Ensure the RtcEventLog parser is backwards compatible

webrtc/logging/rtc_event_log/rtc_event_log_parser.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_LOGGING_RTC_EVENT_LOG_RTC_EVENT_LOG_PARSER_H_
@@ skipping 96 matching lines @@
 
   // Reads packet, direction and packet length from the RTCP event at |index|,
   // and stores the values in the corresponding output parameters.
   // Each output parameter can be set to nullptr if that value isn't needed.
   // NB: The packet must have space for at least IP_PACKET_SIZE bytes.
   void GetRtcpPacket(size_t index,
                      PacketDirection* incoming,
                      uint8_t* packet,
                      size_t* length) const;
 
-  // Reads a config event to a (non-NULL) StreamConfig struct.
+  // Reads a video receive config event to a StreamConfig struct.
   // Only the fields that are stored in the protobuf will be written.
-  void GetVideoReceiveConfig(size_t index, rtclog::StreamConfig* config) const;
+  rtclog::StreamConfig GetVideoReceiveConfig(size_t index) const;
 
-  // Reads a config event to a (non-NULL) StreamConfig struct.
+  // Reads a video send config event to a StreamConfig struct. If the proto
+  // contains multiple SSRCs and RTX SSRCs (this used to be the case for
+  // simulcast streams) then we return one StreamConfig per SSRC,RTX_SSRC pair.
   // Only the fields that are stored in the protobuf will be written.
-  void GetVideoSendConfig(size_t index, rtclog::StreamConfig* config) const;
+  std::vector<rtclog::StreamConfig> GetVideoSendConfig(size_t index) const;
 
-  // Reads a config event to a (non-NULL) StreamConfig struct.
+  // Reads a audio receive config event to a StreamConfig struct.
   // Only the fields that are stored in the protobuf will be written.
-  void GetAudioReceiveConfig(size_t index, rtclog::StreamConfig* config) const;
+  rtclog::StreamConfig GetAudioReceiveConfig(size_t index) const;
 
-  // Reads a config event to a (non-NULL) StreamConfig struct.
+  // Reads a config event to a StreamConfig struct.
   // Only the fields that are stored in the protobuf will be written.
-  void GetAudioSendConfig(size_t index, rtclog::StreamConfig* config) const;
+  rtclog::StreamConfig GetAudioSendConfig(size_t index) const;
 
   // Reads the SSRC from the audio playout event at |index|. The SSRC is stored
   // in the output parameter ssrc. The output parameter can be set to nullptr
   // and in that case the function only asserts that the event is well formed.
   void GetAudioPlayout(size_t index, uint32_t* ssrc) const;
 
   // Reads bitrate, fraction loss (as defined in RFC 1889) and total number of
   // expected packets from the loss based BWE event at |index| and stores the
   // values in
   // the corresponding output parameters. Each output parameter can be set to
@@ skipping 16 matching lines @@
   void GetAudioNetworkAdaptation(size_t index,
                                  AudioEncoderRuntimeConfig* config) const;
 
   BweProbeClusterCreatedEvent GetBweProbeClusterCreated(size_t index) const;
 
   BweProbeResultEvent GetBweProbeResult(size_t index) const;
 
   MediaType GetMediaType(uint32_t ssrc, PacketDirection direction) const;
 
  private:
-  void GetVideoReceiveConfig(const rtclog::Event& event,
-                             rtclog::StreamConfig* config) const;
-  void GetVideoSendConfig(const rtclog::Event& event,
-                          rtclog::StreamConfig* config) const;
-  void GetAudioReceiveConfig(const rtclog::Event& event,
-                             rtclog::StreamConfig* config) const;
-  void GetAudioSendConfig(const rtclog::Event& event,
-                          rtclog::StreamConfig* config) const;
+  rtclog::StreamConfig GetVideoReceiveConfig(const rtclog::Event& event) const;
+  std::vector<rtclog::StreamConfig> GetVideoSendConfig(
+      const rtclog::Event& event) const;
+  rtclog::StreamConfig GetAudioReceiveConfig(const rtclog::Event& event) const;
+  rtclog::StreamConfig GetAudioSendConfig(const rtclog::Event& event) const;
 
   std::vector<rtclog::Event> events_;
 
   struct Stream {
     Stream(uint32_t ssrc,
            MediaType media_type,
            webrtc::PacketDirection direction)
         : ssrc(ssrc), media_type(media_type), direction(direction) {}
     uint32_t ssrc;
     MediaType media_type;
     webrtc::PacketDirection direction;
   };
 
   // All configured streams found in the event log.
   std::vector<Stream> streams_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_LOGGING_RTC_EVENT_LOG_RTC_EVENT_LOG_PARSER_H_