[mythtvnz] No sound on videos

[Nick Rout]

On Thu, Feb 18, 2010 at 4:07 PM, Steve Hodge <stevehodge at gmail.com> wrote:
> On Thu, Feb 18, 2010 at 1:59 PM, Nick Rout <nick.rout at gmail.com> wrote:
>
>>
>> On Thu, Feb 18, 2010 at 3:53 PM, Steve Hodge <stevehodge at gmail.com> wrote:
>> > On Thu, Feb 18, 2010 at 1:40 PM, Robin Gilks <g8ecj at gilks.org> wrote:
>> >>
>> >> > On Wed, 17 Feb 2010 19:17:55 +1300, you wrote:
>> >> > Next problem: One of the files I want to be able to play has 24 kHz
>> >> > audio, and that still does not play.  I am guessing that means that
>> >> > the sound chip on the motherboard does not work below 32 kHz.  So
>> >> > does
>> >> > anyone know how to tell Alsa to upsample anything below 32 kHz?  I
>> >> > imagine what is needed is:
>> >> >
>> >> >   24 kHz => 48 kHz
>> >> >   22.5 kHz => 44.1 kHz
>> >> >
>> >>
>> >> Create (if you don't already have one) a file called .asoundrc in the
>> >> home
>> >> account of the user running mythtv with the following
>> >>
>> >> pcm.!default {
>> >>    type plug
>> >>    slave.pcm "spdif"
>> >>    slave.rate 48000
>> >> }
>> >>
>> >> Works for me....
>> >
>> > I've done it that way as well, but it's not quite ideal as it resamples
>> > everything to 48kHz, regardless of what the hardware can actually take.
>> > Most
>> > S/PDIF inputs take 32, 44.1, and 48kHz so ideally you don't want to
>> > resample
>> > if the source is one of those rates. Anyone know if/how ALSA can be
>> > instructed to leave 32kHz and 44.1kHz data alone and resample everything
>> > else to 48kHz?
>>
>>
>> Yes the standard says spdif should take a number of sample rates,
>> however commonly the audio hardware in soundcards will only pass
>> 48kHz. At least that's the way I understand it. So leaving 44.1 as
>> 44.1 may not work, hardware dependent.
>>
>
>
> I believe almost all PC sound hardware will pass 44.1kHz - it's the standard
> for CDs after all. I know the hardware I have certainly does. Many do not
> support 32kHz though. The point is that if your hardware can do it, it's
> desirable to pass 44.1kHz audio in particular with resampling so it'd be
> great if ALSA could do that while resampling everything else to 48kHz.

I certainly agree with your conclusion. There must be a lot of boards
that don't pass 44.1k, given the number of "spdif|hdmi sound not
working in mythmusic" threads I have seen!

Out of interest, what is your hardware?