Implement media::VideoDecodeAccelerator on Mac

content/common/gpu/media/video_decode_accelerator_mac.h

+// Copyright (c) 2012 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_VIDEO_DECODE_ACCELERATOR_MAC_H_
+#define CONTENT_COMMON_GPU_MEDIA_VIDEO_DECODE_ACCELERATOR_MAC_H_
+
+#include <CoreVideo/CoreVideo.h>
+#include <map>
+#include <list>
+
+#include "base/mac/scoped_refptr_cftype.h"
+#include "base/memory/ref_counted.h"
+#include "media/video/video_decode_accelerator.h"
+
+namespace base {
+class RefCountedBytes;
+}
+namespace gfx {
+class GLContext;
+class VideoDecodeAccelerationSupport;
+}
+
+class GpuCommandBufferStub;
+
+class VideoDecodeAcceleratorMac : public media::VideoDecodeAccelerator {

[Ami GONE FROM CHROMIUM, 2012/05/15 17:55:22]

FWIW, the other VDA's follow the convention FooVDA, not VDAFoo.

[sail, 2012/05/15 23:53:31]

Done.

+ public:
+  // Does not take ownership of |client| which must outlive |*this|.
+  VideoDecodeAcceleratorMac(media::VideoDecodeAccelerator::Client* client);
+
+  // Set the OpenGL context to use.
+  void SetGLContext(void* gl_context);
+
+  // Set extra data required to initialize the H.264 video decoder.
+  // TODO(sail): Move this into Initialize.

[Ami GONE FROM CHROMIUM, 2012/05/15 17:55:22]

Initialize() is a member of the VDA interface, and correspondingly of the IPC
message used to initialize VDA's.  width/height aren't a part of that API.  

Does the underlying video decode API you're using not support mid-stream
dimensions change?  IOW, is it possible to start out with a fake size of 0,0 and
have the decoder divine from the stream what the media's dimensions are?

[sail, 2012/05/15 23:53:31]

These are the dimensions stored in the extra_data() portion of the H.264 stream.
See:
http://code.google.com/searchframe#OAMlx_jo-ck/src/media/base/video_decoder_c...

Unfortunately the Mac decoder will fail to initialize without this data. Passing
0,0 doesn't see to work either.

My plan was to extend the IPC message with these 3 parameters and mark them as
optional.

+  bool SetConfigInfo(uint32_t frame_width,
+                     uint32_t frame_height,
+                     const std::vector<uint8_t>& avc_data);
+
+  // media::VideoDecodeAccelerator implementation.
+  virtual bool Initialize(media::VideoCodecProfile profile) OVERRIDE;
+  virtual void Decode(const media::BitstreamBuffer& bitstream_buffer) OVERRIDE;
+  virtual void AssignPictureBuffers(
+      const std::vector<media::PictureBuffer>& buffers) OVERRIDE;
+  virtual void ReusePictureBuffer(int32 picture_buffer_id) OVERRIDE;
+  virtual void Flush() OVERRIDE;
+  virtual void Reset() OVERRIDE;
+  virtual void Destroy() OVERRIDE;
+
+ private:
+  virtual ~VideoDecodeAcceleratorMac();
+
+  // Callback for a completed frame.
+  void OnFrameReady(int32 bitstream_buffer_id,
+                    scoped_refptr<base::RefCountedBytes> bytes,
+                    CVImageBufferRef image,
+                    int status);
+
+  // Sends available decoded frames to the client.
+  void SendImages();
+
+  // Calls the client's flush completed callback.
+  void NotifyFlushDone();
+
+  // Calls the client's reset completed callback.
+  void NotifyResetDone();
+
+  // To expose client callbacks from VideoDecodeAccelerator.
+  Client* client_;
+  // C++ wrapper around the Mac VDA API.
+  scoped_refptr<gfx::VideoDecodeAccelerationSupport> vda_;
+  // Picture buffers that are available for use by the decoder to draw decoded
+  // video frames on.
+  std::list<media::PictureBuffer> available_pictures_;
+
+  // Maps ids to picture buffers that are in use by the client.
+  struct PendingPictureInfo {
+    PendingPictureInfo(media::PictureBuffer pic,
+                       CVImageBufferRef image);
+    ~PendingPictureInfo();
+    media::PictureBuffer picture_buffer;
+    base::mac::scoped_refptr_cftype<CVImageBufferRef> image;
+  };
+  std::map<int32, PendingPictureInfo> pending_pictures_;
+
+  // List of decoded images waiting to be sent to the client.
+  struct DecodedImageInfo {
+    DecodedImageInfo();
+    ~DecodedImageInfo();
+    base::mac::scoped_refptr_cftype<CVImageBufferRef> image;
+    int32 bitstream_buffer_id;
+  };
+  std::list<DecodedImageInfo> decoded_images_;
+
+  // The context to use to perform OpenGL operations.
+  CGLContextObj cgl_context_;
+
+  // The number of bytes used to store the frame buffer size.
+  size_t nalu_len_field_size_;
+
+  // Width of a video frame.
+  uint32_t frame_width_;
+  // Height of a video frame.
+  uint32_t frame_height_;
+  // Flag to check if pictures have been requested from the client.
+  bool did_request_pictures_;
+};
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_VIDEO_DECODE_ACCELERATOR_MAC_H_