fn create(&mut self, strmgr: &StreamManager) -> MuxerResult<()> {
if strmgr.get_num_streams() == 0 {
return Err(MuxerError::InvalidArgument);
fn create(&mut self, strmgr: &StreamManager) -> MuxerResult<()> {
if strmgr.get_num_streams() == 0 {
return Err(MuxerError::InvalidArgument);