src/media/cast/sender/external_video_encoder.cc

   1 // Copyright 2014 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 "media/cast/sender/external_video_encoder.h"
   6
   7 #include "base/bind.h"
   8 #include "base/logging.h"
   9 #include "base/memory/scoped_vector.h"
  10 #include "base/memory/shared_memory.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "base/metrics/histogram.h"
  13 #include "media/base/video_frame.h"
  14 #include "media/base/video_util.h"
  15 #include "media/cast/cast_defines.h"
  16 #include "media/cast/logging/logging_defines.h"
  17 #include "media/cast/net/cast_transport_config.h"
  18 #include "media/video/video_encode_accelerator.h"
  19
  20 namespace media {
  21 namespace cast {
  22 class LocalVideoEncodeAcceleratorClient;
  23 }  // namespace cast
  24 }  // namespace media
  25
  26 namespace {
  27 static const size_t kOutputBufferCount = 3;
  28
  29 void LogFrameEncodedEvent(
  30     const scoped_refptr<media::cast::CastEnvironment>& cast_environment,
  31     base::TimeTicks event_time,
  32     media::cast::RtpTimestamp rtp_timestamp,
  33     uint32 frame_id) {
  34   cast_environment->Logging()->InsertFrameEvent(
  35       event_time, media::cast::FRAME_ENCODED, media::cast::VIDEO_EVENT,
  36       rtp_timestamp, frame_id);
  37 }
  38 }  // namespace
  39
  40 namespace media {
  41 namespace cast {
  42
  43 // Container for the associated data of a video frame being processed.
  44 struct EncodedFrameReturnData {
  45   EncodedFrameReturnData(base::TimeTicks c_time,
  46                          VideoEncoder::FrameEncodedCallback callback) {
  47     capture_time = c_time;
  48     frame_encoded_callback = callback;
  49   }
  50   base::TimeTicks capture_time;
  51   VideoEncoder::FrameEncodedCallback frame_encoded_callback;
  52 };
  53
  54 // The ExternalVideoEncoder class can be deleted directly by cast, while
  55 // LocalVideoEncodeAcceleratorClient stays around long enough to properly shut
  56 // down the VideoEncodeAccelerator.
  57 class LocalVideoEncodeAcceleratorClient
  58     : public VideoEncodeAccelerator::Client,
  59       public base::RefCountedThreadSafe<LocalVideoEncodeAcceleratorClient> {
  60  public:
  61   // Create an instance of this class and post a task to create
  62   // video_encode_accelerator_. A ref to |this| will be kept, awaiting reply
  63   // via ProxyCreateVideoEncodeAccelerator, which will provide us with the
  64   // encoder task runner and vea instance. We cannot be destroyed until we
  65   // receive the reply, otherwise the VEA object created may leak.
  66   static scoped_refptr<LocalVideoEncodeAcceleratorClient> Create(
  67       scoped_refptr<CastEnvironment> cast_environment,
  68       const CreateVideoEncodeAcceleratorCallback& create_vea_cb,
  69       const CreateVideoEncodeMemoryCallback& create_video_encode_mem_cb,
  70       const base::WeakPtr<ExternalVideoEncoder>& weak_owner) {
  71     scoped_refptr<LocalVideoEncodeAcceleratorClient> client(
  72         new LocalVideoEncodeAcceleratorClient(
  73             cast_environment, create_video_encode_mem_cb, weak_owner));
  74
  75     // This will keep a ref to |client|, if weak_owner is destroyed before
  76     // ProxyCreateVideoEncodeAccelerator is called, we will stay alive until
  77     // we can properly destroy the VEA.
  78     create_vea_cb.Run(base::Bind(
  79         &LocalVideoEncodeAcceleratorClient::OnCreateVideoEncodeAcceleratorProxy,
  80         client));
  81
  82     return client;
  83   }
  84
  85   // Initialize the real HW encoder.
  86   void Initialize(const VideoSenderConfig& video_config) {
  87     DCHECK(encoder_task_runner_);
  88     DCHECK(encoder_task_runner_->RunsTasksOnCurrentThread());
  89
  90     VideoCodecProfile output_profile = media::VIDEO_CODEC_PROFILE_UNKNOWN;
  91     switch (video_config.codec) {
  92       case CODEC_VIDEO_VP8:
  93         output_profile = media::VP8PROFILE_ANY;
  94         break;
  95       case CODEC_VIDEO_H264:
  96         output_profile = media::H264PROFILE_MAIN;
  97         break;
  98       case CODEC_VIDEO_FAKE:
  99         NOTREACHED() << "Fake software video encoder cannot be external";
 100         break;
 101       default:
 102         NOTREACHED() << "Video codec not specified or not supported";
 103         break;
 104     }
 105     max_frame_rate_ = video_config.max_frame_rate;
 106
 107     bool result = video_encode_accelerator_->Initialize(
 108         media::VideoFrame::I420,
 109         gfx::Size(video_config.width, video_config.height),
 110         output_profile,
 111         video_config.start_bitrate,
 112         this);
 113
 114     UMA_HISTOGRAM_BOOLEAN("Cast.Sender.VideoEncodeAcceleratorInitializeSuccess",
 115                           result);
 116     if (!result) {
 117       NotifyError(VideoEncodeAccelerator::kInvalidArgumentError);
 118       return;
 119     }
 120
 121     // Wait until shared memory is allocated to indicate that encoder is
 122     // initialized.
 123   }
 124
 125   // Destroy the VEA on the correct thread.
 126   void Destroy() {
 127     DCHECK(encoder_task_runner_);
 128     if (!video_encode_accelerator_)
 129       return;
 130
 131     if (encoder_task_runner_->RunsTasksOnCurrentThread()) {
 132       video_encode_accelerator_.reset();
 133     } else {
 134       // We do this instead of just reposting to encoder_task_runner_, because
 135       // we are called from the destructor.
 136       encoder_task_runner_->PostTask(
 137           FROM_HERE,
 138           base::Bind(&DestroyVideoEncodeAcceleratorOnEncoderThread,
 139                      base::Passed(&video_encode_accelerator_)));
 140     }
 141   }
 142
 143   void SetBitRate(uint32 bit_rate) {
 144     DCHECK(encoder_task_runner_);
 145     DCHECK(encoder_task_runner_->RunsTasksOnCurrentThread());
 146
 147     video_encode_accelerator_->RequestEncodingParametersChange(bit_rate,
 148                                                                max_frame_rate_);
 149   }
 150
 151   void EncodeVideoFrame(
 152       const scoped_refptr<media::VideoFrame>& video_frame,
 153       const base::TimeTicks& capture_time,
 154       bool key_frame_requested,
 155       const VideoEncoder::FrameEncodedCallback& frame_encoded_callback) {
 156     DCHECK(encoder_task_runner_);
 157     DCHECK(encoder_task_runner_->RunsTasksOnCurrentThread());
 158
 159     encoded_frame_data_storage_.push_back(
 160         EncodedFrameReturnData(capture_time, frame_encoded_callback));
 161
 162     // BitstreamBufferReady will be called once the encoder is done.
 163     video_encode_accelerator_->Encode(video_frame, key_frame_requested);
 164   }
 165
 166  protected:
 167   virtual void NotifyError(VideoEncodeAccelerator::Error error) OVERRIDE {
 168     DCHECK(encoder_task_runner_);
 169     DCHECK(encoder_task_runner_->RunsTasksOnCurrentThread());
 170     VLOG(1) << "ExternalVideoEncoder NotifyError: " << error;
 171
 172     cast_environment_->PostTask(
 173         CastEnvironment::MAIN,
 174         FROM_HERE,
 175         base::Bind(&ExternalVideoEncoder::EncoderError, weak_owner_));
 176   }
 177
 178   // Called to allocate the input and output buffers.
 179   virtual void RequireBitstreamBuffers(unsigned int input_count,
 180                                        const gfx::Size& input_coded_size,
 181                                        size_t output_buffer_size) OVERRIDE {
 182     DCHECK(encoder_task_runner_);
 183     DCHECK(encoder_task_runner_->RunsTasksOnCurrentThread());
 184     DCHECK(video_encode_accelerator_);
 185
 186     for (size_t j = 0; j < kOutputBufferCount; ++j) {
 187       create_video_encode_memory_cb_.Run(
 188           output_buffer_size,
 189           base::Bind(&LocalVideoEncodeAcceleratorClient::OnCreateSharedMemory,
 190                      this));
 191     }
 192   }
 193
 194   // Encoder has encoded a frame and it's available in one of out output
 195   // buffers.
 196   virtual void BitstreamBufferReady(int32 bitstream_buffer_id,
 197                                     size_t payload_size,
 198                                     bool key_frame) OVERRIDE {
 199     DCHECK(encoder_task_runner_);
 200     DCHECK(encoder_task_runner_->RunsTasksOnCurrentThread());
 201     if (bitstream_buffer_id < 0 ||
 202         bitstream_buffer_id >= static_cast<int32>(output_buffers_.size())) {
 203       NOTREACHED();
 204       VLOG(1) << "BitstreamBufferReady(): invalid bitstream_buffer_id="
 205               << bitstream_buffer_id;
 206       NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
 207       return;
 208     }
 209     base::SharedMemory* output_buffer = output_buffers_[bitstream_buffer_id];
 210     if (payload_size > output_buffer->mapped_size()) {
 211       NOTREACHED();
 212       VLOG(1) << "BitstreamBufferReady(): invalid payload_size = "
 213               << payload_size;
 214       NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
 215       return;
 216     }
 217     if (key_frame)
 218       key_frame_encountered_ = true;
 219     if (!key_frame_encountered_) {
 220       // Do not send video until we have encountered the first key frame.
 221       // Save the bitstream buffer in |stream_header_| to be sent later along
 222       // with the first key frame.
 223       stream_header_.append(static_cast<const char*>(output_buffer->memory()),
 224                             payload_size);
 225     } else if (!encoded_frame_data_storage_.empty()) {
 226       scoped_ptr<EncodedFrame> encoded_frame(
 227           new EncodedFrame());
 228       encoded_frame->dependency = key_frame ? EncodedFrame::KEY :
 229           EncodedFrame::DEPENDENT;
 230       encoded_frame->frame_id = ++last_encoded_frame_id_;
 231       if (key_frame)
 232         encoded_frame->referenced_frame_id = encoded_frame->frame_id;
 233       else
 234         encoded_frame->referenced_frame_id = encoded_frame->frame_id - 1;
 235       encoded_frame->reference_time =
 236           encoded_frame_data_storage_.front().capture_time;
 237       encoded_frame->rtp_timestamp =
 238           GetVideoRtpTimestamp(encoded_frame->reference_time);
 239       if (!stream_header_.empty()) {
 240         encoded_frame->data = stream_header_;
 241         stream_header_.clear();
 242       }
 243       encoded_frame->data.append(
 244           static_cast<const char*>(output_buffer->memory()), payload_size);
 245
 246       cast_environment_->PostTask(
 247           CastEnvironment::MAIN,
 248           FROM_HERE,
 249           base::Bind(&LogFrameEncodedEvent,
 250                      cast_environment_,
 251                      cast_environment_->Clock()->NowTicks(),
 252                      encoded_frame->rtp_timestamp,
 253                      encoded_frame->frame_id));
 254
 255       cast_environment_->PostTask(
 256           CastEnvironment::MAIN,
 257           FROM_HERE,
 258           base::Bind(encoded_frame_data_storage_.front().frame_encoded_callback,
 259                      base::Passed(&encoded_frame)));
 260
 261       encoded_frame_data_storage_.pop_front();
 262     } else {
 263       VLOG(1) << "BitstreamBufferReady(): no encoded frame data available";
 264     }
 265
 266     // We need to re-add the output buffer to the encoder after we are done
 267     // with it.
 268     video_encode_accelerator_->UseOutputBitstreamBuffer(media::BitstreamBuffer(
 269         bitstream_buffer_id,
 270         output_buffers_[bitstream_buffer_id]->handle(),
 271         output_buffers_[bitstream_buffer_id]->mapped_size()));
 272   }
 273
 274  private:
 275   LocalVideoEncodeAcceleratorClient(
 276       scoped_refptr<CastEnvironment> cast_environment,
 277       const CreateVideoEncodeMemoryCallback& create_video_encode_mem_cb,
 278       const base::WeakPtr<ExternalVideoEncoder>& weak_owner)
 279       : cast_environment_(cast_environment),
 280         create_video_encode_memory_cb_(create_video_encode_mem_cb),
 281         weak_owner_(weak_owner),
 282         last_encoded_frame_id_(kStartFrameId),
 283         key_frame_encountered_(false) {}
 284
 285   // Trampoline VEA creation callback to OnCreateVideoEncodeAccelerator()
 286   // on encoder_task_runner. Normally we would just repost the same method to
 287   // it, and would not need a separate proxy method, but we can't
 288   // ThreadTaskRunnerHandle::Get() in unittests just yet.
 289   void OnCreateVideoEncodeAcceleratorProxy(
 290       scoped_refptr<base::SingleThreadTaskRunner> encoder_task_runner,
 291       scoped_ptr<media::VideoEncodeAccelerator> vea) {
 292     encoder_task_runner->PostTask(
 293         FROM_HERE,
 294         base::Bind(&media::cast::LocalVideoEncodeAcceleratorClient::
 295                        OnCreateVideoEncodeAccelerator,
 296                    this,
 297                    encoder_task_runner,
 298                    base::Passed(&vea)));
 299   }
 300
 301   void OnCreateVideoEncodeAccelerator(
 302       scoped_refptr<base::SingleThreadTaskRunner> encoder_task_runner,
 303       scoped_ptr<media::VideoEncodeAccelerator> vea) {
 304     encoder_task_runner_ = encoder_task_runner;
 305     video_encode_accelerator_.reset(vea.release());
 306
 307     cast_environment_->PostTask(
 308         CastEnvironment::MAIN,
 309         FROM_HERE,
 310         base::Bind(&ExternalVideoEncoder::OnCreateVideoEncodeAccelerator,
 311                    weak_owner_,
 312                    encoder_task_runner_));
 313   }
 314
 315   // Note: This method can be called on any thread.
 316   void OnCreateSharedMemory(scoped_ptr<base::SharedMemory> memory) {
 317     encoder_task_runner_->PostTask(
 318         FROM_HERE,
 319         base::Bind(&LocalVideoEncodeAcceleratorClient::ReceivedSharedMemory,
 320                    this,
 321                    base::Passed(&memory)));
 322   }
 323
 324   void ReceivedSharedMemory(scoped_ptr<base::SharedMemory> memory) {
 325     DCHECK(encoder_task_runner_);
 326     DCHECK(encoder_task_runner_->RunsTasksOnCurrentThread());
 327
 328     output_buffers_.push_back(memory.release());
 329
 330     // Wait until all requested buffers are received.
 331     if (output_buffers_.size() < kOutputBufferCount)
 332       return;
 333
 334     // Immediately provide all output buffers to the VEA.
 335     for (size_t i = 0; i < output_buffers_.size(); ++i) {
 336       video_encode_accelerator_->UseOutputBitstreamBuffer(
 337           media::BitstreamBuffer(static_cast<int32>(i),
 338                                  output_buffers_[i]->handle(),
 339                                  output_buffers_[i]->mapped_size()));
 340     }
 341
 342     cast_environment_->PostTask(
 343         CastEnvironment::MAIN,
 344         FROM_HERE,
 345         base::Bind(&ExternalVideoEncoder::EncoderInitialized, weak_owner_));
 346   }
 347
 348   static void DestroyVideoEncodeAcceleratorOnEncoderThread(
 349       scoped_ptr<media::VideoEncodeAccelerator> vea) {
 350     // VEA::~VEA specialization takes care of calling Destroy() on the VEA impl.
 351   }
 352
 353   friend class base::RefCountedThreadSafe<LocalVideoEncodeAcceleratorClient>;
 354
 355   virtual ~LocalVideoEncodeAcceleratorClient() {
 356     Destroy();
 357     DCHECK(!video_encode_accelerator_);
 358   }
 359
 360   const scoped_refptr<CastEnvironment> cast_environment_;
 361   scoped_refptr<base::SingleThreadTaskRunner> encoder_task_runner_;
 362   scoped_ptr<media::VideoEncodeAccelerator> video_encode_accelerator_;
 363   const CreateVideoEncodeMemoryCallback create_video_encode_memory_cb_;
 364   const base::WeakPtr<ExternalVideoEncoder> weak_owner_;
 365   int max_frame_rate_;
 366   uint32 last_encoded_frame_id_;
 367   bool key_frame_encountered_;
 368   std::string stream_header_;
 369
 370   // Shared memory buffers for output with the VideoAccelerator.
 371   ScopedVector<base::SharedMemory> output_buffers_;
 372
 373   // FIFO list.
 374   std::list<EncodedFrameReturnData> encoded_frame_data_storage_;
 375
 376   DISALLOW_COPY_AND_ASSIGN(LocalVideoEncodeAcceleratorClient);
 377 };
 378
 379 ExternalVideoEncoder::ExternalVideoEncoder(
 380     scoped_refptr<CastEnvironment> cast_environment,
 381     const VideoSenderConfig& video_config,
 382     const CreateVideoEncodeAcceleratorCallback& create_vea_cb,
 383     const CreateVideoEncodeMemoryCallback& create_video_encode_mem_cb)
 384     : video_config_(video_config),
 385       cast_environment_(cast_environment),
 386       encoder_active_(false),
 387       key_frame_requested_(false),
 388       weak_factory_(this) {
 389   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
 390
 391   video_accelerator_client_ =
 392       LocalVideoEncodeAcceleratorClient::Create(cast_environment_,
 393                                                 create_vea_cb,
 394                                                 create_video_encode_mem_cb,
 395                                                 weak_factory_.GetWeakPtr());
 396   DCHECK(video_accelerator_client_);
 397 }
 398
 399 ExternalVideoEncoder::~ExternalVideoEncoder() {
 400 }
 401
 402 void ExternalVideoEncoder::EncoderInitialized() {
 403   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
 404   encoder_active_ = true;
 405 }
 406
 407 void ExternalVideoEncoder::EncoderError() {
 408   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
 409   encoder_active_ = false;
 410 }
 411
 412 void ExternalVideoEncoder::OnCreateVideoEncodeAccelerator(
 413     scoped_refptr<base::SingleThreadTaskRunner> encoder_task_runner) {
 414   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
 415   encoder_task_runner_ = encoder_task_runner;
 416
 417   encoder_task_runner_->PostTask(
 418       FROM_HERE,
 419       base::Bind(&LocalVideoEncodeAcceleratorClient::Initialize,
 420                  video_accelerator_client_,
 421                  video_config_));
 422 }
 423
 424 bool ExternalVideoEncoder::EncodeVideoFrame(
 425     const scoped_refptr<media::VideoFrame>& video_frame,
 426     const base::TimeTicks& capture_time,
 427     const FrameEncodedCallback& frame_encoded_callback) {
 428   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
 429
 430   if (!encoder_active_)
 431     return false;
 432
 433   encoder_task_runner_->PostTask(
 434       FROM_HERE,
 435       base::Bind(&LocalVideoEncodeAcceleratorClient::EncodeVideoFrame,
 436                  video_accelerator_client_,
 437                  video_frame,
 438                  capture_time,
 439                  key_frame_requested_,
 440                  frame_encoded_callback));
 441
 442   key_frame_requested_ = false;
 443   return true;
 444 }
 445
 446 // Inform the encoder about the new target bit rate.
 447 void ExternalVideoEncoder::SetBitRate(int new_bit_rate) {
 448   if (!encoder_active_) {
 449     // If we receive SetBitRate() before VEA creation callback is invoked,
 450     // cache the new bit rate in the encoder config and use the new settings
 451     // to initialize VEA.
 452     video_config_.start_bitrate = new_bit_rate;
 453     return;
 454   }
 455
 456   encoder_task_runner_->PostTask(
 457       FROM_HERE,
 458       base::Bind(&LocalVideoEncodeAcceleratorClient::SetBitRate,
 459                  video_accelerator_client_,
 460                  new_bit_rate));
 461 }
 462
 463 // Inform the encoder to encode the next frame as a key frame.
 464 void ExternalVideoEncoder::GenerateKeyFrame() {
 465   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
 466   key_frame_requested_ = true;
 467 }
 468
 469 // Inform the encoder to only reference frames older or equal to frame_id;
 470 void ExternalVideoEncoder::LatestFrameIdToReference(uint32 /*frame_id*/) {
 471   // Do nothing not supported.
 472 }
 473 }  //  namespace cast
 474 }  //  namespace media