Hi All,

I have found some code to change the ALSA volume level and I am making good use of it, now I am looking for more of a general mixer code. One issue is I now have an audio offset delay from the video I am sending across by UDP, I found I can fix this by setting a -1500 ms latency offset via ALSA mixer.

How would I do this from within Gambas to remotely set the latency offset of a default audio device?

What code are you using to change the ALSA volume level ?

Hi Vuott,

I found this link and I did a English translate to get a better understanding of how to change ALSA volume levels.

Impostare il volume principale del mixer di ALSA - Gambas-it.org - Wikipedia

I hope this is helpful?

Ah, yes, I wrote that page.

I :? suppose you use that code in the 'receiving' program to change the level of ALSA mixer.

You would have to check whether there is a function in the Gambas resources, pertaining to the mixer, that also allows you to manage latency.

 Yes, it is in the receiver part, controlling the main mixer level.

As for "a function in the Gambas resources", where would I start on this and where would I look to rework the mixer level for latency (if possible)?

As this is very new to me, working with the ALSA setup.

GrantXTV said

As for "a function in the Gambas resources", where would I start on this and where would I look to rework the mixer level for latency (if possible)?

In ALSA A.P.I.:

ALSA project - the C library reference: /packaging/alsa-lib/include/mixer.h File Reference
ALSA project - the C library reference: Simple Mixer Interface

Ehmmm… but… do you know C language ?

GrantXTV said

I found I can fix this by setting a -1500 ms latency offset via ALSA mixer.

How do you do this?

No, I have worked with C in the passed in editing code, but my programming history is in BASIC, Such as Spectrum Basic, QBasic, PICBasic, Visual Basic and now Gambas.

I set the latency offset directly from the mixer from within Ubuntu as within this image, I hope this is helpful?
<IMG src=""> </IMG>

From the desktop (Volume, Audio Mixer, Output Devices, Advanced).

(Click to enlarge)

GrantXTV said

 I hope this is helpful?

Darn, we should find out how (the specific external ALSA function) that program handles latency.
We should read its source file.  

So far, I’ve found this ALSA program to test latency:
Test latency.c - AlsaProject
git.alsa-project.org Git - alsa-lib.git/blob - test/latency.c

I will take a look as these links, to get some idea of what is going on and see what is possible.