[Fwd: Re: [oss-devel] [Correction] libgstoss4audio / SNDCTL_MIX_READ]

classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view
|

[Fwd: Re: [oss-devel] [Correction] libgstoss4audio / SNDCTL_MIX_READ]

Clive Wright
Reply from Hannu Savolainen [oss-devel] to my earlier posting about
gstreamer plugin for OSS4 in gst-plugins-bad

Clive Wright kirjoitti:

> The recently added gstreamer plugin for OSS4 has problems handling the
> value returned by SNDCTL_MIX_READ for control type MIXT_MONOSLIDER16
> (and I suspect MIXT_MONOSLIDER).
>
> See attached extract of oss4_mixer.log
>
> This appears to be caused by stereo values being returned by
> SNDCTL_MIX_READ for these control types.
>
> The OSS v4 Programmer's guide is not explicit in this situation stating
> only that:
>
> "The current value of the mixer control will be returned in the value
> field".
Unfortunately there was some syntax error in the source file for the
manual page for SNDCTL_MIX_EXTINFO and almost everything on that page
was cut off. Anyway now the
http://manuals.opensound.com/developer/SNDCTL_MIX_EXTINFO.html page
contains links to the pages for all the MIXT_ types. The encoding of the
value field is defined there.

In short:

MIXT_SLIDER is 31 bit positive integer.
MIXT_MONOSLIDER is 8 bit positive integer (0xVV)
MIXT_MONOSLIDER is 16 bit positive integer (0xVVVV).
MIXT_STEREOSLIDER is a pair of 8 bit positive integers (0xRRLL)
MIXT_STEREOSLIDER16 is a pair of 16 bit positive integers (0xRRRRLLLL).
Both LLLL and RRRR limited to 0..32767 range.

Best regards,

Hannu
_______________________________________________
oss-devel mailing list
[hidden email]
http://mailman.opensound.com/mailman/listinfo/oss-devel

-------------------------------------------------------------------------
This SF.net email is sponsored by the 2008 JavaOne(SM) Conference
Don't miss this year's exciting event. There's still time to save $100.
Use priority code J8TL2D2.
http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone
_______________________________________________
gstreamer-devel mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/gstreamer-devel