xref: /btstack/src/classic/btstack_sbc_plc.c (revision 3e90877db8cb17795c6b27a3cef2cb84d0aa93cf)
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_sbc_plc.c"
39 
40 /*
41  * btstack_sbc_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_sbc_plc.h"
54 #include "btstack_debug.h"
55 
56 #define SAMPLE_FORMAT int16_t
57 
58 static uint8_t indices0[] = { 0xad, 0x00, 0x00, 0xc5, 0x00, 0x00, 0x00, 0x00, 0x77, 0x6d,
59 0xb6, 0xdd, 0xdb, 0x6d, 0xb7, 0x76, 0xdb, 0x6d, 0xdd, 0xb6, 0xdb, 0x77, 0x6d,
60 0xb6, 0xdd, 0xdb, 0x6d, 0xb7, 0x76, 0xdb, 0x6d, 0xdd, 0xb6, 0xdb, 0x77, 0x6d,
61 0xb6, 0xdd, 0xdb, 0x6d, 0xb7, 0x76, 0xdb, 0x6d, 0xdd, 0xb6, 0xdb, 0x77, 0x6d,
62 0xb6, 0xdd, 0xdb, 0x6d, 0xb7, 0x76, 0xdb, 0x6c};
63 
64 /* Raised COSine table for OLA */
65 static float rcos[SBC_OLAL] = {
66     0.99148655f,0.96623611f,0.92510857f,0.86950446f,
67     0.80131732f,0.72286918f,0.63683150f,0.54613418f,
68     0.45386582f,0.36316850f,0.27713082f,0.19868268f,
69     0.13049554f,0.07489143f,0.03376389f,0.00851345f};
70 
71 // taken from http://www.codeproject.com/Articles/69941/Best-Square-Root-Method-Algorithm-Function-Precisi
72 // Algorithm: Babylonian Method + some manipulations on IEEE 32 bit floating point representation
73 static float sqrt3(const float x){
74     union {
75         int i;
76         float x;
77     } u;
78     u.x = x;
79     u.i = (1<<29) + (u.i >> 1) - (1<<22);
80 
81     // Two Babylonian Steps (simplified from:)
82     // u.x = 0.5f * (u.x + x/u.x);
83     // u.x = 0.5f * (u.x + x/u.x);
84     u.x =       u.x + (x/u.x);
85     u.x = (0.25f*u.x) + (x/u.x);
86 
87     return u.x;
88 }
89 
90 static float absolute(float x){
91      if (x < 0) x = -x;
92      return x;
93 }
94 
95 static float CrossCorrelation(SAMPLE_FORMAT *x, SAMPLE_FORMAT *y){
96     float num = 0;
97     float den = 0;
98     float x2 = 0;
99     float y2 = 0;
100     int   m;
101     for (m=0;m<SBC_M;m++){
102         num+=((float)x[m])*y[m];
103         x2+=((float)x[m])*x[m];
104         y2+=((float)y[m])*y[m];
105     }
106     den = (float)sqrt3(x2*y2);
107     return num/den;
108 }
109 
110 static int PatternMatch(SAMPLE_FORMAT *y){
111     float maxCn = -999999.0;  // large negative number
112     int   bestmatch = 0;
113     float Cn;
114     int   n;
115     for (n=0;n<SBC_N;n++){
116         Cn = CrossCorrelation(&y[SBC_LHIST-SBC_M], &y[n]);
117         if (Cn>maxCn){
118             bestmatch=n;
119             maxCn = Cn;
120         }
121     }
122     return bestmatch;
123 }
124 
125 static float AmplitudeMatch(SAMPLE_FORMAT *y, SAMPLE_FORMAT bestmatch) {
126     int   i;
127     float sumx = 0;
128     float sumy = 0.000001f;
129     float sf;
130 
131     for (i=0;i<SBC_FS;i++){
132         sumx += absolute(y[SBC_LHIST-SBC_FS+i]);
133         sumy += absolute(y[bestmatch+i]);
134     }
135     sf = sumx/sumy;
136     // This is not in the paper, but limit the scaling factor to something reasonable to avoid creating artifacts
137     if (sf<0.75f) sf=0.75f;
138     if (sf>1.0f) sf=1.0f;
139     return sf;
140 }
141 
142 static SAMPLE_FORMAT crop_sample(float val){
143     float croped_val = val;
144     if (croped_val > 32767.0)  croped_val= 32767.0;
145     if (croped_val < -32768.0) croped_val=-32768.0;
146     return (SAMPLE_FORMAT) croped_val;
147 }
148 
149 uint8_t * btstack_sbc_plc_zero_signal_frame(void){
150     return (uint8_t *)&indices0;
151 }
152 
153 void btstack_sbc_plc_init(btstack_sbc_plc_state_t *plc_state){
154     plc_state->nbf=0;
155     plc_state->bestlag=0;
156     memset(plc_state->hist,0,sizeof(plc_state->hist));
157 }
158 
159 #ifdef OCTAVE_OUTPUT
160 typedef enum {
161     OCTAVE_FRAME_TYPE_UNKNOWN = 0,
162     OCTAVE_FRAME_TYPE_GOOD,
163     OCTAVE_FRAME_TYPE_BAD
164 } octave_frame_type_t;
165 
166 static const char * octave_frame_type_name[] = {
167     "unknown",
168     "good",
169     "bad"
170 };
171 
172 static octave_frame_type_t octave_frame_type;
173 static char octave_base_name[1000];
174 
175 const char * octave_frame_type2str(int index){
176     if (index <= 0 || index >= sizeof(octave_frame_type_t)) return octave_frame_type_name[0];
177     return octave_frame_type_name[index];
178 }
179 
180 void btstack_sbc_plc_octave_set_base_name(const char * base_name){
181     strcpy(octave_base_name, base_name);
182     printf("OCTAVE: base name set to %s\n", octave_base_name);
183 }
184 
185 static void octave_fprintf_array_int16(FILE * oct_file, char * name, int data_len, int16_t * data){
186     fprintf(oct_file, "%s = [", name);
187     int i;
188     for (i = 0; i < data_len - 1; i++){
189         fprintf(oct_file, "%d, ", data[i]);
190     }
191     fprintf(oct_file, "%d", data[i]);
192     fprintf(oct_file, "%s", "];\n");
193 }
194 
195 static FILE * open_octave_file(btstack_sbc_plc_state_t *plc_state, octave_frame_type_t frame_type){
196     char oct_file_name[1200];
197     octave_frame_type = frame_type;
198     sprintf(oct_file_name, "%s_octave_plc_%d_%s.m", octave_base_name, plc_state->frame_count, octave_frame_type2str(octave_frame_type));
199 
200     FILE * oct_file = fopen(oct_file_name, "wb");
201     if (oct_file == NULL){
202         printf("OCTAVE: could not open file %s\n", oct_file_name);
203         return NULL;
204     }
205     printf("OCTAVE: opened file %s\n", oct_file_name);
206     return oct_file;
207 }
208 
209 static void octave_fprintf_plot_history_frame(btstack_sbc_plc_state_t *plc_state, FILE * oct_file, int frame_nr){
210     char title[100];
211     char hist_name[10];
212     sprintf(hist_name, "hist%d", plc_state->nbf);
213 
214     octave_fprintf_array_int16(oct_file, hist_name, SBC_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", SBC_LHIST+SBC_FS+SBC_RT+SBC_OLAL);
219 
220     int pos = SBC_FS;
221     fprintf(oct_file, "shift_x = x + %d;\n", pos);
222 
223     pos = SBC_LHIST - 1;
224     fprintf(oct_file, "lhist_x = x + %d;\n", pos);
225     pos += SBC_OLAL;
226     fprintf(oct_file, "lhist_olal1_x = x + %d;\n", pos);
227     pos += SBC_FS - SBC_OLAL;
228     fprintf(oct_file, "lhist_fs_x = x + %d;\n", pos);
229     pos += SBC_OLAL;
230     fprintf(oct_file, "lhist_olal2_x = x + %d;\n", pos);
231     pos += SBC_RT;
232     fprintf(oct_file, "lhist_rt_x = x + %d;\n", pos);
233 
234     fprintf(oct_file, "pattern_window_x = x + %d;\n", SBC_LHIST - SBC_M);
235 
236     fprintf(oct_file, "hf = figure();\n");
237     sprintf(title, "PLC %s frame %d", octave_frame_type2str(octave_frame_type), frame_nr);
238 
239     fprintf(oct_file, "hold on;\n");
240     fprintf(oct_file, "h1 = plot(%s); \n", hist_name);
241 
242     fprintf(oct_file, "title(\"%s\");\n", title);
243 
244     fprintf(oct_file, "plot(lhist_x, y, 'k'); \n");
245     fprintf(oct_file, "text(max(lhist_x) - 10, max(y)+1000, 'lhist'); \n");
246 
247     fprintf(oct_file, "plot(lhist_olal1_x, y, 'k'); \n");
248     fprintf(oct_file, "text(max(lhist_olal1_x) - 10, max(y)+1000, 'OLAL'); \n");
249 
250     fprintf(oct_file, "plot(lhist_fs_x, y, 'k'); \n");
251     fprintf(oct_file, "text(max(lhist_fs_x) - 10, max(y)+1000, 'FS'); \n");
252 
253     fprintf(oct_file, "plot(lhist_olal2_x, y, 'k'); \n");
254     fprintf(oct_file, "text(max(lhist_olal2_x) - 10, max(y)+1000, 'OLAL'); \n");
255 
256     fprintf(oct_file, "plot(lhist_rt_x, y, 'k');\n");
257     fprintf(oct_file, "text(max(lhist_rt_x) - 10, max(y)+1000, 'RT'); \n");
258 
259     if (octave_frame_type == OCTAVE_FRAME_TYPE_GOOD) return;
260 
261     int x0 = plc_state->bestlag;
262     int x1 = plc_state->bestlag + SBC_M - 1;
263     fprintf(oct_file, "plot(b(%d:%d), %s(%d:%d), 'rd'); \n", x0, x1, hist_name, x0, x1);
264     fprintf(oct_file, "text(%d - 10, -10, 'bestlag'); \n", x0);
265 
266     x0 = plc_state->bestlag + SBC_M ;
267     x1 = plc_state->bestlag + SBC_M + SBC_FS - 1;
268     fprintf(oct_file, "plot(b(%d:%d), %s(%d:%d), 'kd'); \n", x0, x1, hist_name, x0, x1);
269 
270     x0 = SBC_LHIST - SBC_M;
271     x1 = SBC_LHIST - 1;
272     fprintf(oct_file, "plot(b(%d:%d), %s(%d:%d), 'rd'); \n", x0, x1, hist_name, x0, x1);
273     fprintf(oct_file, "plot(pattern_window_x, y, 'g'); \n");
274     fprintf(oct_file, "text(max(pattern_window_x) - 10, max(y)+1000, 'M'); \n");
275 }
276 
277 static void octave_fprintf_plot_output(btstack_sbc_plc_state_t *plc_state, FILE * oct_file){
278     if (!oct_file) return;
279     char out_name[10];
280     sprintf(out_name, "out%d", plc_state->nbf);
281     int x0  = SBC_LHIST;
282     int x1  = x0 + SBC_FS - 1;
283     octave_fprintf_array_int16(oct_file, out_name, SBC_FS, plc_state->hist+x0);
284     fprintf(oct_file, "h2 = plot(b(%d:%d), %s, 'cd'); \n", x0, x1, out_name);
285 
286     char rest_hist_name[10];
287     sprintf(rest_hist_name, "rest%d", plc_state->nbf);
288     x0  = SBC_LHIST + SBC_FS;
289     x1  = x0 + SBC_OLAL + SBC_RT - 1;
290     octave_fprintf_array_int16(oct_file, rest_hist_name, SBC_OLAL + SBC_RT, plc_state->hist+x0);
291     fprintf(oct_file, "h3 = plot(b(%d:%d), %s, 'kd'); \n", x0, x1, rest_hist_name);
292 
293     char new_hist_name[10];
294     sprintf(new_hist_name, "hist%d", plc_state->nbf);
295     octave_fprintf_array_int16(oct_file, new_hist_name, SBC_LHIST, plc_state->hist);
296     fprintf(oct_file, "h4 = plot(%s, 'r--'); \n", new_hist_name);
297 
298     fprintf(oct_file, "legend ([h1, h2, h3, h4], {\"hist\", \"out\", \"rest\", \"new hist\"}, \"location\", \"northeast\");\n ");
299 
300     char fig_name[1200];
301     sprintf(fig_name, "../%s_octave_plc_%d_%s", octave_base_name, plc_state->frame_count, octave_frame_type2str(octave_frame_type));
302     fprintf(oct_file, "print(hf, \"%s.jpg\", \"-djpg\");", fig_name);
303 }
304 #endif
305 
306 
307 void btstack_sbc_plc_bad_frame(btstack_sbc_plc_state_t *plc_state, SAMPLE_FORMAT *ZIRbuf, SAMPLE_FORMAT *out){
308     float val;
309     int   i = 0;
310     float sf = 1;
311     plc_state->nbf++;
312 
313     plc_state->bad_frames_nr++;
314     plc_state->frame_count++;
315     if (plc_state->max_consecutive_bad_frames_nr < plc_state->nbf){
316         plc_state->max_consecutive_bad_frames_nr = plc_state->nbf;
317     }
318 
319     if (plc_state->nbf==1){
320         // printf("first bad frame\n");
321         // Perform pattern matching to find where to replicate
322         plc_state->bestlag = PatternMatch(plc_state->hist);
323     }
324 
325 #ifdef OCTAVE_OUTPUT
326     FILE * oct_file = open_octave_file(plc_state, OCTAVE_FRAME_TYPE_BAD);
327     if (oct_file){
328         octave_fprintf_plot_history_frame(plc_state, oct_file, plc_state->frame_count);
329     }
330 #endif
331 
332     if (plc_state->nbf==1){
333         // the replication begins after the template match
334         plc_state->bestlag += SBC_M;
335 
336         // Compute Scale Factor to Match Amplitude of Substitution Packet to that of Preceding Packet
337         sf = AmplitudeMatch(plc_state->hist, plc_state->bestlag);
338         // printf("sf Apmlitude Match %f, new data %d, bestlag+M %d\n", sf, ZIRbuf[0], plc_state->hist[plc_state->bestlag]);
339         for (i=0;i<SBC_OLAL;i++){
340             float left  = ZIRbuf[i];
341             float right = sf*plc_state->hist[plc_state->bestlag+i];
342             val = (left*rcos[i]) + (right*rcos[SBC_OLAL-1-i]);
343             // val = sf*plc_state->hist[plc_state->bestlag+i];
344             plc_state->hist[SBC_LHIST+i] = crop_sample(val);
345         }
346 
347         for (;i<SBC_FS;i++){
348             val = sf*plc_state->hist[plc_state->bestlag+i];
349             plc_state->hist[SBC_LHIST+i] = crop_sample(val);
350         }
351 
352         for (;i<(SBC_FS+SBC_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-SBC_FS])+(right*rcos[SBC_OLAL-1-i+SBC_FS]);
356             plc_state->hist[SBC_LHIST+i] = crop_sample(val);
357         }
358 
359         for (;i<(SBC_FS+SBC_RT+SBC_OLAL);i++){
360             plc_state->hist[SBC_LHIST+i] = plc_state->hist[plc_state->bestlag+i];
361         }
362     } else {
363         // printf("succesive bad frame nr %d\n", plc_state->nbf);
364         for (;i<(SBC_FS+SBC_RT+SBC_OLAL);i++){
365             plc_state->hist[SBC_LHIST+i] = plc_state->hist[plc_state->bestlag+i];
366         }
367     }
368     for (i=0;i<SBC_FS;i++){
369         out[i] = plc_state->hist[SBC_LHIST+i];
370     }
371 
372    // shift the history buffer
373     for (i=0;i<(SBC_LHIST+SBC_RT+SBC_OLAL);i++){
374         plc_state->hist[i] = plc_state->hist[i+SBC_FS];
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_sbc_plc_good_frame(btstack_sbc_plc_state_t *plc_state, SAMPLE_FORMAT *in, SAMPLE_FORMAT *out){
386     float val;
387     int i = 0;
388     plc_state->good_frames_nr++;
389     plc_state->frame_count++;
390 
391 #ifdef OCTAVE_OUTPUT
392     FILE * oct_file = NULL;
393     if (plc_state->nbf>0){
394         oct_file = open_octave_file(plc_state, OCTAVE_FRAME_TYPE_GOOD);
395         if (oct_file){
396             octave_fprintf_plot_history_frame(plc_state, oct_file, plc_state->frame_count);
397         }
398     }
399 #endif
400 
401     if (plc_state->nbf>0){
402         for (i=0;i<SBC_RT;i++){
403             out[i] = plc_state->hist[SBC_LHIST+i];
404         }
405 
406         for (i = SBC_RT;i<(SBC_RT+SBC_OLAL);i++){
407             float left  = plc_state->hist[SBC_LHIST+i];
408             float right = in[i];
409             val = (left*rcos[i-SBC_RT]) + (right*rcos[SBC_OLAL+SBC_RT-1-i]);
410             out[i] = crop_sample(val);
411         }
412     }
413 
414     for (;i<SBC_FS;i++){
415         out[i] = in[i];
416     }
417     // Copy the output to the history buffer
418     for (i=0;i<SBC_FS;i++){
419         plc_state->hist[SBC_LHIST+i] = out[i];
420     }
421 
422     // shift the history buffer
423     for (i=0;i<SBC_LHIST;i++){
424         plc_state->hist[i] = plc_state->hist[i+SBC_FS];
425     }
426 
427 #ifdef OCTAVE_OUTPUT
428     if (oct_file){
429         octave_fprintf_plot_output(plc_state, oct_file);
430         fclose(oct_file);
431     }
432 #endif
433     plc_state->nbf=0;
434 }
435 
436 void btstack_sbc_dump_statistics(btstack_sbc_plc_state_t * state){
437     log_info("Good frames: %d\n", state->good_frames_nr);
438     log_info("Bad frames: %d\n", state->bad_frames_nr);
439     log_info("Max Consecutive bad frames: %d\n", state->max_consecutive_bad_frames_nr);
440 }
441