Audio options:
-aframes number set the number of audio frames to output
-aq quality set audio quality (codec-specific)
-ar rate set audio sampling rate (in Hz)
-ac channels set number of audio channels
-an disable audio
-acodec codec force audio codec ('copy' to copy stream)
-vol volume change audio volume (256=normal)
-af filter_graph set audio filters
Advanced Audio options:
-atag fourcc/tag force audio tag/fourcc
-sample_fmt format set sample format
-channel_layout layout set channel layout
-guess_layout_max set the maximum number of channels to try to guess the channel layout
-absf audio bitstream_filters deprecated
-apre preset set the audio options to the indicated preset