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

[Tim Müller]

On Wed, 2007-11-14 at 14:07 -0800, John Faith wrote:

> On my embedded Power architecture board, I noticed that 'gst-inspect 
> alsasink' produces:
> 
>   ...
>   rate: [ 1, 2147483647 ]
>   channels: [ 1, 2147483647 ]
> 
> , whereas gst_alsa_detect_rates() and gst_alsa_detect_channels() in 
> gst-plugins-base-0.10.12/ext/alsa/gstalsa.c produce minimum rate of 4000 
> and max channels of 8.
> 
> Why are the ranges from gst-inspect and printfs in gstalsa.c different?

gst-inspect prints the so-called 'pad template caps', which comprises
any format theoretically possible.  gst_alsa_detect_rates() is called
when the device has been opened, at which point it is possible to query
the formats the device in question actually supports (which depends on
things such as the alsa device being used, compare e.g. dmix:0 to hw:0
to plughw:0, or the device driver or the capabilities of the hardware in
question).

 Cheers
  -Tim