[MPlayer-users] Getting the best sound from mplayer

[Grant]

...
>> > use it, no need to increase anything else iirc). Then again,
>> > lavcresample is said to use only s16le, so your audio will be
>> > downsampled to 16-bit for sure if mplayer resamples something.
>>
>> Hmmm, so I can use a lower quality resampler that will leave 24-bit
>> Blu-Ray audio intact, or I can use lavcresample which is a higher
>> quality resampler that will convert the 24-bit audio to 16-bit?
>
> You got me confused. I forgot, explain again please why you need
> resampling in mplayer anyway?

I think I was interested in how mplayer resamples because I thought
resampling was necessary to combine the 6 channels into 2.  Now that
you've told me resampling isn't necessary in order to downmix, I guess
I don't need to worry about it.  My sound card handles 16/24 44.1, 48,
88.2, and 96.  mplayer should never resample a DVD or Blu-Ray I play,
correct?

>> >> Doesn't resampling need to take place in order to downmix the 6
>> >> channels to 2?  My question was meant in the context of that downmix
>> >> and resampling.
...
> resampling isn't required to combine two or more digital audio streams
> of same sample rate. It is required when streams have different rate;
> then one will have to be resampled to rate of other first, or (more
> common) each has to be resampled to same common sample rate before
> muxing.

I didn't realize that, thank you.

> If you are not using pulse, however, and mplayer detect that your sound
> card can only accept 48k stream (for example), it might turn on
> resampling to that rate automatically (well, depends on audio driver
> again, sometimes it'll be up to audio driver to behave differently). You
> will see some line about that in mplayer output during playback.

Shouldn't mplayer let ALSA handle any resampling necessary for the sound card?

Another question, is -af-adv force=5 better than force=1?  force=5 is
described as:

"Use automatic insertion of filters according to 1 above, but use
floating point processing when possible."

So I guess the question is whether or not floating point processing
provides an improvement in quality/accuracy?

BTW, it looks like 'ffmpeg -i title.mkv' is a good tool to describe
audio streams including the number of channels so you can specify the
appropriate one in mplayer and apply the correct pan filter.

- Grant