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      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 "base/memory/weak_ptr.h"
     12 #include "media/base/bitstream_buffer.h"
     13 #include "media/base/video_decoder_config.h"
     14 #include "media/video/picture.h"
     15 #include "ui/gfx/size.h"
     16 
     17 namespace media {
     18 
     19 // Video decoder interface.
     20 // This interface is extended by the various components that ultimately
     21 // implement the backend of PPB_VideoDecode_Dev.
     22 class MEDIA_EXPORT VideoDecodeAccelerator
     23     : public base::SupportsWeakPtr<VideoDecodeAccelerator> {
     24  public:
     25   virtual ~VideoDecodeAccelerator();
     26 
     27   // Enumeration of potential errors generated by the API.
     28   // Note: Keep these in sync with PP_VideoDecodeError_Dev. Also do not
     29   // rearrange, reuse or remove values as they are used for gathering UMA
     30   // statistics.
     31   enum Error {
     32     // An operation was attempted during an incompatible decoder state.
     33     ILLEGAL_STATE = 1,
     34     // Invalid argument was passed to an API method.
     35     INVALID_ARGUMENT,
     36     // Encoded input is unreadable.
     37     UNREADABLE_INPUT,
     38     // A failure occurred at the browser layer or one of its dependencies.
     39     // Examples of such failures include GPU hardware failures, GPU driver
     40     // failures, GPU library failures, browser programming errors, and so on.
     41     PLATFORM_FAILURE,
     42     // Largest used enum. This should be adjusted when new errors are added.
     43     LARGEST_ERROR_ENUM,
     44   };
     45 
     46   // Interface for collaborating with picture interface to provide memory for
     47   // output picture and blitting them.
     48   // This interface is extended by the various layers that relay messages back
     49   // to the plugin, through the PPP_VideoDecode_Dev interface the plugin
     50   // implements.
     51   class MEDIA_EXPORT Client {
     52    public:
     53     // Callback to notify client that decoder has been initialized.
     54     virtual void NotifyInitializeDone() = 0;
     55 
     56     // Callback to tell client how many and what size of buffers to provide.
     57     virtual void ProvidePictureBuffers(uint32 requested_num_of_buffers,
     58                                        const gfx::Size& dimensions,
     59                                        uint32 texture_target) = 0;
     60 
     61     // Callback to dismiss picture buffer that was assigned earlier.
     62     virtual void DismissPictureBuffer(int32 picture_buffer_id) = 0;
     63 
     64     // Callback to deliver decoded pictures ready to be displayed.
     65     virtual void PictureReady(const Picture& picture) = 0;
     66 
     67     // Callback to notify that decoded has decoded the end of the current
     68     // bitstream buffer.
     69     virtual void NotifyEndOfBitstreamBuffer(int32 bitstream_buffer_id) = 0;
     70 
     71     // Flush completion callback.
     72     virtual void NotifyFlushDone() = 0;
     73 
     74     // Reset completion callback.
     75     virtual void NotifyResetDone() = 0;
     76 
     77     // Callback to notify about decoding errors.
     78     virtual void NotifyError(Error error) = 0;
     79 
     80    protected:
     81     virtual ~Client() {}
     82   };
     83 
     84   // Video decoder functions.
     85 
     86   // Initializes the video decoder with specific configuration.
     87   // Parameters:
     88   //  |profile| is the video stream's format profile.
     89   //
     90   // Returns true when command successfully accepted. Otherwise false.
     91   virtual bool Initialize(VideoCodecProfile profile) = 0;
     92 
     93   // Decodes given bitstream buffer that contains at most one frame. Once
     94   // decoder is done with processing |bitstream_buffer| it will call
     95   // NotifyEndOfBitstreamBuffer() with the bitstream buffer id.
     96   // Parameters:
     97   //  |bitstream_buffer| is the input bitstream that is sent for decoding.
     98   virtual void Decode(const BitstreamBuffer& bitstream_buffer) = 0;
     99 
    100   // Assigns a set of texture-backed picture buffers to the video decoder.
    101   //
    102   // Ownership of each picture buffer remains with the client, but the client
    103   // is not allowed to deallocate the buffer before the DismissPictureBuffer
    104   // callback has been initiated for a given buffer.
    105   //
    106   // Parameters:
    107   //  |buffers| contains the allocated picture buffers for the output.
    108   virtual void AssignPictureBuffers(
    109       const std::vector<PictureBuffer>& buffers) = 0;
    110 
    111   // Sends picture buffers to be reused by the decoder. This needs to be called
    112   // for each buffer that has been processed so that decoder may know onto which
    113   // picture buffers it can write the output to.
    114   //
    115   // Parameters:
    116   //  |picture_buffer_id| id of the picture buffer that is to be reused.
    117   virtual void ReusePictureBuffer(int32 picture_buffer_id) = 0;
    118 
    119   // Flushes the decoder: all pending inputs will be decoded and pictures handed
    120   // back to the client, followed by NotifyFlushDone() being called on the
    121   // client.  Can be used to implement "end of stream" notification.
    122   virtual void Flush() = 0;
    123 
    124   // Resets the decoder: all pending inputs are dropped immediately and the
    125   // decoder returned to a state ready for further Decode()s, followed by
    126   // NotifyResetDone() being called on the client.  Can be used to implement
    127   // "seek".
    128   virtual void Reset() = 0;
    129 
    130   // Destroys the decoder: all pending inputs are dropped immediately and the
    131   // component is freed.  This call may asynchornously free system resources,
    132   // but its client-visible effects are synchronous.  After this method returns
    133   // no more callbacks will be made on the client.  Deletes |this|
    134   // unconditionally, so make sure to drop all pointers to it!
    135   virtual void Destroy() = 0;
    136 };
    137 
    138 }  // namespace media
    139 
    140 #endif  // MEDIA_VIDEO_VIDEO_DECODE_ACCELERATOR_H_
    141