[pulseaudio-discuss] The volume control ways in PulseAudio
zhoubb.aaron at gmail.com
Fri Jul 17 09:15:43 UTC 2020
Thanks for your email!
On Fri, Jul 17, 2020 at 4:20 PM Tanu Kaskinen <tanuk at iki.fi> wrote:
> On Fri, 2020-07-17 at 10:57 +0800, Aaron Chou wrote:
> > Hi, all:
> > I am the newer about PulseAudio.
> > When I have some time to learn it, I found that there are two ways in
> > volume control, which is software control and hardware control.
> > I can not understand these two ways.
> > The software way means the volume data will not be sent to the hardware?
> > It is unbelievable.
> Software volume means that PulseAudio modifies the signal to be softer
> or louder. Hardware volume means that PulseAudio sends the signal
> unmodified and tells the hardware to the modification, which requires
> that the hardware provides an interface for controlling the volume (I'm
> currently using a USB sound card that doesn't provide such interface).
I also have an appearance with a USB sound card, and something else is
Such as the volume is set to 0, but it also can play music when the system
reboot or power off.
So I doubt that the volume is not be set to hardware through PulseAudio.
Can I have the following flow chart：
app->pulseaudio(software control)->alsa lib->alsa driver
Do you know how the USB sound driver receives the volume data from
The ioctl? or other else? I can not determine.
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> pulseaudio-discuss at lists.freedesktop.org
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