Use PPS/SPS NALUs to initialize a VTDecompressionSession.

content/common/gpu/media/vt_video_decode_accelerator.h

Index: content/common/gpu/media/vt_video_decode_accelerator.h
diff --git a/content/common/gpu/media/vt_video_decode_accelerator.h b/content/common/gpu/media/vt_video_decode_accelerator.h
index 5b5d8be070c194b13095ba5a39a135103cc6a70d..8c6cb24e95b7fe7730eb8fdf401d88b177d254cb 100644
--- a/content/common/gpu/media/vt_video_decode_accelerator.h
+++ b/content/common/gpu/media/vt_video_decode_accelerator.h
@@ -5,19 +5,24 @@
 #ifndef CONTENT_COMMON_GPU_MEDIA_VT_VIDEO_DECODE_ACCELERATOR_H_
 #define CONTENT_COMMON_GPU_MEDIA_VT_VIDEO_DECODE_ACCELERATOR_H_
 
-#include <stdint.h>
-
+#include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
-#include "base/message_loop/message_loop_proxy.h"
+#include "base/threading/thread.h"
+#include "content/common/gpu/media/vt.h"
+#include "media/filters/h264_parser.h"
 #include "media/video/video_decode_accelerator.h"
 #include "ui/gl/gl_context_cgl.h"
 
+namespace base {
+  class SingleThreadTaskRunner;

[scherkus (not reviewing), 2014/07/09 18:32:49]

de-indent (we don't indent inside namespaces)

[sandersd (OOO until July 31), 2014/07/09 20:07:12]

Done.

+}  // namespace base
+
 namespace content {
 
-// (Stub of a) VideoToolbox.framework implementation of the
-// VideoDecodeAccelerator interface for Mac OS X.
+// VideoToolbox.framework implementation of the VideoDecodeAccelerator
+// interface for Mac OS X (currently limited to 10.9+).
 class VTVideoDecodeAccelerator
     : public media::VideoDecodeAccelerator,
       public base::NonThreadSafe {
@@ -38,15 +43,40 @@ class VTVideoDecodeAccelerator
   virtual void Destroy() OVERRIDE;
   virtual bool CanDecodeOnIOThread() OVERRIDE;
 
+  // Called by VideoToolbox when a frame is decoded.
+  void Output(
+      int32_t bitstream_id,
+      OSStatus status,
+      VTDecodeInfoFlags info_flags,
+      CVImageBufferRef image_buffer);
+
  private:
-  scoped_refptr<base::MessageLoopProxy> loop_proxy_;
+  // Configure a VideoToolbox decompression session from parameter set NALUs.
+  void ConfigureDecoder(
+      const std::vector<const uint8_t*>& nalu_data_ptrs,
+      const std::vector<size_t>& nalu_data_sizes);
+
+  // Decode a frame of bitstream.
+  void DecodeTask(const media::BitstreamBuffer);
+
+  scoped_refptr<base::SingleThreadTaskRunner> gpu_task_runner_;
   CGLContextObj cgl_context_;
   media::VideoDecodeAccelerator::Client* client_;
+  base::Thread decoder_thread_;
+  scoped_refptr<base::SingleThreadTaskRunner> decoder_task_runner_;

[scherkus (not reviewing), 2014/07/09 18:32:49]

there's no need to maintain an extra task runner ref -- you can access
decoder_thread_.message_loop_proxy() inside of Decode()

[sandersd (OOO until July 31), 2014/07/09 20:07:12]

Done.

It's uglier, but doesn't cause any new wrapping.

+
+  // Decoder configuration (used only on decoder thread).
+  VTDecompressionOutputCallbackRecord callback_;
+  CMFormatDescriptionRef format_;
+  VTDecompressionSessionRef session_;
+  media::H264Parser parser_;
+  int32_t coded_width_;
+  int32_t coded_height_;
 
   // Member variables should appear before the WeakPtrFactory, to ensure
   // that any WeakPtrs to Controller are invalidated before its members
   // variable's destructors are executed, rendering them invalid.
-  base::WeakPtrFactory<VTVideoDecodeAccelerator> weak_this_factory_;
+  base::WeakPtrFactory<VTVideoDecodeAccelerator> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VTVideoDecodeAccelerator);
 };