Begin refactor of AVDA to support zero-copy.

content/common/gpu/media/android_video_decode_accelerator.h

Index: content/common/gpu/media/android_video_decode_accelerator.h
diff --git a/content/common/gpu/media/android_video_decode_accelerator.h b/content/common/gpu/media/android_video_decode_accelerator.h
index d5bacfd9af136c4e25111191d92d783629ab355c..e42df36357d0c6fa58c58d5079313afa8c0fecbe 100644
--- a/content/common/gpu/media/android_video_decode_accelerator.h
+++ b/content/common/gpu/media/android_video_decode_accelerator.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Copyright (c) 2015 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.
 
@@ -15,7 +15,6 @@
 #include "base/threading/thread_checker.h"
 #include "base/timer/timer.h"
 #include "content/common/content_export.h"
-#include "gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 #include "media/base/android/media_codec_bridge.h"
 #include "media/video/video_decode_accelerator.h"
@@ -25,146 +24,67 @@ class SurfaceTexture;
 }
 
 namespace content {
-// A VideoDecodeAccelerator implementation for Android.
+// A base class for VideoDecodeAccelerator implementations for Android.
 // This class decodes the input encoded stream by using Android's MediaCodec
 // class. http://developer.android.com/reference/android/media/MediaCodec.html
+// It delegates attaching pictures to PictureBuffers to the client, but
+// otherwise handles the work of transferring data to / from MediaCodec.
 class CONTENT_EXPORT AndroidVideoDecodeAccelerator
     : public media::VideoDecodeAccelerator {
  public:
-  // Does not take ownership of |client| which must outlive |*this|.
-  AndroidVideoDecodeAccelerator(
-      const base::WeakPtr<gpu::gles2::GLES2Decoder> decoder,
-      const base::Callback<bool(void)>& make_context_current);
-
-  // media::VideoDecodeAccelerator implementation.
-  bool Initialize(media::VideoCodecProfile profile, Client* client) override;
-  void Decode(const media::BitstreamBuffer& bitstream_buffer) override;
-  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;
-  bool CanDecodeOnIOThread() override;
 
-  static media::VideoDecodeAccelerator::SupportedProfiles
-      GetSupportedProfiles();
+  // Helper class that provides the BackingStrategy with enough state
+  // to do useful work.
+  class StateProvider {
+   public:
+       virtual ~StateProvider() {}
+       virtual const gfx::Size& GetSize() const = 0;
+       virtual const base::ThreadChecker& ThreadChecker() const = 0;
+       virtual gfx::SurfaceTexture* GetSurfaceTexture() const = 0;
+       virtual uint32 GetSurfaceTextureId() const = 0;
+       virtual gpu::gles2::GLES2Decoder* GetGlDecoder() const = 0;
+       virtual media::VideoCodecBridge* GetMediaCodec() = 0;
+
+       // Helper function to report an error condition and stop decodnig.
+       // This will post NotifyError(), and transition to the error state.
+       // It is meant to be called from the RETURN_ON_FAILURE macro.
+       virtual void PostError(const ::tracked_objects::Location& from_here,
+               media::VideoDecodeAccelerator::Error error) = 0;
 
- private:
-  enum State {
-    NO_ERROR,
-    ERROR,
   };
 
-  static const base::TimeDelta kDecodePollDelay;
-
-  ~AndroidVideoDecodeAccelerator() override;
-
-  // Configures |media_codec_| with the given codec parameters from the client.
-  bool 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();
-
-  // 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_;
+  // A BackingStrategy is responsible for making a PictureBuffer's texture
+  // contain the image that a MediaCodec decoder buffer tells it to.
+  class BackingStrategy : public base::RefCounted<BackingStrategy> {
+   public:
+      virtual ~BackingStrategy(){}
 
-  // To expose client callbacks from VideoDecodeAccelerator.
-  Client* client_;
+      // Notify about the state provider.
+      virtual void SetStateProvider(StateProvider*) = 0;
 
-  // Callback to set the correct gl context.
-  base::Callback<bool(void)> make_context_current_;
+      // Called before the AVDA does any Destroy() work.  This will be
+      // the last call that the BackingStrategy receives.
+      virtual void Cleanup() = 0;
 
-  // Codec type. Used when we configure media codec.
-  media::VideoCodec codec_;
+      // Return the number of picture buffers that we can support.
+      virtual uint32 GetNumPictureBuffers() const = 0;
 
-  // The current state of this class. For now, this is used only for setting
-  // error state.
-  State state_;
+      // Return the GL texture target that the PictureBuffer textures use.
+      virtual uint32 GetTextureTarget() const = 0;
 
-  // 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_;
-
-  // Picture buffer ids which have been dismissed and not yet re-assigned.  Used
-  // to ignore ReusePictureBuffer calls that were in flight when the
-  // DismissPictureBuffer call was made.
-  std::set<int32> dismissed_picture_ids_;
-
-  // The low-level decoder which Android SDK provides.
-  scoped_ptr<media::VideoCodecBridge> media_codec_;
-
-  // A container of texture. Used to set a texture to |media_codec_|.
-  scoped_refptr<gfx::SurfaceTexture> 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_;
-
-  // The resolution of the stream.
-  gfx::Size size_;
-
-  // Encoded bitstream buffers to be passed to media codec, queued until an
-  // input buffer is available, along with the time when they were first
-  // enqueued.
-  typedef std::queue<std::pair<media::BitstreamBuffer, base::Time> >
-      PendingBitstreamBuffers;
-  PendingBitstreamBuffers pending_bitstream_buffers_;
-
-  // Keeps track of bitstream ids notified to the client with
-  // NotifyEndOfBitstreamBuffer() before getting output from the bitstream.
-  std::list<int32> bitstreams_notified_in_advance_;
-
-  // Owner of the GL context. Used to restore the context state.
-  base::WeakPtr<gpu::gles2::GLES2Decoder> gl_decoder_;
-
-  // Used for copy the texture from |surface_texture_| to picture buffers.
-  scoped_ptr<gpu::CopyTextureCHROMIUMResourceManager> copier_;
+      // Use the provided PictureBuffer to hold the current surface.
+      virtual void AssignCurrentSurfaceToPictureBuffer(int32 codec_buffer_index,
+              const media::PictureBuffer&) = 0;
+  };
 
-  // Repeating timer responsible for draining pending IO to the codec.
-  base::RepeatingTimer<AndroidVideoDecodeAccelerator> io_timer_;
+  // Create an AVDA using the given backing strategy.
+  static AndroidVideoDecodeAccelerator* Create(
+      const base::WeakPtr<gpu::gles2::GLES2Decoder> decoder,
+      const base::Callback<bool(void)>& make_context_current,
+      scoped_refptr<BackingStrategy> strategy);
 
-  // WeakPtrFactory for posting tasks back to |this|.
-  base::WeakPtrFactory<AndroidVideoDecodeAccelerator> weak_this_factory_;
+  static media::VideoDecodeAccelerator::SupportedProfiles
+      GetSupportedProfiles();
 
   friend class AndroidVideoDecodeAcceleratorTest;
 };