Add write support for the RtpStreamId and RepairedRtpStreamId header extensions.

webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h

 /*
  *  Copyright (c) 2016 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.
  */
 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_HEADER_EXTENSIONS_H_
 #define WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_HEADER_EXTENSIONS_H_
 
 #include <stdint.h>
 #include <string>
 
 #include "webrtc/api/video/video_content_type.h"
 #include "webrtc/api/video/video_rotation.h"
 #include "webrtc/base/array_view.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 
 namespace webrtc {
 
 class AbsoluteSendTime {
  public:
   static constexpr RTPExtensionType kId = kRtpExtensionAbsoluteSendTime;
   static constexpr uint8_t kValueSizeBytes = 3;
   static constexpr const char* kUri =
       "http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time";
 
+  static size_t ValueSize(int64_t time_ms) { return kValueSizeBytes; }

[danilchap, 2017/05/09 15:40:52]

may be put this function just before Write function to show it's parameter
closely match it.

[erikvarga1, 2017/05/10 10:52:27]

Done.

   static bool Parse(rtc::ArrayView<const uint8_t> data, uint32_t* time_24bits);
   static bool Write(uint8_t* data, int64_t time_ms);
 
   static constexpr uint32_t MsTo24Bits(int64_t time_ms) {
     return static_cast<uint32_t>(((time_ms << 18) + 500) / 1000) & 0x00FFFFFF;
   }
 };
 
 class AudioLevel {
  public:
   static constexpr RTPExtensionType kId = kRtpExtensionAudioLevel;
   static constexpr uint8_t kValueSizeBytes = 1;
   static constexpr const char* kUri =
       "urn:ietf:params:rtp-hdrext:ssrc-audio-level";
 
+  static size_t ValueSize(bool voice_activity, uint8_t audio_level) {
+    return kValueSizeBytes;
+  }
   static bool Parse(rtc::ArrayView<const uint8_t> data,
                     bool* voice_activity,
                     uint8_t* audio_level);
   static bool Write(uint8_t* data, bool voice_activity, uint8_t audio_level);
 };
 
 class TransmissionOffset {
  public:
   static constexpr RTPExtensionType kId = kRtpExtensionTransmissionTimeOffset;
   static constexpr uint8_t kValueSizeBytes = 3;
   static constexpr const char* kUri = "urn:ietf:params:rtp-hdrext:toffset";
 
+  static size_t ValueSize(int32_t rtp_time) { return kValueSizeBytes; }
   static bool Parse(rtc::ArrayView<const uint8_t> data, int32_t* rtp_time);
   static bool Write(uint8_t* data, int32_t rtp_time);
 };
 
 class TransportSequenceNumber {
  public:
   static constexpr RTPExtensionType kId = kRtpExtensionTransportSequenceNumber;
   static constexpr uint8_t kValueSizeBytes = 2;
   static constexpr const char* kUri =
       "http://www.ietf.org/id/"
       "draft-holmer-rmcat-transport-wide-cc-extensions-01";
+  static size_t ValueSize(uint16_t value) { return kValueSizeBytes; }
   static bool Parse(rtc::ArrayView<const uint8_t> data, uint16_t* value);
   static bool Write(uint8_t* data, uint16_t value);
 };
 
 class VideoOrientation {
  public:
   static constexpr RTPExtensionType kId = kRtpExtensionVideoRotation;
   static constexpr uint8_t kValueSizeBytes = 1;
   static constexpr const char* kUri = "urn:3gpp:video-orientation";
 
+  static size_t ValueSize(VideoRotation* value) { return kValueSizeBytes; }

[danilchap, 2017/05/09 15:40:51]

remove *

[erikvarga1, 2017/05/10 10:52:27]

Done.

   static bool Parse(rtc::ArrayView<const uint8_t> data, VideoRotation* value);
   static bool Write(uint8_t* data, VideoRotation value);
+  static size_t ValueSize(uint8_t value) { return kValueSizeBytes; }
   static bool Parse(rtc::ArrayView<const uint8_t> data, uint8_t* value);
   static bool Write(uint8_t* data, uint8_t value);
 };
 
 class PlayoutDelayLimits {
  public:
   static constexpr RTPExtensionType kId = kRtpExtensionPlayoutDelay;
   static constexpr uint8_t kValueSizeBytes = 3;
   static constexpr const char* kUri =
       "http://www.webrtc.org/experiments/rtp-hdrext/playout-delay";
 
   // Playout delay in milliseconds. A playout delay limit (min or max)
   // has 12 bits allocated. This allows a range of 0-4095 values which
   // translates to a range of 0-40950 in milliseconds.
   static constexpr int kGranularityMs = 10;
   // Maximum playout delay value in milliseconds.
   static constexpr int kMaxMs = 0xfff * kGranularityMs;  // 40950.
 
+  static size_t ValueSize(const PlayoutDelay& playout_delay) {

[danilchap, 2017/05/09 15:40:52]

feel free to omit parameter name when it doesn't add any description to the type
name.

[erikvarga1, 2017/05/10 10:52:26]

Done.

+    return kValueSizeBytes;
+  }
   static bool Parse(rtc::ArrayView<const uint8_t> data,
                     PlayoutDelay* playout_delay);
   static bool Write(uint8_t* data, const PlayoutDelay& playout_delay);
 };
 
 class VideoContentTypeExtension {
  public:
   static constexpr RTPExtensionType kId = kRtpExtensionVideoContentType;
   static constexpr uint8_t kValueSizeBytes = 1;
   static constexpr const char* kUri =
       "http://www.webrtc.org/experiments/rtp-hdrext/video-content-type";
 
+  static size_t ValueSize(VideoContentType content_type) {
+    return kValueSizeBytes;
+  }
   static bool Parse(rtc::ArrayView<const uint8_t> data,
                     VideoContentType* content_type);
   static bool Write(uint8_t* data, VideoContentType content_type);
 };
 
 class RtpStreamId {
  public:
   static constexpr RTPExtensionType kId = kRtpExtensionRtpStreamId;
   // TODO(danilchap): Implement write support of dynamic size extension that
   // allows to remove the ValueSize constant.
   static constexpr uint8_t kValueSizeBytes = 1;
   static constexpr const char* kUri =
       "urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id";
 
-  static bool Parse(rtc::ArrayView<const uint8_t> data, StreamId* rid);
-  static bool Parse(rtc::ArrayView<const uint8_t> data, std::string* rid);
+  static size_t ValueSize(const StreamId& rsid) { return rsid.size(); }
+  static bool Parse(rtc::ArrayView<const uint8_t> data, StreamId* rsid);
+  static bool Write(uint8_t* data, const StreamId& rsid);
+
+  static size_t ValueSize(const std::string& rsid) { return rsid.size(); }
+  static bool Parse(rtc::ArrayView<const uint8_t> data, std::string* rsid);
+  static bool Write(uint8_t* data, const std::string& rsid);
 };
 
 class RepairedRtpStreamId {
  public:
   static constexpr RTPExtensionType kId = kRtpExtensionRepairedRtpStreamId;
   // TODO(danilchap): Implement write support of dynamic size extension that
   // allows to remove the ValueSize constant.
   static constexpr uint8_t kValueSizeBytes = 1;
   static constexpr const char* kUri =
       "urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id";
 
-  static bool Parse(rtc::ArrayView<const uint8_t> data, StreamId* rid);
-  static bool Parse(rtc::ArrayView<const uint8_t> data, std::string* rid);
+  static size_t ValueSize(const StreamId& rsid) {
+    return RtpStreamId::ValueSize(rsid);

[danilchap, 2017/05/09 15:40:51]

may be move implementation to .cc for consistency with Parse/Write functions

[erikvarga1, 2017/05/10 10:52:27]

Done. Should this also be done for the ValueSize functions of the other
extensions? Those also have the Parse/Write functions in the .cc file, but
they're just one-liners, so I'm not sure.

[danilchap, 2017/05/10 11:25:17]

it is not required - functions that short are ok to inline.
(personally prefer ValueSize function to be inlined, like you did.)
For RepairedRtpStreamId I asked only to be consistent with other
RepairedRtpStreamId functions.
alternative is to inline Parse/Write function of the RepairedRtpStreamId
instead.

[erikvarga1, 2017/05/10 14:48:19]

Alright, in that case I think it should be OK like it is now.

+  }
+  static bool Parse(rtc::ArrayView<const uint8_t> data, StreamId* rsid);
+  static bool Write(uint8_t* data, const StreamId& rsid);
+
+  static size_t ValueSize(const std::string& rsid) {
+    return RtpStreamId::ValueSize(rsid);
+  }
+  static bool Parse(rtc::ArrayView<const uint8_t> data, std::string* rsid);
+  static bool Write(uint8_t* data, const std::string& rsid);
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_HEADER_EXTENSIONS_H_