Files
LlamaCasty/Services/Audio/AudioLevelMeter.cs
T
gramps dc91c855ef Fix UI polish: scrollbar deselect, web source inline buttons, countdown in Sources, volume click-to-position, meter decay
- Elements scrollbar no longer deselects element on click (check ScrollViewer, not StackPanel)
- Web source: URI + check/revert buttons merged into single DockPanel row, consistent order (✓ rightmost)
- Countdown timer moved from Elements panel to inline in source list row, range clamped to 1-30 min
- Volume slider click-to-position restored: e.Handled prevents IncreaseLarge from overriding position, Thumb drag still works
- Desktop audio meter: asymmetric smoothing (attack 0.2, decay 0.08) for faster response to silence
- 207 tests passing, 0 warnings
2026-08-17 17:36:00 -07:00

63 lines
2.2 KiB
C#

namespace ytLive.Services.Audio;
/// <summary>
/// Computes the smoothed level (0..1) from captured samples. Pure —
/// unit-tested; the <see cref="AudioMixer"/> only feeds it and forwards the
/// result. RMS-based so it tracks perceived loudness, smoothed so the meter
/// does not flicker. Supports asymmetric smoothing: fast attack (rise) and
/// configurable decay (fall) so the meter responds quickly to silence.
/// </summary>
public sealed class AudioLevelMeter
{
private float _level;
public float Level => _level;
public AudioLevelMeter(float attackSmoothing = 0.2f, float decaySmoothing = 0.08f)
{
AttackSmoothing = attackSmoothing;
DecaySmoothing = decaySmoothing;
}
public float AttackSmoothing { get; }
public float DecaySmoothing { get; }
/// <summary>
/// Maps a linear level (0..1) onto the meter's display scale: -60 dBFS..0 dBFS
/// spread linearly across 0..1, with +10 dB of input amplification. Linear RMS
/// of real speech or game audio is ~0.01..0.1 (-40..-20 dBFS), which leaves a
/// flat (linear) meter looking dead; the log scale makes typical levels occupy
/// the bar and the amplification pushes real speech peaks into the red zone
/// (0.8+) at maxed volume instead of hovering at its edge. Inputs at or below
/// -60 dBFS (0.001 linear) read as zero — the meter never idles on background noise.
/// </summary>
public static float ToDisplay(float linear)
{
if (linear <= 0.001f)
return 0f;
var db = 20f * MathF.Log10(linear) + 10f;
return Math.Clamp(1f + db / 60f, 0f, 1f);
}
public float Push(AudioSample sample)
{
if (sample.Samples.Length == 0)
return _level;
double sumSquares = 0;
var count = 0;
foreach (var value in sample.Samples)
{
sumSquares += value * value;
count++;
}
var rms = (float)Math.Sqrt(sumSquares / count);
var smoothing = rms > _level ? AttackSmoothing : DecaySmoothing;
_level = _level * (1 - smoothing) + rms * smoothing;
return _level;
}
public void Reset() => _level = 0;
}