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1 /*
2  * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <stdint.h>
22 
23 #include "libavutil/common.h"
24 #include "libavutil/libm.h"
25 #include "libavutil/samplefmt.h"
26 #include "avresample.h"
27 #include "internal.h"
28 #include "audio_data.h"
29 #include "audio_mix.h"
30 
31 static const char * const coeff_type_names[] = { "q8", "q15", "flt" };
32 
33 struct AudioMix {
34     AVAudioResampleContext *avr;
35     enum AVSampleFormat fmt;
36     enum AVMixCoeffType coeff_type;
37     uint64_t in_layout;
38     uint64_t out_layout;
39     int in_channels;
40     int out_channels;
41 
42     int ptr_align;
43     int samples_align;
44     int has_optimized_func;
45     const char *func_descr;
46     const char *func_descr_generic;
47     mix_func *mix;
48     mix_func *mix_generic;
49 
50     int in_matrix_channels;
51     int out_matrix_channels;
52     int output_zero[AVRESAMPLE_MAX_CHANNELS];
53     int input_skip[AVRESAMPLE_MAX_CHANNELS];
54     int output_skip[AVRESAMPLE_MAX_CHANNELS];
55     int16_t *matrix_q8[AVRESAMPLE_MAX_CHANNELS];
56     int32_t *matrix_q15[AVRESAMPLE_MAX_CHANNELS];
57     float   *matrix_flt[AVRESAMPLE_MAX_CHANNELS];
58     void   **matrix;
59 };
60 
ff_audio_mix_set_func(AudioMix * am,enum AVSampleFormat fmt,enum AVMixCoeffType coeff_type,int in_channels,int out_channels,int ptr_align,int samples_align,const char * descr,void * mix_func)61 void ff_audio_mix_set_func(AudioMix *am, enum AVSampleFormat fmt,
62                            enum AVMixCoeffType coeff_type, int in_channels,
63                            int out_channels, int ptr_align, int samples_align,
64                            const char *descr, void *mix_func)
65 {
66     if (fmt == am->fmt && coeff_type == am->coeff_type &&
67         ( in_channels ==  am->in_matrix_channels ||  in_channels == 0) &&
68         (out_channels == am->out_matrix_channels || out_channels == 0)) {
69         char chan_str[16];
70         am->mix           = mix_func;
71         am->func_descr    = descr;
72         am->ptr_align     = ptr_align;
73         am->samples_align = samples_align;
74         if (ptr_align == 1 && samples_align == 1) {
75             am->mix_generic        = mix_func;
76             am->func_descr_generic = descr;
77         } else {
78             am->has_optimized_func = 1;
79         }
80         if (in_channels) {
81             if (out_channels)
82                 snprintf(chan_str, sizeof(chan_str), "[%d to %d] ",
83                          in_channels, out_channels);
84             else
85                 snprintf(chan_str, sizeof(chan_str), "[%d to any] ",
86                          in_channels);
87         } else if (out_channels) {
88                 snprintf(chan_str, sizeof(chan_str), "[any to %d] ",
89                          out_channels);
90         } else {
91             snprintf(chan_str, sizeof(chan_str), "[any to any] ");
92         }
93         av_log(am->avr, AV_LOG_DEBUG, "audio_mix: found function: [fmt=%s] "
94                "[c=%s] %s(%s)\n", av_get_sample_fmt_name(fmt),
95                coeff_type_names[coeff_type], chan_str, descr);
96     }
97 }
98 
99 #define MIX_FUNC_NAME(fmt, cfmt) mix_any_ ## fmt ##_## cfmt ##_c
100 
101 #define MIX_FUNC_GENERIC(fmt, cfmt, stype, ctype, sumtype, expr)            \
102 static void MIX_FUNC_NAME(fmt, cfmt)(stype **samples, ctype **matrix,       \
103                                      int len, int out_ch, int in_ch)        \
104 {                                                                           \
105     int i, in, out;                                                         \
106     stype temp[AVRESAMPLE_MAX_CHANNELS];                                    \
107     for (i = 0; i < len; i++) {                                             \
108         for (out = 0; out < out_ch; out++) {                                \
109             sumtype sum = 0;                                                \
110             for (in = 0; in < in_ch; in++)                                  \
111                 sum += samples[in][i] * matrix[out][in];                    \
112             temp[out] = expr;                                               \
113         }                                                                   \
114         for (out = 0; out < out_ch; out++)                                  \
115             samples[out][i] = temp[out];                                    \
116     }                                                                       \
117 }
118 
MIX_FUNC_GENERIC(FLTP,FLT,float,float,float,sum)119 MIX_FUNC_GENERIC(FLTP, FLT, float,   float,   float,   sum)
120 MIX_FUNC_GENERIC(S16P, FLT, int16_t, float,   float,   av_clip_int16(lrintf(sum)))
121 MIX_FUNC_GENERIC(S16P, Q15, int16_t, int32_t, int64_t, av_clip_int16(sum >> 15))
122 MIX_FUNC_GENERIC(S16P, Q8,  int16_t, int16_t, int32_t, av_clip_int16(sum >>  8))
123 
124 /* TODO: templatize the channel-specific C functions */
125 
126 static void mix_2_to_1_fltp_flt_c(float **samples, float **matrix, int len,
127                                   int out_ch, int in_ch)
128 {
129     float *src0 = samples[0];
130     float *src1 = samples[1];
131     float *dst  = src0;
132     float m0    = matrix[0][0];
133     float m1    = matrix[0][1];
134 
135     while (len > 4) {
136         *dst++ = *src0++ * m0 + *src1++ * m1;
137         *dst++ = *src0++ * m0 + *src1++ * m1;
138         *dst++ = *src0++ * m0 + *src1++ * m1;
139         *dst++ = *src0++ * m0 + *src1++ * m1;
140         len -= 4;
141     }
142     while (len > 0) {
143         *dst++ = *src0++ * m0 + *src1++ * m1;
144         len--;
145     }
146 }
147 
mix_2_to_1_s16p_flt_c(int16_t ** samples,float ** matrix,int len,int out_ch,int in_ch)148 static void mix_2_to_1_s16p_flt_c(int16_t **samples, float **matrix, int len,
149                                   int out_ch, int in_ch)
150 {
151     int16_t *src0 = samples[0];
152     int16_t *src1 = samples[1];
153     int16_t *dst  = src0;
154     float m0      = matrix[0][0];
155     float m1      = matrix[0][1];
156 
157     while (len > 4) {
158         *dst++ = av_clip_int16(lrintf(*src0++ * m0 + *src1++ * m1));
159         *dst++ = av_clip_int16(lrintf(*src0++ * m0 + *src1++ * m1));
160         *dst++ = av_clip_int16(lrintf(*src0++ * m0 + *src1++ * m1));
161         *dst++ = av_clip_int16(lrintf(*src0++ * m0 + *src1++ * m1));
162         len -= 4;
163     }
164     while (len > 0) {
165         *dst++ = av_clip_int16(lrintf(*src0++ * m0 + *src1++ * m1));
166         len--;
167     }
168 }
169 
mix_2_to_1_s16p_q8_c(int16_t ** samples,int16_t ** matrix,int len,int out_ch,int in_ch)170 static void mix_2_to_1_s16p_q8_c(int16_t **samples, int16_t **matrix, int len,
171                                  int out_ch, int in_ch)
172 {
173     int16_t *src0 = samples[0];
174     int16_t *src1 = samples[1];
175     int16_t *dst  = src0;
176     int16_t m0    = matrix[0][0];
177     int16_t m1    = matrix[0][1];
178 
179     while (len > 4) {
180         *dst++ = (*src0++ * m0 + *src1++ * m1) >> 8;
181         *dst++ = (*src0++ * m0 + *src1++ * m1) >> 8;
182         *dst++ = (*src0++ * m0 + *src1++ * m1) >> 8;
183         *dst++ = (*src0++ * m0 + *src1++ * m1) >> 8;
184         len -= 4;
185     }
186     while (len > 0) {
187         *dst++ = (*src0++ * m0 + *src1++ * m1) >> 8;
188         len--;
189     }
190 }
191 
mix_1_to_2_fltp_flt_c(float ** samples,float ** matrix,int len,int out_ch,int in_ch)192 static void mix_1_to_2_fltp_flt_c(float **samples, float **matrix, int len,
193                                   int out_ch, int in_ch)
194 {
195     float v;
196     float *dst0 = samples[0];
197     float *dst1 = samples[1];
198     float *src  = dst0;
199     float m0    = matrix[0][0];
200     float m1    = matrix[1][0];
201 
202     while (len > 4) {
203         v = *src++;
204         *dst0++ = v * m0;
205         *dst1++ = v * m1;
206         v = *src++;
207         *dst0++ = v * m0;
208         *dst1++ = v * m1;
209         v = *src++;
210         *dst0++ = v * m0;
211         *dst1++ = v * m1;
212         v = *src++;
213         *dst0++ = v * m0;
214         *dst1++ = v * m1;
215         len -= 4;
216     }
217     while (len > 0) {
218         v = *src++;
219         *dst0++ = v * m0;
220         *dst1++ = v * m1;
221         len--;
222     }
223 }
224 
mix_6_to_2_fltp_flt_c(float ** samples,float ** matrix,int len,int out_ch,int in_ch)225 static void mix_6_to_2_fltp_flt_c(float **samples, float **matrix, int len,
226                                   int out_ch, int in_ch)
227 {
228     float v0, v1;
229     float *src0 = samples[0];
230     float *src1 = samples[1];
231     float *src2 = samples[2];
232     float *src3 = samples[3];
233     float *src4 = samples[4];
234     float *src5 = samples[5];
235     float *dst0 = src0;
236     float *dst1 = src1;
237     float *m0   = matrix[0];
238     float *m1   = matrix[1];
239 
240     while (len > 0) {
241         v0 = *src0++;
242         v1 = *src1++;
243         *dst0++ = v0      * m0[0] +
244                   v1      * m0[1] +
245                   *src2   * m0[2] +
246                   *src3   * m0[3] +
247                   *src4   * m0[4] +
248                   *src5   * m0[5];
249         *dst1++ = v0      * m1[0] +
250                   v1      * m1[1] +
251                   *src2++ * m1[2] +
252                   *src3++ * m1[3] +
253                   *src4++ * m1[4] +
254                   *src5++ * m1[5];
255         len--;
256     }
257 }
258 
mix_2_to_6_fltp_flt_c(float ** samples,float ** matrix,int len,int out_ch,int in_ch)259 static void mix_2_to_6_fltp_flt_c(float **samples, float **matrix, int len,
260                                   int out_ch, int in_ch)
261 {
262     float v0, v1;
263     float *dst0 = samples[0];
264     float *dst1 = samples[1];
265     float *dst2 = samples[2];
266     float *dst3 = samples[3];
267     float *dst4 = samples[4];
268     float *dst5 = samples[5];
269     float *src0 = dst0;
270     float *src1 = dst1;
271 
272     while (len > 0) {
273         v0 = *src0++;
274         v1 = *src1++;
275         *dst0++ = v0 * matrix[0][0] + v1 * matrix[0][1];
276         *dst1++ = v0 * matrix[1][0] + v1 * matrix[1][1];
277         *dst2++ = v0 * matrix[2][0] + v1 * matrix[2][1];
278         *dst3++ = v0 * matrix[3][0] + v1 * matrix[3][1];
279         *dst4++ = v0 * matrix[4][0] + v1 * matrix[4][1];
280         *dst5++ = v0 * matrix[5][0] + v1 * matrix[5][1];
281         len--;
282     }
283 }
284 
mix_function_init(AudioMix * am)285 static av_cold int mix_function_init(AudioMix *am)
286 {
287     am->func_descr = am->func_descr_generic = "n/a";
288     am->mix = am->mix_generic = NULL;
289 
290     /* no need to set a mix function when we're skipping mixing */
291     if (!am->in_matrix_channels || !am->out_matrix_channels)
292         return 0;
293 
294     /* any-to-any C versions */
295 
296     ff_audio_mix_set_func(am, AV_SAMPLE_FMT_FLTP, AV_MIX_COEFF_TYPE_FLT,
297                           0, 0, 1, 1, "C", MIX_FUNC_NAME(FLTP, FLT));
298 
299     ff_audio_mix_set_func(am, AV_SAMPLE_FMT_S16P, AV_MIX_COEFF_TYPE_FLT,
300                           0, 0, 1, 1, "C", MIX_FUNC_NAME(S16P, FLT));
301 
302     ff_audio_mix_set_func(am, AV_SAMPLE_FMT_S16P, AV_MIX_COEFF_TYPE_Q15,
303                           0, 0, 1, 1, "C", MIX_FUNC_NAME(S16P, Q15));
304 
305     ff_audio_mix_set_func(am, AV_SAMPLE_FMT_S16P, AV_MIX_COEFF_TYPE_Q8,
306                           0, 0, 1, 1, "C", MIX_FUNC_NAME(S16P, Q8));
307 
308     /* channel-specific C versions */
309 
310     ff_audio_mix_set_func(am, AV_SAMPLE_FMT_FLTP, AV_MIX_COEFF_TYPE_FLT,
311                           2, 1, 1, 1, "C", mix_2_to_1_fltp_flt_c);
312 
313     ff_audio_mix_set_func(am, AV_SAMPLE_FMT_S16P, AV_MIX_COEFF_TYPE_FLT,
314                           2, 1, 1, 1, "C", mix_2_to_1_s16p_flt_c);
315 
316     ff_audio_mix_set_func(am, AV_SAMPLE_FMT_S16P, AV_MIX_COEFF_TYPE_Q8,
317                           2, 1, 1, 1, "C", mix_2_to_1_s16p_q8_c);
318 
319     ff_audio_mix_set_func(am, AV_SAMPLE_FMT_FLTP, AV_MIX_COEFF_TYPE_FLT,
320                           1, 2, 1, 1, "C", mix_1_to_2_fltp_flt_c);
321 
322     ff_audio_mix_set_func(am, AV_SAMPLE_FMT_FLTP, AV_MIX_COEFF_TYPE_FLT,
323                           6, 2, 1, 1, "C", mix_6_to_2_fltp_flt_c);
324 
325     ff_audio_mix_set_func(am, AV_SAMPLE_FMT_FLTP, AV_MIX_COEFF_TYPE_FLT,
326                           2, 6, 1, 1, "C", mix_2_to_6_fltp_flt_c);
327 
328     if (ARCH_X86)
329         ff_audio_mix_init_x86(am);
330 
331     if (!am->mix) {
332         av_log(am->avr, AV_LOG_ERROR, "audio_mix: NO FUNCTION FOUND: [fmt=%s] "
333                "[c=%s] [%d to %d]\n", av_get_sample_fmt_name(am->fmt),
334                coeff_type_names[am->coeff_type], am->in_channels,
335                am->out_channels);
336         return AVERROR_PATCHWELCOME;
337     }
338     return 0;
339 }
340 
ff_audio_mix_alloc(AVAudioResampleContext * avr)341 AudioMix *ff_audio_mix_alloc(AVAudioResampleContext *avr)
342 {
343     AudioMix *am;
344     int ret;
345 
346     am = av_mallocz(sizeof(*am));
347     if (!am)
348         return NULL;
349     am->avr = avr;
350 
351     if (avr->internal_sample_fmt != AV_SAMPLE_FMT_S16P &&
352         avr->internal_sample_fmt != AV_SAMPLE_FMT_FLTP) {
353         av_log(avr, AV_LOG_ERROR, "Unsupported internal format for "
354                "mixing: %s\n",
355                av_get_sample_fmt_name(avr->internal_sample_fmt));
356         goto error;
357     }
358 
359     am->fmt          = avr->internal_sample_fmt;
360     am->coeff_type   = avr->mix_coeff_type;
361     am->in_layout    = avr->in_channel_layout;
362     am->out_layout   = avr->out_channel_layout;
363     am->in_channels  = avr->in_channels;
364     am->out_channels = avr->out_channels;
365 
366     /* build matrix if the user did not already set one */
367     if (avr->mix_matrix) {
368         ret = ff_audio_mix_set_matrix(am, avr->mix_matrix, avr->in_channels);
369         if (ret < 0)
370             goto error;
371         av_freep(&avr->mix_matrix);
372     } else {
373         double *matrix_dbl = av_mallocz(avr->out_channels * avr->in_channels *
374                                         sizeof(*matrix_dbl));
375         if (!matrix_dbl)
376             goto error;
377 
378         ret = avresample_build_matrix(avr->in_channel_layout,
379                                       avr->out_channel_layout,
380                                       avr->center_mix_level,
381                                       avr->surround_mix_level,
382                                       avr->lfe_mix_level,
383                                       avr->normalize_mix_level,
384                                       matrix_dbl,
385                                       avr->in_channels,
386                                       avr->matrix_encoding);
387         if (ret < 0) {
388             av_free(matrix_dbl);
389             goto error;
390         }
391 
392         ret = ff_audio_mix_set_matrix(am, matrix_dbl, avr->in_channels);
393         if (ret < 0) {
394             av_log(avr, AV_LOG_ERROR, "error setting mix matrix\n");
395             av_free(matrix_dbl);
396             goto error;
397         }
398 
399         av_free(matrix_dbl);
400     }
401 
402     return am;
403 
404 error:
405     av_free(am);
406     return NULL;
407 }
408 
ff_audio_mix_free(AudioMix ** am_p)409 void ff_audio_mix_free(AudioMix **am_p)
410 {
411     AudioMix *am;
412 
413     if (!*am_p)
414         return;
415     am = *am_p;
416 
417     if (am->matrix) {
418         av_free(am->matrix[0]);
419         am->matrix = NULL;
420     }
421     memset(am->matrix_q8,  0, sizeof(am->matrix_q8 ));
422     memset(am->matrix_q15, 0, sizeof(am->matrix_q15));
423     memset(am->matrix_flt, 0, sizeof(am->matrix_flt));
424 
425     av_freep(am_p);
426 }
427 
ff_audio_mix(AudioMix * am,AudioData * src)428 int ff_audio_mix(AudioMix *am, AudioData *src)
429 {
430     int use_generic = 1;
431     int len = src->nb_samples;
432     int i, j;
433 
434     /* determine whether to use the optimized function based on pointer and
435        samples alignment in both the input and output */
436     if (am->has_optimized_func) {
437         int aligned_len = FFALIGN(len, am->samples_align);
438         if (!(src->ptr_align % am->ptr_align) &&
439             src->samples_align >= aligned_len) {
440             len = aligned_len;
441             use_generic = 0;
442         }
443     }
444     av_log(am->avr, AV_LOG_TRACE, "audio_mix: %d samples - %d to %d channels (%s)\n",
445             src->nb_samples, am->in_channels, am->out_channels,
446             use_generic ? am->func_descr_generic : am->func_descr);
447 
448     if (am->in_matrix_channels && am->out_matrix_channels) {
449         uint8_t **data;
450         uint8_t *data0[AVRESAMPLE_MAX_CHANNELS] = { NULL };
451 
452         if (am->out_matrix_channels < am->out_channels ||
453              am->in_matrix_channels <  am->in_channels) {
454             for (i = 0, j = 0; i < FFMAX(am->in_channels, am->out_channels); i++) {
455                 if (am->input_skip[i] || am->output_skip[i] || am->output_zero[i])
456                     continue;
457                 data0[j++] = src->data[i];
458             }
459             data = data0;
460         } else {
461             data = src->data;
462         }
463 
464         if (use_generic)
465             am->mix_generic(data, am->matrix, len, am->out_matrix_channels,
466                             am->in_matrix_channels);
467         else
468             am->mix(data, am->matrix, len, am->out_matrix_channels,
469                     am->in_matrix_channels);
470     }
471 
472     if (am->out_matrix_channels < am->out_channels) {
473         for (i = 0; i < am->out_channels; i++)
474             if (am->output_zero[i])
475                 av_samples_set_silence(&src->data[i], 0, len, 1, am->fmt);
476     }
477 
478     ff_audio_data_set_channels(src, am->out_channels);
479 
480     return 0;
481 }
482 
ff_audio_mix_get_matrix(AudioMix * am,double * matrix,int stride)483 int ff_audio_mix_get_matrix(AudioMix *am, double *matrix, int stride)
484 {
485     int i, o, i0, o0;
486 
487     if ( am->in_channels <= 0 ||  am->in_channels > AVRESAMPLE_MAX_CHANNELS ||
488         am->out_channels <= 0 || am->out_channels > AVRESAMPLE_MAX_CHANNELS) {
489         av_log(am->avr, AV_LOG_ERROR, "Invalid channel counts\n");
490         return AVERROR(EINVAL);
491     }
492 
493 #define GET_MATRIX_CONVERT(suffix, scale)                                   \
494     if (!am->matrix_ ## suffix[0]) {                                        \
495         av_log(am->avr, AV_LOG_ERROR, "matrix is not set\n");               \
496         return AVERROR(EINVAL);                                             \
497     }                                                                       \
498     for (o = 0, o0 = 0; o < am->out_channels; o++) {                        \
499         for (i = 0, i0 = 0; i < am->in_channels; i++) {                     \
500             if (am->input_skip[i] || am->output_zero[o])                    \
501                 matrix[o * stride + i] = 0.0;                               \
502             else                                                            \
503                 matrix[o * stride + i] = am->matrix_ ## suffix[o0][i0] *    \
504                                          (scale);                           \
505             if (!am->input_skip[i])                                         \
506                 i0++;                                                       \
507         }                                                                   \
508         if (!am->output_zero[o])                                            \
509             o0++;                                                           \
510     }
511 
512     switch (am->coeff_type) {
513     case AV_MIX_COEFF_TYPE_Q8:
514         GET_MATRIX_CONVERT(q8, 1.0 / 256.0);
515         break;
516     case AV_MIX_COEFF_TYPE_Q15:
517         GET_MATRIX_CONVERT(q15, 1.0 / 32768.0);
518         break;
519     case AV_MIX_COEFF_TYPE_FLT:
520         GET_MATRIX_CONVERT(flt, 1.0);
521         break;
522     default:
523         av_log(am->avr, AV_LOG_ERROR, "Invalid mix coeff type\n");
524         return AVERROR(EINVAL);
525     }
526 
527     return 0;
528 }
529 
reduce_matrix(AudioMix * am,const double * matrix,int stride)530 static void reduce_matrix(AudioMix *am, const double *matrix, int stride)
531 {
532     int i, o;
533 
534     memset(am->output_zero, 0, sizeof(am->output_zero));
535     memset(am->input_skip,  0, sizeof(am->input_skip));
536     memset(am->output_skip, 0, sizeof(am->output_skip));
537 
538     /* exclude output channels if they can be zeroed instead of mixed */
539     for (o = 0; o < am->out_channels; o++) {
540         int zero = 1;
541 
542         /* check if the output is always silent */
543         for (i = 0; i < am->in_channels; i++) {
544             if (matrix[o * stride + i] != 0.0) {
545                 zero = 0;
546                 break;
547             }
548         }
549         /* check if the corresponding input channel makes a contribution to
550            any output channel */
551         if (o < am->in_channels) {
552             for (i = 0; i < am->out_channels; i++) {
553                 if (matrix[i * stride + o] != 0.0) {
554                     zero = 0;
555                     break;
556                 }
557             }
558         }
559         if (zero) {
560             am->output_zero[o] = 1;
561             am->out_matrix_channels--;
562             if (o < am->in_channels)
563                 am->in_matrix_channels--;
564         }
565     }
566     if (am->out_matrix_channels == 0 || am->in_matrix_channels == 0) {
567         am->out_matrix_channels = 0;
568         am->in_matrix_channels = 0;
569         return;
570     }
571 
572     /* skip input channels that contribute fully only to the corresponding
573        output channel */
574     for (i = 0; i < FFMIN(am->in_channels, am->out_channels); i++) {
575         int skip = 1;
576 
577         for (o = 0; o < am->out_channels; o++) {
578             int i0;
579             if ((o != i && matrix[o * stride + i] != 0.0) ||
580                 (o == i && matrix[o * stride + i] != 1.0)) {
581                 skip = 0;
582                 break;
583             }
584             /* if the input contributes fully to the output, also check that no
585                other inputs contribute to this output */
586             if (o == i) {
587                 for (i0 = 0; i0 < am->in_channels; i0++) {
588                     if (i0 != i && matrix[o * stride + i0] != 0.0) {
589                         skip = 0;
590                         break;
591                     }
592                 }
593             }
594         }
595         if (skip) {
596             am->input_skip[i] = 1;
597             am->in_matrix_channels--;
598         }
599     }
600     /* skip input channels that do not contribute to any output channel */
601     for (; i < am->in_channels; i++) {
602         int contrib = 0;
603 
604         for (o = 0; o < am->out_channels; o++) {
605             if (matrix[o * stride + i] != 0.0) {
606                 contrib = 1;
607                 break;
608             }
609         }
610         if (!contrib) {
611             am->input_skip[i] = 1;
612             am->in_matrix_channels--;
613         }
614     }
615     if (am->in_matrix_channels == 0) {
616         am->out_matrix_channels = 0;
617         return;
618     }
619 
620     /* skip output channels that only get full contribution from the
621        corresponding input channel */
622     for (o = 0; o < FFMIN(am->in_channels, am->out_channels); o++) {
623         int skip = 1;
624         int o0;
625 
626         for (i = 0; i < am->in_channels; i++) {
627             if ((o != i && matrix[o * stride + i] != 0.0) ||
628                 (o == i && matrix[o * stride + i] != 1.0)) {
629                 skip = 0;
630                 break;
631             }
632         }
633         /* check if the corresponding input channel makes a contribution to
634            any other output channel */
635         i = o;
636         for (o0 = 0; o0 < am->out_channels; o0++) {
637             if (o0 != i && matrix[o0 * stride + i] != 0.0) {
638                 skip = 0;
639                 break;
640             }
641         }
642         if (skip) {
643             am->output_skip[o] = 1;
644             am->out_matrix_channels--;
645         }
646     }
647     if (am->out_matrix_channels == 0) {
648         am->in_matrix_channels = 0;
649         return;
650     }
651 }
652 
ff_audio_mix_set_matrix(AudioMix * am,const double * matrix,int stride)653 int ff_audio_mix_set_matrix(AudioMix *am, const double *matrix, int stride)
654 {
655     int i, o, i0, o0, ret;
656     char in_layout_name[128];
657     char out_layout_name[128];
658 
659     if ( am->in_channels <= 0 ||  am->in_channels > AVRESAMPLE_MAX_CHANNELS ||
660         am->out_channels <= 0 || am->out_channels > AVRESAMPLE_MAX_CHANNELS) {
661         av_log(am->avr, AV_LOG_ERROR, "Invalid channel counts\n");
662         return AVERROR(EINVAL);
663     }
664 
665     if (am->matrix) {
666         av_free(am->matrix[0]);
667         am->matrix = NULL;
668     }
669 
670     am->in_matrix_channels  = am->in_channels;
671     am->out_matrix_channels = am->out_channels;
672 
673     reduce_matrix(am, matrix, stride);
674 
675 #define CONVERT_MATRIX(type, expr)                                          \
676     am->matrix_## type[0] = av_mallocz(am->out_matrix_channels *            \
677                                        am->in_matrix_channels  *            \
678                                        sizeof(*am->matrix_## type[0]));     \
679     if (!am->matrix_## type[0])                                             \
680         return AVERROR(ENOMEM);                                             \
681     for (o = 0, o0 = 0; o < am->out_channels; o++) {                        \
682         if (am->output_zero[o] || am->output_skip[o])                       \
683             continue;                                                       \
684         if (o0 > 0)                                                         \
685             am->matrix_## type[o0] = am->matrix_## type[o0 - 1] +           \
686                                      am->in_matrix_channels;                \
687         for (i = 0, i0 = 0; i < am->in_channels; i++) {                     \
688             double v;                                                       \
689             if (am->input_skip[i] || am->output_zero[i])                    \
690                 continue;                                                   \
691             v = matrix[o * stride + i];                                     \
692             am->matrix_## type[o0][i0] = expr;                              \
693             i0++;                                                           \
694         }                                                                   \
695         o0++;                                                               \
696     }                                                                       \
697     am->matrix = (void **)am->matrix_## type;
698 
699     if (am->in_matrix_channels && am->out_matrix_channels) {
700         switch (am->coeff_type) {
701         case AV_MIX_COEFF_TYPE_Q8:
702             CONVERT_MATRIX(q8, av_clip_int16(lrint(256.0 * v)))
703             break;
704         case AV_MIX_COEFF_TYPE_Q15:
705             CONVERT_MATRIX(q15, av_clipl_int32(llrint(32768.0 * v)))
706             break;
707         case AV_MIX_COEFF_TYPE_FLT:
708             CONVERT_MATRIX(flt, v)
709             break;
710         default:
711             av_log(am->avr, AV_LOG_ERROR, "Invalid mix coeff type\n");
712             return AVERROR(EINVAL);
713         }
714     }
715 
716     ret = mix_function_init(am);
717     if (ret < 0)
718         return ret;
719 
720     av_get_channel_layout_string(in_layout_name, sizeof(in_layout_name),
721                                  am->in_channels, am->in_layout);
722     av_get_channel_layout_string(out_layout_name, sizeof(out_layout_name),
723                                  am->out_channels, am->out_layout);
724     av_log(am->avr, AV_LOG_DEBUG, "audio_mix: %s to %s\n",
725            in_layout_name, out_layout_name);
726     av_log(am->avr, AV_LOG_DEBUG, "matrix size: %d x %d\n",
727            am->in_matrix_channels, am->out_matrix_channels);
728     for (o = 0; o < am->out_channels; o++) {
729         for (i = 0; i < am->in_channels; i++) {
730             if (am->output_zero[o])
731                 av_log(am->avr, AV_LOG_DEBUG, "  (ZERO)");
732             else if (am->input_skip[i] || am->output_zero[i] || am->output_skip[o])
733                 av_log(am->avr, AV_LOG_DEBUG, "  (SKIP)");
734             else
735                 av_log(am->avr, AV_LOG_DEBUG, "  %0.3f ",
736                        matrix[o * am->in_channels + i]);
737         }
738         av_log(am->avr, AV_LOG_DEBUG, "\n");
739     }
740 
741     return 0;
742 }
743