GB Audio: Make audio unsigned with bias (fixes #749)

This commit is contained in:
Vicki Pfau 2017-07-08 21:32:51 -07:00
parent 15d66422a9
commit 539e63d49b
2 changed files with 7 additions and 6 deletions

View File

@ -1,6 +1,7 @@
0.7.0: (Future)
Bugfixes:
- GB Audio: Fix zombie mode bit masking
- GB Audio: Make audio unsigned with bias (fixes mgba.io/i/749)
Misc:
- GBA Timer: Use global cycles for timers

View File

@ -620,8 +620,9 @@ void GBAudioSamplePSG(struct GBAudio* audio, int16_t* left, int16_t* right) {
}
}
*left = sampleLeft * (1 + audio->volumeLeft);
*right = sampleRight * (1 + audio->volumeRight);
int dcOffset = audio->style == GB_AUDIO_GBA ? 0 : 0x1FC;
*left = (sampleLeft - dcOffset) * (1 + audio->volumeLeft);
*right = (sampleRight - dcOffset) * (1 + audio->volumeRight);
}
static void _sample(struct mTiming* timing, void* user, uint32_t cyclesLate) {
@ -710,7 +711,7 @@ bool _writeEnvelope(struct GBAudioEnvelope* envelope, uint8_t value) {
}
static void _updateSquareSample(struct GBAudioSquareChannel* ch) {
ch->sample = (ch->control.hi * 2 - 1) * ch->envelope.currentVolume * 0x8;
ch->sample = ch->control.hi * ch->envelope.currentVolume * 0x8;
}
static int32_t _updateSquareChannel(struct GBAudioSquareChannel* ch) {
@ -861,8 +862,7 @@ static void _updateChannel3(struct mTiming* timing, void* user, uint32_t cyclesL
ch->sample = bitsCarry >> 4;
break;
}
ch->sample -= 8;
ch->sample *= volume * 4;
ch->sample *= volume * 2;
audio->ch3.readable = true;
if (audio->style == GB_AUDIO_DMG) {
mTimingDeschedule(audio->timing, &audio->ch3Fade);
@ -889,7 +889,7 @@ static void _updateChannel4(struct mTiming* timing, void* user, uint32_t cyclesL
do {
int lsb = ch->lfsr & 1;
ch->sample = lsb * 0x10 - 0x8;
ch->sample = lsb * 0x8;
ch->sample *= ch->envelope.currentVolume;
ch->lfsr >>= 1;
ch->lfsr ^= (lsb * 0x60) << (ch->power ? 0 : 8);