[mythtvnz] No sound on videos

[Robin Gilks]

> On Wed, 17 Feb 2010 19:17:55 +1300, you wrote:
>
>>On Wed, Feb 17, 2010 at 5:39 PM, Stephen Worthington
>><stephen_agent at jsw.gen.nz> wrote:
>>> On my mother's MythTV box, I have just tried to play a video file (as
>>> opposed to a recorded TV program) for the first time, and there is no
>>> sound.  I tried using the builtin player, and using mplayer.  The
>>> "Audio output device" setting is "ALSA:hdmi" - the sound goes via the
>>> HDMI audio to the TV, and the TV sends it to the amplifier.  It works
>>> fine for TV programs.
>>>
>>> I have tried playing a DivX/MP3 AVI file, and a flash file (VP6/MP3).
>>> Both files play with sound on my own MythTV box using the builtin
>>> player.  My box has the "Audio output device" set to "ALSA:default"
>>> and the sound goes via SPDIF to my DAC and amplifier.
>>>
>>> Does anyone have any ideas what I should do to fix this?  Do I need to
>>> set my mother's box to "ALSA:default" too and find some way in the
>>> ALSA config files to send the audio to the HDMI port?  I have never
>>> found any good documentation on what to put in the ALSA config files -
>>> they seem to be a black magical art.
>>>
>>
>>possibly/probably an audio bitrate other than 48000 in the video file?
>
> Got it in one, thank you.  It looks like the HDMI audio can only be 48
> kHz.  So I have had to get another cable and use the line out from the
> motherboard, with "ALSA: Default".  Fortunately the amplifier had one
> more input left, so that is going now and my mother can play
> downloaded files from TVNZ On Demand.
>
> 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....

-- 
Robin Gilks