xref: /btstack/src/classic/btstack_cvsd_plc.c (revision fbd9085d679240e60bad03926cf8538e726fac89)
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,0.92510857f,
58     0.80131732f,0.63683150f,
59     0.45386582f,0.27713082f,
60     0.13049554f,0.03376389f};
61 
62 // taken from http://www.codeproject.com/Articles/69941/Best-Square-Root-Method-Algorithm-Function-Precisi
63 // Algorithm: Babylonian Method + some manipulations on IEEE 32 bit floating point representation
64 static float sqrt3(const float x){
65     union {
66         int i;
67         float x;
68     } u;
69     u.x = x;
70     u.i = (1<<29) + (u.i >> 1) - (1<<22);
71 
72     // Two Babylonian Steps (simplified from:)
73     // u.x = 0.5f * (u.x + x/u.x);
74     // u.x = 0.5f * (u.x + x/u.x);
75     u.x =       u.x + (x/u.x);
76     u.x = (0.25f*u.x) + (x/u.x);
77 
78     return u.x;
79 }
80 
81 static float btstack_cvsd_plc_absolute(float x){
82      if (x < 0) x = -x;
83      return x;
84 }
85 
86 static float btstack_cvsd_plc_cross_correlation(BTSTACK_CVSD_PLC_SAMPLE_FORMAT *x, BTSTACK_CVSD_PLC_SAMPLE_FORMAT *y){
87     float num = 0;
88     float den = 0;
89     float x2 = 0;
90     float y2 = 0;
91     int   m;
92     for (m=0;m<CVSD_M;m++){
93         num+=((float)x[m])*y[m];
94         x2+=((float)x[m])*x[m];
95         y2+=((float)y[m])*y[m];
96     }
97     den = (float)sqrt3(x2*y2);
98     return num/den;
99 }
100 
101 int btstack_cvsd_plc_pattern_match(BTSTACK_CVSD_PLC_SAMPLE_FORMAT *y){
102     float maxCn = -999999.0;  // large negative number
103     int   bestmatch = 0;
104     float Cn;
105     int   n;
106     for (n=0;n<CVSD_N;n++){
107         Cn = btstack_cvsd_plc_cross_correlation(&y[CVSD_LHIST-CVSD_M], &y[n]);
108         if (Cn>maxCn){
109             bestmatch=n;
110             maxCn = Cn;
111         }
112     }
113     return bestmatch;
114 }
115 
116 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){
117     UNUSED(plc_state);
118     int   i;
119     float sumx = 0;
120     float sumy = 0.000001f;
121     float sf;
122 
123     for (i=0;i<num_samples;i++){
124         sumx += btstack_cvsd_plc_absolute(y[CVSD_LHIST-num_samples+i]);
125         sumy += btstack_cvsd_plc_absolute(y[bestmatch+i]);
126     }
127     sf = sumx/sumy;
128     // This is not in the paper, but limit the scaling factor to something reasonable to avoid creating artifacts
129     if (sf<0.75f) sf=0.75f;
130     if (sf>1.0) sf=1.0f;
131     return sf;
132 }
133 
134 BTSTACK_CVSD_PLC_SAMPLE_FORMAT btstack_cvsd_plc_crop_sample(float val){
135     float croped_val = val;
136     if (croped_val > 32767.0)  croped_val= 32767.0;
137     if (croped_val < -32768.0) croped_val=-32768.0;
138     return (BTSTACK_CVSD_PLC_SAMPLE_FORMAT) croped_val;
139 }
140 
141 void btstack_cvsd_plc_init(btstack_cvsd_plc_state_t *plc_state){
142     memset(plc_state, 0, sizeof(btstack_cvsd_plc_state_t));
143 }
144 
145 #ifdef OCTAVE_OUTPUT
146 typedef enum {
147     OCTAVE_FRAME_TYPE_UNKNOWN = 0,
148     OCTAVE_FRAME_TYPE_GOOD,
149     OCTAVE_FRAME_TYPE_BAD
150 } octave_frame_type_t;
151 
152 static const char * octave_frame_type_name[] = {
153     "unknown",
154     "good",
155     "bad"
156 };
157 
158 static octave_frame_type_t octave_frame_type;
159 static char octave_base_name[1000];
160 
161 const char * octave_frame_type2str(int index){
162     if (index <= 0 || index >= sizeof(octave_frame_type_t)) return octave_frame_type_name[0];
163     return octave_frame_type_name[index];
164 }
165 
166 void btstack_cvsd_plc_octave_set_base_name(const char * base_name){
167     strcpy(octave_base_name, base_name);
168     printf("OCTAVE: base name set to %s\n", octave_base_name);
169 }
170 
171 static void octave_fprintf_array_int16(FILE * oct_file, char * name, int data_len, int16_t * data){
172     fprintf(oct_file, "%s = [", name);
173     int i;
174     for (i = 0; i < data_len - 1; i++){
175         fprintf(oct_file, "%d, ", data[i]);
176     }
177     fprintf(oct_file, "%d", data[i]);
178     fprintf(oct_file, "%s", "];\n");
179 }
180 
181 static FILE * open_octave_file(btstack_cvsd_plc_state_t *plc_state, octave_frame_type_t frame_type){
182     char oct_file_name[1200];
183     octave_frame_type = frame_type;
184     snprintf(oct_file_name, sizeof(oct_file_name), "%s_octave_plc_%d_%s.m",
185              octave_base_name, plc_state->frame_count,
186              octave_frame_type2str(octave_frame_type));
187     oct_file_name[sizeof(oct_file_name) - 1] = 0;
188 
189     FILE * oct_file = fopen(oct_file_name, "wb");
190     if (oct_file == NULL){
191         printf("OCTAVE: could not open file %s\n", oct_file_name);
192         return NULL;
193     }
194     printf("OCTAVE: opened file %s\n", oct_file_name);
195     return oct_file;
196 }
197 
198 static void octave_fprintf_plot_history_frame(btstack_cvsd_plc_state_t *plc_state, FILE * oct_file, int frame_nr){
199     char title[100];
200     char hist_name[10];
201     snprintf(hist_name, sizeof(hist_name), "hist%d", plc_state->nbf);
202     hist_name[sizeof(hist_name) - 1] = 0;
203 
204     octave_fprintf_array_int16(oct_file, hist_name, CVSD_LHIST, plc_state->hist);
205 
206     fprintf(oct_file, "y = [min(%s):1000:max(%s)];\n", hist_name, hist_name);
207     fprintf(oct_file, "x = zeros(1, size(y,2));\n");
208     fprintf(oct_file, "b = [0: %d];\n", CVSD_LHIST+CVSD_FS+CVSD_RT+CVSD_OLAL);
209 
210     int pos = CVSD_FS;
211     fprintf(oct_file, "shift_x = x + %d;\n", pos);
212 
213     pos = CVSD_LHIST - 1;
214     fprintf(oct_file, "lhist_x = x + %d;\n", pos);
215     pos += CVSD_OLAL;
216     fprintf(oct_file, "lhist_olal1_x = x + %d;\n", pos);
217     pos += CVSD_FS - CVSD_OLAL;
218     fprintf(oct_file, "lhist_fs_x = x + %d;\n", pos);
219     pos += CVSD_OLAL;
220     fprintf(oct_file, "lhist_olal2_x = x + %d;\n", pos);
221     pos += CVSD_RT;
222     fprintf(oct_file, "lhist_rt_x = x + %d;\n", pos);
223 
224     fprintf(oct_file, "pattern_window_x = x + %d;\n", CVSD_LHIST - CVSD_M);
225 
226     fprintf(oct_file, "hf = figure();\n");
227     snprintf(title, sizeof(title), "PLC %s frame %d",
228              octave_frame_type2str(octave_frame_type), frame_nr);
229     title[sizeof(title) - 1] = 0;
230 
231     fprintf(oct_file, "hold on;\n");
232     fprintf(oct_file, "h1 = plot(%s); \n", hist_name);
233 
234     fprintf(oct_file, "title(\"%s\");\n", title);
235 
236     fprintf(oct_file, "plot(lhist_x, y, 'k'); \n");
237     fprintf(oct_file, "text(max(lhist_x) - 10, max(y)+1000, 'lhist'); \n");
238 
239     fprintf(oct_file, "plot(lhist_olal1_x, y, 'k'); \n");
240     fprintf(oct_file, "text(max(lhist_olal1_x) - 10, max(y)+1000, 'OLAL'); \n");
241 
242     fprintf(oct_file, "plot(lhist_fs_x, y, 'k'); \n");
243     fprintf(oct_file, "text(max(lhist_fs_x) - 10, max(y)+1000, 'FS'); \n");
244 
245     fprintf(oct_file, "plot(lhist_olal2_x, y, 'k'); \n");
246     fprintf(oct_file, "text(max(lhist_olal2_x) - 10, max(y)+1000, 'OLAL'); \n");
247 
248     fprintf(oct_file, "plot(lhist_rt_x, y, 'k');\n");
249     fprintf(oct_file, "text(max(lhist_rt_x) - 10, max(y)+1000, 'RT'); \n");
250 
251     if (octave_frame_type == OCTAVE_FRAME_TYPE_GOOD) return;
252 
253     int x0 = plc_state->bestlag;
254     int x1 = plc_state->bestlag + CVSD_M - 1;
255     fprintf(oct_file, "plot(b(%d:%d), %s(%d:%d), 'rd'); \n", x0, x1, hist_name, x0, x1);
256     fprintf(oct_file, "text(%d - 10, -10, 'bestlag'); \n", x0);
257 
258     x0 = plc_state->bestlag + CVSD_M ;
259     x1 = plc_state->bestlag + CVSD_M + CVSD_FS - 1;
260     fprintf(oct_file, "plot(b(%d:%d), %s(%d:%d), 'kd'); \n", x0, x1, hist_name, x0, x1);
261 
262     x0 = CVSD_LHIST - CVSD_M;
263     x1 = CVSD_LHIST - 1;
264     fprintf(oct_file, "plot(b(%d:%d), %s(%d:%d), 'rd'); \n", x0, x1, hist_name, x0, x1);
265     fprintf(oct_file, "plot(pattern_window_x, y, 'g'); \n");
266     fprintf(oct_file, "text(max(pattern_window_x) - 10, max(y)+1000, 'M'); \n");
267 }
268 
269 static void octave_fprintf_plot_output(btstack_cvsd_plc_state_t *plc_state, FILE * oct_file){
270     if (!oct_file) return;
271     char out_name[10];
272     snprintf(out_name, sizeof(out_name), "out%d", plc_state->nbf);
273     out_name[sizeof(out_name) - 1] = 0;
274     int x0  = CVSD_LHIST;
275     int x1  = x0 + CVSD_FS - 1;
276     octave_fprintf_array_int16(oct_file, out_name, CVSD_FS, plc_state->hist+x0);
277     fprintf(oct_file, "h2 = plot(b(%d:%d), %s, 'cd'); \n", x0, x1, out_name);
278 
279     char rest_hist_name[10];
280     snprintf(rest_hist_name, sizeof(rest_hist_name), "rest%d", plc_state->nbf);
281     rest_hist_name[sizeof(rest_hist_name) - 1] = 0;
282     x0  = CVSD_LHIST + CVSD_FS;
283     x1  = x0 + CVSD_OLAL + CVSD_RT - 1;
284     octave_fprintf_array_int16(oct_file, rest_hist_name, CVSD_OLAL + CVSD_RT, plc_state->hist+x0);
285     fprintf(oct_file, "h3 = plot(b(%d:%d), %s, 'kd'); \n", x0, x1, rest_hist_name);
286 
287     char new_hist_name[10];
288     snprintf(new_hist_name, sizeof(new_hist_name), "hist%d", plc_state->nbf);
289     new_hist_name[sizeof(new_hist_name) - 1] = 0;
290     octave_fprintf_array_int16(oct_file, new_hist_name, CVSD_LHIST, plc_state->hist);
291     fprintf(oct_file, "h4 = plot(%s, 'r--'); \n", new_hist_name);
292 
293     fprintf(oct_file, "legend ([h1, h2, h3, h4], {\"hist\", \"out\", \"rest\", \"new hist\"}, \"location\", \"northeast\");\n ");
294 
295     char fig_name[1200];
296     snprintf(fig_name, sizeof(fig_name), "../%s_octave_plc_%d_%s",
297              octave_base_name, plc_state->frame_count,
298              octave_frame_type2str(octave_frame_type));
299     fig_name[sizeof(fig_name) - 1] = 0;
300     fprintf(oct_file, "print(hf, \"%s.jpg\", \"-djpg\");", fig_name);
301 }
302 #endif
303 
304 void btstack_cvsd_plc_bad_frame(btstack_cvsd_plc_state_t *plc_state, uint16_t num_samples, BTSTACK_CVSD_PLC_SAMPLE_FORMAT *out){
305     float val;
306     int   i;
307     float sf = 1;
308     plc_state->nbf++;
309 
310     if (plc_state->max_consecutive_bad_frames_nr < plc_state->nbf){
311         plc_state->max_consecutive_bad_frames_nr = plc_state->nbf;
312     }
313     if (plc_state->nbf==1){
314         // printf("first bad frame\n");
315         // Perform pattern matching to find where to replicate
316         plc_state->bestlag = btstack_cvsd_plc_pattern_match(plc_state->hist);
317     }
318 
319 #ifdef OCTAVE_OUTPUT
320     FILE * oct_file = open_octave_file(plc_state, OCTAVE_FRAME_TYPE_BAD);
321     if (oct_file){
322         octave_fprintf_plot_history_frame(plc_state, oct_file, plc_state->frame_count);
323     }
324 #endif
325 
326     if (plc_state->nbf==1){
327         // the replication begins after the template match
328         plc_state->bestlag += CVSD_M;
329 
330         // Compute Scale Factor to Match Amplitude of Substitution Packet to that of Preceding Packet
331         sf = btstack_cvsd_plc_amplitude_match(plc_state, num_samples, plc_state->hist, plc_state->bestlag);
332         for (i=0; i<CVSD_OLAL; i++){
333             val = sf*plc_state->hist[plc_state->bestlag+i];
334             plc_state->hist[CVSD_LHIST+i] = btstack_cvsd_plc_crop_sample(val);
335         }
336 
337         for (i=CVSD_OLAL; i<num_samples; i++){
338             val = sf*plc_state->hist[plc_state->bestlag+i];
339             plc_state->hist[CVSD_LHIST+i] = btstack_cvsd_plc_crop_sample(val);
340         }
341 
342         for (i=num_samples; i<(num_samples+CVSD_OLAL); i++){
343             float left  = sf*plc_state->hist[plc_state->bestlag+i];
344             float right = plc_state->hist[plc_state->bestlag+i];
345             val = (left*rcos[i-num_samples]) + (right*rcos[CVSD_OLAL-1-i+num_samples]);
346             plc_state->hist[CVSD_LHIST+i] = btstack_cvsd_plc_crop_sample(val);
347         }
348 
349         for (i=(num_samples+CVSD_OLAL); i<(num_samples+CVSD_RT+CVSD_OLAL); i++){
350             plc_state->hist[CVSD_LHIST+i] = plc_state->hist[plc_state->bestlag+i];
351         }
352     } else {
353         for (i=0; i<(num_samples+CVSD_RT+CVSD_OLAL); i++){
354             plc_state->hist[CVSD_LHIST+i] = plc_state->hist[plc_state->bestlag+i];
355         }
356     }
357 
358     for (i=0; i<num_samples; i++){
359         out[i] = plc_state->hist[CVSD_LHIST+i];
360     }
361 
362     // shift the history buffer
363     for (i=0; i<(CVSD_LHIST+CVSD_RT+CVSD_OLAL); i++){
364         plc_state->hist[i] = plc_state->hist[i+num_samples];
365     }
366 
367 #ifdef OCTAVE_OUTPUT
368     if (oct_file){
369         octave_fprintf_plot_output(plc_state, oct_file);
370         fclose(oct_file);
371     }
372 #endif
373 }
374 
375 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){
376     float val;
377     int i = 0;
378 #ifdef OCTAVE_OUTPUT
379     FILE * oct_file = NULL;
380     if (plc_state->nbf>0){
381         oct_file = open_octave_file(plc_state, OCTAVE_FRAME_TYPE_GOOD);
382         if (oct_file){
383             octave_fprintf_plot_history_frame(plc_state, oct_file, plc_state->frame_count);
384         }
385     }
386 #endif
387     if (plc_state->nbf>0){
388         for (i=0;i<CVSD_RT;i++){
389             out[i] = plc_state->hist[CVSD_LHIST+i];
390         }
391 
392         for (i=CVSD_RT;i<(CVSD_RT+CVSD_OLAL);i++){
393             float left  = plc_state->hist[CVSD_LHIST+i];
394             float right = in[i];
395             val = (left * rcos[i-CVSD_RT]) + (right *rcos[CVSD_OLAL+CVSD_RT-1-i]);
396             out[i] = btstack_cvsd_plc_crop_sample((BTSTACK_CVSD_PLC_SAMPLE_FORMAT)val);
397         }
398     }
399 
400     for (;i<num_samples;i++){
401         out[i] = in[i];
402     }
403     // Copy the output to the history buffer
404     for (i=0;i<num_samples;i++){
405         plc_state->hist[CVSD_LHIST+i] = out[i];
406     }
407     // shift the history buffer
408     for (i=0;i<CVSD_LHIST;i++){
409         plc_state->hist[i] = plc_state->hist[i+num_samples];
410     }
411 
412 #ifdef OCTAVE_OUTPUT
413     if (oct_file){
414         octave_fprintf_plot_output(plc_state, oct_file);
415         fclose(oct_file);
416     }
417 #endif
418     plc_state->nbf=0;
419 }
420 
421 static int count_equal_samples(BTSTACK_CVSD_PLC_SAMPLE_FORMAT * packet, uint16_t size){
422     int count = 0;
423     int temp_count = 1;
424     int i;
425     for (i = 0; i < (size-1); i++){
426         if (packet[i] == packet[i+1]){
427             temp_count++;
428             continue;
429         }
430         if (count < temp_count){
431             count = temp_count;
432         }
433         temp_count = 1;
434     }
435     if (temp_count > (count + 1)){
436         count = temp_count;
437     }
438     return count;
439 }
440 
441 static int count_zeros(BTSTACK_CVSD_PLC_SAMPLE_FORMAT * frame, uint16_t size){
442     int nr_zeros = 0;
443     int i;
444     for (i = 0; i < (size-1); i++){
445         if (frame[i] == 0){
446             nr_zeros++;
447         }
448     }
449     return nr_zeros;
450 }
451 
452 static int zero_frame(BTSTACK_CVSD_PLC_SAMPLE_FORMAT * frame, uint16_t size){
453     return count_zeros(frame, size) == size;
454 }
455 
456 // more than half the samples are the same -> bad frame
457 static int bad_frame(btstack_cvsd_plc_state_t *plc_state, BTSTACK_CVSD_PLC_SAMPLE_FORMAT * frame, uint16_t size){
458     UNUSED(plc_state);
459     return count_equal_samples(frame, size) >= (size / 2);
460 }
461 
462 
463 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){
464     if (num_samples == 0) return;
465 
466     plc_state->frame_count++;
467 
468     if (!is_bad_frame) {
469         bool is_zero_frame = zero_frame(in, num_samples);
470         if (is_zero_frame){
471             plc_state->zero_frames_nr++;
472         } else {
473             is_bad_frame = bad_frame(plc_state, in, num_samples);
474         }
475     }
476 
477     if (is_bad_frame){
478         (void)memcpy(out, in, num_samples * 2);
479         if (plc_state->good_samples > CVSD_LHIST){
480             btstack_cvsd_plc_bad_frame(plc_state, num_samples, out);
481             plc_state->bad_frames_nr++;
482         } else {
483             memset(out, 0, num_samples * 2);
484         }
485     } else {
486         btstack_cvsd_plc_good_frame(plc_state, num_samples, in, out);
487         plc_state->good_frames_nr++;
488         if (plc_state->good_frames_nr == 1){
489             log_info("First good frame at index %d\n", plc_state->frame_count-1);
490         }
491         plc_state->good_samples += num_samples;
492     }
493 }
494 
495 void btstack_cvsd_dump_statistics(btstack_cvsd_plc_state_t * state){
496     log_info("Good frames: %d\n", state->good_frames_nr);
497     log_info("Bad frames: %d\n", state->bad_frames_nr);
498     log_info("Zero frames: %d\n", state->zero_frames_nr);
499     log_info("Max Consecutive bad frames: %d\n", state->max_consecutive_bad_frames_nr);
500 }
501