1 files changed, 95 insertions, 0 deletions
diff --git a/tensorflow/core/lib/gif/gif_io.cc b/tensorflow/core/lib/gif/gif_io.cc
new file mode 100644
index 0000000000..91a8d6343d
--- /dev/null
+++ b/tensorflow/core/lib/gif/gif_io.cc
@@ -0,0 +1,95 @@
+/* Copyright 2015 Google Inc. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+// Functions to read images in GIF format.
+
+#include "tensorflow/core/lib/gif/gif_io.h"
+#include "tensorflow/core/platform/gif.h"
+#include "tensorflow/core/platform/logging.h"
+#include "tensorflow/core/platform/mem.h"
+#include "tensorflow/core/platform/types.h"
+
+namespace tensorflow {
+namespace gif {
+
+int input_callback(GifFileType* gif_file, GifByteType* buf, int size) {
+  if (gif_file->UserData && memcpy(buf, gif_file->UserData, size)) {
+    gif_file->UserData = ((uint8_t*)gif_file->UserData) + size;
+    return size;
+  }
+  return 0;
+}
+
+uint8* Decode(const void* srcdata, int datasize,
+              std::function<uint8*(int, int, int, int)> allocate_output) {
+  int error_code = D_GIF_SUCCEEDED;
+  GifFileType* gif_file =
+      DGifOpen(const_cast<void*>(srcdata), &input_callback, &error_code);
+  if (error_code != D_GIF_SUCCEEDED) {
+    LOG(ERROR) << "Fail to open gif file, reason: "
+               << GifErrorString(error_code);
+    return nullptr;
+  }
+  if (DGifSlurp(gif_file) != GIF_OK) {
+    LOG(ERROR) << "Fail to slurp gif file, reason: "
+               << GifErrorString(gif_file->Error);
+    return nullptr;
+  }
+  if (gif_file->ImageCount <= 0) {
+    LOG(ERROR) << "Gif file does not contain any image";
+    return nullptr;
+  }
+
+  int num_frames = gif_file->ImageCount;
+  int width = gif_file->SWidth;
+  int height = gif_file->SHeight;
+  int channel = 3;
+
+  uint8* dstdata = allocate_output(num_frames, width, height, channel);
+  for (int k = 0; k < num_frames; k++) {
+    SavedImage* this_image = &gif_file->SavedImages[k];
+    GifImageDesc* img_desc = &this_image->ImageDesc;
+    if (img_desc->Left != 0 || img_desc->Top != 0 || img_desc->Width != width ||
+        img_desc->Height != height) {
+      LOG(ERROR) << "Can't process optimized gif.";
+      return nullptr;
+    }
+
+    ColorMapObject* color_map = this_image->ImageDesc.ColorMap
+                                    ? this_image->ImageDesc.ColorMap
+                                    : gif_file->SColorMap;
+
+    uint8* this_dst = dstdata + k * width * channel * height;
+    for (int i = 0; i < height; ++i) {
+      uint8* p_dst = this_dst + i * width * channel;
+      for (int j = 0; j < width; ++j) {
+        GifByteType color_index = this_image->RasterBits[i * width + j];
+        const GifColorType& gif_color = color_map->Colors[color_index];
+        p_dst[j * channel + 0] = gif_color.Red;
+        p_dst[j * channel + 1] = gif_color.Green;
+        p_dst[j * channel + 2] = gif_color.Blue;
+      }
+    }
+  }
+
+  if (DGifCloseFile(gif_file, &error_code) != GIF_OK) {
+    LOG(WARNING) << "Fail to close gif file, reason: "
+                 << GifErrorString(error_code);
+  }
+  return dstdata;
+}
+
+}  // namespace gif
+}  // namespace tensorflow