libaf/af_scaletempo.c

   1 /*
   2  * scaletempo audio filter
   3  *
   4  * scale tempo while maintaining pitch
   5  * (WSOLA technique with cross correlation)
   6  * inspired by SoundTouch library by Olli Parviainen
   7  *
   8  * basic algorithm
   9  *   - produce 'stride' output samples per loop
  10  *   - consume stride*scale input samples per loop
  11  *
  12  * to produce smoother transitions between strides, blend next overlap
  13  * samples from last stride with correlated samples of current input
  14  *
  15  * Copyright (c) 2007 Robert Juliano
  16  *
  17  * This file is part of MPlayer.
  18  *
  19  * MPlayer is free software; you can redistribute it and/or modify
  20  * it under the terms of the GNU General Public License as published by
  21  * the Free Software Foundation; either version 2 of the License, or
  22  * (at your option) any later version.
  23  *
  24  * MPlayer is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  * GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License along
  30  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  31  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  32  */
  33
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <limits.h>
  37
  38 #include "af.h"
  39 #include "libavutil/common.h"
  40 #include "subopt-helper.h"
  41 #include "help_mp.h"
  42
  43 // Data for specific instances of this filter
  44 typedef struct af_scaletempo_s
  45 {
  46   // stride
  47   float   scale;
  48   float   speed;
  49   float   frames_stride_scaled;
  50   float   frames_stride_error;
  51   int     bytes_per_frame;
  52   int     bytes_stride;
  53   float   bytes_stride_scaled;
  54   int     bytes_queue;
  55   int     bytes_queued;
  56   int     bytes_to_slide;
  57   int8_t* buf_queue;
  58   // overlap
  59   int     samples_overlap;
  60   int     samples_standing;
  61   int     bytes_overlap;
  62   int     bytes_standing;
  63   void*   buf_overlap;
  64   void*   table_blend;
  65   void    (*output_overlap)(struct af_scaletempo_s* s, void* out_buf, int bytes_off);
  66   // best overlap
  67   int     frames_search;
  68   int     num_channels;
  69   void*   buf_pre_corr;
  70   void*   table_window;
  71   int     (*best_overlap_offset)(struct af_scaletempo_s* s);
  72   // command line
  73   float   scale_nominal;
  74   float   ms_stride;
  75   float   percent_overlap;
  76   float   ms_search;
  77   short   speed_tempo;
  78   short   speed_pitch;
  79 } af_scaletempo_t;
  80
  81 static int fill_queue(struct af_instance_s* af, af_data_t* data, int offset)
  82 {
  83   af_scaletempo_t* s = af->setup;
  84   int bytes_in = data->len - offset;
  85   int offset_unchanged = offset;
  86
  87   if (s->bytes_to_slide > 0) {
  88     if (s->bytes_to_slide < s->bytes_queued) {
  89       int bytes_move = s->bytes_queued - s->bytes_to_slide;
  90       memmove(s->buf_queue,
  91               s->buf_queue + s->bytes_to_slide,
  92               bytes_move);
  93       s->bytes_to_slide = 0;
  94       s->bytes_queued = bytes_move;
  95     } else {
  96       int bytes_skip;
  97       s->bytes_to_slide -= s->bytes_queued;
  98       bytes_skip = FFMIN(s->bytes_to_slide, bytes_in);
  99       s->bytes_queued = 0;
 100       s->bytes_to_slide -= bytes_skip;
 101       offset += bytes_skip;
 102       bytes_in -= bytes_skip;
 103     }
 104   }
 105
 106   if (bytes_in > 0) {
 107     int bytes_copy = FFMIN(s->bytes_queue - s->bytes_queued, bytes_in);
 108     memcpy(s->buf_queue + s->bytes_queued,
 109            (int8_t*)data->audio + offset,
 110            bytes_copy);
 111     s->bytes_queued += bytes_copy;
 112     offset += bytes_copy;
 113   }
 114
 115   return offset - offset_unchanged;
 116 }
 117
 118 #define UNROLL_PADDING (4*4)
 119
 120 static int best_overlap_offset_float(af_scaletempo_t* s)
 121 {
 122   float *pw, *po, *ppc, *search_start;
 123   float best_corr = INT_MIN;
 124   int best_off = 0;
 125   int i, off;
 126
 127   pw  = s->table_window;
 128   po  = s->buf_overlap;
 129   po += s->num_channels;
 130   ppc = s->buf_pre_corr;
 131   for (i=s->num_channels; i<s->samples_overlap; i++) {
 132     *ppc++ = *pw++ * *po++;
 133   }
 134
 135   search_start = (float*)s->buf_queue + s->num_channels;
 136   for (off=0; off<s->frames_search; off++) {
 137     float corr = 0;
 138     float* ps = search_start;
 139     ppc = s->buf_pre_corr;
 140     for (i=s->num_channels; i<s->samples_overlap; i++) {
 141       corr += *ppc++ * *ps++;
 142     }
 143     if (corr > best_corr) {
 144       best_corr = corr;
 145       best_off  = off;
 146     }
 147     search_start += s->num_channels;
 148   }
 149
 150   return best_off * 4 * s->num_channels;
 151 }
 152
 153 static int best_overlap_offset_s16(af_scaletempo_t* s)
 154 {
 155   int32_t *pw, *ppc;
 156   int16_t *po, *search_start;
 157   int64_t best_corr = INT64_MIN;
 158   int best_off = 0;
 159   int off;
 160   long i;
 161
 162   pw  = s->table_window;
 163   po  = s->buf_overlap;
 164   po += s->num_channels;
 165   ppc = s->buf_pre_corr;
 166   for (i=s->num_channels; i<s->samples_overlap; i++) {
 167     *ppc++ = ( *pw++ * *po++ ) >> 15;
 168   }
 169
 170   search_start = (int16_t*)s->buf_queue + s->num_channels;
 171   for (off=0; off<s->frames_search; off++) {
 172     int64_t corr = 0;
 173     int16_t* ps = search_start;
 174     ppc = s->buf_pre_corr;
 175     ppc += s->samples_overlap - s->num_channels;
 176     ps  += s->samples_overlap - s->num_channels;
 177     i  = -(s->samples_overlap - s->num_channels);
 178     do {
 179       corr += ppc[i+0] * ps[i+0];
 180       corr += ppc[i+1] * ps[i+1];
 181       corr += ppc[i+2] * ps[i+2];
 182       corr += ppc[i+3] * ps[i+3];
 183       i += 4;
 184     } while (i < 0);
 185     if (corr > best_corr) {
 186       best_corr = corr;
 187       best_off  = off;
 188     }
 189     search_start += s->num_channels;
 190   }
 191
 192   return best_off * 2 * s->num_channels;
 193 }
 194
 195 static void output_overlap_float(af_scaletempo_t* s, void* buf_out,
 196                                   int bytes_off)
 197 {
 198   float* pout = buf_out;
 199   float* pb   = s->table_blend;
 200   float* po   = s->buf_overlap;
 201   float* pin  = (float*)(s->buf_queue + bytes_off);
 202   int i;
 203   for (i=0; i<s->samples_overlap; i++) {
 204     *pout++ = *po - *pb++ * ( *po - *pin++ ); po++;
 205   }
 206 }
 207 static void output_overlap_s16(af_scaletempo_t* s, void* buf_out,
 208                                int bytes_off)
 209 {
 210   int16_t* pout = buf_out;
 211   int32_t* pb   = s->table_blend;
 212   int16_t* po   = s->buf_overlap;
 213   int16_t* pin  = (int16_t*)(s->buf_queue + bytes_off);
 214   int i;
 215   for (i=0; i<s->samples_overlap; i++) {
 216     *pout++ = *po - ( ( *pb++ * ( *po - *pin++ ) ) >> 16 ); po++;
 217   }
 218 }
 219
 220 // Filter data through filter
 221 static af_data_t* play(struct af_instance_s* af, af_data_t* data)
 222 {
 223   af_scaletempo_t* s = af->setup;
 224   int offset_in;
 225   int max_bytes_out;
 226   int8_t* pout;
 227
 228   if (s->scale == 1.0) {
 229     af->delay = 0;
 230     return data;
 231   }
 232
 233   // RESIZE_LOCAL_BUFFER - can't use macro
 234   max_bytes_out = ((int)(data->len / s->bytes_stride_scaled) + 1) * s->bytes_stride;
 235   if (max_bytes_out > af->data->len) {
 236     mp_msg(MSGT_AFILTER, MSGL_V, "[libaf] Reallocating memory in module %s, "
 237           "old len = %i, new len = %i\n",af->info->name,af->data->len,max_bytes_out);
 238     af->data->audio = realloc(af->data->audio, max_bytes_out);
 239     if (!af->data->audio) {
 240       mp_msg(MSGT_AFILTER, MSGL_FATAL, "[libaf] Could not allocate memory\n");
 241       return NULL;
 242     }
 243     af->data->len = max_bytes_out;
 244   }
 245
 246   offset_in = fill_queue(af, data, 0);
 247   pout = af->data->audio;
 248   while (s->bytes_queued >= s->bytes_queue) {
 249     int ti;
 250     float tf;
 251     int bytes_off = 0;
 252
 253     // output stride
 254     if (s->output_overlap) {
 255       if (s->best_overlap_offset)
 256         bytes_off = s->best_overlap_offset(s);
 257       s->output_overlap(s, pout, bytes_off);
 258     }
 259     memcpy(pout + s->bytes_overlap,
 260            s->buf_queue + bytes_off + s->bytes_overlap,
 261            s->bytes_standing);
 262     pout += s->bytes_stride;
 263
 264     // input stride
 265     memcpy(s->buf_overlap,
 266            s->buf_queue + bytes_off + s->bytes_stride,
 267            s->bytes_overlap);
 268     tf = s->frames_stride_scaled + s->frames_stride_error;
 269     ti = (int)tf;
 270     s->frames_stride_error = tf - ti;
 271     s->bytes_to_slide = ti * s->bytes_per_frame;
 272
 273     offset_in += fill_queue(af, data, offset_in);
 274   }
 275
 276   // This filter can have a negative delay when scale > 1:
 277   // output corresponding to some length of input can be decided and written
 278   // after receiving only a part of that input.
 279   af->delay = s->bytes_queued - s->bytes_to_slide;
 280
 281   data->audio = af->data->audio;
 282   data->len   = pout - (int8_t *)af->data->audio;
 283   return data;
 284 }
 285
 286 // Initialization and runtime control
 287 static int control(struct af_instance_s* af, int cmd, void* arg)
 288 {
 289   af_scaletempo_t* s = af->setup;
 290   switch(cmd){
 291   case AF_CONTROL_REINIT:{
 292     af_data_t* data = (af_data_t*)arg;
 293     float srate = data->rate / 1000;
 294     int nch = data->nch;
 295     int bps;
 296     int use_int = 0;
 297     int frames_stride, frames_overlap;
 298     int i, j;
 299
 300     mp_msg(MSGT_AFILTER, MSGL_V,
 301            "[scaletempo] %.3f speed * %.3f scale_nominal = %.3f\n",
 302            s->speed, s->scale_nominal, s->scale);
 303
 304     if (s->scale == 1.0) {
 305       if (s->speed_tempo && s->speed_pitch)
 306         return AF_DETACH;
 307       memcpy(af->data, data, sizeof(af_data_t));
 308       return af_test_output(af, data);
 309     }
 310
 311     af->data->rate = data->rate;
 312     af->data->nch  = data->nch;
 313     if ( data->format == AF_FORMAT_S16_LE
 314          || data->format == AF_FORMAT_S16_BE ) {
 315       use_int = 1;
 316       af->data->format  = AF_FORMAT_S16_NE;
 317       af->data->bps     = bps = 2;
 318     } else {
 319       af->data->format = AF_FORMAT_FLOAT_NE;
 320       af->data->bps    = bps = 4;
 321     }
 322
 323     frames_stride           = srate * s->ms_stride;
 324     s->bytes_stride         = frames_stride * bps * nch;
 325     s->bytes_stride_scaled  = s->scale * s->bytes_stride;
 326     s->frames_stride_scaled = s->scale * frames_stride;
 327     s->frames_stride_error  = 0;
 328     af->mul = (double)s->bytes_stride / s->bytes_stride_scaled;
 329
 330     frames_overlap = frames_stride * s->percent_overlap;
 331     if (frames_overlap <= 0) {
 332       s->bytes_standing   = s->bytes_stride;
 333       s->samples_standing = s->bytes_standing / bps;
 334       s->output_overlap   = NULL;
 335     } else {
 336       s->samples_overlap  = frames_overlap * nch;
 337       s->bytes_overlap    = frames_overlap * nch * bps;
 338       s->bytes_standing   = s->bytes_stride - s->bytes_overlap;
 339       s->samples_standing = s->bytes_standing / bps;
 340       s->buf_overlap      = realloc(s->buf_overlap, s->bytes_overlap);
 341       s->table_blend      = realloc(s->table_blend, s->bytes_overlap * 4);
 342       if(!s->buf_overlap || !s->table_blend) {
 343         mp_msg(MSGT_AFILTER, MSGL_FATAL, "[scaletempo] Out of memory\n");
 344         return AF_ERROR;
 345       }
 346       memset(s->buf_overlap, 0, s->bytes_overlap);
 347       if (use_int) {
 348         int32_t* pb = s->table_blend;
 349         int64_t blend = 0;
 350         for (i=0; i<frames_overlap; i++) {
 351           int32_t v = blend / frames_overlap;
 352           for (j=0; j<nch; j++) {
 353             *pb++ = v;
 354           }
 355           blend += 65536;  // 2^16
 356         }
 357         s->output_overlap = output_overlap_s16;
 358       } else {
 359         float* pb = s->table_blend;
 360         for (i=0; i<frames_overlap; i++) {
 361           float v = i / (float)frames_overlap;
 362           for (j=0; j<nch; j++) {
 363             *pb++ = v;
 364           }
 365         }
 366         s->output_overlap = output_overlap_float;
 367       }
 368     }
 369
 370     s->frames_search = (frames_overlap > 1) ? srate * s->ms_search : 0;
 371     if (s->frames_search <= 0) {
 372       s->best_overlap_offset = NULL;
 373     } else {
 374       if (use_int) {
 375         int64_t t = frames_overlap;
 376         int32_t n = 8589934588LL / (t * t);  // 4 * (2^31 - 1) / t^2
 377         int32_t* pw;
 378         s->buf_pre_corr = realloc(s->buf_pre_corr, s->bytes_overlap * 2 + UNROLL_PADDING);
 379         s->table_window = realloc(s->table_window, s->bytes_overlap * 2 - nch * bps * 2);
 380         if(!s->buf_pre_corr || !s->table_window) {
 381           mp_msg(MSGT_AFILTER, MSGL_FATAL, "[scaletempo] Out of memory\n");
 382           return AF_ERROR;
 383         }
 384         memset((char *)s->buf_pre_corr + s->bytes_overlap * 2, 0, UNROLL_PADDING);
 385         pw = s->table_window;
 386         for (i=1; i<frames_overlap; i++) {
 387           int32_t v = ( i * (t - i) * n ) >> 15;
 388           for (j=0; j<nch; j++) {
 389             *pw++ = v;
 390           }
 391         }
 392         s->best_overlap_offset = best_overlap_offset_s16;
 393       } else {
 394         float* pw;
 395         s->buf_pre_corr = realloc(s->buf_pre_corr, s->bytes_overlap);
 396         s->table_window = realloc(s->table_window, s->bytes_overlap - nch * bps);
 397         if(!s->buf_pre_corr || !s->table_window) {
 398           mp_msg(MSGT_AFILTER, MSGL_FATAL, "[scaletempo] Out of memory\n");
 399           return AF_ERROR;
 400         }
 401         pw = s->table_window;
 402         for (i=1; i<frames_overlap; i++) {
 403           float v = i * (frames_overlap - i);
 404           for (j=0; j<nch; j++) {
 405             *pw++ = v;
 406           }
 407         }
 408         s->best_overlap_offset = best_overlap_offset_float;
 409       }
 410     }
 411
 412     s->bytes_per_frame = bps * nch;
 413     s->num_channels    = nch;
 414
 415     s->bytes_queue
 416       = (s->frames_search + frames_stride + frames_overlap) * bps * nch;
 417     s->buf_queue = realloc(s->buf_queue, s->bytes_queue + UNROLL_PADDING);
 418     if(!s->buf_queue) {
 419       mp_msg(MSGT_AFILTER, MSGL_FATAL, "[scaletempo] Out of memory\n");
 420       return AF_ERROR;
 421     }
 422
 423     mp_msg (MSGT_AFILTER, MSGL_DBG2, "[scaletempo] "
 424             "%.2f stride_in, %i stride_out, %i standing, "
 425             "%i overlap, %i search, %i queue, %s mode\n",
 426             s->frames_stride_scaled,
 427             (int)(s->bytes_stride / nch / bps),
 428             (int)(s->bytes_standing / nch / bps),
 429             (int)(s->bytes_overlap / nch / bps),
 430             s->frames_search,
 431             (int)(s->bytes_queue / nch / bps),
 432             (use_int?"s16":"float"));
 433
 434     return af_test_output(af, (af_data_t*)arg);
 435   }
 436   case AF_CONTROL_PLAYBACK_SPEED | AF_CONTROL_SET:{
 437     if (s->speed_tempo) {
 438       if (s->speed_pitch) {
 439         break;
 440       }
 441       s->speed = *(float*)arg;
 442       s->scale = s->speed * s->scale_nominal;
 443     } else {
 444       if (s->speed_pitch) {
 445         s->speed = 1 / *(float*)arg;
 446         s->scale = s->speed * s->scale_nominal;
 447         break;
 448       }
 449     }
 450     return AF_OK;
 451   }
 452   case AF_CONTROL_SCALETEMPO_AMOUNT | AF_CONTROL_SET:{
 453     s->scale = *(float*)arg;
 454     s->scale = s->speed * s->scale_nominal;
 455     return AF_OK;
 456   }
 457   case AF_CONTROL_SCALETEMPO_AMOUNT | AF_CONTROL_GET:
 458     *(float*)arg = s->scale;
 459     return AF_OK;
 460   case AF_CONTROL_COMMAND_LINE:{
 461     strarg_t speed = {};
 462     opt_t subopts[] = {
 463       {"scale",   OPT_ARG_FLOAT, &s->scale_nominal, NULL},
 464       {"stride",  OPT_ARG_FLOAT, &s->ms_stride, NULL},
 465       {"overlap", OPT_ARG_FLOAT, &s->percent_overlap, NULL},
 466       {"search",  OPT_ARG_FLOAT, &s->ms_search, NULL},
 467       {"speed",   OPT_ARG_STR,   &speed, NULL},
 468       {NULL},
 469     };
 470     if (subopt_parse(arg, subopts) != 0) {
 471       return AF_ERROR;
 472     }
 473     if (s->scale_nominal <= 0) {
 474         mp_msg(MSGT_AFILTER, MSGL_ERR, "[scaletempo] %s: %s: scale > 0\n",
 475                mp_gtext("error parsing command line"),
 476                mp_gtext("value out of range"));
 477       return AF_ERROR;
 478     }
 479     if (s->ms_stride <= 0) {
 480         mp_msg(MSGT_AFILTER, MSGL_ERR, "[scaletempo] %s: %s: stride > 0\n",
 481                mp_gtext("error parsing command line"),
 482                mp_gtext("value out of range"));
 483       return AF_ERROR;
 484     }
 485     if (s->percent_overlap < 0 || s->percent_overlap > 1) {
 486         mp_msg(MSGT_AFILTER, MSGL_ERR,
 487                "[scaletempo] %s: %s: 0 <= overlap <= 1\n",
 488                mp_gtext("error parsing command line"),
 489                mp_gtext("value out of range"));
 490       return AF_ERROR;
 491     }
 492     if (s->ms_search < 0) {
 493         mp_msg(MSGT_AFILTER, MSGL_ERR, "[scaletempo] %s: %s: search >= 0\n",
 494                mp_gtext("error parsing command line"),
 495                mp_gtext("value out of range"));
 496       return AF_ERROR;
 497     }
 498     if (speed.len > 0) {
 499       if (strcmp(speed.str, "pitch") == 0) {
 500         s->speed_tempo = 0;
 501         s->speed_pitch = 1;
 502       } else if (strcmp(speed.str, "tempo") == 0) {
 503         s->speed_tempo = 1;
 504         s->speed_pitch = 0;
 505       } else if (strcmp(speed.str, "none") == 0) {
 506         s->speed_tempo = 0;
 507         s->speed_pitch = 0;
 508       } else if (strcmp(speed.str, "both") == 0) {
 509         s->speed_tempo = 1;
 510         s->speed_pitch = 1;
 511       } else {
 512         mp_msg(MSGT_AFILTER, MSGL_ERR,
 513                "[scaletempo] %s: %s: speed=[pitch|tempo|none|both]\n",
 514                mp_gtext("error parsing command line"),
 515                mp_gtext("value out of range"));
 516         return AF_ERROR;
 517       }
 518     }
 519     s->scale = s->speed * s->scale_nominal;
 520     mp_msg(MSGT_AFILTER, MSGL_DBG2, "[scaletempo] %6.3f scale, %6.2f stride, %6.2f overlap, %6.2f search, speed = %s\n", s->scale_nominal, s->ms_stride, s->percent_overlap, s->ms_search, (s->speed_tempo?(s->speed_pitch?"tempo and speed":"tempo"):(s->speed_pitch?"pitch":"none")));
 521     return AF_OK;
 522   }
 523   }
 524   return AF_UNKNOWN;
 525 }
 526
 527 // Deallocate memory
 528 static void uninit(struct af_instance_s* af)
 529 {
 530   af_scaletempo_t* s = af->setup;
 531   free(af->data->audio);
 532   free(af->data);
 533   free(s->buf_queue);
 534   free(s->buf_overlap);
 535   free(s->buf_pre_corr);
 536   free(s->table_blend);
 537   free(s->table_window);
 538   free(af->setup);
 539 }
 540
 541 // Allocate memory and set function pointers
 542 static int af_open(af_instance_t* af){
 543   af_scaletempo_t* s;
 544
 545   af->control   = control;
 546   af->uninit    = uninit;
 547   af->play      = play;
 548   af->mul       = 1;
 549   af->data      = calloc(1,sizeof(af_data_t));
 550   af->setup     = calloc(1,sizeof(af_scaletempo_t));
 551   if(af->data == NULL || af->setup == NULL)
 552     return AF_ERROR;
 553
 554   s = af->setup;
 555   s->scale = s->speed = s->scale_nominal = 1.0;
 556   s->speed_tempo = 1;
 557   s->speed_pitch = 0;
 558   s->ms_stride = 60;
 559   s->percent_overlap = .20;
 560   s->ms_search = 14;
 561
 562   return AF_OK;
 563 }
 564
 565 // Description of this filter
 566 af_info_t af_info_scaletempo = {
 567   "Scale audio tempo while maintaining pitch",
 568   "scaletempo",
 569   "Robert Juliano",
 570   "",
 571   AF_FLAGS_REENTRANT,
 572   af_open
 573 };