content/renderer/media/rtc_video_decoder.h

   1 // Copyright 2013 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 CONTENT_RENDERER_MEDIA_RTC_VIDEO_DECODER_H_
   6 #define CONTENT_RENDERER_MEDIA_RTC_VIDEO_DECODER_H_
   7
   8 #include <deque>
   9 #include <list>
  10 #include <map>
  11 #include <set>
  12 #include <utility>
  13
  14 #include "base/basictypes.h"
  15 #include "base/gtest_prod_util.h"
  16 #include "base/memory/weak_ptr.h"
  17 #include "base/synchronization/lock.h"
  18 #include "base/threading/thread.h"
  19 #include "content/common/content_export.h"
  20 #include "media/base/bitstream_buffer.h"
  21 #include "media/base/video_decoder.h"
  22 #include "media/video/picture.h"
  23 #include "media/video/video_decode_accelerator.h"
  24 #include "third_party/webrtc/modules/video_coding/codecs/interface/video_codec_interface.h"
  25
  26 namespace base {
  27 class WaitableEvent;
  28 class MessageLoopProxy;
  29 };
  30
  31 namespace media {
  32 class DecoderBuffer;
  33 class GpuVideoAcceleratorFactories;
  34 }
  35
  36 namespace content {
  37
  38 // This class uses hardware accelerated video decoder to decode video for
  39 // WebRTC. |vda_message_loop_| is the message loop proxy of the media thread,
  40 // which VDA::Client methods run on. webrtc::VideoDecoder methods run on WebRTC
  41 // DecodingThread or Chrome_libJingle_WorkerThread, which are trampolined to
  42 // |vda_message_loop_|. Decode() is non-blocking and queues the buffers. Decoded
  43 // frames are delivered to WebRTC on |vda_message_loop_|.
  44 class CONTENT_EXPORT RTCVideoDecoder
  45     : NON_EXPORTED_BASE(public webrtc::VideoDecoder),
  46       public media::VideoDecodeAccelerator::Client {
  47  public:
  48   ~RTCVideoDecoder() override;
  49
  50   // Creates a RTCVideoDecoder. Returns NULL if failed. The video decoder will
  51   // run on the message loop of |factories|.
  52   static scoped_ptr<RTCVideoDecoder> Create(
  53       webrtc::VideoCodecType type,
  54       const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories);
  55
  56   // webrtc::VideoDecoder implementation.
  57   // Called on WebRTC DecodingThread.
  58   int32_t InitDecode(const webrtc::VideoCodec* codecSettings,
  59                      int32_t numberOfCores) override;
  60   // Called on WebRTC DecodingThread.
  61   int32_t Decode(const webrtc::EncodedImage& inputImage,
  62                  bool missingFrames,
  63                  const webrtc::RTPFragmentationHeader* fragmentation,
  64                  const webrtc::CodecSpecificInfo* codecSpecificInfo = NULL,
  65                  int64_t renderTimeMs = -1) override;
  66   // Called on WebRTC DecodingThread.
  67   int32_t RegisterDecodeCompleteCallback(
  68       webrtc::DecodedImageCallback* callback) override;
  69   // Called on Chrome_libJingle_WorkerThread. The child thread is blocked while
  70   // this runs.
  71   int32_t Release() override;
  72   // Called on Chrome_libJingle_WorkerThread. The child thread is blocked while
  73   // this runs.
  74   int32_t Reset() override;
  75
  76   // VideoDecodeAccelerator::Client implementation.
  77   void ProvidePictureBuffers(uint32 count,
  78                              const gfx::Size& size,
  79                              uint32 texture_target) override;
  80   void DismissPictureBuffer(int32 id) override;
  81   void PictureReady(const media::Picture& picture) override;
  82   void NotifyEndOfBitstreamBuffer(int32 id) override;
  83   void NotifyFlushDone() override;
  84   void NotifyResetDone() override;
  85   void NotifyError(media::VideoDecodeAccelerator::Error error) override;
  86
  87  private:
  88   class SHMBuffer;
  89   // Metadata of a bitstream buffer.
  90   struct BufferData {
  91     BufferData(int32 bitstream_buffer_id,
  92                uint32_t timestamp,
  93                size_t size);
  94     BufferData();
  95     ~BufferData();
  96     int32 bitstream_buffer_id;
  97     uint32_t timestamp;  // in 90KHz
  98     size_t size;  // buffer size
  99   };
 100
 101   FRIEND_TEST_ALL_PREFIXES(RTCVideoDecoderTest, IsBufferAfterReset);
 102   FRIEND_TEST_ALL_PREFIXES(RTCVideoDecoderTest, IsFirstBufferAfterReset);
 103
 104   RTCVideoDecoder(
 105       webrtc::VideoCodecType type,
 106       const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories);
 107
 108   // Requests a buffer to be decoded by VDA.
 109   void RequestBufferDecode();
 110
 111   bool CanMoreDecodeWorkBeDone();
 112
 113   // Returns true if bitstream buffer id |id_buffer| comes after |id_reset|.
 114   // This handles the wraparound.
 115   bool IsBufferAfterReset(int32 id_buffer, int32 id_reset);
 116
 117   // Returns true if bitstream buffer |id_buffer| is the first buffer after
 118   // |id_reset|.
 119   bool IsFirstBufferAfterReset(int32 id_buffer, int32 id_reset);
 120
 121   // Saves a WebRTC buffer in |decode_buffers_| for decode.
 122   void SaveToDecodeBuffers_Locked(const webrtc::EncodedImage& input_image,
 123                                   scoped_ptr<SHMBuffer> shm_buffer,
 124                                   const BufferData& buffer_data);
 125
 126   // Saves a WebRTC buffer in |pending_buffers_| waiting for SHM available.
 127   // Returns true on success.
 128   bool SaveToPendingBuffers_Locked(const webrtc::EncodedImage& input_image,
 129                                    const BufferData& buffer_data);
 130
 131   // Gets SHM and moves pending buffers to decode buffers.
 132   void MovePendingBuffersToDecodeBuffers();
 133
 134   scoped_refptr<media::VideoFrame> CreateVideoFrame(
 135       const media::Picture& picture,
 136       const media::PictureBuffer& pb,
 137       uint32_t timestamp);
 138
 139   // Resets VDA.
 140   void ResetInternal();
 141
 142   // Static method is to allow it to run even after RVD is deleted.
 143   static void ReleaseMailbox(
 144       base::WeakPtr<RTCVideoDecoder> decoder,
 145       const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories,
 146       int64 picture_buffer_id,
 147       uint32 texture_id,
 148       uint32 release_sync_point);
 149   // Tells VDA that a picture buffer can be recycled.
 150   void ReusePictureBuffer(int64 picture_buffer_id);
 151
 152   // Create |vda_| on |vda_loop_proxy_|.
 153   void CreateVDA(media::VideoCodecProfile profile, base::WaitableEvent* waiter);
 154
 155   void DestroyTextures();
 156   void DestroyVDA();
 157
 158   // Gets a shared-memory segment of at least |min_size| bytes from
 159   // |available_shm_segments_|. Returns NULL if there is no buffer or the
 160   // buffer is not big enough.
 161   scoped_ptr<SHMBuffer> GetSHM_Locked(size_t min_size);
 162
 163   // Returns a shared-memory segment to the available pool.
 164   void PutSHM_Locked(scoped_ptr<SHMBuffer> shm_buffer);
 165
 166   // Allocates |number| shared memory of at least |min_size| bytes.
 167   void CreateSHM(int number, size_t min_size);
 168
 169   // Stores the buffer metadata to |input_buffer_data_|.
 170   void RecordBufferData(const BufferData& buffer_data);
 171   // Gets the buffer metadata from |input_buffer_data_|.
 172   void GetBufferData(int32 bitstream_buffer_id, uint32_t* timestamp);
 173
 174   // Records the result of InitDecode to UMA and returns |status|.
 175   int32_t RecordInitDecodeUMA(int32_t status);
 176
 177   // Assert the contract that this class is operated on the right thread.
 178   void DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent() const;
 179
 180   enum State {
 181     UNINITIALIZED,  // The decoder has not initialized.
 182     INITIALIZED,    // The decoder has initialized.
 183     RESETTING,      // The decoder is being reset.
 184     DECODE_ERROR,   // Decoding error happened.
 185   };
 186
 187   static const int32 ID_LAST;     // maximum bitstream buffer id
 188   static const int32 ID_HALF;     // half of the maximum bitstream buffer id
 189   static const int32 ID_INVALID;  // indicates Reset or Release never occurred
 190
 191   // The hardware video decoder.
 192   scoped_ptr<media::VideoDecodeAccelerator> vda_;
 193
 194   // The video codec type, as reported by WebRTC.
 195   const webrtc::VideoCodecType video_codec_type_;
 196
 197   // The size of the incoming video frames.
 198   gfx::Size frame_size_;
 199
 200   scoped_refptr<media::GpuVideoAcceleratorFactories> factories_;
 201
 202   // The texture target used for decoded pictures.
 203   uint32 decoder_texture_target_;
 204
 205   // Metadata of the buffers that have been sent for decode.
 206   std::list<BufferData> input_buffer_data_;
 207
 208   // A map from bitstream buffer IDs to bitstream buffers that are being
 209   // processed by VDA. The map owns SHM buffers.
 210   std::map<int32, SHMBuffer*> bitstream_buffers_in_decoder_;
 211
 212   // A map from picture buffer IDs to texture-backed picture buffers.
 213   std::map<int32, media::PictureBuffer> assigned_picture_buffers_;
 214
 215   // PictureBuffers given to us by VDA via PictureReady, which we sent forward
 216   // as VideoFrames to be rendered via read_cb_, and which will be returned
 217   // to us via ReusePictureBuffer.
 218   typedef std::map<int32 /* picture_buffer_id */, uint32 /* texture_id */>
 219       PictureBufferTextureMap;
 220   PictureBufferTextureMap picture_buffers_at_display_;
 221
 222   // The id that will be given to the next picture buffer.
 223   int32 next_picture_buffer_id_;
 224
 225   // Protects |state_|, |decode_complete_callback_| , |num_shm_buffers_|,
 226   // |available_shm_segments_|, |pending_buffers_|, |decode_buffers_|,
 227   // |next_bitstream_buffer_id_| and |reset_bitstream_buffer_id_|.
 228   base::Lock lock_;
 229
 230   // The state of RTCVideoDecoder. Guarded by |lock_|.
 231   State state_;
 232
 233   // Guarded by |lock_|.
 234   webrtc::DecodedImageCallback* decode_complete_callback_;
 235
 236   // Total number of allocated SHM buffers. Guarded by |lock_|.
 237   int num_shm_buffers_;
 238
 239   // Shared-memory buffer pool.  Since allocating SHM segments requires a
 240   // round-trip to the browser process, we keep allocation out of the
 241   // steady-state of the decoder. The vector owns SHM buffers. Guarded by
 242   // |lock_|.
 243   std::vector<SHMBuffer*> available_shm_segments_;
 244
 245   // A queue storing WebRTC encoding images (and their metadata) that are
 246   // waiting for the shared memory. Guarded by |lock_|.
 247   std::deque<std::pair<webrtc::EncodedImage, BufferData> > pending_buffers_;
 248
 249   // A queue storing buffers (and their metadata) that will be sent to VDA for
 250   // decode. The queue owns SHM buffers. Guarded by |lock_|.
 251   std::deque<std::pair<SHMBuffer*, BufferData> > decode_buffers_;
 252
 253   // The id that will be given to the next bitstream buffer. Guarded by |lock_|.
 254   int32 next_bitstream_buffer_id_;
 255
 256   // A buffer that has an id less than this should be dropped because Reset or
 257   // Release has been called. Guarded by |lock_|.
 258   int32 reset_bitstream_buffer_id_;
 259
 260   // Must be destroyed, or invalidated, on |vda_loop_proxy_|
 261   // NOTE: Weak pointers must be invalidated before all other member variables.
 262   base::WeakPtrFactory<RTCVideoDecoder> weak_factory_;
 263
 264   DISALLOW_COPY_AND_ASSIGN(RTCVideoDecoder);
 265 };
 266
 267 }  // namespace content
 268
 269 #endif  // CONTENT_RENDERER_MEDIA_RTC_VIDEO_DECODER_H_