Merge pull request #10 from thekr1s/progressive-voume-control

Change volume control to implement logarithmic scaling.
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Sasha Hilton 2018-01-30 17:38:40 +01:00 committed by GitHub
commit 91647ab2dd
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@ -15,6 +15,7 @@ use protocol::spirc::{PlayStatus, State, MessageType, Frame, DeviceState};
use mixer::Mixer;
use player::Player;
use std;
use rand;
use rand::Rng;
@ -120,6 +121,29 @@ fn initial_device_state(config: ConnectConfig, volume: u16) -> DeviceState {
})
}
fn volume_to_mixer(volume: u16) -> u16 {
// Volume conversion taken from https://www.dr-lex.be/info-stuff/volumecontrols.html#ideal2
// Convert the given volume [0..0xffff] to a dB gain
// We assume a dB range of 60dB.
// Use the equatation: a * exp(b * x)
// in which a = IDEAL_FACTOR, b = 1/1000
const IDEAL_FACTOR: f64 = 6.908;
let normalized_volume = volume as f64 / std::u16::MAX as f64; // To get a value between 0 and 1
let mut val = std::u16::MAX;
// Prevent val > std::u16::MAX due to rounding errors
if normalized_volume < 0.999 {
let new_volume = (normalized_volume * IDEAL_FACTOR).exp() / 1000.0;
val = (new_volume * std::u16::MAX as f64) as u16;
}
debug!("input volume:{} to mixer: {}", volume, val);
// return the scale factor (0..0xffff) (equivalent to a voltage multiplier).
val
}
impl Spirc {
pub fn new(config: ConnectConfig, session: Session, player: Player, mixer: Box<Mixer>)
-> (Spirc, SpircTask)
@ -145,7 +169,7 @@ impl Spirc {
let volume = config.volume as u16;
let device = initial_device_state(config, volume);
mixer.set_volume(volume as u16);
mixer.set_volume(volume_to_mixer(volume as u16));
let mut task = SpircTask {
player: player,
@ -437,9 +461,8 @@ impl SpircTask {
}
MessageType::kMessageTypeVolume => {
let volume = frame.get_volume();
self.device.set_volume(volume);
self.mixer.set_volume(frame.get_volume() as u16);
self.device.set_volume(frame.get_volume());
self.mixer.set_volume(volume_to_mixer(frame.get_volume() as u16));
self.notify(None);
}
@ -534,21 +557,21 @@ impl SpircTask {
}
fn handle_volume_up(&mut self) {
let mut volume: u32 = self.mixer.volume() as u32 + 4096;
let mut volume: u32 = self.device.get_volume() as u32 + 4096;
if volume > 0xFFFF {
volume = 0xFFFF;
}
self.device.set_volume(volume);
self.mixer.set_volume(volume as u16);
self.mixer.set_volume(volume_to_mixer(volume as u16));
}
fn handle_volume_down(&mut self) {
let mut volume: i32 = self.mixer.volume() as i32 - 4096;
let mut volume: i32 = self.device.get_volume() as i32 - 4096;
if volume < 0 {
volume = 0;
}
self.device.set_volume(volume as u32);
self.mixer.set_volume(volume as u16);
self.mixer.set_volume(volume_to_mixer(volume as u16));
}
fn handle_end_of_track(&mut self) {