optimize SDP input probing for video streams

Set max_ts_probe and fpsprobesize to 0 for SDP
video to reduce stream initialization latency.

Change-Id: Idfda66cfc72cb1a9d45c6da4e13c73f82859b1de

src/media/media_decoder.cpp

@@ -175,11 +175,14 @@ MediaDemuxer::openInput(const DeviceParams& params)
     }
 
     // Ask FFmpeg to open the input using the options set above
-    av_opt_set_int(
-        inputCtx_,
-        "fpsprobesize",
-        1,
-        AV_OPT_SEARCH_CHILDREN); // Don't waste time fetching framerate when finding stream info
+    if (params.disable_dts_probe_delay && params.format == "sdp") {
+        av_opt_set_int(inputCtx_, "max_ts_probe", 0, AV_OPT_SEARCH_CHILDREN);
+        av_opt_set_int(inputCtx_, "fpsprobesize", 0, AV_OPT_SEARCH_CHILDREN);
+    } else {
+        // Don't waste time fetching framerate when finding stream info
+        av_opt_set_int(inputCtx_, "fpsprobesize", 1, AV_OPT_SEARCH_CHILDREN);
+    }
+
     int ret = avformat_open_input(&inputCtx_, input.c_str(), iformat, options_ ? &options_ : NULL);
 
     if (ret) {

src/media/media_device.h

@@ -52,6 +52,8 @@ struct DeviceParams
     int fd {}; // file descriptor for PipeWire (only relevant on Wayland)
     std::string node {}; // node id for PipeWire
     int is_area {};
+    // Skip DTS delay while finding stream info when PTS is sufficient
+    bool disable_dts_probe_delay = false;
 };
 
 } // namespace jami

src/media/video/video_receive_thread.cpp

@@ -138,6 +138,8 @@ VideoReceiveThread::setup()
         videoDecoder_->setIOContext(&sdpContext_);
     }
 
+    args_.disable_dts_probe_delay = true;
+
     if (videoDecoder_->openInput(args_)) {
         JAMI_ERR("Unable to open input \"%s\"", args_.input.c_str());
         return false;