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     return data;
 230   }
 231
 232   // RESIZE_LOCAL_BUFFER - can't use macro
 233   max_bytes_out = ((int)(data->len / s->bytes_stride_scaled) + 1) * s->bytes_stride;
 234   if (max_bytes_out > af->data->len) {
 235     mp_msg(MSGT_AFILTER, MSGL_V, "[libaf] Reallocating memory in module %s, "
 236           "old len = %i, new len = %i\n",af->info->name,af->data->len,max_bytes_out);
 237     af->data->audio = realloc(af->data->audio, max_bytes_out);
 238     if (!af->data->audio) {
 239       mp_msg(MSGT_AFILTER, MSGL_FATAL, "[libaf] Could not allocate memory\n");
 240       return NULL;
 241     }
 242     af->data->len = max_bytes_out;
 243   }
 244
 245   offset_in = fill_queue(af, data, 0);
 246   pout = af->data->audio;
 247   while (s->bytes_queued >= s->bytes_queue) {
 248     int ti;
 249     float tf;
 250     int bytes_off = 0;
 251
 252     // output stride
 253     if (s->output_overlap) {
 254       if (s->best_overlap_offset)
 255         bytes_off = s->best_overlap_offset(s);
 256       s->output_overlap(s, pout, bytes_off);
 257     }
 258     memcpy(pout + s->bytes_overlap,
 259            s->buf_queue + bytes_off + s->bytes_overlap,
 260            s->bytes_standing);
 261     pout += s->bytes_stride;
 262
 263     // input stride
 264     memcpy(s->buf_overlap,
 265            s->buf_queue + bytes_off + s->bytes_stride,
 266            s->bytes_overlap);
 267     tf = s->frames_stride_scaled + s->frames_stride_error;
 268     ti = (int)tf;
 269     s->frames_stride_error = tf - ti;
 270     s->bytes_to_slide = ti * s->bytes_per_frame;
 271
 272     offset_in += fill_queue(af, data, offset_in);
 273   }
 274
 275   // This filter can have a negative delay when scale > 1:
 276   // output corresponding to some length of input can be decided and written
 277   // after receiving only a part of that input.
 278   af->delay = s->bytes_queued - s->bytes_to_slide;
 279
 280   data->audio = af->data->audio;
 281   data->len   = pout - (int8_t *)af->data->audio;
 282   return data;
 283 }
 284
 285 // Initialization and runtime control
 286 static int control(struct af_instance_s* af, int cmd, void* arg)
 287 {
 288   af_scaletempo_t* s = af->setup;
 289   switch(cmd){
 290   case AF_CONTROL_REINIT:{
 291     af_data_t* data = (af_data_t*)arg;
 292     float srate = data->rate / 1000;
 293     int nch = data->nch;
 294     int bps;
 295     int use_int = 0;
 296     int frames_stride, frames_overlap;
 297     int i, j;
 298
 299     mp_msg(MSGT_AFILTER, MSGL_V,
 300            "[scaletempo] %.3f speed * %.3f scale_nominal = %.3f\n",
 301            s->speed, s->scale_nominal, s->scale);
 302
 303     if (s->scale == 1.0) {
 304       if (s->speed_tempo && s->speed_pitch)
 305         return AF_DETACH;
 306       memcpy(af->data, data, sizeof(af_data_t));
 307       return af_test_output(af, data);
 308     }
 309
 310     af->data->rate = data->rate;
 311     af->data->nch  = data->nch;
 312     if ( data->format == AF_FORMAT_S16_LE
 313          || data->format == AF_FORMAT_S16_BE ) {
 314       use_int = 1;
 315       af->data->format  = AF_FORMAT_S16_NE;
 316       af->data->bps     = bps = 2;
 317     } else {
 318       af->data->format = AF_FORMAT_FLOAT_NE;
 319       af->data->bps    = bps = 4;
 320     }
 321
 322     frames_stride           = srate * s->ms_stride;
 323     s->bytes_stride         = frames_stride * bps * nch;
 324     s->bytes_stride_scaled  = s->scale * s->bytes_stride;
 325     s->frames_stride_scaled = s->scale * frames_stride;
 326     s->frames_stride_error  = 0;
 327     af->mul = (double)s->bytes_stride / s->bytes_stride_scaled;
 328
 329     frames_overlap = frames_stride * s->percent_overlap;
 330     if (frames_overlap <= 0) {
 331       s->bytes_standing   = s->bytes_stride;
 332       s->samples_standing = s->bytes_standing / bps;
 333       s->output_overlap   = NULL;
 334     } else {
 335       s->samples_overlap  = frames_overlap * nch;
 336       s->bytes_overlap    = frames_overlap * nch * bps;
 337       s->bytes_standing   = s->bytes_stride - s->bytes_overlap;
 338       s->samples_standing = s->bytes_standing / bps;
 339       s->buf_overlap      = realloc(s->buf_overlap, s->bytes_overlap);
 340       s->table_blend      = realloc(s->table_blend, s->bytes_overlap * 4);
 341       if(!s->buf_overlap || !s->table_blend) {
 342         mp_msg(MSGT_AFILTER, MSGL_FATAL, "[scaletempo] Out of memory\n");
 343         return AF_ERROR;
 344       }
 345       memset(s->buf_overlap, 0, s->bytes_overlap);
 346       if (use_int) {
 347         int32_t* pb = s->table_blend;
 348         int64_t blend = 0;
 349         for (i=0; i<frames_overlap; i++) {
 350           int32_t v = blend / frames_overlap;
 351           for (j=0; j<nch; j++) {
 352             *pb++ = v;
 353           }
 354           blend += 65536;  // 2^16
 355         }
 356         s->output_overlap = output_overlap_s16;
 357       } else {
 358         float* pb = s->table_blend;
 359         for (i=0; i<frames_overlap; i++) {
 360           float v = i / (float)frames_overlap;
 361           for (j=0; j<nch; j++) {
 362             *pb++ = v;
 363           }
 364         }
 365         s->output_overlap = output_overlap_float;
 366       }
 367     }
 368
 369     s->frames_search = (frames_overlap > 1) ? srate * s->ms_search : 0;
 370     if (s->frames_search <= 0) {
 371       s->best_overlap_offset = NULL;
 372     } else {
 373       if (use_int) {
 374         int64_t t = frames_overlap;
 375         int32_t n = 8589934588LL / (t * t);  // 4 * (2^31 - 1) / t^2
 376         int32_t* pw;
 377         s->buf_pre_corr = realloc(s->buf_pre_corr, s->bytes_overlap * 2 + UNROLL_PADDING);
 378         s->table_window = realloc(s->table_window, s->bytes_overlap * 2 - nch * bps * 2);
 379         if(!s->buf_pre_corr || !s->table_window) {
 380           mp_msg(MSGT_AFILTER, MSGL_FATAL, "[scaletempo] Out of memory\n");
 381           return AF_ERROR;
 382         }
 383         memset((char *)s->buf_pre_corr + s->bytes_overlap * 2, 0, UNROLL_PADDING);
 384         pw = s->table_window;
 385         for (i=1; i<frames_overlap; i++) {
 386           int32_t v = ( i * (t - i) * n ) >> 15;
 387           for (j=0; j<nch; j++) {
 388             *pw++ = v;
 389           }
 390         }
 391         s->best_overlap_offset = best_overlap_offset_s16;
 392       } else {
 393         float* pw;
 394         s->buf_pre_corr = realloc(s->buf_pre_corr, s->bytes_overlap);
 395         s->table_window = realloc(s->table_window, s->bytes_overlap - nch * bps);
 396         if(!s->buf_pre_corr || !s->table_window) {
 397           mp_msg(MSGT_AFILTER, MSGL_FATAL, "[scaletempo] Out of memory\n");
 398           return AF_ERROR;
 399         }
 400         pw = s->table_window;
 401         for (i=1; i<frames_overlap; i++) {
 402           float v = i * (frames_overlap - i);
 403           for (j=0; j<nch; j++) {
 404             *pw++ = v;
 405           }
 406         }
 407         s->best_overlap_offset = best_overlap_offset_float;
 408       }
 409     }
 410
 411     s->bytes_per_frame = bps * nch;
 412     s->num_channels    = nch;
 413
 414     s->bytes_queue
 415       = (s->frames_search + frames_stride + frames_overlap) * bps * nch;
 416     s->buf_queue = realloc(s->buf_queue, s->bytes_queue + UNROLL_PADDING);
 417     if(!s->buf_queue) {
 418       mp_msg(MSGT_AFILTER, MSGL_FATAL, "[scaletempo] Out of memory\n");
 419       return AF_ERROR;
 420     }
 421
 422     mp_msg (MSGT_AFILTER, MSGL_DBG2, "[scaletempo] "
 423             "%.2f stride_in, %i stride_out, %i standing, "
 424             "%i overlap, %i search, %i queue, %s mode\n",
 425             s->frames_stride_scaled,
 426             (int)(s->bytes_stride / nch / bps),
 427             (int)(s->bytes_standing / nch / bps),
 428             (int)(s->bytes_overlap / nch / bps),
 429             s->frames_search,
 430             (int)(s->bytes_queue / nch / bps),
 431             (use_int?"s16":"float"));
 432
 433     return af_test_output(af, (af_data_t*)arg);
 434   }
 435   case AF_CONTROL_PLAYBACK_SPEED | AF_CONTROL_SET:{
 436     if (s->speed_tempo) {
 437       if (s->speed_pitch) {
 438         break;
 439       }
 440       s->speed = *(float*)arg;
 441       s->scale = s->speed * s->scale_nominal;
 442     } else {
 443       if (s->speed_pitch) {
 444         s->speed = 1 / *(float*)arg;
 445         s->scale = s->speed * s->scale_nominal;
 446         break;
 447       }
 448     }
 449     return AF_OK;
 450   }
 451   case AF_CONTROL_SCALETEMPO_AMOUNT | AF_CONTROL_SET:{
 452     s->scale = *(float*)arg;
 453     s->scale = s->speed * s->scale_nominal;
 454     return AF_OK;
 455   }
 456   case AF_CONTROL_SCALETEMPO_AMOUNT | AF_CONTROL_GET:
 457     *(float*)arg = s->scale;
 458     return AF_OK;
 459   case AF_CONTROL_COMMAND_LINE:{
 460     strarg_t speed = {};
 461     opt_t subopts[] = {
 462       {"scale",   OPT_ARG_FLOAT, &s->scale_nominal, NULL},
 463       {"stride",  OPT_ARG_FLOAT, &s->ms_stride, NULL},
 464       {"overlap", OPT_ARG_FLOAT, &s->percent_overlap, NULL},
 465       {"search",  OPT_ARG_FLOAT, &s->ms_search, NULL},
 466       {"speed",   OPT_ARG_STR,   &speed, NULL},
 467       {NULL},
 468     };
 469     if (subopt_parse(arg, subopts) != 0) {
 470       return AF_ERROR;
 471     }
 472     if (s->scale_nominal <= 0) {
 473       mp_msg(MSGT_AFILTER, MSGL_ERR, "[scaletempo] "
 474              MSGTR_ErrorParsingCommandLine ": " MSGTR_AF_ValueOutOfRange
 475              ": scale > 0\n");
 476       return AF_ERROR;
 477     }
 478     if (s->ms_stride <= 0) {
 479       mp_msg(MSGT_AFILTER, MSGL_ERR, "[scaletempo] "
 480              MSGTR_ErrorParsingCommandLine ": " MSGTR_AF_ValueOutOfRange
 481              ": stride > 0\n");
 482       return AF_ERROR;
 483     }
 484     if (s->percent_overlap < 0 || s->percent_overlap > 1) {
 485       mp_msg(MSGT_AFILTER, MSGL_ERR, "[scaletempo] "
 486              MSGTR_ErrorParsingCommandLine ": " MSGTR_AF_ValueOutOfRange
 487              ": 0 <= overlap <= 1\n");
 488       return AF_ERROR;
 489     }
 490     if (s->ms_search < 0) {
 491       mp_msg(MSGT_AFILTER, MSGL_ERR, "[scaletempo] "
 492              MSGTR_ErrorParsingCommandLine ": " MSGTR_AF_ValueOutOfRange
 493              ": search >= 0\n");
 494       return AF_ERROR;
 495     }
 496     if (speed.len > 0) {
 497       if (strcmp(speed.str, "pitch") == 0) {
 498         s->speed_tempo = 0;
 499         s->speed_pitch = 1;
 500       } else if (strcmp(speed.str, "tempo") == 0) {
 501         s->speed_tempo = 1;
 502         s->speed_pitch = 0;
 503       } else if (strcmp(speed.str, "none") == 0) {
 504         s->speed_tempo = 0;
 505         s->speed_pitch = 0;
 506       } else if (strcmp(speed.str, "both") == 0) {
 507         s->speed_tempo = 1;
 508         s->speed_pitch = 1;
 509       } else {
 510         mp_msg(MSGT_AFILTER, MSGL_ERR, "[scaletempo] "
 511                MSGTR_ErrorParsingCommandLine ": " MSGTR_AF_ValueOutOfRange
 512                ": speed=[pitch|tempo|none|both]\n");
 513         return AF_ERROR;
 514       }
 515     }
 516     s->scale = s->speed * s->scale_nominal;
 517     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")));
 518     return AF_OK;
 519   }
 520   }
 521   return AF_UNKNOWN;
 522 }
 523
 524 // Deallocate memory
 525 static void uninit(struct af_instance_s* af)
 526 {
 527   af_scaletempo_t* s = af->setup;
 528   free(af->data->audio);
 529   free(af->data);
 530   free(s->buf_queue);
 531   free(s->buf_overlap);
 532   free(s->buf_pre_corr);
 533   free(s->table_blend);
 534   free(s->table_window);
 535   free(af->setup);
 536 }
 537
 538 // Allocate memory and set function pointers
 539 static int af_open(af_instance_t* af){
 540   af_scaletempo_t* s;
 541
 542   af->control   = control;
 543   af->uninit    = uninit;
 544   af->play      = play;
 545   af->mul       = 1;
 546   af->data      = calloc(1,sizeof(af_data_t));
 547   af->setup     = calloc(1,sizeof(af_scaletempo_t));
 548   if(af->data == NULL || af->setup == NULL)
 549     return AF_ERROR;
 550
 551   s = af->setup;
 552   s->scale = s->speed = s->scale_nominal = 1.0;
 553   s->speed_tempo = 1;
 554   s->speed_pitch = 0;
 555   s->ms_stride = 60;
 556   s->percent_overlap = .20;
 557   s->ms_search = 14;
 558
 559   return AF_OK;
 560 }
 561
 562 // Description of this filter
 563 af_info_t af_info_scaletempo = {
 564   "Scale audio tempo while maintaining pitch",
 565   "scaletempo",
 566   "Robert Juliano",
 567   "",
 568   AF_FLAGS_REENTRANT,
 569   af_open
 570 };