Re: 5.1 audio on stereo gear

On Sat, Feb 22, 2025 at 16:28 Jan Stary <hans@stare.cz> wrote:

> > Thesr contain 5.1 audio. Playing it on my stereo gear
> > (I only have two ears anyway), I would expect the players
> > (mplayer, ffplay, mpv, vlc) to do the reasonable thing:
> > figure out the "right" position in the stereo panorama
> > and play it "there".
> >
> > But it seems only mplayer does that - for example,
> > all the other players play the "center" channel on the left.
> >
> > If anyone cares about this, can you plese confirm/report what
> > the various players do with this on your stereo hardware?
>
> In short, for ffmpeg, passing `-ac 2` will force it to mix down to
> stereo.

For the record: 'ffplay -ac 2' does not work:
it plays a 5.1 movie silently and slowly.

The fplay(1) manpage doesn't even mention -ac,
but ffplay apparently accepts it, as an ffmpeg option.

Thanks for noting this. I don't recall having tested `-ac 2` with `ffplay`.

> My testing with mpv showed that using the `--audio-channels=stereo`
> configuration option correctly mixes down to stereo with dialog
> correctly mixed across both left & right channels.

That works, thanks.

> $ ffplay -af "aformat=channel_layouts=stereo" ...

That also works, thanks.

Thanks for confirming that they worked for you!