talk/media/webrtc/webrtcmediaengine.cc

/*
 * libjingle
 * Copyright 2014 Google Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "talk/media/webrtc/webrtcmediaengine.h"
#include "talk/media/webrtc/webrtcvideoengine2.h"
#include "talk/media/webrtc/webrtcvoiceengine.h"
#include "webrtc/base/arraysize.h"

namespace cricket {

class WebRtcMediaEngine2
    : public CompositeMediaEngine<WebRtcVoiceEngine, WebRtcVideoEngine2> {
 public:
  WebRtcMediaEngine2(webrtc::AudioDeviceModule* adm,
                     WebRtcVideoEncoderFactory* encoder_factory,
                     WebRtcVideoDecoderFactory* decoder_factory) {
    voice_.SetAudioDeviceModule(adm);
    video_.SetExternalDecoderFactory(decoder_factory);
    video_.SetExternalEncoderFactory(encoder_factory);
  }
};

}  // namespace cricket

cricket::MediaEngineInterface* CreateWebRtcMediaEngine(
    webrtc::AudioDeviceModule* adm,
    cricket::WebRtcVideoEncoderFactory* encoder_factory,
    cricket::WebRtcVideoDecoderFactory* decoder_factory) {
  return new cricket::WebRtcMediaEngine2(adm, encoder_factory,
                                         decoder_factory);
}

void DestroyWebRtcMediaEngine(cricket::MediaEngineInterface* media_engine) {
  delete media_engine;
}

namespace cricket {

// Used by PeerConnectionFactory to create a media engine passed into
// ChannelManager.
MediaEngineInterface* WebRtcMediaEngineFactory::Create(
    webrtc::AudioDeviceModule* adm,
    WebRtcVideoEncoderFactory* encoder_factory,
    WebRtcVideoDecoderFactory* decoder_factory) {
  return CreateWebRtcMediaEngine(adm, encoder_factory, decoder_factory);
}

const char* kBweExtensionPriorities[] = {
    kRtpTransportSequenceNumberHeaderExtension,
    kRtpAbsoluteSenderTimeHeaderExtension, kRtpTimestampOffsetHeaderExtension};

const size_t kBweExtensionPrioritiesLength = arraysize(kBweExtensionPriorities);

int GetPriority(const RtpHeaderExtension& extension,
                const char* extension_prios[],
                size_t extension_prios_length) {
  for (size_t i = 0; i < extension_prios_length; ++i) {
    if (extension.uri == extension_prios[i])
      return static_cast<int>(i);
  }
  return -1;
}

std::vector<RtpHeaderExtension> FilterRedundantRtpExtensions(
    const std::vector<RtpHeaderExtension>& extensions,
    const char* extension_prios[],
    size_t extension_prios_length) {
  if (extensions.empty())
    return std::vector<RtpHeaderExtension>();
  std::vector<RtpHeaderExtension> filtered;
  std::map<int, const RtpHeaderExtension*> sorted;
  for (auto& extension : extensions) {
    int priority =
        GetPriority(extension, extension_prios, extension_prios_length);
    if (priority == -1) {
      filtered.push_back(extension);
      continue;
    } else {
      sorted[priority] = &extension;
    }
  }
  if (!sorted.empty())
    filtered.push_back(*sorted.begin()->second);
  return filtered;
}

}  // namespace cricket