@item -aframes @var{number}
Set the number of audio frames to record.
@item -ar @var{freq}
-Set the audio sampling frequency. For input streams it is set by
-default to 44100 Hz, for output streams it is set by default to the
-frequency of the input stream. If the input file has audio streams
-with different frequencies, the behaviour is undefined.
+Set the audio sampling frequency. there is no default for input streams,
+for output streams it is set by default to the frequency of the input stream.
@item -ab @var{bitrate}
Set the audio bitrate in bit/s (default = 64k).
@item -aq @var{q}
@item -ac @var{channels}
Set the number of audio channels. For input streams it is set by
default to 1, for output streams it is set by default to the same
-number of audio channels in input. If the input file has audio streams
-with different channel count, the behaviour is undefined.
+number of audio channels in input.
@item -an
Disable audio recording.
@item -acodec @var{codec}