[pulseaudio-discuss] 0.9.8 - Invalid value for card

Lennart Poettering lennart at poettering.net
Thu Mar 27 12:17:05 PDT 2008

On Thu, 27.03.08 13:27, Jim Duda (jim at duda.tzo.com) wrote:

> Yes, I do understand that I can only get PCM stereo through the spdif using pulseaudio at this time (no AC3/DTS).
> My understanding (from reading all the posts) is that it's really a flaw with ALSA, which pulseaudio doesn't have a 
> means to resolve (poor API with alsa spdif support).
> I really would love pulseaudio with AC3/DTS passthrough, but I understand we don't have it yet.
> I'm really just playing with stereo support through spdif at this time.
> What might be a useful interim solution is to use the alsa a52 encoder.
> The alsa a52 encoder will take a 6 channel "analog" audio source and encode it to a52 digital and then route out the 
> spdif port.  It has worked very well for me to upmix 2 channel stereo to 6 channel a52.
> In .asoundrc, I have:
> pcm.a52encode {
>     type a52
> }

My recommendation: first try to get alsa to work, than make PA work on
top of it. Try testing your a52 device with aplay first:

  aplay -c 6 -f S16_LE -r 44100 -v -D a52encode < /dev/urandom

If this doesn't work, then please contact the ALSA guys. 


Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
http://0pointer.net/lennart/           GnuPG 0x1A015CC4

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