Content #
Beside the specific -map option, stream specifiers are used with many other options in several forms:
-
stream_index selects the stream with this index (number)
-
stream_type[:stream_index]
stream_type is 1 of letters a (audio), d (data),s (subtitle), t (attachments) or v (video); if stream_index is added, it selects the stream of this type with given index, otherwise it selects all streams of this type
- p:program_id[:stream_index]
if stream_index is added, then selects the stream with stream_index in program with given program_id, else selects all streams in this program
- stream_id
selects the stream by format-specific ID.
For example, to set the bit rate using -b option for the audio and video, we can use the command:
ffmpeg -i input.mpg -b:a 128k -b:v 1500k output.mp4