From 747224ce57a16f185aca1821f68bc9b4a9376051 Mon Sep 17 00:00:00 2001
From: wb2osz <wb2osz@comcast.net>
Date: Wed, 27 Nov 2019 21:26:59 -0500
Subject: [PATCH] Remove obsolete 'F' demodulator.

---
 src/CMakeLists.txt  |  28 ---------
 src/demod.c         |   1 -
 src/demod_afsk.c    | 137 +-------------------------------------------
 test/CMakeLists.txt |   4 --
 4 files changed, 1 insertion(+), 169 deletions(-)

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 5643bda..af5338a 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -16,28 +16,6 @@ if(WIN32 OR CYGWIN)
   )
 endif()
 
-# build gen_fff to create fsk_fast_filter.h
-# optimization for slow processors
-list(APPEND gen_fff_SOURCES
-  demod_afsk.c
-  dsp.c
-  textcolor.c
-  )
-
-add_executable(gen_fff
-  ${gen_fff_SOURCES}
-  )
-
-set_target_properties(gen_fff
-  PROPERTIES COMPILE_FLAGS "-DGEN_FFF"
-  )
-
-add_custom_command(TARGET gen_fff
-  POST_BUILD
-  COMMAND gen_fff > fsk_fast_filter.h
-  WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-  )
-
 
 # direwolf
 list(APPEND direwolf_SOURCES
@@ -131,8 +109,6 @@ add_executable(direwolf
   ${direwolf_SOURCES}
   )
 
-add_dependencies(direwolf gen_fff)
-
 target_link_libraries(direwolf
   ${GEOTRANZ_LIBRARIES}
   ${MISC_LIBRARIES}
@@ -180,8 +156,6 @@ add_executable(decode_aprs
   ${decode_aprs_SOURCES}
   )
 
-add_dependencies(decode_aprs gen_fff)
-
 set_target_properties(decode_aprs
   PROPERTIES COMPILE_FLAGS "-DDECAMAIN -DUSE_REGEX_STATIC"
   )
@@ -339,8 +313,6 @@ add_executable(atest
   ${atest_SOURCES}
   )
 
-add_dependencies(atest gen_fff)
-
 target_link_libraries(atest
   ${MISC_LIBRARIES}
   ${GPSD_LIBRARIES}
diff --git a/src/demod.c b/src/demod.c
index 312123b..6cc594e 100644
--- a/src/demod.c
+++ b/src/demod.c
@@ -47,7 +47,6 @@
 #include "tune.h"
 #include "fsk_demod_state.h"
 #include "fsk_gen_filter.h"
-#include "fsk_fast_filter.h"
 #include "hdlc_rec.h"
 #include "textcolor.h"
 #include "demod_9600.h"
diff --git a/src/demod_afsk.c b/src/demod_afsk.c
index 59afbfa..1633464 100644
--- a/src/demod_afsk.c
+++ b/src/demod_afsk.c
@@ -63,8 +63,6 @@
 #define MAX(a,b) ((a)>(b)?(a):(b))
 
 
-#ifndef GEN_FFF
-
 /* Quick approximation to sqrt(x*x+y*y) */
 /* No benefit for regular PC. */
 /* Should help with microcomputer platform. */
@@ -137,8 +135,6 @@ static inline float agc (float in, float fast_attack, float slow_decay, float *p
 	return (0.0f);
 }
 
-#endif	// ifndef GEN_FFF
-
 
 /*
  * for multi-slicer experiment.
@@ -197,27 +193,11 @@ void demod_afsk_init (int samples_per_sec, int baud, int mark_freq,
 #endif
 
 
-	if (profile == 'F') {
-
-	  if (baud != DEFAULT_BAUD ||
-	      mark_freq != DEFAULT_MARK_FREQ ||
-	      space_freq!= DEFAULT_SPACE_FREQ ||
-	      samples_per_sec != DEFAULT_SAMPLES_PER_SEC) {
-
-	    	text_color_set(DW_COLOR_INFO);
-		dw_printf ("Note: Decoder 'F' works only for %d baud, %d/%d tones, %d samples/sec.\n",
-			DEFAULT_BAUD, DEFAULT_MARK_FREQ, DEFAULT_SPACE_FREQ, DEFAULT_SAMPLES_PER_SEC);
-		dw_printf ("Using Decoder 'A' instead.\n");
-		profile = 'A';
-	  }
-	}
-
 	D->profile = profile;		// so we know whether to take fast path later.
 
 	switch (profile) {
 
 	  case 'A':
-	  case 'F':
 
 		/* Original.  52 taps, truncated bandpass, IIR lowpass */
 		/* 'F' is the fast version for low end processors. */
@@ -317,6 +297,7 @@ void demod_afsk_init (int samples_per_sec, int baud, int mark_freq,
 	    D->pll_searching_inertia = 0.350;
 	    break;
 
+	  case 'F':	// removed obsolete. treat as E for now.
 	  case 'E':
 
 		/* 1200 baud - Started out similar to C but add prefilter. */
@@ -686,7 +667,6 @@ failed experiment
 	  space_gain[j] = space_gain[j-1] * step;
 	}
 
-#ifndef GEN_FFF
 #if 0
 	text_color_set(DW_COLOR_DEBUG);
 	for (j=0; j<MAX_SUBCHANS; j++) {
@@ -694,90 +674,10 @@ failed experiment
 	  dw_printf ("G = %.3f, %+.1f dB\n", space_gain[j], db);
 	}
 #endif
-#endif
 
 }  /* fsk_gen_filter */
 
 
-#if GEN_FFF
-
-
-
-// Properties of the radio channels.
-
-static struct audio_s modem;
-
-
-// Filters will be stored here. 
-
-static struct demodulator_state_s ds;
-
-
-#define SPARSE 3
-
-
-static void emit_macro (char *name, int size, float *coeff)
-{
-	int i;
-
-	dw_printf ("#define %s(x) \\\n", name);
-
-	for (i=SPARSE/2; i<size; i+=SPARSE) {
-	  dw_printf ("\t%c (%.6ff * x[%d]) \\\n", (i==0 ? ' ' : '+'), coeff[i], i);
-	}
-	dw_printf ("\n");
-}
-
-int main (void)
-{
-	//int n;
-	char fff_profile;
-
-	fff_profile = 'F';		
-
-	memset (&modem, 0, sizeof(modem));
-	memset (&ds, 0, sizeof(ds));
-
-	modem.adev[0].num_channels = 1;
-	modem.adev[0].samples_per_sec = DEFAULT_SAMPLES_PER_SEC;
-	modem.achan[0].mark_freq = DEFAULT_MARK_FREQ;
-	modem.achan[0].space_freq = DEFAULT_SPACE_FREQ;
-	modem.achan[0].baud = DEFAULT_BAUD;
- 	modem.achan[0].num_subchan = 1;
- 	modem.achan[0].num_slicers = 1;
-
-
-	demod_afsk_init (modem.adev[0].samples_per_sec, modem.achan[0].baud,
-			modem.achan[0].mark_freq, modem.achan[0].space_freq, fff_profile, &ds);
-	
-	printf ("/* This is an automatically generated file.  Do not edit. */\n");
-	printf ("\n");
-	printf ("#define FFF_SAMPLES_PER_SEC %d\n", modem.adev[0].samples_per_sec);
-	printf ("#define FFF_BAUD %d\n", modem.achan[0].baud);
-	printf ("#define FFF_MARK_FREQ %d\n", modem.achan[0].mark_freq);
-	printf ("#define FFF_SPACE_FREQ %d\n", modem.achan[0].space_freq);
-	printf ("#define FFF_PROFILE '%c'\n", fff_profile);
-	printf ("\n");
-
-	emit_macro ("CALC_M_SUM1", ds.ms_filter_size, ds.m_sin_table);
-	emit_macro ("CALC_M_SUM2", ds.ms_filter_size, ds.m_cos_table);
-	emit_macro ("CALC_S_SUM1", ds.ms_filter_size, ds.s_sin_table);
-	emit_macro ("CALC_S_SUM2", ds.ms_filter_size, ds.s_cos_table);
-
-	exit(EXIT_SUCCESS);
-}
-
-#endif
-
-
-
-#ifndef GEN_FFF
-
-/* Optimization for slow processors. */
-
-#include "fsk_fast_filter.h"
-
-
 
 /*-------------------------------------------------------------------
  *
@@ -881,37 +781,8 @@ void demod_afsk_process_sample (int chan, int subchan, int sam, struct demodulat
 
 /*
  * Next we have bandpass filters for the mark and space tones.
- *
- * This takes a lot of computation.
- * It's not a problem on a typical (Intel x86 based) PC.
- * Dire Wolf takes only about 2 or 3% of the CPU time.
- *
- * It might be too much for a little microcomputer to handle.
- *
- * Here we have an optimized case for the default values.
  */
 
-
-
-// TODO1.2:   is this right or do we need to store profile in the modulator info?
-
-	
-	if (D->profile == toupper(FFF_PROFILE)) {
-
-				/* ========== Faster for default values on slower processors. ========== */
-
-	  m_sum1 = CALC_M_SUM1(D->ms_in_cb);
-	  m_sum2 = CALC_M_SUM2(D->ms_in_cb);
-	  m_amp = z(m_sum1,m_sum2);
-
-	  s_sum1 = CALC_S_SUM1(D->ms_in_cb);
-	  s_sum2 = CALC_S_SUM2(D->ms_in_cb);
-	  s_amp = z(s_sum1,s_sum2);
-	}
-	else {
-
-				/* ========== General case to handle all situations. ========== */
-	
 /*
  * find amplitude of "Mark" tone.
  */
@@ -928,9 +799,6 @@ void demod_afsk_process_sample (int chan, int subchan, int sam, struct demodulat
 
 	  s_amp = sqrtf(s_sum1 * s_sum1 + s_sum2 * s_sum2);
 
-				/* ========== End of general case. ========== */
-	}
-		
 
 /* 
  * Apply some low pass filtering BEFORE the AGC to remove
@@ -1240,7 +1108,4 @@ inline static void nudge_pll (int chan, int subchan, int slice, int demod_data,
 } /* end nudge_pll */
 
 
-#endif   /* GEN_FFF */
-
-
 /* end demod_afsk.c */
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index d3db28b..e33c0a1 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -127,8 +127,6 @@ add_executable(atest9
   ${atest9_SOURCES}
   )
 
-add_dependencies(atest9 gen_fff)
-
 target_link_libraries(atest9
   ${MISC_LIBRARIES}
   ${REGEX_LIBRARIES}
@@ -529,8 +527,6 @@ if(OPTIONAL_TEST)
     ${testagc_SOURCES}
     )
 
-  add_dependencies(testagc gen_fff)
-
   target_link_libraries(testagc
     ${MISC_LIBRARIES}
     ${GPSD_LIBRARIES}