[gst-devel] Alsasink rates/channels from gst-inspect versus gstalsa.c

[Tim Müller]

On Wed, 2007-11-14 at 16:45 -0800, John Faith wrote:

> I started looking at this since "gst-launch audiotestsrc ! audioconvert 
> ! audioresample ! alsasink" failed with:
> 
> ...
> Setting pipeline to PAUSED ...
> Pipeline is PREROLLING ...
> Negotiating to 1 channels @ 44100 Hz (format = S16_BE)
> ERROR: from element /pipeline0/alsasink0: Could not get/set settings 
> from/on resource.
> Additional debug info:
> gstalsasink.c(438): set_hwparams (): /pipeline0/alsasink0:
> Sample format not available for playback: Invalid argument

> I thought maybe the right formats/rates were not being returned by 
> alsasink and in this case hardcoding the format to S16_LE gets past this 
> failure.  I've generated debug output (level=5), but the cause of the 
> failure was not obvious to me.
> 
> I'm able to play audio with 'aplay', so I assume that the driver is 
> working at least to some degree.  Is something else required to make 
> alsasink happy?

This looks like a bug somewhere, so I'd recommend you file a bug against
gst-plugins-base (see http://gstreamer.freedesktop.org/bugs/) with the
output of aplay -v, and the output of

  $ GST_DEBUG=*alsa*:5 gst-launch-0.10 ..... ! alsasink 2>dbg.log

(which requires a gstreamer built with gst-debug support).

Cheers
 -Tim