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VIA AC97: Change FM data format after an exhaustive probe

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This commit is contained in:
RichardG867
2021-08-04 01:00:44 -03:00
parent 9d953623e5
commit 6ee9274582
1 changed files with 9 additions and 6 deletions
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15
src/sound/snd_ac97_via.c
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@@ -57,7 +57,7 @@ typedef struct _ac97_via_ {
ac97_via_sgd_t sgd[6];
pc_timer_t timer_count, timer_count_fm;
uint64_t timer_latch;
uint64_t timer_latch, timer_latch_fm;
int16_t out_l, out_r, fm_out_l, fm_out_r;
int master_vol_l, master_vol_r, pcm_vol_l, pcm_vol_r, cd_vol_l, cd_vol_r;
int32_t buffer[SOUNDBUFLEN * 2], fm_buffer[SOUNDBUFLEN * 2];
@@ -713,16 +713,18 @@ ac97_via_poll_fm(void *priv)
/* Schedule next run if FM playback is enabled. */
if (dev->fm_enabled)
timer_advance_u64(&dev->timer_count_fm, dev->timer_latch);
timer_advance_u64(&dev->timer_count_fm, dev->timer_latch_fm);
/* Update FM audio buffer. */
ac97_via_update_fm(dev);
/* Feed next sample from the FIFO.
Unknown data format assumed to be 8-bit stereo. */
if ((sgd->fifo_end - sgd->fifo_pos) >= 2) {
dev->fm_out_l = (sgd->fifo[sgd->fifo_pos++ & (sizeof(sgd->fifo) - 1)] ^ 0x80) << 8;
dev->fm_out_r = (sgd->fifo[sgd->fifo_pos++ & (sizeof(sgd->fifo) - 1)] ^ 0x80) << 8;
The data format is not documented, but it probes as 16-bit stereo at 24 KHz. */
if ((sgd->fifo_end - sgd->fifo_pos) >= 4) {
dev->out_l = *((uint16_t *) &sgd->fifo[sgd->fifo_pos & (sizeof(sgd->fifo) - 1)]);
sgd->fifo_pos += 2;
dev->out_r = *((uint16_t *) &sgd->fifo[sgd->fifo_pos & (sizeof(sgd->fifo) - 1)]);
sgd->fifo_pos += 2;
return;
}
@@ -772,6 +774,7 @@ ac97_via_speed_changed(void *priv)
freq = 48000.0;
dev->timer_latch = (uint64_t) ((double) TIMER_USEC * (1000000.0 / freq));
dev->timer_latch_fm = (uint64_t) ((double) TIMER_USEC * (1000000.0 / 24000.0));
}