[H264][Simulcast] Implement the simulcast logic for h264 encoder

webrtc/video/payload_router.cc

 /*
  *  Copyright (c) 2015 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.
  */
 
@@ skipping 57 matching lines @@
         rtp->codecHeader.VP9.gof.CopyGofInfoVP9(info->codecSpecific.VP9.gof);
       }
 
       rtp->codecHeader.VP9.num_ref_pics = info->codecSpecific.VP9.num_ref_pics;
       for (int i = 0; i < info->codecSpecific.VP9.num_ref_pics; ++i)
         rtp->codecHeader.VP9.pid_diff[i] = info->codecSpecific.VP9.p_diff[i];
       return;
     }
     case kVideoCodecH264:
       rtp->codec = kRtpVideoH264;
+      rtp->simulcastIdx = info->codecSpecific.H264.simulcastIdx;
       return;
     case kVideoCodecGeneric:
       rtp->codec = kRtpVideoGeneric;
       rtp->simulcastIdx = info->codecSpecific.generic.simulcast_idx;
       return;
     default:
       return;
   }
 }
 
@@ skipping 102 matching lines @@
   rtc::CritScope lock(&crit_);
   for (size_t i = 0; i < num_sending_modules_; ++i) {
     size_t module_payload_length = rtp_modules_[i]->MaxDataPayloadLength();
     if (module_payload_length < min_payload_length)
       min_payload_length = module_payload_length;
   }
   return min_payload_length;
 }
 
 }  // namespace webrtc