Monorepo for Aesthetic.Computer
aesthetic.computer
native: fix -80dB attenuation from system_volume=-1 + software volume keys
ROOT CAUSE of super-quiet speaker audio: read_system_volume_card()
returns -1 when no "Master" mixer exists (SOF cards). The audio
thread's gain stage computed vol = (-0.01)^2 = 0.0001 → -80dB!
Fixes:
- Treat system_volume < 0 as 100% (no attenuation)
- Volume keys: when no hardware Master, step software gain ±5%
- S32_LE shift: <<8 instead of <<16 (24-bit DAI alignment)
- Dither reduced to ±1 LSB (±160 was audible as 24kHz fizz)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
+30
-7
+30
-7
fedac/native/src/audio.c
+30
-7
fedac/native/src/audio.c
···
1480
1480
1481
1481
// Apply system volume (software gain — hardware mixer may not attenuate)
1482
1482
{
1483
-
double vol = audio->system_volume * 0.01; // 0-100 → 0.0-1.0
1483
+
int sv = audio->system_volume;
1484
+
// -1 means no Master mixer found (SOF cards) — treat as 100%
1485
+
if (sv < 0) sv = 100;
1486
+
double vol = sv * 0.01; // 0-100 → 0.0-1.0
1484
1487
// Use squared curve for more natural volume perception
1485
1488
vol = vol * vol;
1486
1489
mix_l *= vol;
···
1589
1592
}
1590
1593
}
1591
1594
/* Widen int16→int32 for S32_LE PCMs (SOF topology).
1592
-
* Left-shift by 16 places the 16-bit sample in the top half
1593
-
* of the 32-bit word, which maps correctly to the S24_LE BE
1594
-
* DAI after the DSP truncates the bottom 8 bits. */
1595
+
* The SSP1 BE DAI runs S24_LE. SOF DSP uses the bottom 24
1596
+
* bits of the S32 container (bits 23:0). Shifting int16 by
1597
+
* 8 places our 16-bit audio in bits 23:8, which fills the
1598
+
* top portion of the 24-bit window — correct for S24-in-S32
1599
+
* bottom-aligned format. (<<16 put data in bits 31:16 which
1600
+
* the DSP's 24-bit window barely saw → super quiet.) */
1595
1601
const void *write_buf = buffer;
1596
1602
if (buffer32) {
1597
1603
for (int j = 0; j < (int)(period_frames * AUDIO_CHANNELS); j++)
1598
-
buffer32[j] = (int32_t)buffer[j] << 16;
1604
+
buffer32[j] = (int32_t)buffer[j] << 8;
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1605
write_buf = buffer32;
1600
1606
}
1601
1607
int remaining = (int)period_frames;
···
3452
3458
}
3453
3459
snd_mixer_close(mixer);
3454
3460
3455
-
// Update cached system volume
3456
-
audio->system_volume = muted ? 0 : read_system_volume_card(audio->card_index);
3461
+
// Update cached system volume. On SOF cards without a "Master" mixer,
3462
+
// read_system_volume_card returns -1. In that case, use software-only
3463
+
// volume: start at 100 and step ±5 with volume keys.
3464
+
if (muted) {
3465
+
audio->system_volume = 0;
3466
+
} else {
3467
+
int hw_vol = read_system_volume_card(audio->card_index);
3468
+
if (hw_vol >= 0) {
3469
+
audio->system_volume = hw_vol;
3470
+
} else {
3471
+
// No Master mixer — software gain mode
3472
+
int sv = audio->system_volume;
3473
+
if (sv < 0) sv = 100; // first call: default 100%
3474
+
if (delta > 0) sv = (sv + 5 > 100) ? 100 : sv + 5;
3475
+
else if (delta < 0) sv = (sv - 5 < 0) ? 0 : sv - 5;
3476
+
audio->system_volume = sv;
3477
+
ac_log("[audio] Software volume: %d%%\n", sv);
3478
+
}
3479
+
}
3457
3480
}
3458
3481
3459
3482
void audio_boot_beep(ACAudio *audio) {