Thanks for your email! On Fri, Jul 17, 2020 at 4:20 PM Tanu Kaskinen <[email protected]> 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). > em... I also have an appearance with a USB sound card, and something else is abnormal. 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 BTW: Do you know how the USB sound driver receives the volume data from PulseAudio? The ioctl? or other else? I can not determine. Regards. Aaron. > -- > Tanu > > _______________________________________________ > pulseaudio-discuss mailing list > [email protected] > https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss >
_______________________________________________ pulseaudio-discuss mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
