MJPEG acceleration for video capture using VAAPI, the GPU and IPC part

media/video/jpeg_decode_accelerator.h

Index: media/video/jpeg_decode_accelerator.h
diff --git a/media/video/jpeg_decode_accelerator.h b/media/video/jpeg_decode_accelerator.h
index 83c59403134c3b32da3eab711d30415abd70449f..b56756f4e0b0973323ebbae2c66104bad72c47cd 100644
--- a/media/video/jpeg_decode_accelerator.h
+++ b/media/video/jpeg_decode_accelerator.h
@@ -17,7 +17,7 @@ namespace media {
 // The output color format is I420. The decoder will convert the color format
 // to I420 if the color space or subsampling does not match that and if it is
 // capable of doing so. The client is responsible for allocating buffers and
-// keeps the ownership of them. All methods must be called on the same thread.
+// keeps the ownership of them.

[Pawel Osciak, 2015/05/28 09:13:18]

Don't all methods must still be called on the same thread?

[kcwu, 2015/05/28 12:10:28]

Not always. For GpuJpegDecodeAccelerator, it call Initialize on child thred and
call Decode on IO thread directly.

 // The intended use case of this interface is decoding MJPEG images coming
 // from camera capture. It can also be used for normal still JPEG image
 // decoding, but normal JPEG images may use more JPEG features that may not be
@@ -28,6 +28,8 @@ class MEDIA_EXPORT JpegDecodeAccelerator {
 
   // Enumeration of decode errors generated by NotifyError callback.
   enum Error {
+    // No error. Decode succeeded.
+    NO_ERROR,

[Pawel Osciak, 2015/05/28 09:13:18]

Can we NotifyError with NO_ERROR? NotifyError is always fatal...

[kcwu, 2015/05/28 12:10:28]

Do you have any suggestions? Is saying NotifyError won't take NO_ERROR enough?
Or should NotifyError and VideoFrameReady be merged like gpu message?

     // Invalid argument was passed to an API method, e.g. the output buffer is
     // too small, JPEG width/height are too big for JDA.
     INVALID_ARGUMENT,
@@ -71,6 +73,12 @@ class MEDIA_EXPORT JpegDecodeAccelerator {
     virtual ~Client() {}
   };
 
+  // Destroys the decoder: all pending inputs are dropped immediately. This
+  // call may asynchronously free system resources, but its client-visible
+  // effects are synchronous. After destructor returns, no more callbacks
+  // will be made on the client.
+  virtual ~JpegDecodeAccelerator() = 0;
+
   // JPEG decoder functions.
 
   // Initializes the JPEG decoder. Should be called once per decoder
@@ -78,7 +86,7 @@ class MEDIA_EXPORT JpegDecodeAccelerator {
   // is successful.
   // Parameters:
   //  |client| is the Client interface for decode callback. The provided
-  //  pointer must be valid until Destroy() is called.
+  //  pointer must be valid until destructor is called.
   virtual bool Initialize(Client* client) = 0;
 
   // Decodes the given bitstream buffer that contains one JPEG picture. It
@@ -100,35 +108,8 @@ class MEDIA_EXPORT JpegDecodeAccelerator {
   //  |bitstream_buffer|, or Destroy() returns.
   virtual void Decode(const BitstreamBuffer& bitstream_buffer,
                       const scoped_refptr<media::VideoFrame>& video_frame) = 0;
-
-  // Destroys the decoder: all pending inputs are dropped immediately. This
-  // call may asynchronously free system resources, but its client-visible
-  // effects are synchronous. After this method returns, no more callbacks
-  // will be made on the client. Deletes |this| unconditionally, so make sure
-  // to drop all pointers to it!
-  virtual void Destroy() = 0;
-
- protected:
-  // Do not delete directly; use Destroy() or own it with a scoped_ptr, which
-  // will Destroy() it properly by default.
-  virtual ~JpegDecodeAccelerator();
 };
 
 }  // namespace media
 
-namespace base {
-
-template <class T>
-struct DefaultDeleter;
-
-// Specialize DefaultDeleter so that scoped_ptr<JpegDecodeAccelerator> always
-// uses "Destroy()" instead of trying to use the destructor.
-template <>
-struct MEDIA_EXPORT DefaultDeleter<media::JpegDecodeAccelerator> {
- public:
-  void operator()(void* jpeg_decode_accelerator) const;
-};
-
-}  // namespace base
-
 #endif  // MEDIA_VIDEO_JPEG_DECODE_ACCELERATOR_H_