anim_dump: small tool to dump frames from animated WebP

dumps frames to PNG, PAM or TIFF files. Change-Id: I86a4d7e235cb7040cf5bbcae28270cb5a84be087
2025-07-12 22:14:29 +02:00 · 2017-08-28 16:03:40 +02:00
parent 6eba857b75
commit f66f94ef36
4 changed files with 136 additions and 2 deletions
--- a/examples/anim_dump.c
+++ b/examples/anim_dump.c
@ -0,0 +1,104 @@
+// Copyright 2017 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.
+// -----------------------------------------------------------------------------
+//
+// Decodes an animated WebP file and dumps the decoded frames as PNG or TIFF.
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include <stdio.h>
+#include <string.h>  // for 'strcmp'.
+
+#include "./anim_util.h"
+#include "webp/decode.h"
+#include "../imageio/image_enc.h"
+
+#if defined(_MSC_VER) && _MSC_VER < 1900
+#define snprintf _snprintf
+#endif
+
+static void Help(void) {
+  printf("Usage: anim_dump [options] files...\n");
+  printf("\nOptions:\n");
+  printf("  -folder <string> .... dump folder (default: '.')\n");
+  printf("  -prefix <string> .... prefix for dumped frames "
+                                  "(default: 'dump_')\n");
+  printf("  -tiff ............... save frames as TIFF\n");
+  printf("  -pam ................ save frames as PAM\n");
+}
+
+int main(int argc, const char* argv[]) {
+  int error = 0;
+  const char* dump_folder = ".";
+  const char* prefix = "dump_";
+  const char* suffix = "png";
+  WebPOutputFileFormat format = PNG;
+  int c;
+
+  if (argc < 2) {
+    Help();
+    return -1;
+  }
+
+  for (c = 1; !error && c < argc; ++c) {
+    if (!strcmp(argv[c], "-folder")) {
+      if (c + 1 == argc) {
+        fprintf(stderr, "missing argument after option '%s'\n", argv[c]);
+        error = 1;
+        break;
+      }
+      dump_folder = argv[++c];
+    } else if (!strcmp(argv[c], "-prefix")) {
+      if (c + 1 == argc) {
+        fprintf(stderr, "missing argument after option '%s'\n", argv[c]);
+        error = 1;
+        break;
+      }
+      prefix = argv[++c];
+    } else if (!strcmp(argv[c], "-tiff")) {
+      format = TIFF;
+      suffix = "tiff";
+    } else if (!strcmp(argv[c], "-pam")) {
+      format = PAM;
+      suffix = "pam";
+    } else {
+      uint32_t i;
+      AnimatedImage image;
+      const char* const file = argv[c];
+      memset(&image, 0, sizeof(image));
+      printf("Decoding file: %s as %s/%sxxxx.%s\n",
+             file, dump_folder, prefix, suffix);
+      if (!ReadAnimatedImage(file, &image, 0, NULL)) {
+        fprintf(stderr, "Error decoding file: %s\n Aborting.\n", file);
+        error = 1;
+        break;
+      }
+      for (i = 0; !error && i < image.num_frames; ++i) {
+        char out_file[1024];
+        WebPDecBuffer buffer;
+        WebPInitDecBuffer(&buffer);
+        buffer.colorspace = MODE_RGBA;
+        buffer.is_external_memory = 1;
+        buffer.width = image.canvas_width;
+        buffer.height = image.canvas_height;
+        buffer.u.RGBA.rgba = image.frames[i].rgba;
+        buffer.u.RGBA.stride = buffer.width * sizeof(uint32_t);
+        buffer.u.RGBA.size = buffer.u.RGBA.stride * buffer.height;
+        snprintf(out_file, sizeof(out_file), "%s/%s%.4d.%s",
+                 dump_folder, prefix, i, suffix);
+        if (!WebPSaveImage(&buffer, format, out_file)) {
+          fprintf(stderr, "Error while saving image '%s'\n", out_file);
+          error = 1;
+        }
+        WebPFreeDecBuffer(&buffer);
+      }
+      ClearAnimatedImage(&image);
+    }
+  }
+  return error ? 1 : 0;
+}