* (de)muxers in libavdevice are of the AVFMT_NOFILE type (they use their own
* I/O functions). The filename passed to avformat_open_input() often does not
* refer to an actually existing file, but has some special device-specific
* (de)muxers in libavdevice are of the AVFMT_NOFILE type (they use their own
* I/O functions). The filename passed to avformat_open_input() often does not
* refer to an actually existing file, but has some special device-specific