summaryrefslogtreecommitdiffstats
path: root/media/libwebp/src/dec/idec_dec.c
diff options
context:
space:
mode:
Diffstat (limited to 'media/libwebp/src/dec/idec_dec.c')
-rw-r--r--media/libwebp/src/dec/idec_dec.c908
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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-29 01:05:41 +0000