[EXPERIMENTAL] Generic stereo codec with index header sending single frames

modules/video_coding/video_codec_initializer.cc

Index: modules/video_coding/video_codec_initializer.cc
diff --git a/modules/video_coding/video_codec_initializer.cc b/modules/video_coding/video_codec_initializer.cc
index 51131ed83f3cf4fcc61a8bfc2eb284cc2bf5ded4..7cd9b10b0795372b58f618702020a568837dfd01 100644
--- a/modules/video_coding/video_codec_initializer.cc
+++ b/modules/video_coding/video_codec_initializer.cc
@@ -39,9 +39,9 @@ bool VideoCodecInitializer::SetupCodec(
     bool nack_enabled,
     VideoCodec* codec,
     std::unique_ptr<VideoBitrateAllocator>* bitrate_allocator) {
-  *codec =
-      VideoEncoderConfigToVideoCodec(config, streams, settings.payload_name,
-                                     settings.payload_type, nack_enabled);
+  *codec = VideoEncoderConfigToVideoCodec(
+      config, streams, settings.payload_name, settings.payload_type,
+      settings.stereo_associated_payload_name, nack_enabled);
 
   std::unique_ptr<TemporalLayersFactory> tl_factory;
   switch (codec->codecType) {
@@ -97,6 +97,7 @@ VideoCodec VideoCodecInitializer::VideoEncoderConfigToVideoCodec(
     const std::vector<VideoStream>& streams,
     const std::string& payload_name,
     int payload_type,
+    const std::string& stereo_associated_payload_name,
     bool nack_enabled) {
   static const int kEncoderMinBitrateKbps = 30;
   RTC_DCHECK(!streams.empty());
@@ -106,6 +107,12 @@ VideoCodec VideoCodecInitializer::VideoEncoderConfigToVideoCodec(
   memset(&video_codec, 0, sizeof(video_codec));
   video_codec.codecType = PayloadStringToCodecType(payload_name);
 
+  const bool is_stereo_codec = video_codec.codecType == kVideoCodecStereo;
+  if (is_stereo_codec) {
+    video_codec.codecType =
+        PayloadStringToCodecType(stereo_associated_payload_name);
+  }
+
   switch (config.content_type) {
     case VideoEncoderConfig::ContentType::kRealtimeVideo:
       video_codec.mode = kRealtimeVideo;
@@ -238,6 +245,10 @@ VideoCodec VideoCodecInitializer::VideoEncoderConfigToVideoCodec(
 
   RTC_DCHECK_GT(streams[0].max_framerate, 0);
   video_codec.maxFramerate = streams[0].max_framerate;
+
+  if (is_stereo_codec)
+    video_codec.codecType = kVideoCodecStereo;
+
   return video_codec;
 }