[mythtv] [mythtv-commits] Ticket #1104: multi channel audiosupport

Neil Garratt ngarratt at gmail.com
Mon Feb 18 17:20:15 UTC 2008

>  how does mythmusic like this setting?
>  this impacts time to paused. I thought 1/2 second was excessive.
>  does 200000 work?
>  is it only passthru or does the same thing happen with analog out?

At anything less than 40000 I still get occasional loss of audio. This
only affects passthru; normal audio (which is sent to a PCM device
that routes over IEC958 to my receiver) works correctly with 10000.
Given the variety of hardware out there, 50000 is probably the safest

I don't use MythMusic, but I can built it if necessary for testing.

I've also looked at timestretch on AC3 streams and hit some problems.
When enabling timestretch it switches from my passthru device to my
default device (which only handles PCM and the card routes to S/PDIF).
Obviously this doesn't work and I just get clicking.

Setting my default device to iec958 fixes this, but I have volume
problems with PCM sent directly to this device so it's not really a
solution. Shouldn't it continue to use the original device given that
it's still going to be the same type of stream?

Lastly, I only get 2-channel AC-3 when in timestretch. You mentioned
that it should re-encode to the original number of channels?

This is with internal FFmpeg AC-3 and FFTW3; if I switch to A52 I get
garbled sound when in timestretch.

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