WebPIDecoder* const idec, VP8StatusCode status) { if (status == VP8_STATUS_SUSPENDED || status == VP8_STATUS_NOT_ENOUGH_DATA) { return VP8_STATUS_SUSPENDED; } return IDecError(idec, status); } static VP8StatusCode DecodeVP8LHeader(WebPIDecoder* const idec) { VP8Io* const io = &idec->io_; VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; const WebPDecParams* const params = &idec->params_; WebPDecBuffer* const output = params->output; size_t curr_size = MemDataSize(&idec->mem_); assert(idec->is_lossless_); // Wait until there's enough data for decoding header. if (curr_size < (idec->chunk_size_ >> 3)) { return VP8_STATUS_SUSPENDED; } if (!VP8LDecodeHeader(dec, io)) { return ErrorStatusLossless(idec, dec->status_); } // Allocate/verify output buffer now. dec->status_ = WebPAllocateDecBuffer(io->width, io->height, params->options, output); if (dec->status_ != VP8_STATUS_OK) { return IDecError(idec, dec->status_); } idec->state_ = STATE_VP8L_DATA; return VP8_STATUS_OK; } static VP8StatusCode DecodeVP8LData(WebPIDecoder* const idec) { VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; const size_t curr_size = MemDataSize(&idec->mem_); assert(idec->is_lossless_); // At present Lossless decoder can't decode image incrementally. So wait till // all the image data is aggregated before image can be decoded. if (curr_size < idec->chunk_size_) { return VP8_STATUS_SUSPENDED; } if (!VP8LDecodeImage(dec)) { // The decoding is called after all the data-bytes are aggregated. Change // the error to VP8_BITSTREAM_ERROR in case lossless decoder fails to decode // all the pixels (VP8_STATUS_SUSPENDED). if (dec->status_ == VP8_STATUS_SUSPENDED) { dec->status_ = VP8_STATUS_BITSTREAM_ERROR; } return ErrorStatusLossless(idec, dec->status_); } return FinishDecoding(idec); } // Main decoding loop static VP8StatusCode IDecode(WebPIDecoder* idec) { VP8StatusCode status = VP8_STATUS_SUSPENDED; if (idec->state_ == STATE_WEBP_HEADER) { status = DecodeWebPHeaders(idec); } else { if (idec->dec_ == NULL) { return VP8_STATUS_SUSPENDED; // can't continue if we have no decoder. } } if (idec->state_ == STATE_VP8_HEADER) { status = DecodeVP8FrameHeader(idec); } if (idec->state_ == STATE_VP8_PARTS0) { status = DecodePartition0(idec); } if (idec->state_ == STATE_VP8_DATA) { status = DecodeRemaining(idec); } if (idec->state_ == STATE_VP8L_HEADER) { status = DecodeVP8LHeader(idec); } if (idec->state_ == STATE_VP8L_DATA) { status = DecodeVP8LData(idec); } return status; } //------------------------------------------------------------------------------ // Public functions WebPIDecoder* WebPINewDecoder(WebPDecBuffer* output_buffer) { WebPIDecoder* idec = (WebPIDecoder*)WebPSafeCalloc(1ULL, sizeof(*idec)); if (idec == NULL) { return NULL; } idec->state_ = STATE_WEBP_HEADER; idec->chunk_size_ = 0; idec->last_mb_y_ = -1; InitMemBuffer(&idec->mem_); WebPInitDecBuffer(&idec->output_); VP8InitIo(&idec->io_); WebPResetDecParams(&idec->params_); idec->params_.output = (output_buffer != NULL) ? output_buffer : &idec->output_; WebPInitCustomIo(&idec->params_, &idec->io_); // Plug the I/O functions. return idec; } WebPIDecoder* WebPIDecode(const uint8_t* data, size_t data_size, WebPDecoderConfig* config) { WebPIDecoder* idec; // Parse the bitstream's features, if requested: if (data != NULL && data_size > 0 && config != NULL) { if (WebPGetFeatures(data, data_size, &config->input) != VP8_STATUS_OK) { return NULL; } } // Create an instance of the incremental decoder idec = WebPINewDecoder(config ? &config->output : NULL); if (idec == NULL) { return NULL; } // Finish initialization if (config != NULL) { idec->params_.options = &config->options; } return idec; } void WebPIDelete(WebPIDecoder* idec) { if (idec == NULL) return; if (idec->dec_ != NULL) { if (!idec->is_lossless_) { if (idec->state_ == STATE_VP8_DATA) { // Synchronize the thread, clean-up and check for errors. VP8ExitCritical((VP8Decoder*)idec->dec_, &idec->io_); } VP8Delete((VP8Decoder*)idec->dec_); } else { VP8LDelete((VP8LDecoder*)idec->dec_); } } ClearMemBuffer(&idec->mem_); WebPFreeDecBuffer(&idec->output_); WebPSafeFree(idec); } //------------------------------------------------------------------------------ // Wrapper toward WebPINewDecoder WebPIDecoder* WebPINewRGB(WEBP_CSP_MODE mode, uint8_t* output_buffer, size_t output_buffer_size, int output_stride) { const int is_external_memory = (output_buffer != NULL); WebPIDecoder* idec; if (mode >= MODE_YUV) return NULL; if (!is_external_memory) { // Overwrite parameters to sane values. output_buffer_size = 0; output_stride = 0; } else { // A buffer was passed. Validate the other params. if (output_stride == 0 || output_buffer_size == 0) { return NULL; // invalid parameter. } } idec = WebPINewDecoder(NULL); if (idec == NULL) return NULL; idec->output_.colorspace = mode; idec->output_.is_external_memory = is_external_memory; idec->output_.u.RGBA.rgba = output_buffer; idec->output_.u.RGBA.stride = output_stride; idec->output_.u.RGBA.size = output_buffer_size; return idec; } WebPIDecoder* WebPINewYUVA(uint8_t* luma, size_t luma_size, int luma_stride, uint8_t* u, size_t u_size, int u_stride, uint8_t* v, size_t v_size, int v_stride, uint8_t* a, size_t a_size, int a_stride) { const int is_external_memory = (luma != NULL); WebPIDecoder* idec; WEBP_CSP_MODE colorspace; if (!is_external_memory) { // Overwrite parameters to sane values. luma_size = u_size = v_size = a_size = 0; luma_stride = u_stride = v_stride = a_stride = 0; u = v = a = NULL; colorspace = MODE_YUVA; } else { // A luma buffer was passed. Validate the other parameters. if (u == NULL || v == NULL) return NULL; if (luma_size == 0 || u_size == 0 || v_size == 0) return NULL; if (luma_stride == 0 || u_stride == 0 || v_stride == 0) return NULL; if (a != NULL) { if (a_size == 0 || a_stride == 0) return NULL; } colorspace = (a == NULL) ? MODE_YUV : MODE_YUVA; } idec = WebPINewDecoder(NULL); if (idec == NULL) return NULL; idec->output_.colorspace = colorspace; idec->output_.is_external_memory = is_external_memory; idec->output_.u.YUVA.y = luma; idec->output_.u.YUVA.y_stride = luma_stride; idec->output_.u.YUVA.y_size = luma_size; idec->output_.u.YUVA.u = u; idec->output_.u.YUVA.u_stride = u_stride; idec->output_.u.YUVA.u_size = u_size; idec->output_.u.YUVA.v = v; idec->output_.u.YUVA.v_stride = v_stride; idec->output_.u.YUVA.v_size = v_size; idec->output_.u.YUVA.a = a; idec->output_.u.YUVA.a_stride = a_stride; idec->output_.u.YUVA.a_size = a_size; return idec; } WebPIDecoder* WebPINewYUV(uint8_t* luma, size_t luma_size, int luma_stride, uint8_t* u, size_t u_size, int u_stride, uint8_t* v, size_t v_size, int v_stride) { return WebPINewYUVA(luma, luma_size, luma_stride, u, u_size, u_stride, v, v_size, v_stride, NULL, 0, 0); } //------------------------------------------------------------------------------ static VP8StatusCode IDecCheckStatus(const WebPIDecoder* const idec) { assert(idec); if (idec->state_ == STATE_ERROR) { return VP8_STATUS_BITSTREAM_ERROR; } if (idec->state_ == STATE_DONE) { return VP8_STATUS_OK; } return VP8_STATUS_SUSPENDED; } VP8StatusCode WebPIAppend(WebPIDecoder* idec, const uint8_t* data, size_t data_size) { VP8StatusCode status; if (idec == NULL || data == NULL) { return VP8_STATUS_INVALID_PARAM; } status = IDecCheckStatus(idec); if (status != VP8_STATUS_SUSPENDED) { return status; } // Check mixed calls between RemapMemBuffer and AppendToMemBuffer. if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_APPEND)) { return VP8_STATUS_INVALID_PARAM; } // Append data to memory buffer if (!AppendToMemBuffer(idec, data, data_size)) { return VP8_STATUS_OUT_OF_MEMORY; } return IDecode(idec); } VP8StatusCode WebPIUpdate(WebPIDecoder* idec, const uint8_t* data, size_t data_size) { VP8StatusCode status; if (idec == NULL || data == NULL) { return VP8_STATUS_INVALID_PARAM; } status = IDecCheckStatus(idec); if (status != VP8_STATUS_SUSPENDED) { return status; } // Check mixed calls between RemapMemBuffer and AppendToMemBuffer. if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_MAP)) { return VP8_STATUS_INVALID_PARAM; } // Make the memory buffer point to the new buffer if (!RemapMemBuffer(idec, data, data_size)) { return VP8_STATUS_INVALID_PARAM; } return IDecode(idec); } //------------------------------------------------------------------------------ static const WebPDecBuffer* GetOutputBuffer(const WebPIDecoder* const idec) { if (idec == NULL || idec->dec_ == NULL) { return NULL; } if (idec->state_ <= STATE_VP8_PARTS0) { return NULL; } return idec->params_.output; } const WebPDecBuffer* WebPIDecodedArea(const WebPIDecoder* idec, int* left, int* top, int* width, int* height) { const WebPDecBuffer* const src = GetOutputBuffer(idec); if (left != NULL) *left = 0; if (top != NULL) *top = 0; // TODO(skal): later include handling of rotations. if (src) { if (width != NULL) *width = src->width; if (height != NULL) *height = idec->params_.last_y; } else { if (width != NULL) *width = 0; if (height != NULL) *height = 0; } return src; } uint8_t* WebPIDecGetRGB(const WebPIDecoder* idec, int* last_y, int* width, int* height, int* stride) { const WebPDecBuffer* const src = GetOutputBuffer(idec); if (src == NULL) return NULL; if (src->colorspace >= MODE_YUV) { return NULL; } if (last_y != NULL) *last_y = idec->params_.last_y; if (width != NULL) *width = src->width; if (height != NULL) *height = src->height; if (stride != NULL) *stride = src->u.RGBA.stride; return src->u.RGBA.rgba; } uint8_t* WebPIDecGetYUVA(const WebPIDecoder* idec, int* last_y, uint8_t** u, uint8_t** v, uint8_t** a, int* width, int* height, int* stride, int* uv_stride, int* a_stride) { const WebPDecBuffer* const src = GetOutputBuffer(idec); if (src == NULL) return NULL; if (src->colorspace < MODE_YUV) { return NULL; } if (last_y != NULL) *last_y = idec->params_.last_y; if (u != NULL) *u = src->u.YUVA.u; if (v != NULL) *v = src->u.YUVA.v; if (a != NULL) *a = src->u.YUVA.a; if (width != NULL) *width = src->width; if (height != NULL) *height = src->height; if (stride != NULL) *stride = src->u.YUVA.y_stride; if (uv_stride != NULL) *uv_stride = src->u.YUVA.u_stride; if (a_stride != NULL) *a_stride = src->u.YUVA.a_stride; return src->u.YUVA.y; } int WebPISetIOHooks(WebPIDecoder* const idec, VP8IoPutHook put, VP8IoSetupHook setup, VP8IoTeardownHook teardown, void* user_data) { if (idec == NULL || idec->state_ > STATE_WEBP_HEADER) { return 0; } idec->io_.put = put; idec->io_.setup = setup; idec->io_.teardown = teardown; idec->io_.opaque = user_data; return 1; }