b4fbd30b70
This change was a long time in the making ever since we obtained sample rate awareness in the system. Now, each client has its own sample rate, accessible via new IPC APIs, and the device sample rate is only accessible via the management interface. AudioServer takes care of resampling client streams into the device sample rate. Therefore, the main improvement introduced with this commit is full responsiveness to sample rate changes; all open audio programs will continue to play at correct speed with the audio resampled to the new device rate. The immediate benefits are manifold: - Gets rid of the legacy hardware sample rate IPC message in the non-managing client - Removes duplicate resampling and sample index rescaling code everywhere - Avoids potential sample index scaling bugs in SoundPlayer (which have happened many times before) and fixes a sample index scaling bug in aplay - Removes several FIXMEs - Reduces amount of sample copying in all applications (especially Piano, where this is critical), improving performance - Reduces number of resampling users, making future API changes (which will need to happen for correct resampling to be implemented) easier I also threw in a simple race condition fix for Piano's audio player loop.
1.9 KiB
Name
asctl - Send control signals to the audio server and hardware
Synopsis
$ asctl [--human-readable] <command> [args...]
Description
This program is used to send control signals to the AudioServer and the sound hardware. This allows changing audio server variables like volume and mute state, as well as querying the state of these variables.
Options
-h,--human-readable: Print human-readable output. If this option is not given, the output ofgetwill be machine-readable and only consist of one line.
Arguments
command: The command to execute, eithergetorset.args: The arguments to the command.
There are two commands available: get reports the state of audio variables, and set changes these variables.
get expects a list of variables to report back, and it will report them in the order given. The exact format of the report depends on the --human-readable flag. If no variables are given, get will report all available variables, in the order that they are listed below.
set expects one or more variables followed by a value to set them to, and will set the variables to the given values. A variable can be given multiple times and the last specified value will remain with the audio server.
The available variables are:
(v)olume: Audio server volume, in percent. Integer value.(m)ute: Mute state. Boolean value, may be set with0,falseor1,true.sample(r)ate: Sample rate of the sound card. Integer value.
Both commands and arguments can be abbreviated: Commands by their first letter, arguments by the letter in parenthesis.
Examples
Get the current volume (machine format)
$ asctl get volume
100
Get all variables
$ asctl -h get
Volume: 100
Muted: No
Sample rate: 48000 Hz
Set the volume to 100%
$ asctl set volume 100
Mute all audio
$ asctl set mute true
Unmute all audio, set volume to 80%
$ asctl s m 0 v 80
Set sample rate
$ asctl s samplerate 48000