decoder: reduce delay before receiving video

avformat_find_stream_info takes a few seconds to compute the
real/average framerate if it is not in the metadata. We don't
need this, so we can safely skip it.

Change-Id: I134b6f478e4275c3588788c475cdfb630f3f76b5

src/media/media_decoder.cpp

@@ -122,6 +122,7 @@ MediaDemuxer::openInput(const DeviceParams& params)
     JAMI_DBG("Trying to open device %s with format %s, pixel format %s, size %dx%d, rate %lf", params.input.c_str(),
                                                         params.format.c_str(), params.pixel_format.c_str(), params.width, params.height, params.framerate.real());
 
+    inputCtx_->probesize = 1; // Don't waste time fetching framerate when finding stream info
     int ret = avformat_open_input(
         &inputCtx_,
         params.input.c_str(),