Audio/video data streaming over shared memory.

chromecast/media/cma/ipc_streamer/av_streamer_proxy.h

+// Copyright 2014 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 CHROMECAST_MEDIA_CMA_IPC_STREAMER_AV_STREAMER_PROXY_H_
+#define CHROMECAST_MEDIA_CMA_IPC_STREAMER_AV_STREAMER_PROXY_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "media/base/audio_decoder_config.h"
+#include "media/base/video_decoder_config.h"
+
+namespace chromecast {
+namespace media {
+class CodedFrameProvider;
+class DecoderBufferBase;
+class MediaMessageFifo;
+
+// AvStreamerProxy streams audio/video data from a coded frame provider
+// to a media message fifo.
+class AvStreamerProxy {
+ public:
+  AvStreamerProxy();
+  ~AvStreamerProxy();
+
+  // AvStreamerProxy gets frames and audio/video config
+  // from the |frame_provider| and feed them into the |fifo|.
+  void SetCodedFrameProvider(scoped_ptr<CodedFrameProvider> frame_provider);
+  void SetMediaMessageFifo(scoped_ptr<MediaMessageFifo> fifo);
+
+  // Starts fetching A/V buffers.
+  void Start();
+
+  // Stops fetching A/V buffers and flush the pending buffers,
+  // invoking |flush_cb| when done.
+  void StopAndFlush(const base::Closure& flush_cb);
+
+  // Event invoked when some data have been read from the fifo.
+  // This means some data can now possibly be written into the fifo.
+  void OnFifoReadEvent();
+
+ private:
+  void RequestBufferIfNeeded();
+
+  void OnNewBuffer(const scoped_refptr<DecoderBufferBase>& buffer,
+                   const ::media::AudioDecoderConfig& audio_config,
+                   const ::media::VideoDecoderConfig& video_config);
+
+  void ProcessPendingData();
+
+  bool SendAudioDecoderConfig(const ::media::AudioDecoderConfig& config);
+  bool SendVideoDecoderConfig(const ::media::VideoDecoderConfig& config);
+  bool SendBuffer(const scoped_refptr<DecoderBufferBase>& buffer);
+
+  base::ThreadChecker thread_checker_;
+
+  scoped_ptr<CodedFrameProvider> frame_provider_;
+
+  // Fifo used to convey A/V configs and buffers.
+  scoped_ptr<MediaMessageFifo> fifo_;
+
+  // State.
+  bool is_running_;
+
+  // Indicates if there is a pending request to the coded frame provider.
+  bool pending_read_;
+
+  // Pending config & buffer.
+  // |pending_av_data_| is set as long as one of the pending audio/video
+  // config or buffer is valid.
+  bool pending_av_data_;
+  ::media::AudioDecoderConfig pending_audio_config_;
+  ::media::VideoDecoderConfig pending_video_config_;
+  scoped_refptr<DecoderBufferBase> pending_buffer_;
+
+  base::WeakPtrFactory<AvStreamerProxy> weak_factory_;
+  base::WeakPtr<AvStreamerProxy> weak_this_;
+
+  DISALLOW_COPY_AND_ASSIGN(AvStreamerProxy);
+};
+
+}  // namespace media
+}  // namespace chromecast
+
+#endif  // CHROMECAST_MEDIA_CMA_IPC_STREAMER_AV_STREAMER_PROXY_H_