libwebp-0.6.0-rc1

third_party/libwebp/dec/vp8.c

Index: third_party/libwebp/dec/vp8.c
diff --git a/third_party/libwebp/dec/vp8.c b/third_party/libwebp/dec/vp8.c
deleted file mode 100644
index 336680c38c03bc3f52fe79f02b9dc115a18c7a5f..0000000000000000000000000000000000000000
--- a/third_party/libwebp/dec/vp8.c
+++ /dev/null
@@ -1,667 +0,0 @@
-// Copyright 2010 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.
-// -----------------------------------------------------------------------------
-//
-// main entry for the decoder
-//
-// Author: Skal (pascal.massimino@gmail.com)
-
-#include <stdlib.h>
-
-#include "./alphai.h"
-#include "./vp8i.h"
-#include "./vp8li.h"
-#include "./webpi.h"
-#include "../utils/bit_reader_inl.h"
-#include "../utils/utils.h"
-
-//------------------------------------------------------------------------------
-
-int WebPGetDecoderVersion(void) {
-  return (DEC_MAJ_VERSION << 16) | (DEC_MIN_VERSION << 8) | DEC_REV_VERSION;
-}
-
-//------------------------------------------------------------------------------
-// VP8Decoder
-
-static void SetOk(VP8Decoder* const dec) {
-  dec->status_ = VP8_STATUS_OK;
-  dec->error_msg_ = "OK";
-}
-
-int VP8InitIoInternal(VP8Io* const io, int version) {
-  if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) {
-    return 0;  // mismatch error
-  }
-  if (io != NULL) {
-    memset(io, 0, sizeof(*io));
-  }
-  return 1;
-}
-
-VP8Decoder* VP8New(void) {
-  VP8Decoder* const dec = (VP8Decoder*)WebPSafeCalloc(1ULL, sizeof(*dec));
-  if (dec != NULL) {
-    SetOk(dec);
-    WebPGetWorkerInterface()->Init(&dec->worker_);
-    dec->ready_ = 0;
-    dec->num_parts_minus_one_ = 0;
-  }
-  return dec;
-}
-
-VP8StatusCode VP8Status(VP8Decoder* const dec) {
-  if (!dec) return VP8_STATUS_INVALID_PARAM;
-  return dec->status_;
-}
-
-const char* VP8StatusMessage(VP8Decoder* const dec) {
-  if (dec == NULL) return "no object";
-  if (!dec->error_msg_) return "OK";
-  return dec->error_msg_;
-}
-
-void VP8Delete(VP8Decoder* const dec) {
-  if (dec != NULL) {
-    VP8Clear(dec);
-    WebPSafeFree(dec);
-  }
-}
-
-int VP8SetError(VP8Decoder* const dec,
-                VP8StatusCode error, const char* const msg) {
-  // The oldest error reported takes precedence over the new one.
-  if (dec->status_ == VP8_STATUS_OK) {
-    dec->status_ = error;
-    dec->error_msg_ = msg;
-    dec->ready_ = 0;
-  }
-  return 0;
-}
-
-//------------------------------------------------------------------------------
-
-int VP8CheckSignature(const uint8_t* const data, size_t data_size) {
-  return (data_size >= 3 &&
-          data[0] == 0x9d && data[1] == 0x01 && data[2] == 0x2a);
-}
-
-int VP8GetInfo(const uint8_t* data, size_t data_size, size_t chunk_size,
-               int* const width, int* const height) {
-  if (data == NULL || data_size < VP8_FRAME_HEADER_SIZE) {
-    return 0;         // not enough data
-  }
-  // check signature
-  if (!VP8CheckSignature(data + 3, data_size - 3)) {
-    return 0;         // Wrong signature.
-  } else {
-    const uint32_t bits = data[0] | (data[1] << 8) | (data[2] << 16);
-    const int key_frame = !(bits & 1);
-    const int w = ((data[7] << 8) | data[6]) & 0x3fff;
-    const int h = ((data[9] << 8) | data[8]) & 0x3fff;
-
-    if (!key_frame) {   // Not a keyframe.
-      return 0;
-    }
-
-    if (((bits >> 1) & 7) > 3) {
-      return 0;         // unknown profile
-    }
-    if (!((bits >> 4) & 1)) {
-      return 0;         // first frame is invisible!
-    }
-    if (((bits >> 5)) >= chunk_size) {  // partition_length
-      return 0;         // inconsistent size information.
-    }
-    if (w == 0 || h == 0) {
-      return 0;         // We don't support both width and height to be zero.
-    }
-
-    if (width) {
-      *width = w;
-    }
-    if (height) {
-      *height = h;
-    }
-
-    return 1;
-  }
-}
-
-//------------------------------------------------------------------------------
-// Header parsing
-
-static void ResetSegmentHeader(VP8SegmentHeader* const hdr) {
-  assert(hdr != NULL);
-  hdr->use_segment_ = 0;
-  hdr->update_map_ = 0;
-  hdr->absolute_delta_ = 1;
-  memset(hdr->quantizer_, 0, sizeof(hdr->quantizer_));
-  memset(hdr->filter_strength_, 0, sizeof(hdr->filter_strength_));
-}
-
-// Paragraph 9.3
-static int ParseSegmentHeader(VP8BitReader* br,
-                              VP8SegmentHeader* hdr, VP8Proba* proba) {
-  assert(br != NULL);
-  assert(hdr != NULL);
-  hdr->use_segment_ = VP8Get(br);
-  if (hdr->use_segment_) {
-    hdr->update_map_ = VP8Get(br);
-    if (VP8Get(br)) {   // update data
-      int s;
-      hdr->absolute_delta_ = VP8Get(br);
-      for (s = 0; s < NUM_MB_SEGMENTS; ++s) {
-        hdr->quantizer_[s] = VP8Get(br) ? VP8GetSignedValue(br, 7) : 0;
-      }
-      for (s = 0; s < NUM_MB_SEGMENTS; ++s) {
-        hdr->filter_strength_[s] = VP8Get(br) ? VP8GetSignedValue(br, 6) : 0;
-      }
-    }
-    if (hdr->update_map_) {
-      int s;
-      for (s = 0; s < MB_FEATURE_TREE_PROBS; ++s) {
-        proba->segments_[s] = VP8Get(br) ? VP8GetValue(br, 8) : 255u;
-      }
-    }
-  } else {
-    hdr->update_map_ = 0;
-  }
-  return !br->eof_;
-}
-
-// Paragraph 9.5
-// This function returns VP8_STATUS_SUSPENDED if we don't have all the
-// necessary data in 'buf'.
-// This case is not necessarily an error (for incremental decoding).
-// Still, no bitreader is ever initialized to make it possible to read
-// unavailable memory.
-// If we don't even have the partitions' sizes, than VP8_STATUS_NOT_ENOUGH_DATA
-// is returned, and this is an unrecoverable error.
-// If the partitions were positioned ok, VP8_STATUS_OK is returned.
-static VP8StatusCode ParsePartitions(VP8Decoder* const dec,
-                                     const uint8_t* buf, size_t size) {
-  VP8BitReader* const br = &dec->br_;
-  const uint8_t* sz = buf;
-  const uint8_t* buf_end = buf + size;
-  const uint8_t* part_start;
-  size_t size_left = size;
-  size_t last_part;
-  size_t p;
-
-  dec->num_parts_minus_one_ = (1 << VP8GetValue(br, 2)) - 1;
-  last_part = dec->num_parts_minus_one_;
-  if (size < 3 * last_part) {
-    // we can't even read the sizes with sz[]! That's a failure.
-    return VP8_STATUS_NOT_ENOUGH_DATA;
-  }
-  part_start = buf + last_part * 3;
-  size_left -= last_part * 3;
-  for (p = 0; p < last_part; ++p) {
-    size_t psize = sz[0] | (sz[1] << 8) | (sz[2] << 16);
-    if (psize > size_left) psize = size_left;
-    VP8InitBitReader(dec->parts_ + p, part_start, psize);
-    part_start += psize;
-    size_left -= psize;
-    sz += 3;
-  }
-  VP8InitBitReader(dec->parts_ + last_part, part_start, size_left);
-  return (part_start < buf_end) ? VP8_STATUS_OK :
-           VP8_STATUS_SUSPENDED;   // Init is ok, but there's not enough data
-}
-
-// Paragraph 9.4
-static int ParseFilterHeader(VP8BitReader* br, VP8Decoder* const dec) {
-  VP8FilterHeader* const hdr = &dec->filter_hdr_;
-  hdr->simple_    = VP8Get(br);
-  hdr->level_     = VP8GetValue(br, 6);
-  hdr->sharpness_ = VP8GetValue(br, 3);
-  hdr->use_lf_delta_ = VP8Get(br);
-  if (hdr->use_lf_delta_) {
-    if (VP8Get(br)) {   // update lf-delta?
-      int i;
-      for (i = 0; i < NUM_REF_LF_DELTAS; ++i) {
-        if (VP8Get(br)) {
-          hdr->ref_lf_delta_[i] = VP8GetSignedValue(br, 6);
-        }
-      }
-      for (i = 0; i < NUM_MODE_LF_DELTAS; ++i) {
-        if (VP8Get(br)) {
-          hdr->mode_lf_delta_[i] = VP8GetSignedValue(br, 6);
-        }
-      }
-    }
-  }
-  dec->filter_type_ = (hdr->level_ == 0) ? 0 : hdr->simple_ ? 1 : 2;
-  return !br->eof_;
-}
-
-// Topmost call
-int VP8GetHeaders(VP8Decoder* const dec, VP8Io* const io) {
-  const uint8_t* buf;
-  size_t buf_size;
-  VP8FrameHeader* frm_hdr;
-  VP8PictureHeader* pic_hdr;
-  VP8BitReader* br;
-  VP8StatusCode status;
-
-  if (dec == NULL) {
-    return 0;
-  }
-  SetOk(dec);
-  if (io == NULL) {
-    return VP8SetError(dec, VP8_STATUS_INVALID_PARAM,
-                       "null VP8Io passed to VP8GetHeaders()");
-  }
-  buf = io->data;
-  buf_size = io->data_size;
-  if (buf_size < 4) {
-    return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
-                       "Truncated header.");
-  }
-
-  // Paragraph 9.1
-  {
-    const uint32_t bits = buf[0] | (buf[1] << 8) | (buf[2] << 16);
-    frm_hdr = &dec->frm_hdr_;
-    frm_hdr->key_frame_ = !(bits & 1);
-    frm_hdr->profile_ = (bits >> 1) & 7;
-    frm_hdr->show_ = (bits >> 4) & 1;
-    frm_hdr->partition_length_ = (bits >> 5);
-    if (frm_hdr->profile_ > 3)
-      return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
-                         "Incorrect keyframe parameters.");
-    if (!frm_hdr->show_)
-      return VP8SetError(dec, VP8_STATUS_UNSUPPORTED_FEATURE,
-                         "Frame not displayable.");
-    buf += 3;
-    buf_size -= 3;
-  }
-
-  pic_hdr = &dec->pic_hdr_;
-  if (frm_hdr->key_frame_) {
-    // Paragraph 9.2
-    if (buf_size < 7) {
-      return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
-                         "cannot parse picture header");
-    }
-    if (!VP8CheckSignature(buf, buf_size)) {
-      return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
-                         "Bad code word");
-    }
-    pic_hdr->width_ = ((buf[4] << 8) | buf[3]) & 0x3fff;
-    pic_hdr->xscale_ = buf[4] >> 6;   // ratio: 1, 5/4 5/3 or 2
-    pic_hdr->height_ = ((buf[6] << 8) | buf[5]) & 0x3fff;
-    pic_hdr->yscale_ = buf[6] >> 6;
-    buf += 7;
-    buf_size -= 7;
-
-    dec->mb_w_ = (pic_hdr->width_ + 15) >> 4;
-    dec->mb_h_ = (pic_hdr->height_ + 15) >> 4;
-
-    // Setup default output area (can be later modified during io->setup())
-    io->width = pic_hdr->width_;
-    io->height = pic_hdr->height_;
-    // IMPORTANT! use some sane dimensions in crop_* and scaled_* fields.
-    // So they can be used interchangeably without always testing for
-    // 'use_cropping'.
-    io->use_cropping = 0;
-    io->crop_top  = 0;
-    io->crop_left = 0;
-    io->crop_right  = io->width;
-    io->crop_bottom = io->height;
-    io->use_scaling  = 0;
-    io->scaled_width = io->width;
-    io->scaled_height = io->height;
-
-    io->mb_w = io->width;   // sanity check
-    io->mb_h = io->height;  // ditto
-
-    VP8ResetProba(&dec->proba_);
-    ResetSegmentHeader(&dec->segment_hdr_);
-  }
-
-  // Check if we have all the partition #0 available, and initialize dec->br_
-  // to read this partition (and this partition only).
-  if (frm_hdr->partition_length_ > buf_size) {
-    return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
-                       "bad partition length");
-  }
-
-  br = &dec->br_;
-  VP8InitBitReader(br, buf, frm_hdr->partition_length_);
-  buf += frm_hdr->partition_length_;
-  buf_size -= frm_hdr->partition_length_;
-
-  if (frm_hdr->key_frame_) {
-    pic_hdr->colorspace_ = VP8Get(br);
-    pic_hdr->clamp_type_ = VP8Get(br);
-  }
-  if (!ParseSegmentHeader(br, &dec->segment_hdr_, &dec->proba_)) {
-    return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
-                       "cannot parse segment header");
-  }
-  // Filter specs
-  if (!ParseFilterHeader(br, dec)) {
-    return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
-                       "cannot parse filter header");
-  }
-  status = ParsePartitions(dec, buf, buf_size);
-  if (status != VP8_STATUS_OK) {
-    return VP8SetError(dec, status, "cannot parse partitions");
-  }
-
-  // quantizer change
-  VP8ParseQuant(dec);
-
-  // Frame buffer marking
-  if (!frm_hdr->key_frame_) {
-    return VP8SetError(dec, VP8_STATUS_UNSUPPORTED_FEATURE,
-                       "Not a key frame.");
-  }
-
-  VP8Get(br);   // ignore the value of update_proba_
-
-  VP8ParseProba(br, dec);
-
-  // sanitized state
-  dec->ready_ = 1;
-  return 1;
-}
-
-//------------------------------------------------------------------------------
-// Residual decoding (Paragraph 13.2 / 13.3)
-
-static const uint8_t kCat3[] = { 173, 148, 140, 0 };
-static const uint8_t kCat4[] = { 176, 155, 140, 135, 0 };
-static const uint8_t kCat5[] = { 180, 157, 141, 134, 130, 0 };
-static const uint8_t kCat6[] =
-  { 254, 254, 243, 230, 196, 177, 153, 140, 133, 130, 129, 0 };
-static const uint8_t* const kCat3456[] = { kCat3, kCat4, kCat5, kCat6 };
-static const uint8_t kZigzag[16] = {
-  0, 1, 4, 8,  5, 2, 3, 6,  9, 12, 13, 10,  7, 11, 14, 15
-};
-
-// See section 13-2: http://tools.ietf.org/html/rfc6386#section-13.2
-static int GetLargeValue(VP8BitReader* const br, const uint8_t* const p) {
-  int v;
-  if (!VP8GetBit(br, p[3])) {
-    if (!VP8GetBit(br, p[4])) {
-      v = 2;
-    } else {
-      v = 3 + VP8GetBit(br, p[5]);
-    }
-  } else {
-    if (!VP8GetBit(br, p[6])) {
-      if (!VP8GetBit(br, p[7])) {
-        v = 5 + VP8GetBit(br, 159);
-      } else {
-        v = 7 + 2 * VP8GetBit(br, 165);
-        v += VP8GetBit(br, 145);
-      }
-    } else {
-      const uint8_t* tab;
-      const int bit1 = VP8GetBit(br, p[8]);
-      const int bit0 = VP8GetBit(br, p[9 + bit1]);
-      const int cat = 2 * bit1 + bit0;
-      v = 0;
-      for (tab = kCat3456[cat]; *tab; ++tab) {
-        v += v + VP8GetBit(br, *tab);
-      }
-      v += 3 + (8 << cat);
-    }
-  }
-  return v;
-}
-
-// Returns the position of the last non-zero coeff plus one
-static int GetCoeffs(VP8BitReader* const br, const VP8BandProbas* const prob[],
-                     int ctx, const quant_t dq, int n, int16_t* out) {
-  const uint8_t* p = prob[n]->probas_[ctx];
-  for (; n < 16; ++n) {
-    if (!VP8GetBit(br, p[0])) {
-      return n;  // previous coeff was last non-zero coeff
-    }
-    while (!VP8GetBit(br, p[1])) {       // sequence of zero coeffs
-      p = prob[++n]->probas_[0];
-      if (n == 16) return 16;
-    }
-    {        // non zero coeff
-      const VP8ProbaArray* const p_ctx = &prob[n + 1]->probas_[0];
-      int v;
-      if (!VP8GetBit(br, p[2])) {
-        v = 1;
-        p = p_ctx[1];
-      } else {
-        v = GetLargeValue(br, p);
-        p = p_ctx[2];
-      }
-      out[kZigzag[n]] = VP8GetSigned(br, v) * dq[n > 0];
-    }
-  }
-  return 16;
-}
-
-static WEBP_INLINE uint32_t NzCodeBits(uint32_t nz_coeffs, int nz, int dc_nz) {
-  nz_coeffs <<= 2;
-  nz_coeffs |= (nz > 3) ? 3 : (nz > 1) ? 2 : dc_nz;
-  return nz_coeffs;
-}
-
-static int ParseResiduals(VP8Decoder* const dec,
-                          VP8MB* const mb, VP8BitReader* const token_br) {
-  const VP8BandProbas* (* const bands)[16 + 1] = dec->proba_.bands_ptr_;
-  const VP8BandProbas* const * ac_proba;
-  VP8MBData* const block = dec->mb_data_ + dec->mb_x_;
-  const VP8QuantMatrix* const q = &dec->dqm_[block->segment_];
-  int16_t* dst = block->coeffs_;
-  VP8MB* const left_mb = dec->mb_info_ - 1;
-  uint8_t tnz, lnz;
-  uint32_t non_zero_y = 0;
-  uint32_t non_zero_uv = 0;
-  int x, y, ch;
-  uint32_t out_t_nz, out_l_nz;
-  int first;
-
-  memset(dst, 0, 384 * sizeof(*dst));
-  if (!block->is_i4x4_) {    // parse DC
-    int16_t dc[16] = { 0 };
-    const int ctx = mb->nz_dc_ + left_mb->nz_dc_;
-    const int nz = GetCoeffs(token_br, bands[1], ctx, q->y2_mat_, 0, dc);
-    mb->nz_dc_ = left_mb->nz_dc_ = (nz > 0);
-    if (nz > 1) {   // more than just the DC -> perform the full transform
-      VP8TransformWHT(dc, dst);
-    } else {        // only DC is non-zero -> inlined simplified transform
-      int i;
-      const int dc0 = (dc[0] + 3) >> 3;
-      for (i = 0; i < 16 * 16; i += 16) dst[i] = dc0;
-    }
-    first = 1;
-    ac_proba = bands[0];
-  } else {
-    first = 0;
-    ac_proba = bands[3];
-  }
-
-  tnz = mb->nz_ & 0x0f;
-  lnz = left_mb->nz_ & 0x0f;
-  for (y = 0; y < 4; ++y) {
-    int l = lnz & 1;
-    uint32_t nz_coeffs = 0;
-    for (x = 0; x < 4; ++x) {
-      const int ctx = l + (tnz & 1);
-      const int nz = GetCoeffs(token_br, ac_proba, ctx, q->y1_mat_, first, dst);
-      l = (nz > first);
-      tnz = (tnz >> 1) | (l << 7);
-      nz_coeffs = NzCodeBits(nz_coeffs, nz, dst[0] != 0);
-      dst += 16;
-    }
-    tnz >>= 4;
-    lnz = (lnz >> 1) | (l << 7);
-    non_zero_y = (non_zero_y << 8) | nz_coeffs;
-  }
-  out_t_nz = tnz;
-  out_l_nz = lnz >> 4;
-
-  for (ch = 0; ch < 4; ch += 2) {
-    uint32_t nz_coeffs = 0;
-    tnz = mb->nz_ >> (4 + ch);
-    lnz = left_mb->nz_ >> (4 + ch);
-    for (y = 0; y < 2; ++y) {
-      int l = lnz & 1;
-      for (x = 0; x < 2; ++x) {
-        const int ctx = l + (tnz & 1);
-        const int nz = GetCoeffs(token_br, bands[2], ctx, q->uv_mat_, 0, dst);
-        l = (nz > 0);
-        tnz = (tnz >> 1) | (l << 3);
-        nz_coeffs = NzCodeBits(nz_coeffs, nz, dst[0] != 0);
-        dst += 16;
-      }
-      tnz >>= 2;
-      lnz = (lnz >> 1) | (l << 5);
-    }
-    // Note: we don't really need the per-4x4 details for U/V blocks.
-    non_zero_uv |= nz_coeffs << (4 * ch);
-    out_t_nz |= (tnz << 4) << ch;
-    out_l_nz |= (lnz & 0xf0) << ch;
-  }
-  mb->nz_ = out_t_nz;
-  left_mb->nz_ = out_l_nz;
-
-  block->non_zero_y_ = non_zero_y;
-  block->non_zero_uv_ = non_zero_uv;
-
-  // We look at the mode-code of each block and check if some blocks have less
-  // than three non-zero coeffs (code < 2). This is to avoid dithering flat and
-  // empty blocks.
-  block->dither_ = (non_zero_uv & 0xaaaa) ? 0 : q->dither_;
-
-  return !(non_zero_y | non_zero_uv);  // will be used for further optimization
-}
-
-//------------------------------------------------------------------------------
-// Main loop
-
-int VP8DecodeMB(VP8Decoder* const dec, VP8BitReader* const token_br) {
-  VP8MB* const left = dec->mb_info_ - 1;
-  VP8MB* const mb = dec->mb_info_ + dec->mb_x_;
-  VP8MBData* const block = dec->mb_data_ + dec->mb_x_;
-  int skip = dec->use_skip_proba_ ? block->skip_ : 0;
-
-  if (!skip) {
-    skip = ParseResiduals(dec, mb, token_br);
-  } else {
-    left->nz_ = mb->nz_ = 0;
-    if (!block->is_i4x4_) {
-      left->nz_dc_ = mb->nz_dc_ = 0;
-    }
-    block->non_zero_y_ = 0;
-    block->non_zero_uv_ = 0;
-    block->dither_ = 0;
-  }
-
-  if (dec->filter_type_ > 0) {  // store filter info
-    VP8FInfo* const finfo = dec->f_info_ + dec->mb_x_;
-    *finfo = dec->fstrengths_[block->segment_][block->is_i4x4_];
-    finfo->f_inner_ |= !skip;
-  }
-
-  return !token_br->eof_;
-}
-
-void VP8InitScanline(VP8Decoder* const dec) {
-  VP8MB* const left = dec->mb_info_ - 1;
-  left->nz_ = 0;
-  left->nz_dc_ = 0;
-  memset(dec->intra_l_, B_DC_PRED, sizeof(dec->intra_l_));
-  dec->mb_x_ = 0;
-}
-
-static int ParseFrame(VP8Decoder* const dec, VP8Io* io) {
-  for (dec->mb_y_ = 0; dec->mb_y_ < dec->br_mb_y_; ++dec->mb_y_) {
-    // Parse bitstream for this row.
-    VP8BitReader* const token_br =
-        &dec->parts_[dec->mb_y_ & dec->num_parts_minus_one_];
-    if (!VP8ParseIntraModeRow(&dec->br_, dec)) {
-      return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
-                         "Premature end-of-partition0 encountered.");
-    }
-    for (; dec->mb_x_ < dec->mb_w_; ++dec->mb_x_) {
-      if (!VP8DecodeMB(dec, token_br)) {
-        return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
-                           "Premature end-of-file encountered.");
-      }
-    }
-    VP8InitScanline(dec);   // Prepare for next scanline
-
-    // Reconstruct, filter and emit the row.
-    if (!VP8ProcessRow(dec, io)) {
-      return VP8SetError(dec, VP8_STATUS_USER_ABORT, "Output aborted.");
-    }
-  }
-  if (dec->mt_method_ > 0) {
-    if (!WebPGetWorkerInterface()->Sync(&dec->worker_)) return 0;
-  }
-
-  return 1;
-}
-
-// Main entry point
-int VP8Decode(VP8Decoder* const dec, VP8Io* const io) {
-  int ok = 0;
-  if (dec == NULL) {
-    return 0;
-  }
-  if (io == NULL) {
-    return VP8SetError(dec, VP8_STATUS_INVALID_PARAM,
-                       "NULL VP8Io parameter in VP8Decode().");
-  }
-
-  if (!dec->ready_) {
-    if (!VP8GetHeaders(dec, io)) {
-      return 0;
-    }
-  }
-  assert(dec->ready_);
-
-  // Finish setting up the decoding parameter. Will call io->setup().
-  ok = (VP8EnterCritical(dec, io) == VP8_STATUS_OK);
-  if (ok) {   // good to go.
-    // Will allocate memory and prepare everything.
-    if (ok) ok = VP8InitFrame(dec, io);
-
-    // Main decoding loop
-    if (ok) ok = ParseFrame(dec, io);
-
-    // Exit.
-    ok &= VP8ExitCritical(dec, io);
-  }
-
-  if (!ok) {
-    VP8Clear(dec);
-    return 0;
-  }
-
-  dec->ready_ = 0;
-  return ok;
-}
-
-void VP8Clear(VP8Decoder* const dec) {
-  if (dec == NULL) {
-    return;
-  }
-  WebPGetWorkerInterface()->End(&dec->worker_);
-  WebPDeallocateAlphaMemory(dec);
-  WebPSafeFree(dec->mem_);
-  dec->mem_ = NULL;
-  dec->mem_size_ = 0;
-  memset(&dec->br_, 0, sizeof(dec->br_));
-  dec->ready_ = 0;
-}
-
-//------------------------------------------------------------------------------