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Merge pull request #215 from luarvique/master
Fixed subsampling in AFSK12, CLIPFSK, EAS, FMSFSK, UFSK12 decoders
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
|
|
@@ -3,6 +3,8 @@ | |
| * | ||
| * Copyright (C) 1996 | ||
| * Thomas Sailer ([email protected], [email protected]) | ||
| * Copyright (C) 2024 | ||
| * Marat Fayzullin ([email protected]) | ||
| * | ||
| * This program is free software; you can redistribute it and/or modify | ||
| * it under the terms of the GNU General Public License as published by | ||
|
|
@@ -79,16 +81,15 @@ static void afsk12_demod(struct demod_state *s, buffer_t buffer, int length) | |
| unsigned char curbit; | ||
|
|
||
| if (s->l1.afsk12.subsamp) { | ||
| int numfill = SUBSAMP - s->l1.afsk12.subsamp; | ||
| if (length < numfill) { | ||
| s->l1.afsk12.subsamp += length; | ||
| if (length <= (int)s->l1.afsk12.subsamp) { | ||
| s->l1.afsk12.subsamp -= length; | ||
| return; | ||
| } | ||
| buffer.fbuffer += numfill; | ||
| length -= numfill; | ||
| buffer.fbuffer += s->l1.afsk12.subsamp; | ||
| length -= s->l1.afsk12.subsamp; | ||
| s->l1.afsk12.subsamp = 0; | ||
| } | ||
| for (; length >= SUBSAMP; length -= SUBSAMP, buffer.fbuffer += SUBSAMP) { | ||
| for (; length > 0; length -= SUBSAMP, buffer.fbuffer += SUBSAMP) { | ||
| f = fsqr(mac(buffer.fbuffer, corr_mark_i, CORRLEN)) + | ||
| fsqr(mac(buffer.fbuffer, corr_mark_q, CORRLEN)) - | ||
| fsqr(mac(buffer.fbuffer, corr_space_i, CORRLEN)) - | ||
|
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@@ -116,7 +117,7 @@ static void afsk12_demod(struct demod_state *s, buffer_t buffer, int length) | |
| hdlc_rxbit(s, curbit); | ||
| } | ||
| } | ||
| s->l1.afsk12.subsamp = length; | ||
| s->l1.afsk12.subsamp = -length; | ||
| } | ||
|
|
||
| /* ---------------------------------------------------------------------- */ | ||
|
|
||
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
|
|
@@ -5,6 +5,8 @@ | |
| * | ||
| * Copyright (C) 2000 | ||
| * A. Maitland Bottoms <[email protected]> | ||
| * Copyright (C) 2024 | ||
| * Marat Fayzullin <[email protected]> | ||
| * | ||
| * Licensed under same terms and based upon the | ||
| * demod_afsk12.c -- 1200 baud AFSK demodulator | ||
|
|
@@ -253,20 +255,19 @@ static void eas_demod(struct demod_state *s, buffer_t buffer, int length) | |
| float f; | ||
| unsigned char curbit; | ||
| float dll_gain; | ||
|
|
||
| if (s->l1.eas.subsamp) { | ||
| int numfill = SUBSAMP - s->l1.eas.subsamp; | ||
| if (length < numfill) { | ||
| s->l1.eas.subsamp += length; | ||
| if (length <= (int)s->l1.eas.subsamp) { | ||
| s->l1.eas.subsamp -= length; | ||
| return; | ||
| } | ||
| buffer.fbuffer += numfill; | ||
| length -= numfill; | ||
| buffer.fbuffer += s->l1.eas.subsamp; | ||
| length -= s->l1.eas.subsamp; | ||
| s->l1.eas.subsamp = 0; | ||
| } | ||
| // We use a sliding window correlator which advances by SUBSAMP | ||
| // each time. One correlator sample is output for each SUBSAMP symbols | ||
| for (; length >= SUBSAMP; length -= SUBSAMP, buffer.fbuffer += SUBSAMP) { | ||
| for (; length > 0; length -= SUBSAMP, buffer.fbuffer += SUBSAMP) { | ||
| f = fsqr(mac(buffer.fbuffer, eascorr_mark_i, CORRLEN)) + | ||
| fsqr(mac(buffer.fbuffer, eascorr_mark_q, CORRLEN)) - | ||
| fsqr(mac(buffer.fbuffer, eascorr_space_i, CORRLEN)) - | ||
|
|
@@ -286,14 +287,13 @@ static void eas_demod(struct demod_state *s, buffer_t buffer, int length) | |
| { | ||
| s->l1.eas.dcd_integrator -= 1; | ||
| } | ||
|
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||
| verbprintf(9, "%c", '0'+(s->l1.afsk12.dcd_shreg & 1)); | ||
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| /* | ||
| * check if transition occurred on time | ||
| */ | ||
|
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||
| if (s->l2.eas.state != EAS_L2_IDLE) | ||
| dll_gain = DLL_GAIN_SYNC; | ||
| else | ||
|
|
@@ -313,7 +313,6 @@ static void eas_demod(struct demod_state *s, buffer_t buffer, int length) | |
| else | ||
| { | ||
| // after center; check for increment | ||
|
|
||
| if (s->l1.eas.sphase < (0x10000u - SPHASEINC/2)) | ||
| { | ||
| s->l1.eas.sphase += MIN((int)((0x10000u - s->l1.eas.sphase)* | ||
|
|
@@ -325,20 +324,20 @@ static void eas_demod(struct demod_state *s, buffer_t buffer, int length) | |
| } | ||
|
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||
| s->l1.eas.sphase += SPHASEINC; | ||
|
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||
| if (s->l1.eas.sphase >= 0x10000u) { | ||
| // end of bit period. | ||
| s->l1.eas.sphase = 1; //was &= 0xffffu; | ||
| s->l1.eas.lasts >>= 1; | ||
|
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||
| // if at least half of the values in the integrator are 1, | ||
| // declare a 1 received | ||
| s->l1.afsk12.lasts |= ((s->l1.eas.dcd_integrator >= 0) << 7) & 0x80u; | ||
|
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||
| curbit = (s->l1.eas.lasts >> 7) & 0x1u; | ||
| verbprintf(9, " "); | ||
| verbprintf(7, "%c", '0'+curbit); | ||
|
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| // check for sync sequence | ||
| // do not resync when we're reading a message! | ||
| if (s->l1.eas.lasts == PREAMBLE | ||
|
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@@ -369,12 +368,11 @@ static void eas_demod(struct demod_state *s, buffer_t buffer, int length) | |
| s->l1.eas.byte_counter = 0; | ||
| } | ||
| } | ||
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| verbprintf(9, "\n"); | ||
| } | ||
| } | ||
| s->l1.eas.subsamp = length; | ||
| s->l1.eas.subsamp = -length; | ||
| } | ||
|
|
||
| /* ---------------------------------------------------------------------- */ | ||
|
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||
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