540 lines
18 KiB
C
540 lines
18 KiB
C
// Copyright 2012 Google Inc. All Rights Reserved.
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//
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// This code is licensed under the same terms as WebM:
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// Software License Agreement: http://www.webmproject.org/license/software/
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// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
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// -----------------------------------------------------------------------------
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//
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// simple tool to convert animated GIFs to WebP
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//
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// Getting the prerequisites:
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// Debian-like linux:
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// sudo apt-get install libgif-dev
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// MacPorts
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// sudo port install giflib
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//
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// Compiling:
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// gcc -o gif2webp gif2webp.c -O3 -lwebpmux -lwebp -lgif -lpthread -lm
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//
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// Authors: Skal (pascal.massimino@gmail.com)
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// Urvang (urvang@google.com)
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#include <assert.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <gif_lib.h>
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#include "webp/encode.h"
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#include "webp/mux.h"
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#include "./example_util.h"
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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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#define TRANSPARENT_COLOR 0x00ffffff
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#define WHITE_COLOR 0xffffffff
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//------------------------------------------------------------------------------
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static int transparent_index = -1; // No transparency by default.
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static void ClearPicture(WebPPicture* const picture, uint32_t color) {
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int x, y;
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for (y = 0; y < picture->height; ++y) {
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uint32_t* const dst = picture->argb + y * picture->argb_stride;
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for (x = 0; x < picture->width; ++x) dst[x] = color;
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}
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}
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static void Remap(const uint8_t* const src, const GifFileType* const gif,
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uint32_t* dst, int len) {
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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;
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colors = cmap->Colors;
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for (i = 0; i < len; ++i) {
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const GifColorType c = colors[src[i]];
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dst[i] = (src[i] == transparent_index) ? TRANSPARENT_COLOR
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: c.Blue | (c.Green << 8) | (c.Red << 16) | (0xff << 24);
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}
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}
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static int ReadSubImage(GifFileType* gif, WebPPicture* pic, WebPPicture* view) {
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const GifImageDesc image_desc = gif->Image;
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const int offset_x = image_desc.Left;
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const int offset_y = image_desc.Top;
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const int sub_w = image_desc.Width;
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const int sub_h = image_desc.Height;
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uint32_t* dst = NULL;
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uint8_t* tmp = NULL;
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int ok = 0;
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// Use a view for the sub-picture:
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if (!WebPPictureView(pic, offset_x, offset_y, sub_w, sub_h, view)) {
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fprintf(stderr, "Sub-image %dx%d at position %d,%d is invalid!\n",
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sub_w, sub_h, offset_x, offset_y);
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goto End;
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}
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dst = view->argb;
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tmp = (uint8_t*)malloc(sub_w * 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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int y;
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for (y = interlace_offsets[pass]; y < sub_h; y += interlace_jumps[pass]) {
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if (DGifGetLine(gif, tmp, sub_w) == GIF_ERROR) goto End;
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Remap(tmp, gif, dst + y * view->argb_stride, sub_w);
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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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for (y = 0; y < sub_h; ++y) {
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if (DGifGetLine(gif, tmp, sub_w) == GIF_ERROR) goto End;
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Remap(tmp, gif, dst + y * view->argb_stride, sub_w);
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}
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}
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// re-align the view with even offset (and adjust dimensions if needed).
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WebPPictureView(pic, offset_x & ~1, offset_y & ~1,
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sub_w + (offset_x & 1), sub_h + (offset_y & 1), view);
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ok = 1;
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End:
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free(tmp);
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return ok;
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}
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static int GetBackgroundColor(const ColorMapObject* const color_map,
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GifWord bgcolor_idx, uint32_t* const bgcolor) {
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if (transparent_index != -1 && bgcolor_idx == transparent_index) {
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*bgcolor = TRANSPARENT_COLOR; // Special case.
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return 1;
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} else if (color_map == NULL || color_map->Colors == NULL
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|| bgcolor_idx >= color_map->ColorCount) {
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return 0; // Invalid color map or index.
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} else {
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const GifColorType color = color_map->Colors[bgcolor_idx];
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*bgcolor = (0xff << 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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return 1;
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}
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}
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static void DisplayGifError(const GifFileType* const gif, int gif_error) {
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// GIFLIB_MAJOR is only defined in libgif >= 4.2.0.
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// libgif 4.2.0 has retired PrintGifError() and added GifErrorString().
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#if defined(GIFLIB_MAJOR) && defined(GIFLIB_MINOR) && \
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((GIFLIB_MAJOR == 4 && GIFLIB_MINOR >= 2) || GIFLIB_MAJOR > 4)
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#if GIFLIB_MAJOR >= 5
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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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static const char* const kErrorMessages[] = {
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"WEBP_MUX_NOT_FOUND", "WEBP_MUX_INVALID_ARGUMENT", "WEBP_MUX_BAD_DATA",
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"WEBP_MUX_MEMORY_ERROR", "WEBP_MUX_NOT_ENOUGH_DATA"
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};
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static const char* ErrorString(WebPMuxError err) {
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assert(err <= WEBP_MUX_NOT_FOUND && err >= WEBP_MUX_NOT_ENOUGH_DATA);
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return kErrorMessages[-err];
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}
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//------------------------------------------------------------------------------
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static void Help(void) {
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printf("Usage:\n");
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printf(" gif2webp [options] gif_file -o webp_file\n");
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printf("options:\n");
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printf(" -h / -help ............ this help\n");
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printf(" -lossy ................. Encode image using lossy compression.\n");
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printf(" -q <float> ............. quality factor (0:small..100:big)\n");
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printf(" -m <int> ............... compression method (0=fast, 6=slowest)\n");
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printf(" -f <int> ............... filter strength (0=off..100)\n");
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printf("\n");
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printf(" -version ............... print version number and exit.\n");
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printf(" -v ..................... verbose.\n");
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printf(" -quiet ................. don't print anything.\n");
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printf("\n");
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}
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//------------------------------------------------------------------------------
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int main(int argc, const char *argv[]) {
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int verbose = 0;
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int gif_error = GIF_ERROR;
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WebPMuxError err = WEBP_MUX_OK;
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int ok = 0;
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const char *in_file = NULL, *out_file = NULL;
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FILE* out = NULL;
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GifFileType* gif = NULL;
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WebPPicture picture;
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WebPPicture view;
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WebPMemoryWriter memory;
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WebPMuxFrameInfo frame;
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WebPMuxAnimParams anim = { WHITE_COLOR, 0 };
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int is_first_frame = 1;
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int done;
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int c;
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int quiet = 0;
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WebPConfig config;
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WebPMux* mux = NULL;
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WebPData webp_data = { NULL, 0 };
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int stored_icc = 0; // Whether we have already stored an ICC profile.
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int stored_xmp = 0;
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memset(&frame, 0, sizeof(frame));
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frame.id = WEBP_CHUNK_ANMF;
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frame.dispose_method = WEBP_MUX_DISPOSE_BACKGROUND;
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if (!WebPConfigInit(&config) || !WebPPictureInit(&picture)) {
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fprintf(stderr, "Error! Version mismatch!\n");
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return -1;
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}
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config.lossless = 1; // Use lossless compression by default.
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if (argc == 1) {
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Help();
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return 0;
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}
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for (c = 1; c < argc; ++c) {
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if (!strcmp(argv[c], "-h") || !strcmp(argv[c], "-help")) {
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Help();
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return 0;
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} else if (!strcmp(argv[c], "-o") && c < argc - 1) {
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out_file = argv[++c];
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} else if (!strcmp(argv[c], "-lossy")) {
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config.lossless = 0;
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} else if (!strcmp(argv[c], "-q") && c < argc - 1) {
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config.quality = (float)strtod(argv[++c], NULL);
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} else if (!strcmp(argv[c], "-m") && c < argc - 1) {
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config.method = strtol(argv[++c], NULL, 0);
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} else if (!strcmp(argv[c], "-f") && c < argc - 1) {
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config.filter_strength = strtol(argv[++c], NULL, 0);
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} else if (!strcmp(argv[c], "-version")) {
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const int enc_version = WebPGetEncoderVersion();
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const int mux_version = WebPGetMuxVersion();
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printf("WebP Encoder version: %d.%d.%d\nWebP Mux version: %d.%d.%d\n",
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(enc_version >> 16) & 0xff, (enc_version >> 8) & 0xff,
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enc_version & 0xff, (mux_version >> 16) & 0xff,
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(mux_version >> 8) & 0xff, mux_version & 0xff);
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return 0;
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} else if (!strcmp(argv[c], "-quiet")) {
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quiet = 1;
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} else if (!strcmp(argv[c], "-v")) {
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verbose = 1;
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} else if (argv[c][0] == '-') {
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fprintf(stderr, "Error! Unknown option '%s'\n", argv[c]);
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Help();
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return -1;
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} else {
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in_file = argv[c];
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}
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}
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if (!WebPValidateConfig(&config)) {
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fprintf(stderr, "Error! Invalid configuration.\n");
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goto End;
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}
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if (in_file == NULL) {
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fprintf(stderr, "No input file specified!\n");
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Help();
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goto End;
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}
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// Start the decoder object
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#if defined(GIFLIB_MAJOR) && (GIFLIB_MAJOR >= 5)
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// There was an API change in version 5.0.0.
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gif = DGifOpenFileName(in_file, &gif_error);
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#else
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gif = DGifOpenFileName(in_file);
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#endif
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if (gif == NULL) goto End;
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// Allocate picture buffer
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picture.width = gif->SWidth;
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picture.height = gif->SHeight;
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picture.use_argb = 1;
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picture.writer = WebPMemoryWrite;
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picture.custom_ptr = &memory;
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if (!WebPPictureAlloc(&picture)) goto End;
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mux = WebPMuxNew();
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if (mux == NULL) {
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fprintf(stderr, "ERROR: could not create a mux object.\n");
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goto End;
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}
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// Loop over GIF images
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done = 0;
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do {
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GifRecordType type;
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if (DGifGetRecordType(gif, &type) == GIF_ERROR) goto End;
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switch (type) {
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case IMAGE_DESC_RECORD_TYPE: {
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if (frame.dispose_method == WEBP_MUX_DISPOSE_BACKGROUND) {
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ClearPicture(&picture, anim.bgcolor);
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}
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if (!DGifGetImageDesc(gif)) goto End;
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if (!ReadSubImage(gif, &picture, &view)) goto End;
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WebPMemoryWriterInit(&memory);
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if (!config.lossless) {
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// We need to call BGRA variant because of the way we do Remap().
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// TODO(later): This works for little-endian only due to uint32_t to
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// uint8_t conversion. Make it work for big-endian too.
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WebPPictureImportBGRA(&view, (uint8_t*)view.argb,
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view.argb_stride * sizeof(*view.argb));
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view.use_argb = 0;
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} else {
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view.use_argb = 1;
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}
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if (!WebPEncode(&config, &view)) {
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fprintf(stderr, "Error! Cannot encode picture as WebP\n");
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fprintf(stderr, "Error code: %d\n", view.error_code);
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goto End;
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}
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// Now we have all the info about the frame, as a Graphic Control
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// Extension Block always appears before the Image Descriptor Block.
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// So add the frame to mux.
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frame.x_offset = gif->Image.Left & ~1;
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frame.y_offset = gif->Image.Top & ~1;
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frame.bitstream.bytes = memory.mem;
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frame.bitstream.size = memory.size;
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err = WebPMuxPushFrame(mux, &frame, 1);
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if (err != WEBP_MUX_OK) {
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fprintf(stderr, "ERROR (%s): Could not add animation frame.\n",
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ErrorString(err));
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goto End;
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}
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if (verbose) {
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printf("Added frame %dx%d (offset:%d,%d duration:%d) ",
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view.width, view.height, frame.x_offset, frame.y_offset,
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frame.duration);
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printf("dispose:%d transparent index:%d\n",
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frame.dispose_method, transparent_index);
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}
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WebPDataClear(&frame.bitstream);
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break;
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}
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case EXTENSION_RECORD_TYPE: {
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int extension;
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GifByteType *data = NULL;
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if (DGifGetExtension(gif, &extension, &data) == GIF_ERROR) {
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goto End;
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}
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switch (extension) {
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case COMMENT_EXT_FUNC_CODE: {
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break; // Do nothing for now.
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}
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case GRAPHICS_EXT_FUNC_CODE: {
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const int flags = data[1];
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const int dispose = (flags >> GIF_DISPOSE_SHIFT) & GIF_DISPOSE_MASK;
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const int delay = data[2] | (data[3] << 8); // In 10 ms units.
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if (data[0] != 4) goto End;
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frame.duration = delay * 10; // Duration is in 1 ms units for WebP.
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if (dispose == 3) {
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fprintf(stderr, "WARNING: GIF_DISPOSE_RESTORE not supported.");
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// failsafe. TODO(urvang): emulate the correct behaviour by
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// recoding the whole frame.
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frame.dispose_method = WEBP_MUX_DISPOSE_BACKGROUND;
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} else {
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frame.dispose_method =
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(dispose == 2) ? WEBP_MUX_DISPOSE_BACKGROUND
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: WEBP_MUX_DISPOSE_NONE;
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}
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transparent_index = (flags & GIF_TRANSPARENT_MASK) ? data[4] : -1;
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if (is_first_frame) {
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if (!GetBackgroundColor(gif->SColorMap, gif->SBackGroundColor,
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&anim.bgcolor)) {
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fprintf(stderr, "GIF decode warning: invalid background color "
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"index. Assuming white background.\n");
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}
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ClearPicture(&picture, anim.bgcolor);
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is_first_frame = 0;
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}
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break;
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}
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case PLAINTEXT_EXT_FUNC_CODE: {
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break;
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}
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case APPLICATION_EXT_FUNC_CODE: {
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if (data[0] != 11) break; // Chunk is too short
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if (!memcmp(data + 1, "NETSCAPE2.0", 11)) {
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// Recognize and parse Netscape2.0 NAB extension for loop count.
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if (DGifGetExtensionNext(gif, &data) == GIF_ERROR) goto End;
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if (data == NULL) goto End; // Loop count sub-block missing.
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if (data[0] != 3 && data[1] != 1) break; // wrong size/marker
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anim.loop_count = data[2] | (data[3] << 8);
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if (verbose) printf("Loop count: %d\n", anim.loop_count);
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} else { // An extension containing metadata.
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// We only store the first encountered chunk of each type.
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const int is_xmp =
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!stored_xmp && !memcmp(data + 1, "XMP DataXMP", 11);
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const int is_icc =
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!stored_icc && !memcmp(data + 1, "ICCRGBG1012", 11);
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if (is_xmp || is_icc) {
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const char fourccs[2][4] = { "XMP " , "ICCP" };
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const char* const features[2] = { "XMP" , "ICC" };
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WebPData metadata = { NULL, 0 };
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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 prev_metadata = metadata;
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WebPData subblock;
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if (DGifGetExtensionNext(gif, &data) == GIF_ERROR) {
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WebPDataClear(&metadata);
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goto End;
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}
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if (data == NULL) break; // Finished.
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subblock.size = is_xmp ? data[0] + 1 : data[0];
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assert(subblock.size > 0);
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subblock.bytes = is_xmp ? data : data + 1;
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metadata.bytes =
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(uint8_t*)realloc((void*)metadata.bytes,
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prev_metadata.size + subblock.size);
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if (metadata.bytes == NULL) {
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WebPDataClear(&prev_metadata);
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goto End;
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}
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metadata.size += subblock.size;
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memcpy((void*)metadata.bytes + prev_metadata.size,
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subblock.bytes, 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 int 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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// Add metadata chunk.
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err = WebPMuxSetChunk(mux, fourccs[is_icc], &metadata, 1);
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if (verbose) {
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printf("%s size: %d\n", features[is_icc], (int)metadata.size);
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}
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WebPDataClear(&metadata);
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if (err != WEBP_MUX_OK) {
|
|
fprintf(stderr, "ERROR (%s): Could not set %s chunk.\n",
|
|
ErrorString(err), features[is_icc]);
|
|
goto End;
|
|
}
|
|
if (is_icc) {
|
|
stored_icc = 1;
|
|
} else if (is_xmp) {
|
|
stored_xmp = 1;
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
default: {
|
|
break; // skip
|
|
}
|
|
}
|
|
while (data != NULL) {
|
|
if (DGifGetExtensionNext(gif, &data) == GIF_ERROR) goto End;
|
|
}
|
|
break;
|
|
}
|
|
case TERMINATE_RECORD_TYPE: {
|
|
done = 1;
|
|
break;
|
|
}
|
|
default: {
|
|
if (verbose) {
|
|
fprintf(stderr, "Skipping over unknown record type %d\n", type);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
} while (!done);
|
|
|
|
// Finish muxing
|
|
err = WebPMuxSetAnimationParams(mux, &anim);
|
|
if (err != WEBP_MUX_OK) {
|
|
fprintf(stderr, "ERROR (%s): Could not set animation parameters.\n",
|
|
ErrorString(err));
|
|
goto End;
|
|
}
|
|
|
|
err = WebPMuxAssemble(mux, &webp_data);
|
|
if (err != WEBP_MUX_OK) {
|
|
fprintf(stderr, "ERROR (%s) assembling the WebP file.\n", ErrorString(err));
|
|
goto End;
|
|
}
|
|
if (out_file != NULL) {
|
|
if (!ExUtilWriteFile(out_file, webp_data.bytes, webp_data.size)) {
|
|
fprintf(stderr, "Error writing output file: %s\n", out_file);
|
|
goto End;
|
|
}
|
|
if (!quiet) {
|
|
printf("Saved output file: %s\n", out_file);
|
|
}
|
|
} else {
|
|
if (!quiet) {
|
|
printf("Nothing written; use -o flag to save the result.\n");
|
|
}
|
|
}
|
|
|
|
// All OK.
|
|
ok = 1;
|
|
gif_error = GIF_OK;
|
|
|
|
End:
|
|
WebPDataClear(&webp_data);
|
|
WebPMuxDelete(mux);
|
|
WebPPictureFree(&picture);
|
|
if (out != NULL && out_file != NULL) fclose(out);
|
|
|
|
if (gif_error != GIF_OK) {
|
|
DisplayGifError(gif, gif_error);
|
|
}
|
|
if (gif != NULL) {
|
|
DGifCloseFile(gif);
|
|
}
|
|
|
|
return !ok;
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|