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Fix PCM data calculation

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This commit is contained in:
Zachary Hall 2024-10-15 15:13:18 -07:00
parent acf868d412
commit 76a6b17e47
2 changed files with 32 additions and 20 deletions
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21
backends/playback/zsm/x16emu/vera_pcm.c
View file

@ -181,11 +181,22 @@ pcm_render(int16_t *buf, unsigned num_samples)
}
}
uint32_t pcm_fifo_avail(void) {
uint32_t cnt_adj = fifo_cnt;
switch ((ctrl >> 4) & 3) {
case 0: return fifo_cnt;
case 1: return fifo_cnt / 2;
case 2: return fifo_cnt / 2;
case 3: return fifo_cnt / 4;
case 3: cnt_adj /= 2;
case 2:
case 1: cnt_adj /= 2;
case 0: break;
}
return 0;
uint32_t output = 0;
uint32_t _phase = phase;
while (cnt_adj != 0) {
uint32_t _prev_phase = _phase;
_phase += rate;
if ((_phase & 0x80) != (_prev_phase & 0x80)) {
output++;
cnt_adj--;
}
}
return output;
}

31
backends/playback/zsm/zsm_backend.hpp
View file

@ -84,22 +84,23 @@ class ZsmBackend : public PlaybackBackend {
return (int16_t)((((int32_t)a) + ((int32_t)b)) >> 1);
}
void audio_step(size_t samples) {
while (pcm_fifo_avail() < samples && remain > 0) {
remain--;
size_t oldpos = file->get_pos();
file->seek((cur++), SeekType::SET);
uint8_t sample;
file->read(&sample, 1, 1);
pcm_write_fifo(sample);
if (remain == 0) {
if (islooped) {
cur = loop;
remain = loop_rem;
}
}
file->seek(oldpos, SeekType::SET);
}
if (samples == 0) return;
while (pcm_fifo_avail() < samples && remain > 0) {
if (pcm_read_rate() == 0) break;
remain--;
size_t oldpos = file->get_pos();
file->seek((cur++), SeekType::SET);
uint8_t sample;
file->read(&sample, 1, 1);
pcm_write_fifo(sample);
if (remain == 0) {
if (islooped) {
cur = loop;
remain = loop_rem;
}
}
file->seek(oldpos, SeekType::SET);
}
samples *= 2;
int16_t *psg_ptr = psg_buf.get_item_sized<int16_t>(samples);
int16_t *pcm_ptr = pcm_buf.get_item_sized<int16_t>(samples);