output_gstreamer.o: In function `my_bus_callback':
output_gstreamer.c:(.text+0xf68): undefined reference to `gst_pad_get_negotiated_caps'
collect2: error: ld returned 1 exit status
make[6]: *** [gmediarender] Error 1
gst_pad_get_negotiated_caps修改成gst_pad_get_current_caps，原因是高版本的gstreamer里面支持的gst_pad_get_current_caps