libwebp-0.6.0-rc1

third_party/libwebp/dec/alpha.c

Index: third_party/libwebp/dec/alpha.c
diff --git a/third_party/libwebp/dec/alpha.c b/third_party/libwebp/dec/alpha.c
deleted file mode 100644
index d88f01d8de875a67139e915435eb391b35eaf988..0000000000000000000000000000000000000000
--- a/third_party/libwebp/dec/alpha.c
+++ /dev/null
@@ -1,232 +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.
-// -----------------------------------------------------------------------------
-//
-// Alpha-plane decompression.
-//
-// Author: Skal (pascal.massimino@gmail.com)
-
-#include <stdlib.h>
-#include "./alphai.h"
-#include "./vp8i.h"
-#include "./vp8li.h"
-#include "../dsp/dsp.h"
-#include "../utils/quant_levels_dec.h"
-#include "../utils/utils.h"
-#include "../webp/format_constants.h"
-
-//------------------------------------------------------------------------------
-// ALPHDecoder object.
-
-// Allocates a new alpha decoder instance.
-static ALPHDecoder* ALPHNew(void) {
-  ALPHDecoder* const dec = (ALPHDecoder*)WebPSafeCalloc(1ULL, sizeof(*dec));
-  return dec;
-}
-
-// Clears and deallocates an alpha decoder instance.
-static void ALPHDelete(ALPHDecoder* const dec) {
-  if (dec != NULL) {
-    VP8LDelete(dec->vp8l_dec_);
-    dec->vp8l_dec_ = NULL;
-    WebPSafeFree(dec);
-  }
-}
-
-//------------------------------------------------------------------------------
-// Decoding.
-
-// Initialize alpha decoding by parsing the alpha header and decoding the image
-// header for alpha data stored using lossless compression.
-// Returns false in case of error in alpha header (data too short, invalid
-// compression method or filter, error in lossless header data etc).
-static int ALPHInit(ALPHDecoder* const dec, const uint8_t* data,
-                    size_t data_size, const VP8Io* const src_io,
-                    uint8_t* output) {
-  int ok = 0;
-  const uint8_t* const alpha_data = data + ALPHA_HEADER_LEN;
-  const size_t alpha_data_size = data_size - ALPHA_HEADER_LEN;
-  int rsrv;
-  VP8Io* const io = &dec->io_;
-
-  assert(data != NULL && output != NULL && src_io != NULL);
-
-  VP8FiltersInit();
-  dec->output_ = output;
-  dec->width_ = src_io->width;
-  dec->height_ = src_io->height;
-  assert(dec->width_ > 0 && dec->height_ > 0);
-
-  if (data_size <= ALPHA_HEADER_LEN) {
-    return 0;
-  }
-
-  dec->method_ = (data[0] >> 0) & 0x03;
-  dec->filter_ = (WEBP_FILTER_TYPE)((data[0] >> 2) & 0x03);
-  dec->pre_processing_ = (data[0] >> 4) & 0x03;
-  rsrv = (data[0] >> 6) & 0x03;
-  if (dec->method_ < ALPHA_NO_COMPRESSION ||
-      dec->method_ > ALPHA_LOSSLESS_COMPRESSION ||
-      dec->filter_ >= WEBP_FILTER_LAST ||
-      dec->pre_processing_ > ALPHA_PREPROCESSED_LEVELS ||
-      rsrv != 0) {
-    return 0;
-  }
-
-  // Copy the necessary parameters from src_io to io
-  VP8InitIo(io);
-  WebPInitCustomIo(NULL, io);
-  io->opaque = dec;
-  io->width = src_io->width;
-  io->height = src_io->height;
-
-  io->use_cropping = src_io->use_cropping;
-  io->crop_left = src_io->crop_left;
-  io->crop_right = src_io->crop_right;
-  io->crop_top = src_io->crop_top;
-  io->crop_bottom = src_io->crop_bottom;
-  // No need to copy the scaling parameters.
-
-  if (dec->method_ == ALPHA_NO_COMPRESSION) {
-    const size_t alpha_decoded_size = dec->width_ * dec->height_;
-    ok = (alpha_data_size >= alpha_decoded_size);
-  } else {
-    assert(dec->method_ == ALPHA_LOSSLESS_COMPRESSION);
-    ok = VP8LDecodeAlphaHeader(dec, alpha_data, alpha_data_size);
-  }
-
-  return ok;
-}
-
-// Decodes, unfilters and dequantizes *at least* 'num_rows' rows of alpha
-// starting from row number 'row'. It assumes that rows up to (row - 1) have
-// already been decoded.
-// Returns false in case of bitstream error.
-static int ALPHDecode(VP8Decoder* const dec, int row, int num_rows) {
-  ALPHDecoder* const alph_dec = dec->alph_dec_;
-  const int width = alph_dec->width_;
-  const int height = alph_dec->io_.crop_bottom;
-  if (alph_dec->method_ == ALPHA_NO_COMPRESSION) {
-    int y;
-    const uint8_t* prev_line = dec->alpha_prev_line_;
-    const uint8_t* deltas = dec->alpha_data_ + ALPHA_HEADER_LEN + row * width;
-    uint8_t* dst = dec->alpha_plane_ + row * width;
-    assert(deltas <= &dec->alpha_data_[dec->alpha_data_size_]);
-    if (alph_dec->filter_ != WEBP_FILTER_NONE) {
-      assert(WebPUnfilters[alph_dec->filter_] != NULL);
-      for (y = 0; y < num_rows; ++y) {
-        WebPUnfilters[alph_dec->filter_](prev_line, deltas, dst, width);
-        prev_line = dst;
-        dst += width;
-        deltas += width;
-      }
-    } else {
-      for (y = 0; y < num_rows; ++y) {
-        memcpy(dst, deltas, width * sizeof(*dst));
-        prev_line = dst;
-        dst += width;
-        deltas += width;
-      }
-    }
-    dec->alpha_prev_line_ = prev_line;
-  } else {  // alph_dec->method_ == ALPHA_LOSSLESS_COMPRESSION
-    assert(alph_dec->vp8l_dec_ != NULL);
-    if (!VP8LDecodeAlphaImageStream(alph_dec, row + num_rows)) {
-      return 0;
-    }
-  }
-
-  if (row + num_rows >= height) {
-    dec->is_alpha_decoded_ = 1;
-  }
-  return 1;
-}
-
-static int AllocateAlphaPlane(VP8Decoder* const dec, const VP8Io* const io) {
-  const int stride = io->width;
-  const int height = io->crop_bottom;
-  const uint64_t alpha_size = (uint64_t)stride * height;
-  assert(dec->alpha_plane_mem_ == NULL);
-  dec->alpha_plane_mem_ =
-      (uint8_t*)WebPSafeMalloc(alpha_size, sizeof(*dec->alpha_plane_));
-  if (dec->alpha_plane_mem_ == NULL) {
-    return 0;
-  }
-  dec->alpha_plane_ = dec->alpha_plane_mem_;
-  dec->alpha_prev_line_ = NULL;
-  return 1;
-}
-
-void WebPDeallocateAlphaMemory(VP8Decoder* const dec) {
-  assert(dec != NULL);
-  WebPSafeFree(dec->alpha_plane_mem_);
-  dec->alpha_plane_mem_ = NULL;
-  dec->alpha_plane_ = NULL;
-  ALPHDelete(dec->alph_dec_);
-  dec->alph_dec_ = NULL;
-}
-
-//------------------------------------------------------------------------------
-// Main entry point.
-
-const uint8_t* VP8DecompressAlphaRows(VP8Decoder* const dec,
-                                      const VP8Io* const io,
-                                      int row, int num_rows) {
-  const int width = io->width;
-  const int height = io->crop_bottom;
-
-  assert(dec != NULL && io != NULL);
-
-  if (row < 0 || num_rows <= 0 || row + num_rows > height) {
-    return NULL;    // sanity check.
-  }
-
-  if (!dec->is_alpha_decoded_) {
-    if (dec->alph_dec_ == NULL) {    // Initialize decoder.
-      dec->alph_dec_ = ALPHNew();
-      if (dec->alph_dec_ == NULL) return NULL;
-      if (!AllocateAlphaPlane(dec, io)) goto Error;
-      if (!ALPHInit(dec->alph_dec_, dec->alpha_data_, dec->alpha_data_size_,
-                    io, dec->alpha_plane_)) {
-        goto Error;
-      }
-      // if we allowed use of alpha dithering, check whether it's needed at all
-      if (dec->alph_dec_->pre_processing_ != ALPHA_PREPROCESSED_LEVELS) {
-        dec->alpha_dithering_ = 0;   // disable dithering
-      } else {
-        num_rows = height - row;     // decode everything in one pass
-      }
-    }
-
-    assert(dec->alph_dec_ != NULL);
-    assert(row + num_rows <= height);
-    if (!ALPHDecode(dec, row, num_rows)) goto Error;
-
-    if (dec->is_alpha_decoded_) {   // finished?
-      ALPHDelete(dec->alph_dec_);
-      dec->alph_dec_ = NULL;
-      if (dec->alpha_dithering_ > 0) {
-        uint8_t* const alpha = dec->alpha_plane_ + io->crop_top * width
-                             + io->crop_left;
-        if (!WebPDequantizeLevels(alpha,
-                                  io->crop_right - io->crop_left,
-                                  io->crop_bottom - io->crop_top,
-                                  width, dec->alpha_dithering_)) {
-          goto Error;
-        }
-      }
-    }
-  }
-
-  // Return a pointer to the current decoded row.
-  return dec->alpha_plane_ + row * width;
-
- Error:
-  WebPDeallocateAlphaMemory(dec);
-  return NULL;
-}