AndroidVDA by using Android's MediaCodec API.

content/common/gpu/media/android_video_decode_accelerator.h

+// Copyright (c) 2013 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 CONTENT_COMMON_GPU_MEDIA_ANDROID_VIDEO_DECODE_ACCELERATOR_H_
+#define CONTENT_COMMON_GPU_MEDIA_ANDROID_VIDEO_DECODE_ACCELERATOR_H_
+
+#include <dlfcn.h>
+#include <list>
+#include <map>
+#include <queue>
+#include <string>
+#include <vector>
+
+#include "base/compiler_specific.h"
+#include "base/threading/thread_checker.h"
+#include "content/common/content_export.h"
+#include "media/base/android/media_codec_bridge.h"
+#include "media/video/video_decode_accelerator.h"
+
+namespace content {
+
+class SurfaceTextureBridge;
+class Gles2ExternalTextureCopier;
+
+// A VideoDecodeAccelerator implementation for Android.
+// This class decodes the input encoded stream by using Android's MediaCodec
+// class. http://developer.android.com/reference/android/media/MediaCodec.html
+class CONTENT_EXPORT AndroidVideoDecodeAccelerator :
+    public media::VideoDecodeAccelerator {
+ public:
+  // Does not take ownership of |client| which must outlive |*this|.
+  AndroidVideoDecodeAccelerator(
+      media::VideoDecodeAccelerator::Client* client,
+      const base::Callback<bool(void)>& make_context_current);
+
+  // media::VideoDecodeAccelerator implementation.
+  bool Initialize(media::VideoCodecProfile profile) OVERRIDE;
+  void Decode(const media::BitstreamBuffer& bitstream_buffer) OVERRIDE;
+  virtual void AssignPictureBuffers(
+      const std::vector<media::PictureBuffer>& buffers) OVERRIDE;
+  void ReusePictureBuffer(int32 picture_buffer_id) OVERRIDE;
+  void Flush() OVERRIDE;
+  void Reset() OVERRIDE;
+  void Destroy() OVERRIDE;
+
+ private:
+  enum State {
+    NO_ERROR,
+    ERROR,
+  };
+
+  static const base::TimeDelta kDecodePollDelay;
+
+  virtual ~AndroidVideoDecodeAccelerator();
+
+  // Configures |media_codec_| with the given codec parameters from the client.
+  void ConfigureMediaCodec();
+
+  // Sends the current picture on the surface to the client.
+  void SendCurrentSurfaceToClient(int32 bitstream_id);
+
+  // Does pending IO tasks if any. Once this is called, it polls |media_codec_|
+  // until it finishes pending tasks. For the polling, |kDecodePollDelay| is
+  // used.
+  void DoIOTask();
+
+  // Feeds input data to |media_codec_|. This checks
+  // |pending_bitstream_buffers_| and queues a buffer to |media_codec_|.
+  void QueueInput();
+
+  // Dequeues output from |media_codec_| and feeds the decoded frame to the
+  // client.
+  void DequeueOutput();
+
+  // Notifies the client that initialize was completed.
+  void NotifyInitializeDone();
+
+  // Requests picture buffers from the client.
+  void RequestPictureBuffers();
+
+  // Notifies the client about the availability of a picture.
+  void NotifyPictureReady(const media::Picture& picture);
+
+  // Notifies the client that the input buffer identifed by input_buffer_id has
+  // been processed.
+  void NotifyEndOfBitstreamBuffer(int input_buffer_id);
+
+  // Notifies the client that the decoder was flushed.
+  void NotifyFlushDone();
+
+  // Notifies the client that the decoder was reset.
+  void NotifyResetDone();
+
+  // Notifies about decoding errors.
+  void NotifyError(media::VideoDecodeAccelerator::Error error);
+
+  // Used to DCHECK that we are called on the correct thread.
+  base::ThreadChecker thread_checker_;
+
+  // To expose client callbacks from VideoDecodeAccelerator.
+  Client* client_;
+
+  // Callback to set the correct gl context.
+  base::Callback<bool(void)> make_context_current_;
+
+  // Codec type. Used when we configure media codec.
+  media::MediaCodecBridge::Codec codec_;
+
+  // The current state of this class. For now, this is used only for setting
+  // error state.
+  State state_;
+
+  // This map maintains the picture buffers passed to the client for decoding.
+  // The key is the picture buffer id.
+  typedef std::map<int32, media::PictureBuffer> OutputBufferMap;
+  OutputBufferMap output_picture_buffers_;
+
+  // This keeps the free picture buffer ids which can be used for sending
+  // decoded frames to the client.
+  std::queue<int32> free_picture_ids_;
+
+  // The low-level decoder which Android SDK provides.
+  scoped_ptr<media::MediaCodecBridge> media_codec_;
+
+  // A container of texture. Used to set a texture to |media_codec_|.
+  scoped_refptr<SurfaceTextureBridge> surface_texture_;
+
+  // The texture id which is set to |surface_texture_|.
+  uint32 surface_texture_id_;
+
+  // Set to true after requesting picture buffers to the client.
+  bool picturebuffers_requested_;
+
+  // Set to true when DoIOTask is in the message loop.
+  bool io_task_is_posted_;
+
+  // Set to true when decoder outputs EOS (end of stream).
+  bool decoder_met_eos_;
+
+  // The resolution of the stream.
+  gfx::Size size_;
+
+  // Encoded bitstream buffers to be passed to media codec, queued until a input
+  // buffer is available.
+  typedef std::queue<media::BitstreamBuffer> BitstreamBufferList;
+  BitstreamBufferList pending_bitstream_buffers_;
+
+  // Indicates the number of bytes already passed to the decoder in the first
+  // buffer in |pending_bitstream_buffers_|.
+  size_t num_bytes_used_in_the_pending_buffer_;
+
+  // Keeps track of bitstream ids notified to the client with
+  // NotifyEndOfBitstreamBuffer() before getting output from the bitstream.
+  std::list<int32> bitstreams_notified_in_advance_;
+
+  // A helper which copies the given external texture
+  // (GL_TEXTURE_EXTERNAL_OES) to the target texture (GL_TEXTURE_2D).
+  scoped_ptr<Gles2ExternalTextureCopier> texture_copier_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_ANDROID_VIDEO_DECODE_ACCELERATOR_H_