libwebp-0.6.0-rc1

third_party/libwebp/dec/idec.c

Index: third_party/libwebp/dec/idec.c
diff --git a/third_party/libwebp/dec/idec.c b/third_party/libwebp/dec/idec.c
deleted file mode 100644
index 8de131916e035c5c441b9bcf90868e4fa89551ea..0000000000000000000000000000000000000000
--- a/third_party/libwebp/dec/idec.c
+++ /dev/null
@@ -1,892 +0,0 @@
-// 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,
-                           // 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) {
-          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) {
-  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) {
-    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;
-    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_;
-
-  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_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);
-        }
-        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)) {
-    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) {
-    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 mode, 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 (mode >= 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 = 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) ? 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;
-}