src/content/renderer/media/rtc_video_decoder.cc

   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 #include "content/renderer/media/rtc_video_decoder.h"
   6
   7 #include "base/bind.h"
   8 #include "base/logging.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/message_loop/message_loop_proxy.h"
  11 #include "base/metrics/histogram.h"
  12 #include "base/numerics/safe_conversions.h"
  13 #include "base/stl_util.h"
  14 #include "base/synchronization/waitable_event.h"
  15 #include "base/task_runner_util.h"
  16 #include "content/child/child_thread.h"
  17 #include "content/renderer/media/native_handle_impl.h"
  18 #include "gpu/command_buffer/common/mailbox_holder.h"
  19 #include "media/base/bind_to_current_loop.h"
  20 #include "media/filters/gpu_video_accelerator_factories.h"
  21 #include "third_party/skia/include/core/SkBitmap.h"
  22 #include "third_party/webrtc/common_video/interface/texture_video_frame.h"
  23 #include "third_party/webrtc/system_wrappers/interface/ref_count.h"
  24
  25 namespace content {
  26
  27 const int32 RTCVideoDecoder::ID_LAST = 0x3FFFFFFF;
  28 const int32 RTCVideoDecoder::ID_HALF = 0x20000000;
  29 const int32 RTCVideoDecoder::ID_INVALID = -1;
  30
  31 // Maximum number of concurrent VDA::Decode() operations RVD will maintain.
  32 // Higher values allow better pipelining in the GPU, but also require more
  33 // resources.
  34 static const size_t kMaxInFlightDecodes = 8;
  35
  36 // Size of shared-memory segments we allocate.  Since we reuse them we let them
  37 // be on the beefy side.
  38 static const size_t kSharedMemorySegmentBytes = 100 << 10;
  39
  40 // Maximum number of allocated shared-memory segments.
  41 static const int kMaxNumSharedMemorySegments = 16;
  42
  43 // Maximum number of pending WebRTC buffers that are waiting for the shared
  44 // memory. 10 seconds for 30 fps.
  45 static const size_t kMaxNumOfPendingBuffers = 300;
  46
  47 // A shared memory segment and its allocated size. This class has the ownership
  48 // of |shm|.
  49 class RTCVideoDecoder::SHMBuffer {
  50  public:
  51   SHMBuffer(base::SharedMemory* shm, size_t size);
  52   ~SHMBuffer();
  53   base::SharedMemory* const shm;
  54   const size_t size;
  55 };
  56
  57 RTCVideoDecoder::SHMBuffer::SHMBuffer(base::SharedMemory* shm, size_t size)
  58     : shm(shm), size(size) {}
  59
  60 RTCVideoDecoder::SHMBuffer::~SHMBuffer() { shm->Close(); }
  61
  62 RTCVideoDecoder::BufferData::BufferData(int32 bitstream_buffer_id,
  63                                         uint32_t timestamp,
  64                                         int width,
  65                                         int height,
  66                                         size_t size)
  67     : bitstream_buffer_id(bitstream_buffer_id),
  68       timestamp(timestamp),
  69       width(width),
  70       height(height),
  71       size(size) {}
  72
  73 RTCVideoDecoder::BufferData::BufferData() {}
  74
  75 RTCVideoDecoder::BufferData::~BufferData() {}
  76
  77 RTCVideoDecoder::RTCVideoDecoder(
  78     const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories)
  79     : factories_(factories),
  80       decoder_texture_target_(0),
  81       next_picture_buffer_id_(0),
  82       state_(UNINITIALIZED),
  83       decode_complete_callback_(NULL),
  84       num_shm_buffers_(0),
  85       next_bitstream_buffer_id_(0),
  86       reset_bitstream_buffer_id_(ID_INVALID),
  87       weak_factory_(this) {
  88   DCHECK(!factories_->GetTaskRunner()->BelongsToCurrentThread());
  89 }
  90
  91 RTCVideoDecoder::~RTCVideoDecoder() {
  92   DVLOG(2) << "~RTCVideoDecoder";
  93   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
  94   DestroyVDA();
  95
  96   // Delete all shared memories.
  97   STLDeleteElements(&available_shm_segments_);
  98   STLDeleteValues(&bitstream_buffers_in_decoder_);
  99   STLDeleteContainerPairFirstPointers(decode_buffers_.begin(),
 100                                       decode_buffers_.end());
 101   decode_buffers_.clear();
 102
 103   // Delete WebRTC input buffers.
 104   for (std::deque<std::pair<webrtc::EncodedImage, BufferData> >::iterator it =
 105            pending_buffers_.begin();
 106        it != pending_buffers_.end();
 107        ++it) {
 108     delete[] it->first._buffer;
 109   }
 110 }
 111
 112 // static
 113 scoped_ptr<RTCVideoDecoder> RTCVideoDecoder::Create(
 114     webrtc::VideoCodecType type,
 115     const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories) {
 116   scoped_ptr<RTCVideoDecoder> decoder;
 117   // Convert WebRTC codec type to media codec profile.
 118   media::VideoCodecProfile profile;
 119   switch (type) {
 120     case webrtc::kVideoCodecVP8:
 121       profile = media::VP8PROFILE_MAIN;
 122       break;
 123     default:
 124       DVLOG(2) << "Video codec not supported:" << type;
 125       return decoder.Pass();
 126   }
 127
 128   base::WaitableEvent waiter(true, false);
 129   decoder.reset(new RTCVideoDecoder(factories));
 130   decoder->factories_->GetTaskRunner()->PostTask(
 131       FROM_HERE,
 132       base::Bind(&RTCVideoDecoder::CreateVDA,
 133                  base::Unretained(decoder.get()),
 134                  profile,
 135                  &waiter));
 136   waiter.Wait();
 137   // vda can be NULL if VP8 is not supported.
 138   if (decoder->vda_ != NULL) {
 139     decoder->state_ = INITIALIZED;
 140   } else {
 141     factories->GetTaskRunner()->DeleteSoon(FROM_HERE, decoder.release());
 142   }
 143   return decoder.Pass();
 144 }
 145
 146 int32_t RTCVideoDecoder::InitDecode(const webrtc::VideoCodec* codecSettings,
 147                                     int32_t /*numberOfCores*/) {
 148   DVLOG(2) << "InitDecode";
 149   DCHECK_EQ(codecSettings->codecType, webrtc::kVideoCodecVP8);
 150   if (codecSettings->codecSpecific.VP8.feedbackModeOn) {
 151     LOG(ERROR) << "Feedback mode not supported";
 152     return RecordInitDecodeUMA(WEBRTC_VIDEO_CODEC_ERROR);
 153   }
 154
 155   base::AutoLock auto_lock(lock_);
 156   if (state_ == UNINITIALIZED || state_ == DECODE_ERROR) {
 157     LOG(ERROR) << "VDA is not initialized. state=" << state_;
 158     return RecordInitDecodeUMA(WEBRTC_VIDEO_CODEC_UNINITIALIZED);
 159   }
 160   // Create some shared memory if the queue is empty.
 161   if (available_shm_segments_.size() == 0) {
 162     factories_->GetTaskRunner()->PostTask(
 163         FROM_HERE,
 164         base::Bind(&RTCVideoDecoder::CreateSHM,
 165                    weak_factory_.GetWeakPtr(),
 166                    kMaxInFlightDecodes,
 167                    kSharedMemorySegmentBytes));
 168   }
 169   return RecordInitDecodeUMA(WEBRTC_VIDEO_CODEC_OK);
 170 }
 171
 172 int32_t RTCVideoDecoder::Decode(
 173     const webrtc::EncodedImage& inputImage,
 174     bool missingFrames,
 175     const webrtc::RTPFragmentationHeader* /*fragmentation*/,
 176     const webrtc::CodecSpecificInfo* /*codecSpecificInfo*/,
 177     int64_t /*renderTimeMs*/) {
 178   DVLOG(3) << "Decode";
 179
 180   base::AutoLock auto_lock(lock_);
 181
 182   if (state_ == UNINITIALIZED || decode_complete_callback_ == NULL) {
 183     LOG(ERROR) << "The decoder has not initialized.";
 184     return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
 185   }
 186
 187   if (state_ == DECODE_ERROR) {
 188     LOG(ERROR) << "Decoding error occurred.";
 189     return WEBRTC_VIDEO_CODEC_ERROR;
 190   }
 191
 192   if (missingFrames || !inputImage._completeFrame) {
 193     DLOG(ERROR) << "Missing or incomplete frames.";
 194     // Unlike the SW decoder in libvpx, hw decoder cannot handle broken frames.
 195     // Return an error to request a key frame.
 196     return WEBRTC_VIDEO_CODEC_ERROR;
 197   }
 198
 199   // Most platforms' VDA implementations support mid-stream resolution change
 200   // internally.  Platforms whose VDAs fail to support mid-stream resolution
 201   // change gracefully need to have their clients cover for them, and we do that
 202   // here.
 203 #ifdef ANDROID
 204   const bool kVDACanHandleMidstreamResize = false;
 205 #else
 206   const bool kVDACanHandleMidstreamResize = true;
 207 #endif
 208
 209   bool need_to_reset_for_midstream_resize = false;
 210   if (inputImage._frameType == webrtc::kKeyFrame) {
 211     DVLOG(2) << "Got key frame. size=" << inputImage._encodedWidth << "x"
 212              << inputImage._encodedHeight;
 213     gfx::Size prev_frame_size = frame_size_;
 214     frame_size_.SetSize(inputImage._encodedWidth, inputImage._encodedHeight);
 215     if (!kVDACanHandleMidstreamResize && !prev_frame_size.IsEmpty() &&
 216         prev_frame_size != frame_size_) {
 217       need_to_reset_for_midstream_resize = true;
 218     }
 219   } else if (IsFirstBufferAfterReset(next_bitstream_buffer_id_,
 220                                      reset_bitstream_buffer_id_)) {
 221     // TODO(wuchengli): VDA should handle it. Remove this when
 222     // http://crosbug.com/p/21913 is fixed.
 223     DVLOG(1) << "The first frame should be a key frame. Drop this.";
 224     return WEBRTC_VIDEO_CODEC_ERROR;
 225   }
 226
 227   // Create buffer metadata.
 228   BufferData buffer_data(next_bitstream_buffer_id_,
 229                          inputImage._timeStamp,
 230                          frame_size_.width(),
 231                          frame_size_.height(),
 232                          inputImage._length);
 233   // Mask against 30 bits, to avoid (undefined) wraparound on signed integer.
 234   next_bitstream_buffer_id_ = (next_bitstream_buffer_id_ + 1) & ID_LAST;
 235
 236   // If a shared memory segment is available, there are no pending buffers, and
 237   // this isn't a mid-stream resolution change, then send the buffer for decode
 238   // immediately. Otherwise, save the buffer in the queue for later decode.
 239   scoped_ptr<SHMBuffer> shm_buffer;
 240   if (!need_to_reset_for_midstream_resize && pending_buffers_.size() == 0)
 241     shm_buffer = GetSHM_Locked(inputImage._length);
 242   if (!shm_buffer) {
 243     if (!SaveToPendingBuffers_Locked(inputImage, buffer_data))
 244       return WEBRTC_VIDEO_CODEC_ERROR;
 245     if (need_to_reset_for_midstream_resize) {
 246       base::AutoUnlock auto_unlock(lock_);
 247       Reset();
 248     }
 249     return WEBRTC_VIDEO_CODEC_OK;
 250   }
 251
 252   SaveToDecodeBuffers_Locked(inputImage, shm_buffer.Pass(), buffer_data);
 253   factories_->GetTaskRunner()->PostTask(
 254       FROM_HERE,
 255       base::Bind(&RTCVideoDecoder::RequestBufferDecode,
 256                  weak_factory_.GetWeakPtr()));
 257   return WEBRTC_VIDEO_CODEC_OK;
 258 }
 259
 260 int32_t RTCVideoDecoder::RegisterDecodeCompleteCallback(
 261     webrtc::DecodedImageCallback* callback) {
 262   DVLOG(2) << "RegisterDecodeCompleteCallback";
 263   base::AutoLock auto_lock(lock_);
 264   decode_complete_callback_ = callback;
 265   return WEBRTC_VIDEO_CODEC_OK;
 266 }
 267
 268 int32_t RTCVideoDecoder::Release() {
 269   DVLOG(2) << "Release";
 270   // Do not destroy VDA because WebRTC can call InitDecode and start decoding
 271   // again.
 272   return Reset();
 273 }
 274
 275 int32_t RTCVideoDecoder::Reset() {
 276   DVLOG(2) << "Reset";
 277   base::AutoLock auto_lock(lock_);
 278   if (state_ == UNINITIALIZED) {
 279     LOG(ERROR) << "Decoder not initialized.";
 280     return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
 281   }
 282   if (next_bitstream_buffer_id_ != 0)
 283     reset_bitstream_buffer_id_ = next_bitstream_buffer_id_ - 1;
 284   else
 285     reset_bitstream_buffer_id_ = ID_LAST;
 286   // If VDA is already resetting, no need to request the reset again.
 287   if (state_ != RESETTING) {
 288     state_ = RESETTING;
 289     factories_->GetTaskRunner()->PostTask(
 290         FROM_HERE,
 291         base::Bind(&RTCVideoDecoder::ResetInternal,
 292                    weak_factory_.GetWeakPtr()));
 293   }
 294   return WEBRTC_VIDEO_CODEC_OK;
 295 }
 296
 297 void RTCVideoDecoder::ProvidePictureBuffers(uint32 count,
 298                                             const gfx::Size& size,
 299                                             uint32 texture_target) {
 300   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 301   DVLOG(3) << "ProvidePictureBuffers. texture_target=" << texture_target;
 302
 303   if (!vda_)
 304     return;
 305
 306   std::vector<uint32> texture_ids;
 307   std::vector<gpu::Mailbox> texture_mailboxes;
 308   decoder_texture_target_ = texture_target;
 309   if (!factories_->CreateTextures(count,
 310                                   size,
 311                                   &texture_ids,
 312                                   &texture_mailboxes,
 313                                   decoder_texture_target_)) {
 314     NotifyError(media::VideoDecodeAccelerator::PLATFORM_FAILURE);
 315     return;
 316   }
 317   DCHECK_EQ(count, texture_ids.size());
 318   DCHECK_EQ(count, texture_mailboxes.size());
 319
 320   std::vector<media::PictureBuffer> picture_buffers;
 321   for (size_t i = 0; i < texture_ids.size(); ++i) {
 322     picture_buffers.push_back(media::PictureBuffer(
 323         next_picture_buffer_id_++, size, texture_ids[i], texture_mailboxes[i]));
 324     bool inserted = assigned_picture_buffers_.insert(std::make_pair(
 325         picture_buffers.back().id(), picture_buffers.back())).second;
 326     DCHECK(inserted);
 327   }
 328   vda_->AssignPictureBuffers(picture_buffers);
 329 }
 330
 331 void RTCVideoDecoder::DismissPictureBuffer(int32 id) {
 332   DVLOG(3) << "DismissPictureBuffer. id=" << id;
 333   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 334
 335   std::map<int32, media::PictureBuffer>::iterator it =
 336       assigned_picture_buffers_.find(id);
 337   if (it == assigned_picture_buffers_.end()) {
 338     NOTREACHED() << "Missing picture buffer: " << id;
 339     return;
 340   }
 341
 342   media::PictureBuffer buffer_to_dismiss = it->second;
 343   assigned_picture_buffers_.erase(it);
 344
 345   if (!picture_buffers_at_display_.count(id)) {
 346     // We can delete the texture immediately as it's not being displayed.
 347     factories_->DeleteTexture(buffer_to_dismiss.texture_id());
 348     return;
 349   }
 350   // Not destroying a texture in display in |picture_buffers_at_display_|.
 351   // Postpone deletion until after it's returned to us.
 352 }
 353
 354 void RTCVideoDecoder::PictureReady(const media::Picture& picture) {
 355   DVLOG(3) << "PictureReady";
 356   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 357
 358   std::map<int32, media::PictureBuffer>::iterator it =
 359       assigned_picture_buffers_.find(picture.picture_buffer_id());
 360   if (it == assigned_picture_buffers_.end()) {
 361     NOTREACHED() << "Missing picture buffer: " << picture.picture_buffer_id();
 362     NotifyError(media::VideoDecodeAccelerator::PLATFORM_FAILURE);
 363     return;
 364   }
 365   const media::PictureBuffer& pb = it->second;
 366
 367   // Create a media::VideoFrame.
 368   uint32_t timestamp = 0, width = 0, height = 0;
 369   size_t size = 0;
 370   GetBufferData(
 371       picture.bitstream_buffer_id(), &timestamp, &width, &height, &size);
 372   scoped_refptr<media::VideoFrame> frame =
 373       CreateVideoFrame(picture, pb, timestamp, width, height, size);
 374   bool inserted =
 375       picture_buffers_at_display_.insert(std::make_pair(
 376                                              picture.picture_buffer_id(),
 377                                              pb.texture_id())).second;
 378   DCHECK(inserted);
 379
 380   // Create a WebRTC video frame.
 381   webrtc::RefCountImpl<NativeHandleImpl>* handle =
 382       new webrtc::RefCountImpl<NativeHandleImpl>(frame);
 383   webrtc::TextureVideoFrame decoded_image(handle, width, height, timestamp, 0);
 384
 385   // Invoke decode callback. WebRTC expects no callback after Reset or Release.
 386   {
 387     base::AutoLock auto_lock(lock_);
 388     DCHECK(decode_complete_callback_ != NULL);
 389     if (IsBufferAfterReset(picture.bitstream_buffer_id(),
 390                            reset_bitstream_buffer_id_)) {
 391       decode_complete_callback_->Decoded(decoded_image);
 392     }
 393   }
 394 }
 395
 396 static void ReadPixelsSyncInner(
 397     const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories,
 398     uint32 texture_id,
 399     const gfx::Rect& visible_rect,
 400     const SkBitmap& pixels,
 401     base::WaitableEvent* event) {
 402   factories->ReadPixels(texture_id, visible_rect, pixels);
 403   event->Signal();
 404 }
 405
 406 static void ReadPixelsSync(
 407     const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories,
 408     uint32 texture_id,
 409     const gfx::Rect& visible_rect,
 410     const SkBitmap& pixels) {
 411   base::WaitableEvent event(true, false);
 412   if (!factories->GetTaskRunner()->PostTask(FROM_HERE,
 413                                             base::Bind(&ReadPixelsSyncInner,
 414                                                        factories,
 415                                                        texture_id,
 416                                                        visible_rect,
 417                                                        pixels,
 418                                                        &event)))
 419     return;
 420   event.Wait();
 421 }
 422
 423 scoped_refptr<media::VideoFrame> RTCVideoDecoder::CreateVideoFrame(
 424     const media::Picture& picture,
 425     const media::PictureBuffer& pb,
 426     uint32_t timestamp,
 427     uint32_t width,
 428     uint32_t height,
 429     size_t size) {
 430   gfx::Rect visible_rect(width, height);
 431   DCHECK(decoder_texture_target_);
 432   // Convert timestamp from 90KHz to ms.
 433   base::TimeDelta timestamp_ms = base::TimeDelta::FromInternalValue(
 434       base::checked_cast<uint64_t>(timestamp) * 1000 / 90);
 435   return media::VideoFrame::WrapNativeTexture(
 436       make_scoped_ptr(new gpu::MailboxHolder(
 437           pb.texture_mailbox(), decoder_texture_target_, 0)),
 438       media::BindToCurrentLoop(base::Bind(&RTCVideoDecoder::ReleaseMailbox,
 439                                           weak_factory_.GetWeakPtr(),
 440                                           factories_,
 441                                           picture.picture_buffer_id(),
 442                                           pb.texture_id())),
 443       pb.size(),
 444       visible_rect,
 445       visible_rect.size(),
 446       timestamp_ms,
 447       base::Bind(&ReadPixelsSync, factories_, pb.texture_id(), visible_rect));
 448 }
 449
 450 void RTCVideoDecoder::NotifyEndOfBitstreamBuffer(int32 id) {
 451   DVLOG(3) << "NotifyEndOfBitstreamBuffer. id=" << id;
 452   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 453
 454   std::map<int32, SHMBuffer*>::iterator it =
 455       bitstream_buffers_in_decoder_.find(id);
 456   if (it == bitstream_buffers_in_decoder_.end()) {
 457     NotifyError(media::VideoDecodeAccelerator::PLATFORM_FAILURE);
 458     NOTREACHED() << "Missing bitstream buffer: " << id;
 459     return;
 460   }
 461
 462   {
 463     base::AutoLock auto_lock(lock_);
 464     PutSHM_Locked(scoped_ptr<SHMBuffer>(it->second));
 465   }
 466   bitstream_buffers_in_decoder_.erase(it);
 467
 468   RequestBufferDecode();
 469 }
 470
 471 void RTCVideoDecoder::NotifyFlushDone() {
 472   DVLOG(3) << "NotifyFlushDone";
 473   NOTREACHED() << "Unexpected flush done notification.";
 474 }
 475
 476 void RTCVideoDecoder::NotifyResetDone() {
 477   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 478   DVLOG(3) << "NotifyResetDone";
 479
 480   if (!vda_)
 481     return;
 482
 483   input_buffer_data_.clear();
 484   {
 485     base::AutoLock auto_lock(lock_);
 486     state_ = INITIALIZED;
 487   }
 488   // Send the pending buffers for decoding.
 489   RequestBufferDecode();
 490 }
 491
 492 void RTCVideoDecoder::NotifyError(media::VideoDecodeAccelerator::Error error) {
 493   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 494   if (!vda_)
 495     return;
 496
 497   LOG(ERROR) << "VDA Error:" << error;
 498   UMA_HISTOGRAM_ENUMERATION("Media.RTCVideoDecoderError",
 499                             error,
 500                             media::VideoDecodeAccelerator::LARGEST_ERROR_ENUM);
 501   DestroyVDA();
 502
 503   base::AutoLock auto_lock(lock_);
 504   state_ = DECODE_ERROR;
 505 }
 506
 507 void RTCVideoDecoder::RequestBufferDecode() {
 508   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 509   if (!vda_)
 510     return;
 511
 512   MovePendingBuffersToDecodeBuffers();
 513
 514   while (CanMoreDecodeWorkBeDone()) {
 515     // Get a buffer and data from the queue.
 516     SHMBuffer* shm_buffer = NULL;
 517     BufferData buffer_data;
 518     {
 519       base::AutoLock auto_lock(lock_);
 520       // Do not request decode if VDA is resetting.
 521       if (decode_buffers_.size() == 0 || state_ == RESETTING)
 522         return;
 523       shm_buffer = decode_buffers_.front().first;
 524       buffer_data = decode_buffers_.front().second;
 525       decode_buffers_.pop_front();
 526       // Drop the buffers before Reset or Release is called.
 527       if (!IsBufferAfterReset(buffer_data.bitstream_buffer_id,
 528                               reset_bitstream_buffer_id_)) {
 529         PutSHM_Locked(scoped_ptr<SHMBuffer>(shm_buffer));
 530         continue;
 531       }
 532     }
 533
 534     // Create a BitstreamBuffer and send to VDA to decode.
 535     media::BitstreamBuffer bitstream_buffer(buffer_data.bitstream_buffer_id,
 536                                             shm_buffer->shm->handle(),
 537                                             buffer_data.size);
 538     bool inserted = bitstream_buffers_in_decoder_
 539         .insert(std::make_pair(bitstream_buffer.id(), shm_buffer)).second;
 540     DCHECK(inserted);
 541     RecordBufferData(buffer_data);
 542     vda_->Decode(bitstream_buffer);
 543   }
 544 }
 545
 546 bool RTCVideoDecoder::CanMoreDecodeWorkBeDone() {
 547   return bitstream_buffers_in_decoder_.size() < kMaxInFlightDecodes;
 548 }
 549
 550 bool RTCVideoDecoder::IsBufferAfterReset(int32 id_buffer, int32 id_reset) {
 551   if (id_reset == ID_INVALID)
 552     return true;
 553   int32 diff = id_buffer - id_reset;
 554   if (diff <= 0)
 555     diff += ID_LAST + 1;
 556   return diff < ID_HALF;
 557 }
 558
 559 bool RTCVideoDecoder::IsFirstBufferAfterReset(int32 id_buffer, int32 id_reset) {
 560   if (id_reset == ID_INVALID)
 561     return id_buffer == 0;
 562   return id_buffer == ((id_reset + 1) & ID_LAST);
 563 }
 564
 565 void RTCVideoDecoder::SaveToDecodeBuffers_Locked(
 566     const webrtc::EncodedImage& input_image,
 567     scoped_ptr<SHMBuffer> shm_buffer,
 568     const BufferData& buffer_data) {
 569   memcpy(shm_buffer->shm->memory(), input_image._buffer, input_image._length);
 570   std::pair<SHMBuffer*, BufferData> buffer_pair =
 571       std::make_pair(shm_buffer.release(), buffer_data);
 572
 573   // Store the buffer and the metadata to the queue.
 574   decode_buffers_.push_back(buffer_pair);
 575 }
 576
 577 bool RTCVideoDecoder::SaveToPendingBuffers_Locked(
 578     const webrtc::EncodedImage& input_image,
 579     const BufferData& buffer_data) {
 580   DVLOG(2) << "SaveToPendingBuffers_Locked"
 581            << ". pending_buffers size=" << pending_buffers_.size()
 582            << ". decode_buffers_ size=" << decode_buffers_.size()
 583            << ". available_shm size=" << available_shm_segments_.size();
 584   // Queued too many buffers. Something goes wrong.
 585   if (pending_buffers_.size() >= kMaxNumOfPendingBuffers) {
 586     LOG(WARNING) << "Too many pending buffers!";
 587     return false;
 588   }
 589
 590   // Clone the input image and save it to the queue.
 591   uint8_t* buffer = new uint8_t[input_image._length];
 592   // TODO(wuchengli): avoid memcpy. Extend webrtc::VideoDecoder::Decode()
 593   // interface to take a non-const ptr to the frame and add a method to the
 594   // frame that will swap buffers with another.
 595   memcpy(buffer, input_image._buffer, input_image._length);
 596   webrtc::EncodedImage encoded_image(
 597       buffer, input_image._length, input_image._length);
 598   std::pair<webrtc::EncodedImage, BufferData> buffer_pair =
 599       std::make_pair(encoded_image, buffer_data);
 600
 601   pending_buffers_.push_back(buffer_pair);
 602   return true;
 603 }
 604
 605 void RTCVideoDecoder::MovePendingBuffersToDecodeBuffers() {
 606   base::AutoLock auto_lock(lock_);
 607   while (pending_buffers_.size() > 0) {
 608     // Get a pending buffer from the queue.
 609     const webrtc::EncodedImage& input_image = pending_buffers_.front().first;
 610     const BufferData& buffer_data = pending_buffers_.front().second;
 611
 612     // Drop the frame if it comes before Reset or Release.
 613     if (!IsBufferAfterReset(buffer_data.bitstream_buffer_id,
 614                             reset_bitstream_buffer_id_)) {
 615       delete[] input_image._buffer;
 616       pending_buffers_.pop_front();
 617       continue;
 618     }
 619     // Get shared memory and save it to decode buffers.
 620     scoped_ptr<SHMBuffer> shm_buffer = GetSHM_Locked(input_image._length);
 621     if (!shm_buffer)
 622       return;
 623     SaveToDecodeBuffers_Locked(input_image, shm_buffer.Pass(), buffer_data);
 624     delete[] input_image._buffer;
 625     pending_buffers_.pop_front();
 626   }
 627 }
 628
 629 void RTCVideoDecoder::ResetInternal() {
 630   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 631   DVLOG(2) << "ResetInternal";
 632   if (vda_)
 633     vda_->Reset();
 634 }
 635
 636 // static
 637 void RTCVideoDecoder::ReleaseMailbox(
 638     base::WeakPtr<RTCVideoDecoder> decoder,
 639     const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories,
 640     int64 picture_buffer_id,
 641     uint32 texture_id,
 642     const std::vector<uint32>& release_sync_points) {
 643   DCHECK(factories->GetTaskRunner()->BelongsToCurrentThread());
 644
 645   for (size_t i = 0; i < release_sync_points.size(); i++)
 646     factories->WaitSyncPoint(release_sync_points[i]);
 647
 648   if (decoder) {
 649     decoder->ReusePictureBuffer(picture_buffer_id);
 650     return;
 651   }
 652   // It's the last chance to delete the texture after display,
 653   // because RTCVideoDecoder was destructed.
 654   factories->DeleteTexture(texture_id);
 655 }
 656
 657 void RTCVideoDecoder::ReusePictureBuffer(int64 picture_buffer_id) {
 658   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 659   DVLOG(3) << "ReusePictureBuffer. id=" << picture_buffer_id;
 660
 661   DCHECK(!picture_buffers_at_display_.empty());
 662   PictureBufferTextureMap::iterator display_iterator =
 663       picture_buffers_at_display_.find(picture_buffer_id);
 664   uint32 texture_id = display_iterator->second;
 665   DCHECK(display_iterator != picture_buffers_at_display_.end());
 666   picture_buffers_at_display_.erase(display_iterator);
 667
 668   if (!assigned_picture_buffers_.count(picture_buffer_id)) {
 669     // This picture was dismissed while in display, so we postponed deletion.
 670     factories_->DeleteTexture(texture_id);
 671     return;
 672   }
 673
 674   // DestroyVDA() might already have been called.
 675   if (vda_)
 676     vda_->ReusePictureBuffer(picture_buffer_id);
 677 }
 678
 679 void RTCVideoDecoder::CreateVDA(media::VideoCodecProfile profile,
 680                                 base::WaitableEvent* waiter) {
 681   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 682   vda_ = factories_->CreateVideoDecodeAccelerator();
 683   if (vda_ && !vda_->Initialize(profile, this))
 684     vda_.release()->Destroy();
 685   waiter->Signal();
 686 }
 687
 688 void RTCVideoDecoder::DestroyTextures() {
 689   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 690
 691   // Not destroying PictureBuffers in |picture_buffers_at_display_| yet, since
 692   // their textures may still be in use by the user of this RTCVideoDecoder.
 693   for (PictureBufferTextureMap::iterator it =
 694            picture_buffers_at_display_.begin();
 695        it != picture_buffers_at_display_.end();
 696        ++it) {
 697     assigned_picture_buffers_.erase(it->first);
 698   }
 699
 700   for (std::map<int32, media::PictureBuffer>::iterator it =
 701            assigned_picture_buffers_.begin();
 702        it != assigned_picture_buffers_.end();
 703        ++it) {
 704     factories_->DeleteTexture(it->second.texture_id());
 705   }
 706   assigned_picture_buffers_.clear();
 707 }
 708
 709 void RTCVideoDecoder::DestroyVDA() {
 710   DVLOG(2) << "DestroyVDA";
 711   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 712   if (vda_)
 713     vda_.release()->Destroy();
 714   DestroyTextures();
 715   base::AutoLock auto_lock(lock_);
 716   state_ = UNINITIALIZED;
 717 }
 718
 719 scoped_ptr<RTCVideoDecoder::SHMBuffer> RTCVideoDecoder::GetSHM_Locked(
 720     size_t min_size) {
 721   // Reuse a SHM if possible.
 722   SHMBuffer* ret = NULL;
 723   if (!available_shm_segments_.empty() &&
 724       available_shm_segments_.back()->size >= min_size) {
 725     ret = available_shm_segments_.back();
 726     available_shm_segments_.pop_back();
 727   }
 728   // Post to vda thread to create shared memory if SHM cannot be reused or the
 729   // queue is almost empty.
 730   if (num_shm_buffers_ < kMaxNumSharedMemorySegments &&
 731       (ret == NULL || available_shm_segments_.size() <= 1)) {
 732     factories_->GetTaskRunner()->PostTask(
 733         FROM_HERE,
 734         base::Bind(&RTCVideoDecoder::CreateSHM,
 735                    weak_factory_.GetWeakPtr(),
 736                    1,
 737                    min_size));
 738   }
 739   return scoped_ptr<SHMBuffer>(ret);
 740 }
 741
 742 void RTCVideoDecoder::PutSHM_Locked(scoped_ptr<SHMBuffer> shm_buffer) {
 743   available_shm_segments_.push_back(shm_buffer.release());
 744 }
 745
 746 void RTCVideoDecoder::CreateSHM(int number, size_t min_size) {
 747   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 748   DVLOG(2) << "CreateSHM. size=" << min_size;
 749   int number_to_allocate;
 750   {
 751     base::AutoLock auto_lock(lock_);
 752     number_to_allocate =
 753         std::min(kMaxNumSharedMemorySegments - num_shm_buffers_, number);
 754   }
 755   size_t size_to_allocate = std::max(min_size, kSharedMemorySegmentBytes);
 756   for (int i = 0; i < number_to_allocate; i++) {
 757     base::SharedMemory* shm = factories_->CreateSharedMemory(size_to_allocate);
 758     if (shm != NULL) {
 759       base::AutoLock auto_lock(lock_);
 760       num_shm_buffers_++;
 761       PutSHM_Locked(
 762           scoped_ptr<SHMBuffer>(new SHMBuffer(shm, size_to_allocate)));
 763     }
 764   }
 765   // Kick off the decoding.
 766   RequestBufferDecode();
 767 }
 768
 769 void RTCVideoDecoder::RecordBufferData(const BufferData& buffer_data) {
 770   input_buffer_data_.push_front(buffer_data);
 771   // Why this value?  Because why not.  avformat.h:MAX_REORDER_DELAY is 16, but
 772   // that's too small for some pathological B-frame test videos.  The cost of
 773   // using too-high a value is low (192 bits per extra slot).
 774   static const size_t kMaxInputBufferDataSize = 128;
 775   // Pop from the back of the list, because that's the oldest and least likely
 776   // to be useful in the future data.
 777   if (input_buffer_data_.size() > kMaxInputBufferDataSize)
 778     input_buffer_data_.pop_back();
 779 }
 780
 781 void RTCVideoDecoder::GetBufferData(int32 bitstream_buffer_id,
 782                                     uint32_t* timestamp,
 783                                     uint32_t* width,
 784                                     uint32_t* height,
 785                                     size_t* size) {
 786   for (std::list<BufferData>::iterator it = input_buffer_data_.begin();
 787        it != input_buffer_data_.end();
 788        ++it) {
 789     if (it->bitstream_buffer_id != bitstream_buffer_id)
 790       continue;
 791     *timestamp = it->timestamp;
 792     *width = it->width;
 793     *height = it->height;
 794     return;
 795   }
 796   NOTREACHED() << "Missing bitstream buffer id: " << bitstream_buffer_id;
 797 }
 798
 799 int32_t RTCVideoDecoder::RecordInitDecodeUMA(int32_t status) {
 800   // Logging boolean is enough to know if HW decoding has been used. Also,
 801   // InitDecode is less likely to return an error so enum is not used here.
 802   bool sample = (status == WEBRTC_VIDEO_CODEC_OK) ? true : false;
 803   UMA_HISTOGRAM_BOOLEAN("Media.RTCVideoDecoderInitDecodeSuccess", sample);
 804   return status;
 805 }
 806
 807 void RTCVideoDecoder::DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent()
 808     const {
 809   DCHECK(factories_->GetTaskRunner()->BelongsToCurrentThread());
 810 }
 811
 812 }  // namespace content