decoder: set fpsprobesize, use default probesize

Setting probesize to 1 has negative impact on file streaming.
Libavformat exposes fpsprobesize option, so we can still keep a minimal
delay before receiving video.

Change-Id: I4121dbbf46b11ed843d78cc148306fba84c1cedc

src/media/media_decoder.cpp

@@ -122,7 +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
+    av_opt_set_int(inputCtx_, "fpsprobesize", 1, AV_OPT_SEARCH_CHILDREN); // Don't waste time fetching framerate when finding stream info
     int ret = avformat_open_input(
         &inputCtx_,
         params.input.c_str(),