kode54
/
cog
2
1
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Equalizer: Better handle interpolating presets 

The old quadra method was broken, too. Now it uses a simple linear
difference sliding scale for the extra points, which seems to work much
better for the 20 kHz band. And the 16 kHz band doesn't get predicted to
heck any more, either.

Signed-off-by: Christopher Snowhill <kode54@gmail.com>
CQTexperiment
Christopher Snowhill 2022-01-27 14:30:14 -08:00
parent 7c012b2714
commit 9caf704630
1 changed files with 13 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
Window/AUPlayerView.m
View File

@ -35,14 +35,12 @@ static NSString* cog_equalizer_extra_genres = @"altGenres";
static const float apple_equalizer_bands_31[31] = { 20, 25, 31.5, 40, 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800, 1000, 1200, 1600, 2000, 2500, 3100, 4000, 5000, 6300, 8000, 10000, 12000, 16000, 20000 };
static const float apple_equalizer_bands_10[10] = { 32, 64, 128, 256, 512, 1000, 2000, 4000, 8000, 16000 };
static inline float quadra(float *p, float frac) { return (((((((((p[0] + p[2]) * 0.5) - p[1]) * frac) * 0.5) + p[1]) - ((p[2] + p[0] + (p[0] * 2.0)) / 2.0)) * frac) * 2.0) + p[0]; }
static inline float interpolatePoint(NSDictionary * preset, float freqTarget) {
if (!cog_equalizer_items)
cog_equalizer_items = _cog_equalizer_items();
// predict extra bands! lpc was too broken, so use quadratic interpolation!
if (freqTarget <= cog_equalizer_bands[0]) {
// predict extra bands! lpc was too broken, quadra was broken, let's try simple linear steps
if (freqTarget < cog_equalizer_bands[0]) {
float work[14];
float work_freq[14];
for (unsigned int i = 0; i < 10; ++i) {
@ -50,8 +48,8 @@ static inline float interpolatePoint(NSDictionary * preset, float freqTarget) {
work_freq[9 - i] = cog_equalizer_bands[i];
}
for (unsigned int i = 10; i < 14; ++i) {
work[i] = quadra(work + i - 3, 0.94);
work_freq[i] = quadra(work_freq + i - 3, 0.94);
work[i] = work[i - 1] + (work[i - 1] - work[i - 2]) * 1.05;
work_freq[i] = work_freq[i - 1] + (work_freq[i - 1] - work_freq[i - 2]) * 1.05;
}
for (unsigned int i = 0; i < 13; ++i) {
if (freqTarget >= work_freq[13 - i] &&
@ -69,7 +67,7 @@ static inline float interpolatePoint(NSDictionary * preset, float freqTarget) {
return work[13];
}
else if (freqTarget >= cog_equalizer_bands[9]) {
else if (freqTarget > cog_equalizer_bands[9]) {
float work[14];
float work_freq[14];
for (unsigned int i = 0; i < 10; ++i) {
@ -77,8 +75,8 @@ static inline float interpolatePoint(NSDictionary * preset, float freqTarget) {
work_freq[i] = cog_equalizer_bands[i];
}
for (unsigned int i = 10; i < 14; ++i) {
work[i] = quadra(work + i - 3, 0.94);
work_freq[i] = quadra(work_freq + i - 3, 0.94);
work[i] = work[i - 1] + (work[i - 1] - work[i - 2]) * 1.05;
work_freq[i] = work_freq[i - 1] + (work_freq[i - 1] - work_freq[i - 2]) * 1.05;
}
for (unsigned int i = 0; i < 13; ++i) {
if (freqTarget >= work_freq[i] &&
@ -97,6 +95,12 @@ static inline float interpolatePoint(NSDictionary * preset, float freqTarget) {
return work[13];
}
// Pick the extremes
if (freqTarget == cog_equalizer_bands[0])
return [[preset objectForKey:[cog_equalizer_items objectAtIndex:1]] floatValue];
else if (freqTarget == cog_equalizer_bands[9])
return [[preset objectForKey:[cog_equalizer_items objectAtIndex:10]] floatValue];
// interpolation time! linear is fine for this
for (size_t i = 0; i < 9; ++i) {