Make audio bus channels' peak volume consistent

Channels that are inactive -or when playback has not started yet- will report -200 dB as their peak value (which is also the lowest value possible during playback).
This commit is contained in:
Pedro J. Estébanez 2021-02-02 11:25:40 +01:00
parent 6ddfc8e718
commit a2b3a73e2d
3 changed files with 6 additions and 2 deletions

View file

@ -47,6 +47,9 @@ static inline float undenormalise(volatile float f) {
return (v.i & 0x7f800000) < 0x08000000 ? 0.0f : f; return (v.i & 0x7f800000) < 0x08000000 ? 0.0f : f;
} }
static const float AUDIO_PEAK_OFFSET = 0.0000000001f;
static const float AUDIO_MIN_PEAK_DB = -200.0f; // linear2db(AUDIO_PEAK_OFFSET)
struct AudioFrame { struct AudioFrame {
//left and right samples //left and right samples
float l, r; float l, r;

View file

@ -401,6 +401,7 @@ void AudioServer::_mix_step() {
for (int k = 0; k < bus->channels.size(); k++) { for (int k = 0; k < bus->channels.size(); k++) {
if (!bus->channels[k].active) { if (!bus->channels[k].active) {
bus->channels.write[k].peak_volume = AudioFrame(AUDIO_MIN_PEAK_DB, AUDIO_MIN_PEAK_DB);
continue; continue;
} }
@ -434,7 +435,7 @@ void AudioServer::_mix_step() {
} }
} }
bus->channels.write[k].peak_volume = AudioFrame(Math::linear2db(peak.l + 0.0000000001), Math::linear2db(peak.r + 0.0000000001)); bus->channels.write[k].peak_volume = AudioFrame(Math::linear2db(peak.l + AUDIO_PEAK_OFFSET), Math::linear2db(peak.r + AUDIO_PEAK_OFFSET));
if (!bus->channels[k].used) { if (!bus->channels[k].used) {
//see if any audio is contained, because channel was not used //see if any audio is contained, because channel was not used

View file

@ -199,7 +199,7 @@ private:
last_mix_with_audio = 0; last_mix_with_audio = 0;
used = false; used = false;
active = false; active = false;
peak_volume = AudioFrame(0, 0); peak_volume = AudioFrame(AUDIO_MIN_PEAK_DB, AUDIO_MIN_PEAK_DB);
} }
}; };