MJPEG acceleration for video capture using VAAPI

media/video/capture/video_capture_device.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.
 //
 // VideoCaptureDevice is the abstract base class for realizing video capture
 // device support in Chromium. It provides the interface for OS dependent
 // implementations.
 // The class is created and functions are invoked on a thread owned by
 // VideoCaptureManager. Capturing is done on other threads, depending on the OS
 // specific implementation.
@@ skipping 185 matching lines @@
    class MEDIA_EXPORT Client {
    public:
     // Memory buffer returned by Client::ReserveOutputBuffer().
     class MEDIA_EXPORT Buffer {
      public:
       virtual ~Buffer() = 0;
       virtual int id() const = 0;
       virtual size_t size() const = 0;
       virtual void* data() = 0;
       virtual ClientBuffer AsClientBuffer() = 0;
+      virtual base::SharedMemoryHandle AsPlatformHandle() = 0;

[mcasas, 2015/05/07 00:59:03]

Can you use base::PlatformFile instead of base::SharedMemoryHandle.

The implementation would be something like:
base::PlatformFile AsPlatformFile() override {
#if defined(OS_POSIX)
  return shared_memory_.handle().fd;
#else
  return shared_memory_.handle();
#endif
}

The point being that, in the immediate future, not all Buffers
will be memory backed, some will be Ozone Native Buffers,
and those have no SharedMemoryHandle. See [1].

[1]
https://code.google.com/p/chromium/codesearch#chromium/src/content/browser/re...

[kcwu, 2015/05/08 14:42:43]

Done.
I'm not sure my GpuMemoryBufferBufferHandle::AsPlatformHandle() is correct or
not. Please take a look.

     };
 
     virtual ~Client() {}
 
     // Captured a new video frame, data for which is pointed to by |data|.
     //
     // The format of the frame is described by |frame_format|, and is assumed to
     // be tightly packed. This method will try to reserve an output buffer and
     // copy from |data| into the output buffer. If no output buffer is
     // available, the frame will be silently dropped.
@@ skipping 79 matching lines @@
   int GetPowerLineFrequencyForLocation() const;
 
  protected:
   static const int kPowerLine50Hz = 50;
   static const int kPowerLine60Hz = 60;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_VIDEO_CAPTURE_VIDEO_CAPTURE_DEVICE_H_