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Diffstat (limited to '')
| -rw-r--r-- | media/libwebp/src/dec/idec_dec.c | 908 |
1 files changed, 908 insertions, 0 deletions
diff --git a/media/libwebp/src/dec/idec_dec.c b/media/libwebp/src/dec/idec_dec.c new file mode 100644 index 0000000000..9035df5659 --- /dev/null +++ b/media/libwebp/src/dec/idec_dec.c @@ -0,0 +1,908 @@ +// 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 "src/dec/alphai_dec.h" +#include "src/dec/webpi_dec.h" +#include "src/dec/vp8i_dec.h" +#include "src/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, + // or if the external one has slow-memory) + WebPDecBuffer* final_output_; // Slow-memory output to copy to eventually. + 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 uint32_t last_part = dec->num_parts_minus_one_; + if (offset != 0) { + uint32_t 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); + } + } + { + const uint8_t* const last_start = dec->parts_[last_part].buf_; + VP8BitReaderSetBuffer(&dec->parts_[last_part], last_start, + mem->buf_ + mem->end_ - last_start); + } + if (NeedCompressedAlpha(idec)) { + ALPHDecoder* const alph_dec = dec->alph_dec_; + dec->alpha_data_ += offset; + if (alph_dec != NULL && alph_dec->vp8l_dec_ != NULL) { + if (alph_dec->method_ == ALPHA_LOSSLESS_COMPRESSION) { + VP8LDecoder* const alph_vp8l_dec = alph_dec->vp8l_dec_; + 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_ == NULL) ? NULL : mem->buf_ + mem->start_; + const uint8_t* const old_base = + need_compressed_alpha ? dec->alpha_data_ : old_start; + assert(mem->buf_ != NULL || mem->start_ == 0); + 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; + if (old_base != NULL) 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; + } + + assert(mem->buf_ != NULL); + 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 == NULL) ? NULL : old_buf + mem->start_; + assert(old_buf != NULL || mem->start_ == 0); + 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) { + const WebPDecoderOptions* const options = idec->params_.options; + WebPDecBuffer* const output = idec->params_.output; + + idec->state_ = STATE_DONE; + if (options != NULL && options->flip) { + const VP8StatusCode status = WebPFlipBuffer(output); + if (status != VP8_STATUS_OK) return status; + } + if (idec->final_output_ != NULL) { + WebPCopyDecBufferPixels(output, idec->final_output_); // do the slow-copy + WebPFreeDecBuffer(&idec->output_); + *output = *idec->final_output_; + idec->final_output_ = NULL; + } + 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) { + // Synchronize the thread, clean-up and check for errors. + VP8ExitCritical((VP8Decoder*)idec->dec_, &idec->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; + VP8BitReaderSetBuffer(br, 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_; + + // Make sure partition #0 has been read before, to set dec to ready_. + if (!dec->ready_) { + return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); + } + 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_minus_one_]; + 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_minus_one_ == 0 && + MemDataSize(&idec->mem_) > MAX_MB_SIZE) { + return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); + } + // Synchronize the threads. + if (dec->mt_method_ > 0) { + if (!WebPGetWorkerInterface()->Sync(&dec->worker_)) { + 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_minus_one_ == 0) { + 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)) { + idec->state_ = STATE_ERROR; // prevent re-entry in IDecError + 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)) { + dec->status_ = VP8_STATUS_SUSPENDED; + return ErrorStatusLossless(idec, dec->status_); + } + + if (!VP8LDecodeHeader(dec, io)) { + if (dec->status_ == VP8_STATUS_BITSTREAM_ERROR && + curr_size < idec->chunk_size_) { + dec->status_ = VP8_STATUS_SUSPENDED; + } + 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_); + + // Switch to incremental decoding if we don't have all the bytes available. + dec->incremental_ = (curr_size < idec->chunk_size_); + + if (!VP8LDecodeImage(dec)) { + return ErrorStatusLossless(idec, dec->status_); + } + assert(dec->status_ == VP8_STATUS_OK || dec->status_ == VP8_STATUS_SUSPENDED); + return (dec->status_ == VP8_STATUS_SUSPENDED) ? dec->status_ + : 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) { + const VP8Decoder* const dec = (VP8Decoder*)idec->dec_; + if (dec == NULL) { + return VP8_STATUS_SUSPENDED; // can't continue if we have no decoder. + } + status = DecodeRemaining(idec); + } + if (idec->state_ == STATE_VP8L_HEADER) { + status = DecodeVP8LHeader(idec); + } + if (idec->state_ == STATE_VP8L_DATA) { + status = DecodeVP8LData(idec); + } + return status; +} + +//------------------------------------------------------------------------------ +// Internal constructor + +static WebPIDecoder* NewDecoder(WebPDecBuffer* const output_buffer, + const WebPBitstreamFeatures* const features) { + 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_); + if (output_buffer == NULL || WebPAvoidSlowMemory(output_buffer, features)) { + idec->params_.output = &idec->output_; + idec->final_output_ = output_buffer; + if (output_buffer != NULL) { + idec->params_.output->colorspace = output_buffer->colorspace; + } + } else { + idec->params_.output = output_buffer; + idec->final_output_ = NULL; + } + WebPInitCustomIo(&idec->params_, &idec->io_); // Plug the I/O functions. + + return idec; +} + +//------------------------------------------------------------------------------ +// Public functions + +WebPIDecoder* WebPINewDecoder(WebPDecBuffer* output_buffer) { + return NewDecoder(output_buffer, NULL); +} + +WebPIDecoder* WebPIDecode(const uint8_t* data, size_t data_size, + WebPDecoderConfig* config) { + WebPIDecoder* idec; + WebPBitstreamFeatures tmp_features; + WebPBitstreamFeatures* const features = + (config == NULL) ? &tmp_features : &config->input; + memset(&tmp_features, 0, sizeof(tmp_features)); + + // Parse the bitstream's features, if requested: + if (data != NULL && data_size > 0) { + if (WebPGetFeatures(data, data_size, features) != VP8_STATUS_OK) { + return NULL; + } + } + + // Create an instance of the incremental decoder + idec = (config != NULL) ? NewDecoder(&config->output, features) + : NewDecoder(NULL, features); + 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 csp, uint8_t* output_buffer, + size_t output_buffer_size, int output_stride) { + const int is_external_memory = (output_buffer != NULL) ? 1 : 0; + WebPIDecoder* idec; + + if (csp >= MODE_YUV) return NULL; + if (is_external_memory == 0) { // 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 = csp; + 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) ? 1 : 0; + WebPIDecoder* idec; + WEBP_CSP_MODE colorspace; + + if (is_external_memory == 0) { // 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; + } + if (idec->final_output_ != NULL) { + return NULL; // not yet slow-copied + } + 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; + if (src != NULL) { + 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; +} |