toCliList method
Returns the video and audio handles for this stream in a list,
to pass into a filter graph as filter inputs or outputs, e.g.,
"0:v
0:a
".
Implementation
List<String> toCliList() {
final streams = <String>[];
if (videoId != null) {
streams.add(videoId!);
}
if (audioId != null) {
streams.add(audioId!);
}
return streams;
}