Features/VolumeControl

Volume Control

Owner

• Name: LennartPoettering

Current status

• Targeted release:
• Last updated: 2007-10-17
• Percentage of completion: 0%

Detailed Description

With the use of Pulse'Audio by default, it makes sense to no longer expose the unintuitive plethora of volume controls and channels that alsa exports, and which is currently reflected 1-1 in the gnome volume control tools (gnome-volume-control and mixer applet). Pulse'Audio already ships with a volume control app, pavucontrol, that is packaged for Fedora (but not installed by default).

The changes that we want to implement for volume control in Fedora 9 are:

• Give pavucontrol a face-lift to bring the user interface up to par with the rest of desktop, and replace gnome-volume-control with it
• Write a replacement for the mixer applet that directly exposes the PA volume concepts. While there is no detailed design for this yet, here are some key ideas:
• Display one slider per active device, with indented additional sliders for active streams on each device
• Maybe we also want a mute button, and some smart snapping for tying stream volume to device volume
• Devices and streams will be identified by icon and name
• Maybe it should be possible to activate an application by clicking on the icon next to its stream
• Advanced features like control of individual channels (left/right or 5-1) or moving of streams between devices will be left to out. They are available through pavucontrol.

Bryan Clark collected some inspirational screenshots .

Benefit to Fedora

The multimedia experience of Fedora users is improved by an easily understandable and much more flexible volume control model.

Scope

Requires changes to pavucontrol, possibly also to Pulse'Audio itself. Requires a replacement mixer applet to be written.

Test Plan

• Verify that pavucontrol is in the default install instead of gnome-volume-control, and the mixer applet on the panel is the new one.

• Verify that pavucontrol and the new mixer applet allow to control the volume of streams and devices; also make sure that feedback works correctly (ie changing the volume in the mixer applet should be reflected in a concurrently running pavucontrol, and vice versa)

• Verify that volume settings are remembered across logouts and reboots

Contingency Plan

Stay with gnome-volume-control and the old mixer applet. No changes, no improvements.

Comments

• How does this relate to non-ALSA mixers such as the HW volume controls on thinkpads? - BillNottingham
• There are already patches to make the thinkpad mixer a normal ALSA mixer. And Takashi intends to merge the Thinkpad mixer track directly into the normal sound card mixer, i.e. a mixer with two Master mixer tracks of which one is controlled via the thinkpad hw controls in addition to sw. Then, we would just use the thinkpad mixer for our volume control and set the master and PCM tracks of the soundchip to 0 db. And everything is fine! - LennartPoettering
• I have created workaround for GNOME to run pavucontrol instead of gnome-volume-control. Requires renaming g-v-c executable by adding ".real" suffix. It is gnome-wm script based. The script and the schema to add to g-v-c.schemas. - JakubRusinek

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