Monorepo for Aesthetic.Computer
aesthetic.computer
fix: default audio to 48kHz — codecs that claim 192kHz often can't sustain it
MacBook Pro 2011 Cirrus Logic CS4206 reports 32k-192kHz range but XRUNs
constantly at 192kHz. Default to 48kHz for all laptop HDA codecs.
AC_AUDIO_RATE env var overrides for known-good 192kHz hardware.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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fedac/native/src/audio.c
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fedac/native/src/audio.c
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snd_pcm_hw_params_get_rate_max(params, &rate_max, NULL);
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fprintf(stderr, "[audio] Hardware rate range: %u–%u Hz\n", rate_min, rate_max);
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// Try rates from highest to lowest — pick the best the hardware supports
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unsigned int preferred_rates[] = { 192000, 96000, 48000, 44100, 0 };
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unsigned int rate = 0;
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for (int i = 0; preferred_rates[i]; i++) {
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unsigned int try_rate = preferred_rates[i];
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if (try_rate > rate_max || try_rate < rate_min) continue;
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// Test if this exact rate works
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if (snd_pcm_hw_params_test_rate(pcm, params, try_rate, 0) == 0) {
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rate = try_rate;
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fprintf(stderr, "[audio] Selected rate: %u Hz\n", rate);
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break;
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}
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// Pick sample rate: 48kHz is the safe default that all hardware can sustain.
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// Many codecs (e.g. Cirrus Logic CS4206) claim 192kHz support but can't
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// sustain it without constant XRUNs. Only use high rates on known-good
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// hardware (ThinkPad HDA with Realtek codec handles 192kHz fine).
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// Heuristic: if max rate > 48kHz AND min rate <= 32kHz, the codec is
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// likely a laptop HDA that works better at 48kHz.
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unsigned int rate = 48000;
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if (rate_max >= 192000 && rate_min > 44100) {
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// Dedicated audio interface — likely supports high rates reliably
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rate = 192000;
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} else if (rate_max >= 96000 && rate_min > 44100) {
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rate = 96000;
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}
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if (rate == 0) {
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// Fallback: let ALSA pick the nearest to 48kHz
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rate = 48000;
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fprintf(stderr, "[audio] No preferred rate supported, falling back to nearest-48kHz\n");
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// Override: environment variable AC_AUDIO_RATE forces a specific rate
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const char *env_rate = getenv("AC_AUDIO_RATE");
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if (env_rate) {
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unsigned int r = (unsigned int)atoi(env_rate);
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if (r >= rate_min && r <= rate_max) rate = r;
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}
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fprintf(stderr, "[audio] Selected rate: %u Hz (hw range %u–%u)\n", rate, rate_min, rate_max);
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snd_pcm_hw_params_set_rate_near(pcm, params, &rate, 0);
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// Scale period and buffer to ~1ms latency at the negotiated rate