And python generator to copy files and fix headers, required for vend…

…or bundling

capi.go

@@ -1,13 +1,11 @@
 package webpanimation
 
 /*
-#cgo CFLAGS: -I./internal/libwebp-1.1/
-#cgo CFLAGS: -I./internal/libwebp-1.1/src/
-#cgo CFLAGS: -Wno-pointer-sign -DWEBP_USE_THREAD
+#cgo CFLAGS: -Wno-pointer-sign -DHAVE_CONFIG_H
 #cgo !windows LDFLAGS: -lm
 
-#include <webp/encode.h>
-#include <webp/mux.h>
+#include "webp_encode.h"
+#include "webp_mux.h"
 */
 import "C"
 import (

config.h

@@ -0,0 +1,4 @@
+#ifndef WEBANIMATION_HPP
+#define WEBANIMATION_HPP
+#define WEBP_USE_THREAD
+#endif

dec_alpha_dec.c

@@ -0,0 +1,232 @@
+// 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 ([email protected])
+
+#include <stdlib.h>
+#include "dec_alphai_dec.h"
+#include "dec_vp8i_dec.h"
+#include "dec_vp8li_dec.h"
+#include "dsp_dsp.h"
+#include "utils_quant_levels_dec_utils.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;
+}

dec_alphai_dec.h

@@ -0,0 +1,54 @@
+// Copyright 2013 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 decoder: internal header.
+//
+// Author: Urvang ([email protected])
+
+#ifndef WEBP_DEC_ALPHAI_DEC_H_
+#define WEBP_DEC_ALPHAI_DEC_H_
+
+#include "dec_webpi_dec.h"
+#include "utils_filters_utils.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct VP8LDecoder;  // Defined in dec/vp8li.h.
+
+typedef struct ALPHDecoder ALPHDecoder;
+struct ALPHDecoder {
+  int width_;
+  int height_;
+  int method_;
+  WEBP_FILTER_TYPE filter_;
+  int pre_processing_;
+  struct VP8LDecoder* vp8l_dec_;
+  VP8Io io_;
+  int use_8b_decode_;  // Although alpha channel requires only 1 byte per
+                       // pixel, sometimes VP8LDecoder may need to allocate
+                       // 4 bytes per pixel internally during decode.
+  uint8_t* output_;
+  const uint8_t* prev_line_;   // last output row (or NULL)
+};
+
+//------------------------------------------------------------------------------
+// internal functions. Not public.
+
+// Deallocate memory associated to dec->alpha_plane_ decoding
+void WebPDeallocateAlphaMemory(VP8Decoder* const dec);
+
+//------------------------------------------------------------------------------
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_DEC_ALPHAI_DEC_H_