webrtc/common_video/incoming_video_stream.cc

/*
 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "webrtc/common_video/include/incoming_video_stream.h"

#include <assert.h>

#include "webrtc/base/platform_thread.h"
#include "webrtc/base/timeutils.h"
#include "webrtc/common_video/video_render_frames.h"
#include "webrtc/system_wrappers/include/critical_section_wrapper.h"
#include "webrtc/system_wrappers/include/event_wrapper.h"

namespace webrtc {

IncomingVideoStream::IncomingVideoStream(bool disable_prerenderer_smoothing)
    : disable_prerenderer_smoothing_(disable_prerenderer_smoothing),
      incoming_render_thread_(),
      deliver_buffer_event_(EventTimerWrapper::Create()),
      running_(false),
      external_callback_(nullptr),
      render_buffers_(new VideoRenderFrames()) {}

IncomingVideoStream::~IncomingVideoStream() {
  Stop();
}

void IncomingVideoStream::OnFrame(const VideoFrame& video_frame) {
  rtc::CritScope csS(&stream_critsect_);

  if (!running_) {
    return;
  }

  // Hand over or insert frame.
  if (disable_prerenderer_smoothing_) {
    DeliverFrame(video_frame);
  } else {
    rtc::CritScope csB(&buffer_critsect_);
    if (render_buffers_->AddFrame(video_frame) == 1) {
      deliver_buffer_event_->Set();
    }
  }
}

int32_t IncomingVideoStream::SetExpectedRenderDelay(
    int32_t delay_ms) {
  rtc::CritScope csS(&stream_critsect_);
  if (running_) {
    return -1;
  }
  rtc::CritScope cs(&buffer_critsect_);
  return render_buffers_->SetRenderDelay(delay_ms);
}

void IncomingVideoStream::SetExternalCallback(
    rtc::VideoSinkInterface<VideoFrame>* external_callback) {
  rtc::CritScope cs(&thread_critsect_);
  external_callback_ = external_callback;
}

int32_t IncomingVideoStream::Start() {
  rtc::CritScope csS(&stream_critsect_);
  if (running_) {
    return 0;
  }

  if (!disable_prerenderer_smoothing_) {
    rtc::CritScope csT(&thread_critsect_);
    assert(incoming_render_thread_ == NULL);

    incoming_render_thread_.reset(new rtc::PlatformThread(
        IncomingVideoStreamThreadFun, this, "IncomingVideoStreamThread"));
    if (!incoming_render_thread_) {
      return -1;
    }

    incoming_render_thread_->Start();
    incoming_render_thread_->SetPriority(rtc::kRealtimePriority);
    deliver_buffer_event_->StartTimer(false, kEventStartupTimeMs);
  }

  running_ = true;
  return 0;
}

int32_t IncomingVideoStream::Stop() {
  rtc::CritScope cs_stream(&stream_critsect_);

  if (!running_) {
    return 0;
  }

  rtc::PlatformThread* thread = NULL;
  {
    rtc::CritScope cs_thread(&thread_critsect_);
    if (incoming_render_thread_) {
      // Setting the incoming render thread to NULL marks that we're performing
      // a shutdown and will make IncomingVideoStreamProcess abort after wakeup.
      thread = incoming_render_thread_.release();
      deliver_buffer_event_->StopTimer();
      // Set the event to allow the thread to wake up and shut down without
      // waiting for a timeout.
      deliver_buffer_event_->Set();
    }
  }
  if (thread) {
    thread->Stop();
    delete thread;
  }
  running_ = false;
  return 0;
}

bool IncomingVideoStream::IncomingVideoStreamThreadFun(void* obj) {
  return static_cast<IncomingVideoStream*>(obj)->IncomingVideoStreamProcess();
}

bool IncomingVideoStream::IncomingVideoStreamProcess() {
  if (kEventError != deliver_buffer_event_->Wait(kEventMaxWaitTimeMs)) {
    rtc::CritScope cs(&thread_critsect_);
    if (incoming_render_thread_ == NULL) {
      // Terminating
      return false;
    }

    // Get a new frame to render and the time for the frame after this one.
    rtc::Optional<VideoFrame> frame_to_render;
    uint32_t wait_time;
    {
      rtc::CritScope cs(&buffer_critsect_);
      frame_to_render = render_buffers_->FrameToRender();
      wait_time = render_buffers_->TimeToNextFrameRelease();
    }

    // Set timer for next frame to render.
    if (wait_time > kEventMaxWaitTimeMs) {
      wait_time = kEventMaxWaitTimeMs;
    }
    deliver_buffer_event_->StartTimer(false, wait_time);

    if (frame_to_render)
      DeliverFrame(*frame_to_render);
  }
  return true;
}

void IncomingVideoStream::DeliverFrame(const VideoFrame& video_frame) {
  rtc::CritScope cs(&thread_critsect_);

  // Send frame for rendering.
  if (external_callback_) {
    external_callback_->OnFrame(video_frame);
  }
}

}  // namespace webrtc