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polar stereo?

This commit is contained in:
Kuba 2023-11-15 18:23:22 +00:00
parent e90cb827dd
commit 76e0d5b837
1 changed files with 20 additions and 8 deletions
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28
src/pifmrds/fm_mpx.c
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@ -47,9 +47,12 @@ float low_pass_fir[FIR_PHASES][FIR_TAPS];
float carrier_38[] = {0.0, 0.8660254037844386, 0.8660254037844388, 1.2246467991473532e-16, -0.8660254037844384, -0.8660254037844386};
float carrier_19[] = {0.0, 0.5, 0.8660254037844386, 1.0, 0.8660254037844388, 0.5, 1.2246467991473532e-16, -0.5, -0.8660254037844384, -1.0, -0.8660254037844386, -0.5};
float carrier_31[] = {0.0, 0.7071067811865475, 1.0, 0.7071067811865476, 1.2246467991473532e-16, -0.7071067811865474, -1.0, -0.7071067811865477}; //chatgpt i have hope
int phase_38 = 0;
int phase_19 = 0;
int phase_31 = 0;
float downsample_factor;
@ -319,14 +322,23 @@ int fm_mpx_get_samples(float *mpx_buffer, int drds, float compressor_decay, floa
// Generate the stereo mpx
if( channels > 1 ) {
if(!disablestereo) {
mpx_buffer[i] += 4.05*(out_left+out_right) + // Stereo sum signal
4.05 * carrier_38[phase_38] * (out_left-out_right) + // Stereo difference signal
(pilot_volume-0.1)*carrier_19[phase_19]; // Stereo pilot tone (doing 0.1 minus to balance it out, as by default its 0.9, but to make the 1.0 the normal value of the volume)
if(1) {
mpx_buffer[i] += 4.05*(out_left+out_right) + // Stereo sum signal
4.05 * carrier_38[phase_38] * (out_left-out_right) + // Stereo difference signal
(pilot_volume-0.1)*carrier_19[phase_19]; // Stereo pilot tone (doing 0.1 minus to balance it out, as by default its 0.9, but to make the 1.0 the normal value of the volume)
phase_19++;
phase_38++;
if(phase_19 >= 12) phase_19 = 0;
if(phase_38 >= 6) phase_38 = 0;
phase_19++;
phase_38++;
if(phase_19 >= 12) phase_19 = 0;
if(phase_38 >= 6) phase_38 = 0;
} else { // polar stereo (https://forums.stereotool.com/viewtopic.php?t=6233)
mpx_buffer[i] += 4.05*(out_left+out_right) + // Stereo sum signal (L+R)
4.05 * carrier_31[phase_31] * (out_left-out_right) + // Stereo difference signal
//NO PIOT TONE!!!!!!!!!!!!!!!!!!!!!!!!!!!!
phase_31++;
if(phase_31 >= 8) phase_31 = 0;
}
} else {
mpx_buffer[i] =
mpx_buffer[i] +