mirror of
https://github.com/webmproject/libwebp.git
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1fb9f3dcf1
A void parameter list should be (void), not (). Fixes a -Wstrict-prototypes warning. Change-Id: I180efbf7c58956695359320072cce1171d79e377
417 lines
13 KiB
C
417 lines
13 KiB
C
// Copyright 2012 Google Inc. All Rights Reserved.
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//
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// Use of this source code is governed by a BSD-style license
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// that can be found in the COPYING file in the root of the source
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// tree. An additional intellectual property rights grant can be found
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// in the file PATENTS. All contributing project authors may
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// be found in the AUTHORS file in the root of the source tree.
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// -----------------------------------------------------------------------------
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//
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// GIF decode.
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#include "./gifdec.h"
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#include <stdio.h>
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#ifdef WEBP_HAVE_GIF
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#include <assert.h>
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#include <stdlib.h>
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#include <string.h>
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#include "webp/encode.h"
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#include "webp/mux_types.h"
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#define GIF_TRANSPARENT_COLOR 0x00000000u
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#define GIF_WHITE_COLOR 0xffffffffu
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#define GIF_TRANSPARENT_MASK 0x01
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#define GIF_DISPOSE_MASK 0x07
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#define GIF_DISPOSE_SHIFT 2
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// from utils/utils.h
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#ifdef __cplusplus
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extern "C" {
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#endif
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extern void WebPCopyPlane(const uint8_t* src, int src_stride,
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uint8_t* dst, int dst_stride,
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int width, int height);
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extern void WebPCopyPixels(const WebPPicture* const src,
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WebPPicture* const dst);
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#ifdef __cplusplus
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}
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#endif
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void GIFGetBackgroundColor(const ColorMapObject* const color_map,
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int bgcolor_index, int transparent_index,
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uint32_t* const bgcolor) {
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if (transparent_index != GIF_INDEX_INVALID &&
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bgcolor_index == transparent_index) {
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*bgcolor = GIF_TRANSPARENT_COLOR; // Special case.
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} else if (color_map == NULL || color_map->Colors == NULL
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|| bgcolor_index >= color_map->ColorCount) {
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*bgcolor = GIF_WHITE_COLOR;
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fprintf(stderr,
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"GIF decode warning: invalid background color index. Assuming "
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"white background.\n");
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} else {
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const GifColorType color = color_map->Colors[bgcolor_index];
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*bgcolor = (0xffu << 24)
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| (color.Red << 16)
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| (color.Green << 8)
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| (color.Blue << 0);
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}
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}
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int GIFReadGraphicsExtension(const GifByteType* const buf, int* const duration,
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GIFDisposeMethod* const dispose,
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int* const transparent_index) {
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const int flags = buf[1];
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const int dispose_raw = (flags >> GIF_DISPOSE_SHIFT) & GIF_DISPOSE_MASK;
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const int duration_raw = buf[2] | (buf[3] << 8); // In 10 ms units.
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if (buf[0] != 4) return 0;
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*duration = duration_raw * 10; // Duration is in 1 ms units.
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switch (dispose_raw) {
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case 3:
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*dispose = GIF_DISPOSE_RESTORE_PREVIOUS;
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break;
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case 2:
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*dispose = GIF_DISPOSE_BACKGROUND;
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break;
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case 1:
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case 0:
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default:
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*dispose = GIF_DISPOSE_NONE;
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break;
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}
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*transparent_index =
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(flags & GIF_TRANSPARENT_MASK) ? buf[4] : GIF_INDEX_INVALID;
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return 1;
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}
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static int Remap(const GifFileType* const gif, const uint8_t* const src,
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int len, int transparent_index, uint32_t* dst) {
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int i;
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const GifColorType* colors;
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const ColorMapObject* const cmap =
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gif->Image.ColorMap ? gif->Image.ColorMap : gif->SColorMap;
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if (cmap == NULL) return 1;
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if (cmap->Colors == NULL || cmap->ColorCount <= 0) return 0;
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colors = cmap->Colors;
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for (i = 0; i < len; ++i) {
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if (src[i] == transparent_index) {
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dst[i] = GIF_TRANSPARENT_COLOR;
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} else if (src[i] < cmap->ColorCount) {
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const GifColorType c = colors[src[i]];
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dst[i] = c.Blue | (c.Green << 8) | (c.Red << 16) | (0xffu << 24);
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} else {
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return 0;
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}
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}
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return 1;
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}
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int GIFReadFrame(GifFileType* const gif, int transparent_index,
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GIFFrameRect* const gif_rect, WebPPicture* const picture) {
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WebPPicture sub_image;
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const GifImageDesc* const image_desc = &gif->Image;
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uint32_t* dst = NULL;
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uint8_t* tmp = NULL;
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const GIFFrameRect rect = {
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image_desc->Left, image_desc->Top, image_desc->Width, image_desc->Height
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};
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const uint64_t memory_needed = 4 * rect.width * (uint64_t)rect.height;
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int ok = 0;
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*gif_rect = rect;
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if (memory_needed != (size_t)memory_needed || memory_needed > (4ULL << 32)) {
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fprintf(stderr, "Image is too large (%d x %d).", rect.width, rect.height);
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return 0;
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}
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// Use a view for the sub-picture:
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if (!WebPPictureView(picture, rect.x_offset, rect.y_offset,
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rect.width, rect.height, &sub_image)) {
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fprintf(stderr, "Sub-image %dx%d at position %d,%d is invalid!\n",
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rect.width, rect.height, rect.x_offset, rect.y_offset);
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return 0;
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}
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dst = sub_image.argb;
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tmp = (uint8_t*)WebPMalloc(rect.width * sizeof(*tmp));
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if (tmp == NULL) goto End;
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if (image_desc->Interlace) { // Interlaced image.
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// We need 4 passes, with the following offsets and jumps.
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const int interlace_offsets[] = { 0, 4, 2, 1 };
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const int interlace_jumps[] = { 8, 8, 4, 2 };
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int pass;
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for (pass = 0; pass < 4; ++pass) {
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const size_t stride = (size_t)sub_image.argb_stride;
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int y = interlace_offsets[pass];
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uint32_t* row = dst + y * stride;
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const size_t jump = interlace_jumps[pass] * stride;
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for (; y < rect.height; y += interlace_jumps[pass], row += jump) {
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if (DGifGetLine(gif, tmp, rect.width) == GIF_ERROR) goto End;
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if (!Remap(gif, tmp, rect.width, transparent_index, row)) goto End;
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}
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}
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} else { // Non-interlaced image.
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int y;
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uint32_t* ptr = dst;
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for (y = 0; y < rect.height; ++y, ptr += sub_image.argb_stride) {
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if (DGifGetLine(gif, tmp, rect.width) == GIF_ERROR) goto End;
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if (!Remap(gif, tmp, rect.width, transparent_index, ptr)) goto End;
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}
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}
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ok = 1;
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End:
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if (!ok) picture->error_code = sub_image.error_code;
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WebPPictureFree(&sub_image);
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WebPFree(tmp);
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return ok;
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}
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int GIFReadLoopCount(GifFileType* const gif, GifByteType** const buf,
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int* const loop_count) {
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assert(!memcmp(*buf + 1, "NETSCAPE2.0", 11) ||
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!memcmp(*buf + 1, "ANIMEXTS1.0", 11));
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if (DGifGetExtensionNext(gif, buf) == GIF_ERROR) {
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return 0;
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}
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if (*buf == NULL) {
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return 0; // Loop count sub-block missing.
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}
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if ((*buf)[0] < 3 || (*buf)[1] != 1) {
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return 0; // wrong size/marker
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}
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*loop_count = (*buf)[2] | ((*buf)[3] << 8);
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return 1;
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}
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int GIFReadMetadata(GifFileType* const gif, GifByteType** const buf,
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WebPData* const metadata) {
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const int is_xmp = !memcmp(*buf + 1, "XMP DataXMP", 11);
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const int is_icc = !memcmp(*buf + 1, "ICCRGBG1012", 11);
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assert(is_xmp || is_icc);
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(void)is_icc; // silence unused warning.
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// Construct metadata from sub-blocks.
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// Usual case (including ICC profile): In each sub-block, the
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// first byte specifies its size in bytes (0 to 255) and the
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// rest of the bytes contain the data.
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// Special case for XMP data: In each sub-block, the first byte
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// is also part of the XMP payload. XMP in GIF also has a 257
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// byte padding data. See the XMP specification for details.
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while (1) {
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WebPData subblock;
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const uint8_t* tmp;
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if (DGifGetExtensionNext(gif, buf) == GIF_ERROR) {
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return 0;
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}
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if (*buf == NULL) break; // Finished.
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subblock.size = is_xmp ? (*buf)[0] + 1 : (*buf)[0];
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assert(subblock.size > 0);
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subblock.bytes = is_xmp ? *buf : *buf + 1;
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// Note: We store returned value in 'tmp' first, to avoid
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// leaking old memory in metadata->bytes on error.
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tmp = (uint8_t*)realloc((void*)metadata->bytes,
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metadata->size + subblock.size);
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if (tmp == NULL) {
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return 0;
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}
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memcpy((void*)(tmp + metadata->size),
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subblock.bytes, subblock.size);
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metadata->bytes = tmp;
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metadata->size += subblock.size;
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}
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if (is_xmp) {
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// XMP padding data is 0x01, 0xff, 0xfe ... 0x01, 0x00.
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const size_t xmp_pading_size = 257;
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if (metadata->size > xmp_pading_size) {
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metadata->size -= xmp_pading_size;
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}
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}
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return 1;
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}
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static void ClearRectangle(WebPPicture* const picture,
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int left, int top, int width, int height) {
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int i, j;
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const size_t stride = picture->argb_stride;
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uint32_t* dst = picture->argb + top * stride + left;
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for (j = 0; j < height; ++j, dst += stride) {
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for (i = 0; i < width; ++i) dst[i] = GIF_TRANSPARENT_COLOR;
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}
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}
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void GIFClearPic(WebPPicture* const pic, const GIFFrameRect* const rect) {
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if (rect != NULL) {
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ClearRectangle(pic, rect->x_offset, rect->y_offset,
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rect->width, rect->height);
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} else {
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ClearRectangle(pic, 0, 0, pic->width, pic->height);
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}
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}
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void GIFCopyPixels(const WebPPicture* const src, WebPPicture* const dst) {
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WebPCopyPixels(src, dst);
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}
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void GIFDisposeFrame(GIFDisposeMethod dispose, const GIFFrameRect* const rect,
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const WebPPicture* const prev_canvas,
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WebPPicture* const curr_canvas) {
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assert(rect != NULL);
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if (dispose == GIF_DISPOSE_BACKGROUND) {
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GIFClearPic(curr_canvas, rect);
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} else if (dispose == GIF_DISPOSE_RESTORE_PREVIOUS) {
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const size_t src_stride = prev_canvas->argb_stride;
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const uint32_t* const src = prev_canvas->argb + rect->x_offset
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+ rect->y_offset * src_stride;
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const size_t dst_stride = curr_canvas->argb_stride;
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uint32_t* const dst = curr_canvas->argb + rect->x_offset
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+ rect->y_offset * dst_stride;
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assert(prev_canvas != NULL);
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WebPCopyPlane((uint8_t*)src, (int)(4 * src_stride),
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(uint8_t*)dst, (int)(4 * dst_stride),
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4 * rect->width, rect->height);
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}
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}
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void GIFBlendFrames(const WebPPicture* const src,
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const GIFFrameRect* const rect, WebPPicture* const dst) {
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int i, j;
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const size_t src_stride = src->argb_stride;
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const size_t dst_stride = dst->argb_stride;
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assert(src->width == dst->width && src->height == dst->height);
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for (j = rect->y_offset; j < rect->y_offset + rect->height; ++j) {
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for (i = rect->x_offset; i < rect->x_offset + rect->width; ++i) {
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const uint32_t src_pixel = src->argb[j * src_stride + i];
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const int src_alpha = src_pixel >> 24;
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if (src_alpha != 0) {
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dst->argb[j * dst_stride + i] = src_pixel;
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}
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}
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}
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}
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void GIFDisplayError(const GifFileType* const gif, int gif_error) {
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// libgif 4.2.0 has retired PrintGifError() and added GifErrorString().
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#if LOCAL_GIF_PREREQ(4,2)
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#if LOCAL_GIF_PREREQ(5,0)
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// Static string actually, hence the const char* cast.
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const char* error_str = (const char*)GifErrorString(
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(gif == NULL) ? gif_error : gif->Error);
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#else
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const char* error_str = (const char*)GifErrorString();
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(void)gif;
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#endif
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if (error_str == NULL) error_str = "Unknown error";
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fprintf(stderr, "GIFLib Error %d: %s\n", gif_error, error_str);
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#else
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(void)gif;
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fprintf(stderr, "GIFLib Error %d: ", gif_error);
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PrintGifError();
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fprintf(stderr, "\n");
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#endif
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}
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#else // !WEBP_HAVE_GIF
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static void ErrorGIFNotAvailable(void) {
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fprintf(stderr, "GIF support not compiled. Please install the libgif-dev "
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"package before building.\n");
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}
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void GIFGetBackgroundColor(const struct ColorMapObject* const color_map,
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int bgcolor_index, int transparent_index,
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uint32_t* const bgcolor) {
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(void)color_map;
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(void)bgcolor_index;
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(void)transparent_index;
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(void)bgcolor;
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ErrorGIFNotAvailable();
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}
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int GIFReadGraphicsExtension(const GifByteType* const data, int* const duration,
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GIFDisposeMethod* const dispose,
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int* const transparent_index) {
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(void)data;
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(void)duration;
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(void)dispose;
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(void)transparent_index;
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ErrorGIFNotAvailable();
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return 0;
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}
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int GIFReadFrame(struct GifFileType* const gif, int transparent_index,
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GIFFrameRect* const gif_rect,
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struct WebPPicture* const picture) {
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(void)gif;
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(void)transparent_index;
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(void)gif_rect;
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(void)picture;
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ErrorGIFNotAvailable();
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return 0;
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}
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int GIFReadLoopCount(struct GifFileType* const gif, GifByteType** const buf,
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int* const loop_count) {
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(void)gif;
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(void)buf;
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(void)loop_count;
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ErrorGIFNotAvailable();
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return 0;
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}
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int GIFReadMetadata(struct GifFileType* const gif, GifByteType** const buf,
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struct WebPData* const metadata) {
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(void)gif;
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(void)buf;
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(void)metadata;
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ErrorGIFNotAvailable();
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return 0;
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}
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void GIFDisposeFrame(GIFDisposeMethod dispose, const GIFFrameRect* const rect,
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const struct WebPPicture* const prev_canvas,
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struct WebPPicture* const curr_canvas) {
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(void)dispose;
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(void)rect;
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(void)prev_canvas;
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(void)curr_canvas;
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ErrorGIFNotAvailable();
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}
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void GIFBlendFrames(const struct WebPPicture* const src,
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const GIFFrameRect* const rect,
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struct WebPPicture* const dst) {
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(void)src;
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(void)rect;
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(void)dst;
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ErrorGIFNotAvailable();
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}
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void GIFDisplayError(const struct GifFileType* const gif, int gif_error) {
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(void)gif;
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(void)gif_error;
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ErrorGIFNotAvailable();
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}
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void GIFClearPic(struct WebPPicture* const pic,
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const GIFFrameRect* const rect) {
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(void)pic;
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(void)rect;
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ErrorGIFNotAvailable();
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}
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void GIFCopyPixels(const struct WebPPicture* const src,
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struct WebPPicture* const dst) {
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(void)src;
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(void)dst;
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ErrorGIFNotAvailable();
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}
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#endif // WEBP_HAVE_GIF
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// -----------------------------------------------------------------------------
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