xref: /btstack/src/classic/btstack_cvsd_plc.c (revision 2c4f9bbb6d93b3f1a90ed62ac67e4cd019f0736a)
1 /*
2  * Copyright (C) 2016 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "btstack_cvsd_plc.c"
39 
40 /*
41  * btstack_CVSD_plc.c
42  *
43  */
44 
45 #include <stdint.h>
46 #include <stdlib.h>
47 #include <string.h>
48 
49 #ifdef OCTAVE_OUTPUT
50 #include <stdio.h>
51 #endif
52 
53 #include "btstack_cvsd_plc.h"
54 #include "btstack_debug.h"
55 
56 // static float rcos[CVSD_OLAL] = {
57 //     0.99148655f,0.96623611f,0.92510857f,0.86950446f,
58 //     0.80131732f,0.72286918f,0.63683150f,0.54613418f,
59 //     0.45386582f,0.36316850f,0.27713082f,0.19868268f,
60 //     0.13049554f,0.07489143f,0.03376389f,0.00851345f};
61 
62 static float rcos[CVSD_OLAL] = {
63     0.99148655f,0.92510857f,
64     0.80131732f,0.63683150f,
65     0.45386582f,0.27713082f,
66     0.13049554f,0.03376389f};
67 
68 float btstack_cvsd_plc_rcos(int index){
69     if (index > CVSD_OLAL) return 0;
70     return rcos[index];
71 }
72 // taken from http://www.codeproject.com/Articles/69941/Best-Square-Root-Method-Algorithm-Function-Precisi
73 // Algorithm: Babylonian Method + some manipulations on IEEE 32 bit floating point representation
74 static float sqrt3(const float x){
75     union {
76         int i;
77         float x;
78     } u;
79     u.x = x;
80     u.i = (1<<29) + (u.i >> 1) - (1<<22);
81 
82     // Two Babylonian Steps (simplified from:)
83     // u.x = 0.5f * (u.x + x/u.x);
84     // u.x = 0.5f * (u.x + x/u.x);
85     u.x =       u.x + (x/u.x);
86     u.x = (0.25f*u.x) + (x/u.x);
87 
88     return u.x;
89 }
90 
91 static float btstack_cvsd_plc_absolute(float x){
92      if (x < 0) x = -x;
93      return x;
94 }
95 
96 static float btstack_cvsd_plc_cross_correlation(BTSTACK_CVSD_PLC_SAMPLE_FORMAT *x, BTSTACK_CVSD_PLC_SAMPLE_FORMAT *y){
97     float num = 0;
98     float den = 0;
99     float x2 = 0;
100     float y2 = 0;
101     int   m;
102     for (m=0;m<CVSD_M;m++){
103         num+=((float)x[m])*y[m];
104         x2+=((float)x[m])*x[m];
105         y2+=((float)y[m])*y[m];
106     }
107     den = (float)sqrt3(x2*y2);
108     return num/den;
109 }
110 
111 int btstack_cvsd_plc_pattern_match(BTSTACK_CVSD_PLC_SAMPLE_FORMAT *y){
112     float maxCn = -999999.0;  // large negative number
113     int   bestmatch = 0;
114     float Cn;
115     int   n;
116     for (n=0;n<CVSD_N;n++){
117         Cn = btstack_cvsd_plc_cross_correlation(&y[CVSD_LHIST-CVSD_M], &y[n]);
118         if (Cn>maxCn){
119             bestmatch=n;
120             maxCn = Cn;
121         }
122     }
123     return bestmatch;
124 }
125 
126 float btstack_cvsd_plc_amplitude_match(btstack_cvsd_plc_state_t *plc_state, uint16_t num_samples, BTSTACK_CVSD_PLC_SAMPLE_FORMAT *y, BTSTACK_CVSD_PLC_SAMPLE_FORMAT bestmatch){
127     UNUSED(plc_state);
128     int   i;
129     float sumx = 0;
130     float sumy = 0.000001f;
131     float sf;
132 
133     for (i=0;i<num_samples;i++){
134         sumx += btstack_cvsd_plc_absolute(y[CVSD_LHIST-num_samples+i]);
135         sumy += btstack_cvsd_plc_absolute(y[bestmatch+i]);
136     }
137     sf = sumx/sumy;
138     // This is not in the paper, but limit the scaling factor to something reasonable to avoid creating artifacts
139     if (sf<0.75f) sf=0.75f;
140     if (sf>1.0) sf=1.0f;
141     return sf;
142 }
143 
144 BTSTACK_CVSD_PLC_SAMPLE_FORMAT btstack_cvsd_plc_crop_sample(float val){
145     float croped_val = val;
146     if (croped_val > 32767.0)  croped_val= 32767.0;
147     if (croped_val < -32768.0) croped_val=-32768.0;
148     return (BTSTACK_CVSD_PLC_SAMPLE_FORMAT) croped_val;
149 }
150 
151 void btstack_cvsd_plc_init(btstack_cvsd_plc_state_t *plc_state){
152     memset(plc_state, 0, sizeof(btstack_cvsd_plc_state_t));
153 }
154 
155 #ifdef OCTAVE_OUTPUT
156 typedef enum {
157     OCTAVE_FRAME_TYPE_UNKNOWN = 0,
158     OCTAVE_FRAME_TYPE_GOOD,
159     OCTAVE_FRAME_TYPE_BAD
160 } octave_frame_type_t;
161 
162 static const char * octave_frame_type_name[] = {
163     "unknown",
164     "good",
165     "bad"
166 };
167 
168 static octave_frame_type_t octave_frame_type;
169 static char octave_base_name[1000];
170 
171 const char * octave_frame_type2str(int index){
172     if (index <= 0 || index >= sizeof(octave_frame_type_t)) return octave_frame_type_name[0];
173     return octave_frame_type_name[index];
174 }
175 
176 void btstack_cvsd_plc_octave_set_base_name(const char * base_name){
177     strcpy(octave_base_name, base_name);
178     printf("OCTAVE: base name set to %s\n", octave_base_name);
179 }
180 
181 static void octave_fprintf_array_int16(FILE * oct_file, char * name, int data_len, int16_t * data){
182     fprintf(oct_file, "%s = [", name);
183     int i;
184     for (i = 0; i < data_len - 1; i++){
185         fprintf(oct_file, "%d, ", data[i]);
186     }
187     fprintf(oct_file, "%d", data[i]);
188     fprintf(oct_file, "%s", "];\n");
189 }
190 
191 static FILE * open_octave_file(btstack_cvsd_plc_state_t *plc_state, octave_frame_type_t frame_type){
192     char oct_file_name[1200];
193     octave_frame_type = frame_type;
194     snprintf(oct_file_name, sizeof(oct_file_name), "%s_octave_plc_%d_%s.m",
195              octave_base_name, plc_state->frame_count,
196              octave_frame_type2str(octave_frame_type));
197     oct_file_name[sizeof(oct_file_name) - 1] = 0;
198 
199     FILE * oct_file = fopen(oct_file_name, "wb");
200     if (oct_file == NULL){
201         printf("OCTAVE: could not open file %s\n", oct_file_name);
202         return NULL;
203     }
204     printf("OCTAVE: opened file %s\n", oct_file_name);
205     return oct_file;
206 }
207 
208 static void octave_fprintf_plot_history_frame(btstack_cvsd_plc_state_t *plc_state, FILE * oct_file, int frame_nr){
209     char title[100];
210     char hist_name[10];
211     snprintf(hist_name, sizeof(hist_name), "hist%d", plc_state->nbf);
212     hist_name[sizeof(hist_name) - 1] = 0;
213 
214     octave_fprintf_array_int16(oct_file, hist_name, CVSD_LHIST, plc_state->hist);
215 
216     fprintf(oct_file, "y = [min(%s):1000:max(%s)];\n", hist_name, hist_name);
217     fprintf(oct_file, "x = zeros(1, size(y,2));\n");
218     fprintf(oct_file, "b = [0: %d];\n", CVSD_LHIST+CVSD_FS+CVSD_RT+CVSD_OLAL);
219 
220     int pos = CVSD_FS;
221     fprintf(oct_file, "shift_x = x + %d;\n", pos);
222 
223     pos = CVSD_LHIST - 1;
224     fprintf(oct_file, "lhist_x = x + %d;\n", pos);
225     pos += CVSD_OLAL;
226     fprintf(oct_file, "lhist_olal1_x = x + %d;\n", pos);
227     pos += CVSD_FS - CVSD_OLAL;
228     fprintf(oct_file, "lhist_fs_x = x + %d;\n", pos);
229     pos += CVSD_OLAL;
230     fprintf(oct_file, "lhist_olal2_x = x + %d;\n", pos);
231     pos += CVSD_RT;
232     fprintf(oct_file, "lhist_rt_x = x + %d;\n", pos);
233 
234     fprintf(oct_file, "pattern_window_x = x + %d;\n", CVSD_LHIST - CVSD_M);
235 
236     fprintf(oct_file, "hf = figure();\n");
237     snprintf(title, sizeof(title), "PLC %s frame %d",
238              octave_frame_type2str(octave_frame_type), frame_nr);
239     title[sizeof(title) - 1] = 0;
240 
241     fprintf(oct_file, "hold on;\n");
242     fprintf(oct_file, "h1 = plot(%s); \n", hist_name);
243 
244     fprintf(oct_file, "title(\"%s\");\n", title);
245 
246     fprintf(oct_file, "plot(lhist_x, y, 'k'); \n");
247     fprintf(oct_file, "text(max(lhist_x) - 10, max(y)+1000, 'lhist'); \n");
248 
249     fprintf(oct_file, "plot(lhist_olal1_x, y, 'k'); \n");
250     fprintf(oct_file, "text(max(lhist_olal1_x) - 10, max(y)+1000, 'OLAL'); \n");
251 
252     fprintf(oct_file, "plot(lhist_fs_x, y, 'k'); \n");
253     fprintf(oct_file, "text(max(lhist_fs_x) - 10, max(y)+1000, 'FS'); \n");
254 
255     fprintf(oct_file, "plot(lhist_olal2_x, y, 'k'); \n");
256     fprintf(oct_file, "text(max(lhist_olal2_x) - 10, max(y)+1000, 'OLAL'); \n");
257 
258     fprintf(oct_file, "plot(lhist_rt_x, y, 'k');\n");
259     fprintf(oct_file, "text(max(lhist_rt_x) - 10, max(y)+1000, 'RT'); \n");
260 
261     if (octave_frame_type == OCTAVE_FRAME_TYPE_GOOD) return;
262 
263     int x0 = plc_state->bestlag;
264     int x1 = plc_state->bestlag + CVSD_M - 1;
265     fprintf(oct_file, "plot(b(%d:%d), %s(%d:%d), 'rd'); \n", x0, x1, hist_name, x0, x1);
266     fprintf(oct_file, "text(%d - 10, -10, 'bestlag'); \n", x0);
267 
268     x0 = plc_state->bestlag + CVSD_M ;
269     x1 = plc_state->bestlag + CVSD_M + CVSD_FS - 1;
270     fprintf(oct_file, "plot(b(%d:%d), %s(%d:%d), 'kd'); \n", x0, x1, hist_name, x0, x1);
271 
272     x0 = CVSD_LHIST - CVSD_M;
273     x1 = CVSD_LHIST - 1;
274     fprintf(oct_file, "plot(b(%d:%d), %s(%d:%d), 'rd'); \n", x0, x1, hist_name, x0, x1);
275     fprintf(oct_file, "plot(pattern_window_x, y, 'g'); \n");
276     fprintf(oct_file, "text(max(pattern_window_x) - 10, max(y)+1000, 'M'); \n");
277 }
278 
279 static void octave_fprintf_plot_output(btstack_cvsd_plc_state_t *plc_state, FILE * oct_file){
280     if (!oct_file) return;
281     char out_name[10];
282     snprintf(out_name, sizeof(out_name), "out%d", plc_state->nbf);
283     out_name[sizeof(out_name) - 1] = 0;
284     int x0  = CVSD_LHIST;
285     int x1  = x0 + CVSD_FS - 1;
286     octave_fprintf_array_int16(oct_file, out_name, CVSD_FS, plc_state->hist+x0);
287     fprintf(oct_file, "h2 = plot(b(%d:%d), %s, 'cd'); \n", x0, x1, out_name);
288 
289     char rest_hist_name[10];
290     snprintf(rest_hist_name, sizeof(rest_hist_name), "rest%d", plc_state->nbf);
291     rest_hist_name[sizeof(rest_hist_name) - 1] = 0;
292     x0  = CVSD_LHIST + CVSD_FS;
293     x1  = x0 + CVSD_OLAL + CVSD_RT - 1;
294     octave_fprintf_array_int16(oct_file, rest_hist_name, CVSD_OLAL + CVSD_RT, plc_state->hist+x0);
295     fprintf(oct_file, "h3 = plot(b(%d:%d), %s, 'kd'); \n", x0, x1, rest_hist_name);
296 
297     char new_hist_name[10];
298     snprintf(new_hist_name, sizeof(new_hist_name), "hist%d", plc_state->nbf);
299     new_hist_name[sizeof(new_hist_name) - 1] = 0;
300     octave_fprintf_array_int16(oct_file, new_hist_name, CVSD_LHIST, plc_state->hist);
301     fprintf(oct_file, "h4 = plot(%s, 'r--'); \n", new_hist_name);
302 
303     fprintf(oct_file, "legend ([h1, h2, h3, h4], {\"hist\", \"out\", \"rest\", \"new hist\"}, \"location\", \"northeast\");\n ");
304 
305     char fig_name[1200];
306     snprintf(fig_name, sizeof(fig_name), "../%s_octave_plc_%d_%s",
307              octave_base_name, plc_state->frame_count,
308              octave_frame_type2str(octave_frame_type));
309     fig_name[sizeof(fig_name) - 1] = 0;
310     fprintf(oct_file, "print(hf, \"%s.jpg\", \"-djpg\");", fig_name);
311 }
312 #endif
313 
314 void btstack_cvsd_plc_bad_frame(btstack_cvsd_plc_state_t *plc_state, uint16_t num_samples, BTSTACK_CVSD_PLC_SAMPLE_FORMAT *out){
315     float val;
316     int   i;
317     float sf = 1;
318     plc_state->nbf++;
319 
320     if (plc_state->max_consecutive_bad_frames_nr < plc_state->nbf){
321         plc_state->max_consecutive_bad_frames_nr = plc_state->nbf;
322     }
323     if (plc_state->nbf==1){
324         // printf("first bad frame\n");
325         // Perform pattern matching to find where to replicate
326         plc_state->bestlag = btstack_cvsd_plc_pattern_match(plc_state->hist);
327     }
328 
329 #ifdef OCTAVE_OUTPUT
330     FILE * oct_file = open_octave_file(plc_state, OCTAVE_FRAME_TYPE_BAD);
331     if (oct_file){
332         octave_fprintf_plot_history_frame(plc_state, oct_file, plc_state->frame_count);
333     }
334 #endif
335 
336     if (plc_state->nbf==1){
337         // the replication begins after the template match
338         plc_state->bestlag += CVSD_M;
339 
340         // Compute Scale Factor to Match Amplitude of Substitution Packet to that of Preceding Packet
341         sf = btstack_cvsd_plc_amplitude_match(plc_state, num_samples, plc_state->hist, plc_state->bestlag);
342         for (i=0; i<CVSD_OLAL; i++){
343             val = sf*plc_state->hist[plc_state->bestlag+i];
344             plc_state->hist[CVSD_LHIST+i] = btstack_cvsd_plc_crop_sample(val);
345         }
346 
347         for (i=CVSD_OLAL; i<num_samples; i++){
348             val = sf*plc_state->hist[plc_state->bestlag+i];
349             plc_state->hist[CVSD_LHIST+i] = btstack_cvsd_plc_crop_sample(val);
350         }
351 
352         for (i=num_samples; i<(num_samples+CVSD_OLAL); i++){
353             float left  = sf*plc_state->hist[plc_state->bestlag+i];
354             float right = plc_state->hist[plc_state->bestlag+i];
355             val = (left*rcos[i-num_samples]) + (right*rcos[CVSD_OLAL-1-i+num_samples]);
356             plc_state->hist[CVSD_LHIST+i] = btstack_cvsd_plc_crop_sample(val);
357         }
358 
359         for (i=(num_samples+CVSD_OLAL); i<(num_samples+CVSD_RT+CVSD_OLAL); i++){
360             plc_state->hist[CVSD_LHIST+i] = plc_state->hist[plc_state->bestlag+i];
361         }
362     } else {
363         for (i=0; i<(num_samples+CVSD_RT+CVSD_OLAL); i++){
364             plc_state->hist[CVSD_LHIST+i] = plc_state->hist[plc_state->bestlag+i];
365         }
366     }
367 
368     for (i=0; i<num_samples; i++){
369         out[i] = plc_state->hist[CVSD_LHIST+i];
370     }
371 
372     // shift the history buffer
373     for (i=0; i<(CVSD_LHIST+CVSD_RT+CVSD_OLAL); i++){
374         plc_state->hist[i] = plc_state->hist[i+num_samples];
375     }
376 
377 #ifdef OCTAVE_OUTPUT
378     if (oct_file){
379         octave_fprintf_plot_output(plc_state, oct_file);
380         fclose(oct_file);
381     }
382 #endif
383 }
384 
385 void btstack_cvsd_plc_good_frame(btstack_cvsd_plc_state_t *plc_state, uint16_t num_samples, BTSTACK_CVSD_PLC_SAMPLE_FORMAT *in, BTSTACK_CVSD_PLC_SAMPLE_FORMAT *out){
386     float val;
387     int i = 0;
388 #ifdef OCTAVE_OUTPUT
389     FILE * oct_file = NULL;
390     if (plc_state->nbf>0){
391         oct_file = open_octave_file(plc_state, OCTAVE_FRAME_TYPE_GOOD);
392         if (oct_file){
393             octave_fprintf_plot_history_frame(plc_state, oct_file, plc_state->frame_count);
394         }
395     }
396 #endif
397     if (plc_state->nbf>0){
398         for (i=0;i<CVSD_RT;i++){
399             out[i] = plc_state->hist[CVSD_LHIST+i];
400         }
401 
402         for (i=CVSD_RT;i<(CVSD_RT+CVSD_OLAL);i++){
403             float left  = plc_state->hist[CVSD_LHIST+i];
404             float right = in[i];
405             val = (left * rcos[i-CVSD_RT]) + (right *rcos[CVSD_OLAL+CVSD_RT-1-i]);
406             out[i] = btstack_cvsd_plc_crop_sample((BTSTACK_CVSD_PLC_SAMPLE_FORMAT)val);
407         }
408     }
409 
410     for (;i<num_samples;i++){
411         out[i] = in[i];
412     }
413     // Copy the output to the history buffer
414     for (i=0;i<num_samples;i++){
415         plc_state->hist[CVSD_LHIST+i] = out[i];
416     }
417     // shift the history buffer
418     for (i=0;i<CVSD_LHIST;i++){
419         plc_state->hist[i] = plc_state->hist[i+num_samples];
420     }
421 
422 #ifdef OCTAVE_OUTPUT
423     if (oct_file){
424         octave_fprintf_plot_output(plc_state, oct_file);
425         fclose(oct_file);
426     }
427 #endif
428     plc_state->nbf=0;
429 }
430 
431 static int count_equal_samples(BTSTACK_CVSD_PLC_SAMPLE_FORMAT * packet, uint16_t size){
432     int count = 0;
433     int temp_count = 1;
434     int i;
435     for (i = 0; i < (size-1); i++){
436         if (packet[i] == packet[i+1]){
437             temp_count++;
438             continue;
439         }
440         if (count < temp_count){
441             count = temp_count;
442         }
443         temp_count = 1;
444     }
445     if (temp_count > (count + 1)){
446         count = temp_count;
447     }
448     return count;
449 }
450 
451 static int count_zeros(BTSTACK_CVSD_PLC_SAMPLE_FORMAT * frame, uint16_t size){
452     int nr_zeros = 0;
453     int i;
454     for (i = 0; i < (size-1); i++){
455         if (frame[i] == 0){
456             nr_zeros++;
457         }
458     }
459     return nr_zeros;
460 }
461 
462 static int zero_frame(BTSTACK_CVSD_PLC_SAMPLE_FORMAT * frame, uint16_t size){
463     return count_zeros(frame, size) == size;
464 }
465 
466 // more than half the samples are the same -> bad frame
467 static int bad_frame(btstack_cvsd_plc_state_t *plc_state, BTSTACK_CVSD_PLC_SAMPLE_FORMAT * frame, uint16_t size){
468     UNUSED(plc_state);
469     return count_equal_samples(frame, size) >= (size / 2);
470 }
471 
472 
473 void btstack_cvsd_plc_process_data(btstack_cvsd_plc_state_t * plc_state, bool is_bad_frame, BTSTACK_CVSD_PLC_SAMPLE_FORMAT * in, uint16_t num_samples, BTSTACK_CVSD_PLC_SAMPLE_FORMAT * out){
474     if (num_samples == 0) return;
475 
476     plc_state->frame_count++;
477 
478     if (!is_bad_frame) {
479         bool is_zero_frame = zero_frame(in, num_samples);
480         if (is_zero_frame){
481             plc_state->zero_frames_nr++;
482         } else {
483             is_bad_frame = bad_frame(plc_state, in, num_samples);
484         }
485     }
486 
487     if (is_bad_frame){
488         (void)memcpy(out, in, num_samples * 2);
489         if (plc_state->good_samples > CVSD_LHIST){
490             btstack_cvsd_plc_bad_frame(plc_state, num_samples, out);
491             plc_state->bad_frames_nr++;
492         } else {
493             memset(out, 0, num_samples * 2);
494         }
495     } else {
496         btstack_cvsd_plc_good_frame(plc_state, num_samples, in, out);
497         plc_state->good_frames_nr++;
498         if (plc_state->good_frames_nr == 1){
499             log_info("First good frame at index %d\n", plc_state->frame_count-1);
500         }
501         plc_state->good_samples += num_samples;
502     }
503 }
504 
505 void btstack_cvsd_dump_statistics(btstack_cvsd_plc_state_t * state){
506     log_info("Good frames: %d\n", state->good_frames_nr);
507     log_info("Bad frames: %d\n", state->bad_frames_nr);
508     log_info("Zero frames: %d\n", state->zero_frames_nr);
509     log_info("Max Consecutive bad frames: %d\n", state->max_consecutive_bad_frames_nr);
510 }
511