Make VEA client of command buffer; move sync. IPC to VDA/VEA::Initialize()

media/video/video_decode_accelerator.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 MEDIA_VIDEO_VIDEO_DECODE_ACCELERATOR_H_
 #define MEDIA_VIDEO_VIDEO_DECODE_ACCELERATOR_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
-#include "base/memory/weak_ptr.h"
 #include "media/base/bitstream_buffer.h"
 #include "media/base/video_decoder_config.h"
 #include "media/video/picture.h"
 #include "ui/gfx/size.h"
 
 namespace media {
 
 // Video decoder interface.
 // This interface is extended by the various components that ultimately
 // implement the backend of PPB_VideoDecode_Dev.
-class MEDIA_EXPORT VideoDecodeAccelerator
-    : public base::SupportsWeakPtr<VideoDecodeAccelerator> {
+class MEDIA_EXPORT VideoDecodeAccelerator {
  public:
   virtual ~VideoDecodeAccelerator();
 
   // Enumeration of potential errors generated by the API.
   // Note: Keep these in sync with PP_VideoDecodeError_Dev. Also do not
   // rearrange, reuse or remove values as they are used for gathering UMA
   // statistics.
   enum Error {
     // An operation was attempted during an incompatible decoder state.
     ILLEGAL_STATE = 1,
     // Invalid argument was passed to an API method.
     INVALID_ARGUMENT,
     // Encoded input is unreadable.
     UNREADABLE_INPUT,
     // A failure occurred at the browser layer or one of its dependencies.
     // Examples of such failures include GPU hardware failures, GPU driver
     // failures, GPU library failures, browser programming errors, and so on.
     PLATFORM_FAILURE,
     // Largest used enum. This should be adjusted when new errors are added.
     LARGEST_ERROR_ENUM,
   };
 
   // Interface for collaborating with picture interface to provide memory for
-  // output picture and blitting them.
+  // output picture and blitting them. These callbacks will not be made unless
+  // Initialize() has returned successfully.
   // This interface is extended by the various layers that relay messages back
   // to the plugin, through the PPP_VideoDecode_Dev interface the plugin
   // implements.
   class MEDIA_EXPORT Client {
    public:
-    // Callback to notify client that decoder has been initialized.
-    virtual void NotifyInitializeDone() = 0;
-
     // Callback to tell client how many and what size of buffers to provide.
     virtual void ProvidePictureBuffers(uint32 requested_num_of_buffers,
                                        const gfx::Size& dimensions,
                                        uint32 texture_target) = 0;
 
     // Callback to dismiss picture buffer that was assigned earlier.
     virtual void DismissPictureBuffer(int32 picture_buffer_id) = 0;
 
     // Callback to deliver decoded pictures ready to be displayed.
     virtual void PictureReady(const Picture& picture) = 0;
 
     // Callback to notify that decoded has decoded the end of the current
     // bitstream buffer.
     virtual void NotifyEndOfBitstreamBuffer(int32 bitstream_buffer_id) = 0;
 
     // Flush completion callback.
     virtual void NotifyFlushDone() = 0;
 
     // Reset completion callback.
     virtual void NotifyResetDone() = 0;
 
-    // Callback to notify about decoding errors.
+    // Callback to notify about decoding errors. Note that errors in
+    // Initialize() will not be reported here, but will instead be indicated by
+    // a false return value there.
     virtual void NotifyError(Error error) = 0;
 
    protected:
     virtual ~Client() {}
   };
 
   // Video decoder functions.
 
-  // Initializes the video decoder with specific configuration.
+  // Initializes the video decoder with specific configuration.  Called once per
+  // decoder construction.  This call is synchronous and returns true iff
+  // initialization is successful.
   // Parameters:
   //  |profile| is the video stream's format profile.
   //  |client| is the client of this video decoder.  The provided pointer must
   //  be valid until Destroy() is called.
-  //
-  // Returns true when command successfully accepted. Otherwise false.
   virtual bool Initialize(VideoCodecProfile profile, Client* client) = 0;
 
-  // Decodes given bitstream buffer that contains at most one frame. Once
+  // Decodes given bitstream buffer that contains at most one frame.  Once
   // decoder is done with processing |bitstream_buffer| it will call
   // NotifyEndOfBitstreamBuffer() with the bitstream buffer id.
   // Parameters:
   //  |bitstream_buffer| is the input bitstream that is sent for decoding.
   virtual void Decode(const BitstreamBuffer& bitstream_buffer) = 0;
 
   // Assigns a set of texture-backed picture buffers to the video decoder.
   //
   // Ownership of each picture buffer remains with the client, but the client
   // is not allowed to deallocate the buffer before the DismissPictureBuffer
@@ skipping 27 matching lines @@
   // component is freed.  This call may asynchornously 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;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_VIDEO_VIDEO_DECODE_ACCELERATOR_H_