Motown: New wrapper classes for ffmpeg format context and io context

services/media/framework_ffmpeg/av_codec_context.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SERVICES_MEDIA_FRAMEWORK_FFMPEG_AV_CODEC_CONTEXT_H_
+#define SERVICES_MEDIA_FRAMEWORK_FFMPEG_AV_CODEC_CONTEXT_H_
+
+#include "services/media/framework/stream_type.h"
+extern "C" {
+#include "third_party/ffmpeg/libavformat/avformat.h"
+}
+
+namespace mojo {
+namespace media {
+
+struct AVCodecContextDeleter {
+  void operator()(AVCodecContext* context) const {
+    avcodec_free_context(&context);
+  }
+};
+
+using AvCodecContextPtr =
+    std::unique_ptr<AVCodecContext, AVCodecContextDeleter>;
+
+struct AvCodecContext {
+  static AvCodecContextPtr Create(const StreamType& stream_type);
+
+  static std::unique_ptr<StreamType> GetStreamType(const AVCodecContext& from);
+};
+
+}  // namespace media
+}  // namespace mojo
+
+#endif // SERVICES_MEDIA_FRAMEWORK_FFMPEG_AV_CODEC_CONTEXT_H_