media/video/video_decode_accelerator.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_VIDEO_VIDEO_DECODE_ACCELERATOR_H_
   6 #define MEDIA_VIDEO_VIDEO_DECODE_ACCELERATOR_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "media/base/bitstream_buffer.h"
  12 #include "media/base/video_decoder_config.h"
  13 #include "media/video/picture.h"
  14 #include "ui/gfx/size.h"
  15
  16 namespace media {
  17
  18 // Video decoder interface.
  19 // This interface is extended by the various components that ultimately
  20 // implement the backend of PPB_VideoDecode_Dev.
  21 //
  22 // No thread-safety guarantees are implied by the use of RefCountedThreadSafe
  23 // below.
  24 class MEDIA_EXPORT VideoDecodeAccelerator
  25     : public base::RefCountedThreadSafe<VideoDecodeAccelerator> {
  26  public:
  27   // Enumeration of potential errors generated by the API.
  28   // Note: Keep these in sync with PP_VideoDecodeError_Dev.
  29   enum Error {
  30     // An operation was attempted during an incompatible decoder state.
  31     ILLEGAL_STATE = 1,
  32     // Invalid argument was passed to an API method.
  33     INVALID_ARGUMENT,
  34     // Encoded input is unreadable.
  35     UNREADABLE_INPUT,
  36     // A failure occurred at the browser layer or one of its dependencies.
  37     // Examples of such failures include GPU hardware failures, GPU driver
  38     // failures, GPU library failures, browser programming errors, and so on.
  39     PLATFORM_FAILURE,
  40   };
  41
  42   // Interface for collaborating with picture interface to provide memory for
  43   // output picture and blitting them.
  44   // This interface is extended by the various layers that relay messages back
  45   // to the plugin, through the PPP_VideoDecode_Dev interface the plugin
  46   // implements.
  47   class MEDIA_EXPORT Client {
  48    public:
  49     virtual ~Client() {}
  50
  51     // Callback to notify client that decoder has been initialized.
  52     virtual void NotifyInitializeDone() = 0;
  53
  54     // Callback to tell client how many and what size of buffers to provide.
  55     virtual void ProvidePictureBuffers(
  56         uint32 requested_num_of_buffers, const gfx::Size& dimensions) = 0;
  57
  58     // Callback to dismiss picture buffer that was assigned earlier.
  59     virtual void DismissPictureBuffer(int32 picture_buffer_id) = 0;
  60
  61     // Callback to deliver decoded pictures ready to be displayed.
  62     virtual void PictureReady(const Picture& picture) = 0;
  63
  64     // Callback to notify that decoded has decoded the end of the current
  65     // bitstream buffer.
  66     virtual void NotifyEndOfBitstreamBuffer(int32 bitstream_buffer_id) = 0;
  67
  68     // Flush completion callback.
  69     virtual void NotifyFlushDone() = 0;
  70
  71     // Reset completion callback.
  72     virtual void NotifyResetDone() = 0;
  73
  74     // Callback to notify about decoding errors.
  75     virtual void NotifyError(Error error) = 0;
  76   };
  77
  78   // Video decoder functions.
  79
  80   // Initializes the video decoder with specific configuration.
  81   // Parameters:
  82   //  |profile| is the video stream's format profile.
  83   //
  84   // Returns true when command successfully accepted. Otherwise false.
  85   virtual bool Initialize(VideoCodecProfile profile) = 0;
  86
  87   // Decodes given bitstream buffer. Once decoder is done with processing
  88   // |bitstream_buffer| it will call NotifyEndOfBitstreamBuffer() with the
  89   // bitstream buffer id.
  90   // Parameters:
  91   //  |bitstream_buffer| is the input bitstream that is sent for decoding.
  92   virtual void Decode(const BitstreamBuffer& bitstream_buffer) = 0;
  93
  94   // Assigns a set of texture-backed picture buffers to the video decoder.
  95   //
  96   // Ownership of each picture buffer remains with the client, but the client
  97   // is not allowed to deallocate the buffer before the DismissPictureBuffer
  98   // callback has been initiated for a given buffer.
  99   //
 100   // Parameters:
 101   //  |buffers| contains the allocated picture buffers for the output.
 102   virtual void AssignPictureBuffers(
 103       const std::vector<PictureBuffer>& buffers) = 0;
 104
 105   // Sends picture buffers to be reused by the decoder. This needs to be called
 106   // for each buffer that has been processed so that decoder may know onto which
 107   // picture buffers it can write the output to.
 108   //
 109   // Parameters:
 110   //  |picture_buffer_id| id of the picture buffer that is to be reused.
 111   virtual void ReusePictureBuffer(int32 picture_buffer_id) = 0;
 112
 113   // Flushes the decoder: all pending inputs will be decoded and pictures handed
 114   // back to the client, followed by NotifyFlushDone() being called on the
 115   // client.  Can be used to implement "end of stream" notification.
 116   virtual void Flush() = 0;
 117
 118   // Resets the decoder: all pending inputs are dropped immediately and the
 119   // decoder returned to a state ready for further Decode()s, followed by
 120   // NotifyResetDone() being called on the client.  Can be used to implement
 121   // "seek".
 122   virtual void Reset() = 0;
 123
 124   // Destroys the decoder: all pending inputs are dropped immediately and the
 125   // component is freed.  This call may asynchornously free system resources,
 126   // but its client-visible effects are synchronous.  After this method returns
 127   // no more callbacks will be made on the client.
 128   virtual void Destroy() = 0;
 129
 130  protected:
 131   friend class base::RefCountedThreadSafe<VideoDecodeAccelerator>;
 132   virtual ~VideoDecodeAccelerator();
 133 };
 134
 135 }  // namespace media
 136
 137 #endif  // MEDIA_VIDEO_VIDEO_DECODE_ACCELERATOR_H_