xref: /btstack/src/classic/btstack_cvsd_plc.c (revision d1550f906a6f7312c10521c9150f12effd00dedc)
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 <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 
50 #include "btstack_cvsd_plc.h"
51 #include "btstack_debug.h"
52 
53 // static float rcos[CVSD_OLAL] = {
54 //     0.99148655f,0.96623611f,0.92510857f,0.86950446f,
55 //     0.80131732f,0.72286918f,0.63683150f,0.54613418f,
56 //     0.45386582f,0.36316850f,0.27713082f,0.19868268f,
57 //     0.13049554f,0.07489143f,0.03376389f,0.00851345f};
58 
59 static float rcos[CVSD_OLAL] = {
60     0.99148655f,0.92510857f,
61     0.80131732f,0.63683150f,
62     0.45386582f,0.27713082f,
63     0.13049554f,0.03376389f};
64 
65 float btstack_cvsd_plc_rcos(int index){
66     if (index > CVSD_OLAL) return 0;
67     return rcos[index];
68 }
69 // taken from http://www.codeproject.com/Articles/69941/Best-Square-Root-Method-Algorithm-Function-Precisi
70 // Algorithm: Babylonian Method + some manipulations on IEEE 32 bit floating point representation
71 static float sqrt3(const float x){
72     union {
73         int i;
74         float x;
75     } u;
76     u.x = x;
77     u.i = (1<<29) + (u.i >> 1) - (1<<22);
78 
79     // Two Babylonian Steps (simplified from:)
80     // u.x = 0.5f * (u.x + x/u.x);
81     // u.x = 0.5f * (u.x + x/u.x);
82     u.x =       u.x + x/u.x;
83     u.x = 0.25f*u.x + x/u.x;
84 
85     return u.x;
86 }
87 
88 static float btstack_cvsd_plc_absolute(float x){
89      if (x < 0) x = -x;
90      return x;
91 }
92 
93 static float btstack_cvsd_plc_cross_correlation(BTSTACK_CVSD_PLC_SAMPLE_FORMAT *x, BTSTACK_CVSD_PLC_SAMPLE_FORMAT *y){
94     float num = 0;
95     float den = 0;
96     float x2 = 0;
97     float y2 = 0;
98     int   m;
99     for (m=0;m<CVSD_M;m++){
100         num+=((float)x[m])*y[m];
101         x2+=((float)x[m])*x[m];
102         y2+=((float)y[m])*y[m];
103     }
104     den = (float)sqrt3(x2*y2);
105     return num/den;
106 }
107 
108 int btstack_cvsd_plc_pattern_match(BTSTACK_CVSD_PLC_SAMPLE_FORMAT *y){
109     float maxCn = -999999.0;  // large negative number
110     int   bestmatch = 0;
111     float Cn;
112     int   n;
113     for (n=0;n<CVSD_N;n++){
114         Cn = btstack_cvsd_plc_cross_correlation(&y[CVSD_LHIST-CVSD_M], &y[n]);
115         if (Cn>maxCn){
116             bestmatch=n;
117             maxCn = Cn;
118         }
119     }
120     return bestmatch;
121 }
122 
123 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){
124     int   i;
125     float sumx = 0;
126     float sumy = 0.000001f;
127     float sf;
128 
129     for (i=0;i<num_samples;i++){
130         sumx += btstack_cvsd_plc_absolute(y[CVSD_LHIST-num_samples+i]);
131         sumy += btstack_cvsd_plc_absolute(y[bestmatch+i]);
132     }
133     sf = sumx/sumy;
134     // This is not in the paper, but limit the scaling factor to something reasonable to avoid creating artifacts
135     if (sf<0.75f) sf=0.75f;
136     if (sf>1.0) sf=1.0f;
137     return sf;
138 }
139 
140 BTSTACK_CVSD_PLC_SAMPLE_FORMAT btstack_cvsd_plc_crop_sample(float val){
141     float croped_val = val;
142     if (croped_val > 32767.0)  croped_val= 32767.0;
143     if (croped_val < -32768.0) croped_val=-32768.0;
144     return (BTSTACK_CVSD_PLC_SAMPLE_FORMAT) croped_val;
145 }
146 
147 void btstack_cvsd_plc_init(btstack_cvsd_plc_state_t *plc_state){
148     memset(plc_state, 0, sizeof(btstack_cvsd_plc_state_t));
149 }
150 
151 #ifdef OCTAVE_OUTPUT
152 typedef enum {
153     OCTAVE_FRAME_TYPE_UNKNOWN = 0,
154     OCTAVE_FRAME_TYPE_GOOD,
155     OCTAVE_FRAME_TYPE_BAD
156 } octave_frame_type_t;
157 
158 static const char * octave_frame_type_name[] = {
159     "unknown",
160     "good",
161     "bad"
162 };
163 
164 static octave_frame_type_t octave_frame_type;
165 static char octave_base_name[1000];
166 
167 const char * octave_frame_type2str(int index){
168     if (index <= 0 || index >= sizeof(octave_frame_type_t)) return octave_frame_type_name[0];
169     return octave_frame_type_name[index];
170 }
171 
172 void btstack_cvsd_plc_octave_set_base_name(const char * base_name){
173     strcpy(octave_base_name, base_name);
174     printf("OCTAVE: base name set to %s\n", octave_base_name);
175 }
176 
177 static void octave_fprintf_array_int16(FILE * oct_file, char * name, int data_len, int16_t * data){
178     fprintf(oct_file, "%s = [", name);
179     int i;
180     for (i = 0; i < data_len - 1; i++){
181         fprintf(oct_file, "%d, ", data[i]);
182     }
183     fprintf(oct_file, "%d", data[i]);
184     fprintf(oct_file, "%s", "];\n");
185 }
186 
187 static FILE * open_octave_file(btstack_cvsd_plc_state_t *plc_state, octave_frame_type_t frame_type){
188     char oct_file_name[1200];
189     octave_frame_type = frame_type;
190     sprintf(oct_file_name, "%s_octave_plc_%d_%s.m", octave_base_name, plc_state->frame_count, octave_frame_type2str(octave_frame_type));
191 
192     FILE * oct_file = fopen(oct_file_name, "wb");
193     if (oct_file == NULL){
194         printf("OCTAVE: could not open file %s\n", oct_file_name);
195         return NULL;
196     }
197     printf("OCTAVE: opened file %s\n", oct_file_name);
198     return oct_file;
199 }
200 
201 static void octave_fprintf_plot_history_frame(btstack_cvsd_plc_state_t *plc_state, FILE * oct_file, int frame_nr){
202     char title[100];
203     char hist_name[10];
204     sprintf(hist_name, "hist%d", plc_state->nbf);
205 
206     octave_fprintf_array_int16(oct_file, hist_name, CVSD_LHIST, plc_state->hist);
207 
208     fprintf(oct_file, "y = [min(%s):1000:max(%s)];\n", hist_name, hist_name);
209     fprintf(oct_file, "x = zeros(1, size(y,2));\n");
210     fprintf(oct_file, "b = [0: %d];\n", CVSD_LHIST+CVSD_FS+CVSD_RT+CVSD_OLAL);
211 
212     int pos = CVSD_FS;
213     fprintf(oct_file, "shift_x = x + %d;\n", pos);
214 
215     pos = CVSD_LHIST - 1;
216     fprintf(oct_file, "lhist_x = x + %d;\n", pos);
217     pos += CVSD_OLAL;
218     fprintf(oct_file, "lhist_olal1_x = x + %d;\n", pos);
219     pos += CVSD_FS - CVSD_OLAL;
220     fprintf(oct_file, "lhist_fs_x = x + %d;\n", pos);
221     pos += CVSD_OLAL;
222     fprintf(oct_file, "lhist_olal2_x = x + %d;\n", pos);
223     pos += CVSD_RT;
224     fprintf(oct_file, "lhist_rt_x = x + %d;\n", pos);
225 
226     fprintf(oct_file, "pattern_window_x = x + %d;\n", CVSD_LHIST - CVSD_M);
227 
228     fprintf(oct_file, "hf = figure();\n");
229     sprintf(title, "PLC %s frame %d", octave_frame_type2str(octave_frame_type), frame_nr);
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     sprintf(out_name, "out%d", plc_state->nbf);
273     int x0  = CVSD_LHIST;
274     int x1  = x0 + CVSD_FS - 1;
275     octave_fprintf_array_int16(oct_file, out_name, CVSD_FS, plc_state->hist+x0);
276     fprintf(oct_file, "h2 = plot(b(%d:%d), %s, 'cd'); \n", x0, x1, out_name);
277 
278     char rest_hist_name[10];
279     sprintf(rest_hist_name, "rest%d", plc_state->nbf);
280     x0  = CVSD_LHIST + CVSD_FS;
281     x1  = x0 + CVSD_OLAL + CVSD_RT - 1;
282     octave_fprintf_array_int16(oct_file, rest_hist_name, CVSD_OLAL + CVSD_RT, plc_state->hist+x0);
283     fprintf(oct_file, "h3 = plot(b(%d:%d), %s, 'kd'); \n", x0, x1, rest_hist_name);
284 
285     char new_hist_name[10];
286     sprintf(new_hist_name, "hist%d", plc_state->nbf);
287     octave_fprintf_array_int16(oct_file, new_hist_name, CVSD_LHIST, plc_state->hist);
288     fprintf(oct_file, "h4 = plot(%s, 'r--'); \n", new_hist_name);
289 
290     fprintf(oct_file, "legend ([h1, h2, h3, h4], {\"hist\", \"out\", \"rest\", \"new hist\"}, \"location\", \"northeast\");\n ");
291 
292     char fig_name[1200];
293     sprintf(fig_name, "../%s_octave_plc_%d_%s", octave_base_name, plc_state->frame_count, octave_frame_type2str(octave_frame_type));
294     fprintf(oct_file, "print(hf, \"%s.jpg\", \"-djpg\");", fig_name);
295 }
296 #endif
297 
298 void btstack_cvsd_plc_bad_frame(btstack_cvsd_plc_state_t *plc_state, uint16_t num_samples, BTSTACK_CVSD_PLC_SAMPLE_FORMAT *out){
299     float val;
300     int   i = 0;
301     float sf = 1;
302     plc_state->nbf++;
303 
304     if (plc_state->max_consecutive_bad_frames_nr < plc_state->nbf){
305         plc_state->max_consecutive_bad_frames_nr = plc_state->nbf;
306     }
307     if (plc_state->nbf==1){
308         // printf("first bad frame\n");
309         // Perform pattern matching to find where to replicate
310         plc_state->bestlag = btstack_cvsd_plc_pattern_match(plc_state->hist);
311     }
312 
313 #ifdef OCTAVE_OUTPUT
314     FILE * oct_file = open_octave_file(plc_state, OCTAVE_FRAME_TYPE_BAD);
315     if (oct_file){
316         octave_fprintf_plot_history_frame(plc_state, oct_file, plc_state->frame_count);
317     }
318 #endif
319 
320     if (plc_state->nbf==1){
321         // the replication begins after the template match
322         plc_state->bestlag += CVSD_M;
323 
324         // Compute Scale Factor to Match Amplitude of Substitution Packet to that of Preceding Packet
325         sf = btstack_cvsd_plc_amplitude_match(plc_state, num_samples, plc_state->hist, plc_state->bestlag);
326         for (i=0;i<CVSD_OLAL;i++){
327             val = sf*plc_state->hist[plc_state->bestlag+i];
328             plc_state->hist[CVSD_LHIST+i] = btstack_cvsd_plc_crop_sample(val);
329         }
330 
331         for (;i<num_samples;i++){
332             val = sf*plc_state->hist[plc_state->bestlag+i];
333             plc_state->hist[CVSD_LHIST+i] = btstack_cvsd_plc_crop_sample(val);
334         }
335 
336         for (;i<num_samples+CVSD_OLAL;i++){
337             float left  = sf*plc_state->hist[plc_state->bestlag+i];
338             float right = plc_state->hist[plc_state->bestlag+i];
339             val = left*rcos[i-num_samples] + right*rcos[CVSD_OLAL-1-i+num_samples];
340             plc_state->hist[CVSD_LHIST+i] = btstack_cvsd_plc_crop_sample(val);
341         }
342 
343         for (;i<num_samples+CVSD_RT+CVSD_OLAL;i++){
344             plc_state->hist[CVSD_LHIST+i] = plc_state->hist[plc_state->bestlag+i];
345         }
346     } else {
347         for (;i<num_samples+CVSD_RT+CVSD_OLAL;i++){
348             plc_state->hist[CVSD_LHIST+i] = plc_state->hist[plc_state->bestlag+i];
349         }
350     }
351 
352     for (i=0;i<num_samples;i++){
353         out[i] = plc_state->hist[CVSD_LHIST+i];
354     }
355 
356     // shift the history buffer
357     for (i=0;i<CVSD_LHIST+CVSD_RT+CVSD_OLAL;i++){
358         plc_state->hist[i] = plc_state->hist[i+num_samples];
359     }
360 
361 #ifdef OCTAVE_OUTPUT
362     if (oct_file){
363         octave_fprintf_plot_output(plc_state, oct_file);
364         fclose(oct_file);
365     }
366 #endif
367 }
368 
369 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){
370     float val;
371     int i = 0;
372 #ifdef OCTAVE_OUTPUT
373     FILE * oct_file = NULL;
374     if (plc_state->nbf>0){
375         oct_file = open_octave_file(plc_state, OCTAVE_FRAME_TYPE_GOOD);
376         if (oct_file){
377             octave_fprintf_plot_history_frame(plc_state, oct_file, plc_state->frame_count);
378         }
379     }
380 #endif
381     if (plc_state->nbf>0){
382         for (i=0;i<CVSD_RT;i++){
383             out[i] = plc_state->hist[CVSD_LHIST+i];
384         }
385 
386         for (i=CVSD_RT;i<CVSD_RT+CVSD_OLAL;i++){
387             float left  = plc_state->hist[CVSD_LHIST+i];
388             float right = in[i];
389             val = left * rcos[i-CVSD_RT] + right *rcos[CVSD_OLAL+CVSD_RT-1-i];
390             out[i] = (BTSTACK_CVSD_PLC_SAMPLE_FORMAT)val;
391         }
392     }
393 
394     for (;i<num_samples;i++){
395         out[i] = in[i];
396     }
397     // Copy the output to the history buffer
398     for (i=0;i<num_samples;i++){
399         plc_state->hist[CVSD_LHIST+i] = out[i];
400     }
401     // shift the history buffer
402     for (i=0;i<CVSD_LHIST;i++){
403         plc_state->hist[i] = plc_state->hist[i+num_samples];
404     }
405 
406 #ifdef OCTAVE_OUTPUT
407     if (oct_file){
408         octave_fprintf_plot_output(plc_state, oct_file);
409         fclose(oct_file);
410     }
411 #endif
412     plc_state->nbf=0;
413 }
414 
415 static int count_equal_samples(BTSTACK_CVSD_PLC_SAMPLE_FORMAT * packet, uint16_t size){
416     int count = 0;
417     int temp_count = 1;
418     int i;
419     for (i = 0; i < size-1; i++){
420         if (packet[i] == packet[i+1]){
421             temp_count++;
422             continue;
423         }
424         if (count < temp_count){
425             count = temp_count;
426         }
427         temp_count = 1;
428     }
429     if (temp_count > count + 1){
430         count = temp_count;
431     }
432     return count;
433 }
434 
435 static int count_zeros(BTSTACK_CVSD_PLC_SAMPLE_FORMAT * frame, uint16_t size){
436     int nr_zeros = 0;
437     int i;
438     for (i = 0; i < size-1; i++){
439         if (frame[i] == 0){
440             nr_zeros++;
441         }
442     }
443     return nr_zeros;
444 }
445 
446 // note: a zero_frame is currently also a 'bad_frame'
447 static int zero_frame(BTSTACK_CVSD_PLC_SAMPLE_FORMAT * frame, uint16_t size){
448     return count_zeros(frame, size) > (size/2);
449 }
450 
451 // more than half the samples are the same -> bad frame
452 static int bad_frame(btstack_cvsd_plc_state_t *plc_state, BTSTACK_CVSD_PLC_SAMPLE_FORMAT * frame, uint16_t size){
453     return count_equal_samples(frame, size) > size / 2;
454 }
455 
456 
457 void btstack_cvsd_plc_process_data(btstack_cvsd_plc_state_t * plc_state, BTSTACK_CVSD_PLC_SAMPLE_FORMAT * in, uint16_t num_samples, BTSTACK_CVSD_PLC_SAMPLE_FORMAT * out){
458     if (num_samples == 0) return;
459 
460     plc_state->frame_count++;
461 
462     int is_zero_frame = zero_frame(in, num_samples);
463     int is_bad_frame  = bad_frame(plc_state, in, num_samples);
464 
465     if (is_bad_frame){
466         memcpy(out, in, num_samples * 2);
467         if (plc_state->good_samples > CVSD_LHIST){
468             btstack_cvsd_plc_bad_frame(plc_state, num_samples, out);
469             if (is_zero_frame){
470                 plc_state->zero_frames_nr++;
471             } else {
472                 plc_state->bad_frames_nr++;
473             }
474         } else {
475             memset(out, 0, num_samples * 2);
476         }
477     } else {
478         btstack_cvsd_plc_good_frame(plc_state, num_samples, in, out);
479         plc_state->good_frames_nr++;
480         if (plc_state->good_frames_nr == 1){
481             log_info("First good frame at index %d\n", plc_state->frame_count-1);
482         }
483         plc_state->good_samples += num_samples;
484     }
485 }
486 
487 void btstack_cvsd_dump_statistics(btstack_cvsd_plc_state_t * state){
488     log_info("Good frames: %d\n", state->good_frames_nr);
489     log_info("Bad frames: %d\n", state->bad_frames_nr);
490     log_info("Zero frames: %d\n", state->zero_frames_nr);
491     log_info("Max Consecutive bad frames: %d\n", state->max_consecutive_bad_frames_nr);
492 }
493