Re: [transcode-users] v4l2 - saa7134: Advantages of PCI audiocopared to external soundcard?

[Erik Slagter <erik@xxxxxxxxxxxxx>]

On Tue, 2005-03-01 at 23:55 +0100, Christian Lohmaier wrote:

> What are the advantages of using the PCI-audio instead of using an
> external soundcard? Are there advantages at all?

Better sync keeping (see other message).

> Furthermore the info I found about this are kind of contradictionary.

Yep, documentation is sparse.

> Some pages claim that the device can only capture at 32kHz, other
> (including "modinfo saa7134") claim that you can set it to 48kHz as
> well.

Yes and yes. If you record using the tuner (from broadcast television),
it can only capture at 32 Khz. If you use the modprobe parameter, the
sampling frequency will become 48 Khz and you can only record sound from
external sources (like a VCR).

But before you're going to make a fuss about it, sound quality of VHS
isn't that great that you need 48 Khz sample frequency. Just stick to
the 32 Khz.

> Is it possible at all to capture audio that is passed to the TV-card
> using the audio-in (when using composite or s-video) using PCI at all?

Yep. Note it only works when there is a valid video signal present,
so try it with e.g. xawtv running and then run sox to read /dev/dsp1
and play it on /dev/dsp