Implement FrameMarking header extension support

webrtc/modules/rtp_rtcp/source/rtp_utility.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.
  */
 
@@ skipping 235 matching lines @@
   header->extension.videoRotation = kVideoRotation_0;
 
   // May not be present in packet.
   header->extension.playout_delay.min_ms = -1;
   header->extension.playout_delay.max_ms = -1;
 
   // May not be present in packet.
   header->extension.hasVideoContentType = false;
   header->extension.videoContentType = VideoContentType::UNSPECIFIED;
 
+  // May not be present in packet.
+  header->extension.hasFrameMarks = false;
+
   if (X) {
     /* RTP header extension, RFC 3550.
      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      defined by profile       |           length              |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        header extension                       |
     |                             ....                              |
     */
@@ skipping 200 matching lines @@
         }
         case kRtpExtensionRtpStreamId: {
           header->extension.stream_id.Set(rtc::MakeArrayView(ptr, len + 1));
           break;
         }
         case kRtpExtensionRepairedRtpStreamId: {
           header->extension.repaired_stream_id.Set(
               rtc::MakeArrayView(ptr, len + 1));
           break;
         }
+        case kRtpExtensionFrameMarking: {
+          if (len != 0 && len != 2) {
+            LOG(LS_WARNING) << "Incorrect frame marking len: " << len;
+            return;
+          }
+          // For Frame Marking RTP Header Extension:

[danilchap, 2017/06/28 16:07:07]

may be reuse parsing code:
header->extension.has_frame_marks = FrameMarking::Parse(rtc::MakeArrayView(ptr,
len), &header->extension.frame_marks);

[sergio.garcia.murillo, 2017/06/29 12:58:58]

Acknowledged.

+          //
+          // https://tools.ietf.org/html/draft-ietf-avtext-framemarking-04
+          // This extensions provides meta-information about the RTP streams
+          // outside the encrypted media payload, an RTP switch can do
+          // codec-agnostic selective forwarding without decrypting the payload
+          //
+          // for Non-Scalable Streams
+          //
+          //    0                   1
+          //    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+          //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+          //   |  ID=? |  L=0  |S|E|I|D|0 0 0 0|
+          //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+          //
+          // for Scalable Streams
+          //
+          //    0                   1                   2                   3
+          //    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+          //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+          //   |  ID=? |  L=2  |S|E|I|D|B| TID |   LID         |    TL0PICIDX  |
+          //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+          //
+          // Set frame marking data
+          header->extension.frameMarks.startOfFrame = (ptr[0] & 0x80) != 0;
+          header->extension.frameMarks.endOfFrame = (ptr[0] & 0x40) != 0;
+          header->extension.frameMarks.independent = (ptr[0] & 0x20) != 0;
+          header->extension.frameMarks.discardable = (ptr[0] & 0x10) != 0;
+
+          // Check variable length
+          if (len==1) {
+            // We are non-scalable
+            header->extension.frameMarks.baseLayerSync = 0;
+            header->extension.frameMarks.temporalLayerId = 0;
+            header->extension.frameMarks.spatialLayerId = 0;
+            header->extension.frameMarks.tl0PicIdx = 0;
+          } else if (len==3) {
+            // Set scalable parts
+            header->extension.frameMarks.baseLayerSync = (ptr[0] & 0x08) != 0;
+            header->extension.frameMarks.temporalLayerId = (ptr[0] & 0x07) != 0;
+            header->extension.frameMarks.spatialLayerId = ptr[1];
+            header->extension.frameMarks.tl0PicIdx = ptr[2];
+          }
+          break;
+        }
         case kRtpExtensionNone:
         case kRtpExtensionNumberOfExtensions: {
           RTC_NOTREACHED() << "Invalid extension type: " << type;
           return;
         }
       }
     }
     ptr += (len + 1);
   }
 }
 
 }  // namespace RtpUtility
 }  // namespace webrtc