Is it possible to control the volume on an Amiga?

[Sim085]

Is it possible to control the volume on an Amiga from the operating system, such as; mute / un-mute or increase / decrease the volume? Is this at all possible with software only? Or additional hardware would be needed? And if additional hardware was indeed needed would this mean bypassing Paula completely or something like what is done for keyboards (piggyback on chip) would be possible?

[Minuous]

It depends on how the app is generating the sound: if done through audio.device or AHI then there would be an opportunity for the OS to intercept this and adjust the volume, however if it is done through direct hardware access then alas not.

[Krashan]

Originally Posted by Sim085

And if additional hardware was indeed needed would this mean bypassing Paula completely or something like what is done for keyboards (piggyback on chip) would be possible?

If you intend to grab audio in digital form, you will have to reproduce the audio part of Paula in your hardware, which is not easy. You can grab analog audio from Paula pins, but they are current outputs, so voltage signal on them is near zero. Then you have to reproduce original current to voltage converter (and audio filter) and disconnect the mainboard one. The latter is not easy, as Paula outputs are wired directly to an op-amp inputs. It means track cutting on PCB, at least in Amigas with PLCC Paula.

[pandy71]

Paula is equipped with 4 DMA audio channels and each channel has separate volume control, also channel can be muted while being active.
Audio level as explained by Minuous can be controlled by OS or by directly controlling HW.

[alexh]

Volume control at the hardware channel level is intrinsic to music playback routines.

i.e. You won't be able to "turn volume to 0 on all channels" because any music player that is running will be constantly changing the volume registers.

Maybe the mute register bit isn't used by music playback routines. Have a go?