[mythtvnz] No sound on videos

[Stephen Worthington]

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