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/geometry/size.h"
  15
  16 typedef unsigned int GLenum;
  17
  18 namespace media {
  19
  20 // Video decoder interface.
  21 // This interface is extended by the various components that ultimately
  22 // implement the backend of PPB_VideoDecode_Dev.
  23 class MEDIA_EXPORT VideoDecodeAccelerator {
  24  public:
  25   // Enumeration of potential errors generated by the API.
  26   // Note: Keep these in sync with PP_VideoDecodeError_Dev. Also do not
  27   // rearrange, reuse or remove values as they are used for gathering UMA
  28   // statistics.
  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     // Largest used enum. This should be adjusted when new errors are added.
  41     LARGEST_ERROR_ENUM,
  42   };
  43
  44   // Interface for collaborating with picture interface to provide memory for
  45   // output picture and blitting them. These callbacks will not be made unless
  46   // Initialize() has returned successfully.
  47   // This interface is extended by the various layers that relay messages back
  48   // to the plugin, through the PPP_VideoDecode_Dev interface the plugin
  49   // implements.
  50   class MEDIA_EXPORT Client {
  51    public:
  52     // Callback to tell client how many and what size of buffers to provide.
  53     virtual void ProvidePictureBuffers(uint32 requested_num_of_buffers,
  54                                        const gfx::Size& dimensions,
  55                                        uint32 texture_target) = 0;
  56
  57     // Callback to dismiss picture buffer that was assigned earlier.
  58     virtual void DismissPictureBuffer(int32 picture_buffer_id) = 0;
  59
  60     // Callback to deliver decoded pictures ready to be displayed.
  61     virtual void PictureReady(const Picture& picture) = 0;
  62
  63     // Callback to notify that decoded has decoded the end of the current
  64     // bitstream buffer.
  65     virtual void NotifyEndOfBitstreamBuffer(int32 bitstream_buffer_id) = 0;
  66
  67     // Flush completion callback.
  68     virtual void NotifyFlushDone() = 0;
  69
  70     // Reset completion callback.
  71     virtual void NotifyResetDone() = 0;
  72
  73     // Callback to notify about decoding errors. Note that errors in
  74     // Initialize() will not be reported here, but will instead be indicated by
  75     // a false return value there.
  76     virtual void NotifyError(Error error) = 0;
  77
  78    protected:
  79     virtual ~Client() {}
  80   };
  81
  82   // Video decoder functions.
  83
  84   // Initializes the video decoder with specific configuration.  Called once per
  85   // decoder construction.  This call is synchronous and returns true iff
  86   // initialization is successful.
  87   // Parameters:
  88   //  |profile| is the video stream's format profile.
  89   //  |client| is the client of this video decoder.  The provided pointer must
  90   //  be valid until Destroy() is called.
  91   virtual bool Initialize(VideoCodecProfile profile, Client* client) = 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   // GPU PROCESS ONLY.  Implementations of this interface in the
 138   // content/common/gpu/media should implement this, and implementations in
 139   // other processes should not override the default implementation.
 140   // Returns true if VDA::Decode and VDA::Client callbacks can run on the IO
 141   // thread. Otherwise they will run on the GPU child thread. The purpose of
 142   // running Decode on the IO thread is to reduce decode latency. Note Decode
 143   // should return as soon as possible and not block on the IO thread. Also,
 144   // PictureReady should be run on the child thread if a picture is delivered
 145   // the first time so it can be cleared.
 146   virtual bool CanDecodeOnIOThread();
 147
 148   // Windows creates a BGRA texture.
 149   // TODO(dshwang): after moving to D3D11, remove this. crbug.com/438691
 150   virtual GLenum GetSurfaceInternalFormat() const;
 151
 152  protected:
 153   // Do not delete directly; use Destroy() or own it with a scoped_ptr, which
 154   // will Destroy() it properly by default.
 155   virtual ~VideoDecodeAccelerator();
 156 };
 157
 158 }  // namespace media
 159
 160 namespace base {
 161
 162 template <class T>
 163 struct DefaultDeleter;
 164
 165 // Specialize DefaultDeleter so that scoped_ptr<VideoDecodeAccelerator> always
 166 // uses "Destroy()" instead of trying to use the destructor.
 167 template <>
 168 struct MEDIA_EXPORT DefaultDeleter<media::VideoDecodeAccelerator> {
 169  public:
 170   void operator()(void* video_decode_accelerator) const;
 171 };
 172
 173 }  // namespace base
 174
 175 #endif  // MEDIA_VIDEO_VIDEO_DECODE_ACCELERATOR_H_