snd_mix.c

   1 /*
   2 Copyright (C) 1996-1997 Id Software, Inc.
   3
   4 This program is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU General Public License
   6 as published by the Free Software Foundation; either version 2
   7 of the License, or (at your option) any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  12
  13 See the GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18
  19 */
  20
  21 #include "quakedef.h"
  22 #include "snd_main.h"
  23
  24 extern cvar_t snd_softclip;
  25
  26 static portable_sampleframe_t paintbuffer[PAINTBUFFER_SIZE];
  27 static portable_sampleframe_t paintbuffer_unswapped[PAINTBUFFER_SIZE];
  28
  29 extern speakerlayout_t snd_speakerlayout; // for querying the listeners
  30
  31 static void S_CaptureAVISound(const portable_sampleframe_t *paintbuffer, size_t length)
  32 {
  33         size_t i;
  34         unsigned int j;
  35
  36         if (!cls.capturevideo.active)
  37                 return;
  38
  39         // undo whatever swapping the channel layout (swapstereo, ALSA) did
  40         for(j = 0; j < snd_speakerlayout.channels; ++j)
  41         {
  42                 unsigned int j0 = snd_speakerlayout.listeners[j].channel_unswapped;
  43                 for(i = 0; i < length; ++i)
  44                         paintbuffer_unswapped[i].sample[j0] = paintbuffer[i].sample[j];
  45         }
  46
  47         SCR_CaptureVideo_SoundFrame(paintbuffer_unswapped, length);
  48 }
  49
  50 extern cvar_t snd_softclip;
  51
  52 static void S_SoftClipPaintBuffer(portable_sampleframe_t *painted_ptr, int nbframes, int width, int channels)
  53 {
  54         int i;
  55
  56         if((snd_softclip.integer == 1 && width <= 2) || snd_softclip.integer > 1)
  57         {
  58                 portable_sampleframe_t *p = painted_ptr;
  59
  60 #if 0
  61 /* Soft clipping, the sound of a dream, thanks to Jon Wattes
  62    post to Musicdsp.org */
  63 #define SOFTCLIP(x) (x) = sin(bound(-M_PI/2, (x), M_PI/2)) * 0.25
  64 #endif
  65
  66                 // let's do a simple limiter instead, seems to sound better
  67                 static float maxvol = 0;
  68                 maxvol = max(1.0f, maxvol * (1.0f - nbframes / (0.4f * snd_renderbuffer->format.speed)));
  69 #define SOFTCLIP(x) if(fabs(x)>maxvol) maxvol=fabs(x); (x) /= maxvol;
  70
  71                 if (channels == 8)  // 7.1 surround
  72                 {
  73                         for (i = 0;i < nbframes;i++, p++)
  74                         {
  75                                 SOFTCLIP(p->sample[0]);
  76                                 SOFTCLIP(p->sample[1]);
  77                                 SOFTCLIP(p->sample[2]);
  78                                 SOFTCLIP(p->sample[3]);
  79                                 SOFTCLIP(p->sample[4]);
  80                                 SOFTCLIP(p->sample[5]);
  81                                 SOFTCLIP(p->sample[6]);
  82                                 SOFTCLIP(p->sample[7]);
  83                         }
  84                 }
  85                 else if (channels == 6)  // 5.1 surround
  86                 {
  87                         for (i = 0; i < nbframes; i++, p++)
  88                         {
  89                                 SOFTCLIP(p->sample[0]);
  90                                 SOFTCLIP(p->sample[1]);
  91                                 SOFTCLIP(p->sample[2]);
  92                                 SOFTCLIP(p->sample[3]);
  93                                 SOFTCLIP(p->sample[4]);
  94                                 SOFTCLIP(p->sample[5]);
  95                         }
  96                 }
  97                 else if (channels == 4)  // 4.0 surround
  98                 {
  99                         for (i = 0; i < nbframes; i++, p++)
 100                         {
 101                                 SOFTCLIP(p->sample[0]);
 102                                 SOFTCLIP(p->sample[1]);
 103                                 SOFTCLIP(p->sample[2]);
 104                                 SOFTCLIP(p->sample[3]);
 105                         }
 106                 }
 107                 else if (channels == 2)  // 2.0 stereo
 108                 {
 109                         for (i = 0; i < nbframes; i++, p++)
 110                         {
 111                                 SOFTCLIP(p->sample[0]);
 112                                 SOFTCLIP(p->sample[1]);
 113                         }
 114                 }
 115                 else if (channels == 1)  // 1.0 mono
 116                 {
 117                         for (i = 0; i < nbframes; i++, p++)
 118                         {
 119                                 SOFTCLIP(p->sample[0]);
 120                         }
 121                 }
 122 #undef SOFTCLIP
 123         }
 124 }
 125
 126 static void S_ConvertPaintBuffer(portable_sampleframe_t *painted_ptr, void *rb_ptr, int nbframes, int width, int channels)
 127 {
 128         int i, val;
 129
 130         // FIXME: add 24bit and 32bit float formats
 131         // FIXME: optimize with SSE intrinsics?
 132         if (width == 2)  // 16bit
 133         {
 134                 short *snd_out = (short*)rb_ptr;
 135                 if (channels == 8)  // 7.1 surround
 136                 {
 137                         for (i = 0;i < nbframes;i++, painted_ptr++)
 138                         {
 139                                 val = (int)(painted_ptr->sample[0] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 140                                 val = (int)(painted_ptr->sample[1] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 141                                 val = (int)(painted_ptr->sample[2] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 142                                 val = (int)(painted_ptr->sample[3] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 143                                 val = (int)(painted_ptr->sample[4] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 144                                 val = (int)(painted_ptr->sample[5] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 145                                 val = (int)(painted_ptr->sample[6] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 146                                 val = (int)(painted_ptr->sample[7] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 147                         }
 148                 }
 149                 else if (channels == 6)  // 5.1 surround
 150                 {
 151                         for (i = 0; i < nbframes; i++, painted_ptr++)
 152                         {
 153                                 val = (int)(painted_ptr->sample[0] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 154                                 val = (int)(painted_ptr->sample[1] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 155                                 val = (int)(painted_ptr->sample[2] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 156                                 val = (int)(painted_ptr->sample[3] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 157                                 val = (int)(painted_ptr->sample[4] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 158                                 val = (int)(painted_ptr->sample[5] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 159                         }
 160                 }
 161                 else if (channels == 4)  // 4.0 surround
 162                 {
 163                         for (i = 0; i < nbframes; i++, painted_ptr++)
 164                         {
 165                                 val = (int)(painted_ptr->sample[0] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 166                                 val = (int)(painted_ptr->sample[1] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 167                                 val = (int)(painted_ptr->sample[2] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 168                                 val = (int)(painted_ptr->sample[3] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 169                         }
 170                 }
 171                 else if (channels == 2)  // 2.0 stereo
 172                 {
 173                         for (i = 0; i < nbframes; i++, painted_ptr++)
 174                         {
 175                                 val = (int)(painted_ptr->sample[0] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 176                                 val = (int)(painted_ptr->sample[1] * 32768.0f);*snd_out++ = bound(-32768, val, 32767);
 177                         }
 178                 }
 179                 else if (channels == 1)  // 1.0 mono
 180                 {
 181                         for (i = 0; i < nbframes; i++, painted_ptr++)
 182                         {
 183                                 val = (int)((painted_ptr->sample[0] + painted_ptr->sample[1]) * 16384.0f);*snd_out++ = bound(-32768, val, 32767);
 184                         }
 185                 }
 186
 187                 // noise is really really annoying
 188                 if (cls.timedemo)
 189                         memset(rb_ptr, 0, nbframes * channels * width);
 190         }
 191         else  // 8bit
 192         {
 193                 unsigned char *snd_out = (unsigned char*)rb_ptr;
 194                 if (channels == 8)  // 7.1 surround
 195                 {
 196                         for (i = 0; i < nbframes; i++, painted_ptr++)
 197                         {
 198                                 val = (int)(painted_ptr->sample[0] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 199                                 val = (int)(painted_ptr->sample[1] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 200                                 val = (int)(painted_ptr->sample[2] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 201                                 val = (int)(painted_ptr->sample[3] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 202                                 val = (int)(painted_ptr->sample[4] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 203                                 val = (int)(painted_ptr->sample[5] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 204                                 val = (int)(painted_ptr->sample[6] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 205                                 val = (int)(painted_ptr->sample[7] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 206                         }
 207                 }
 208                 else if (channels == 6)  // 5.1 surround
 209                 {
 210                         for (i = 0; i < nbframes; i++, painted_ptr++)
 211                         {
 212                                 val = (int)(painted_ptr->sample[0] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 213                                 val = (int)(painted_ptr->sample[1] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 214                                 val = (int)(painted_ptr->sample[2] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 215                                 val = (int)(painted_ptr->sample[3] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 216                                 val = (int)(painted_ptr->sample[4] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 217                                 val = (int)(painted_ptr->sample[5] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 218                         }
 219                 }
 220                 else if (channels == 4)  // 4.0 surround
 221                 {
 222                         for (i = 0; i < nbframes; i++, painted_ptr++)
 223                         {
 224                                 val = (int)(painted_ptr->sample[0] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 225                                 val = (int)(painted_ptr->sample[1] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 226                                 val = (int)(painted_ptr->sample[2] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 227                                 val = (int)(painted_ptr->sample[3] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 228                         }
 229                 }
 230                 else if (channels == 2)  // 2.0 stereo
 231                 {
 232                         for (i = 0; i < nbframes; i++, painted_ptr++)
 233                         {
 234                                 val = (int)(painted_ptr->sample[0] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 235                                 val = (int)(painted_ptr->sample[1] * 128.0f) + 128; *snd_out++ = bound(0, val, 255);
 236                         }
 237                 }
 238                 else if (channels == 1)  // 1.0 mono
 239                 {
 240                         for (i = 0;i < nbframes;i++, painted_ptr++)
 241                         {
 242                                 val = (int)((painted_ptr->sample[0] + painted_ptr->sample[1]) * 64.0f) + 128; *snd_out++ = bound(0, val, 255);
 243                         }
 244                 }
 245
 246                 // noise is really really annoying
 247                 if (cls.timedemo)
 248                         memset(rb_ptr, 128, nbframes * channels);
 249         }
 250 }
 251
 252
 253 /*
 254 ===============================================================================
 255
 256 CHANNEL MIXING
 257
 258 ===============================================================================
 259 */
 260
 261 void S_MixToBuffer(void *stream, unsigned int bufferframes)
 262 {
 263         int channelindex;
 264         channel_t *ch;
 265         int totalmixframes;
 266         unsigned char *outbytes = (unsigned char *) stream;
 267         sfx_t *sfx;
 268         portable_sampleframe_t *paint;
 269         int wantframes;
 270         int i;
 271         int count;
 272         int fetched;
 273         int fetch;
 274         int istartframe;
 275         int iendframe;
 276         int ilengthframes;
 277         int totallength;
 278         int loopstart;
 279         int indexfrac;
 280         int indexfracstep;
 281 #define S_FETCHBUFFERSIZE 4096
 282         float fetchsampleframes[S_FETCHBUFFERSIZE*2];
 283         const float *fetchsampleframe;
 284         float vol[SND_LISTENERS];
 285         float lerp[2];
 286         float sample[3];
 287         double posd;
 288         double speedd;
 289         float maxvol;
 290         qboolean looping;
 291         qboolean silent;
 292
 293         // mix as many times as needed to fill the requested buffer
 294         while (bufferframes)
 295         {
 296                 // limit to the size of the paint buffer
 297                 totalmixframes = min(bufferframes, PAINTBUFFER_SIZE);
 298
 299                 // clear the paint buffer
 300                 memset(paintbuffer, 0, totalmixframes * sizeof(paintbuffer[0]));
 301
 302                 // paint in the channels.
 303                 // channels with zero volumes still advance in time but don't paint.
 304                 ch = channels; // cppcheck complains here but it is wrong, channels is a channel_t[MAX_CHANNELS] and not an int
 305                 for (channelindex = 0;channelindex < (int)total_channels;channelindex++, ch++)
 306                 {
 307                         sfx = ch->sfx;
 308                         if (sfx == NULL)
 309                                 continue;
 310                         if (!S_LoadSound (sfx, true))
 311                                 continue;
 312                         if (ch->flags & CHANNELFLAG_PAUSED)
 313                                 continue;
 314                         if (!sfx->total_length)
 315                                 continue;
 316
 317                         // copy the channel information to the stack for reference, otherwise the
 318                         // values might change during a mix if the spatializer is updating them
 319                         // (note: this still may get some old and some new values!)
 320                         posd = ch->position;
 321                         speedd = ch->mixspeed * sfx->format.speed / snd_renderbuffer->format.speed;
 322                         for (i = 0;i < SND_LISTENERS;i++)
 323                                 vol[i] = ch->volume[i];
 324
 325                         // check total volume level, because we can skip some code on silent sounds but other code must still run (position updates mainly)
 326                         maxvol = 0;
 327                         for (i = 0;i < SND_LISTENERS;i++)
 328                                 if(vol[i] > maxvol)
 329                                         maxvol = vol[i];
 330                         switch(snd_renderbuffer->format.width)
 331                         {
 332                                 case 1: // 8bpp
 333                                         silent = maxvol < (1.0f / (256.0f));
 334                                         // so silent it has zero effect
 335                                         break;
 336                                 case 2: // 16bpp
 337                                         silent = maxvol < (1.0f / (65536.0f));
 338                                         // so silent it has zero effect
 339                                         break;
 340                                 default: // floating point
 341                                         silent = maxvol < 1.0e-13f;
 342                                         // 130 dB is difference between hearing
 343                                         // threshold and a jackhammer from
 344                                         // working distance.
 345                                         // therefore, anyone who turns up
 346                                         // volume so much they notice this
 347                                         // cutoff, likely already has their
 348                                         // ear-drums blown out anyway.
 349                                         break;
 350                         }
 351
 352                         // when doing prologic mixing, some channels invert one side
 353                         if (ch->prologic_invert == -1)
 354                                 vol[1] *= -1.0f;
 355
 356                         // get some sfx info in a consistent form
 357                         totallength = sfx->total_length;
 358                         loopstart = (int)sfx->loopstart < totallength ? (int)sfx->loopstart : ((ch->flags & CHANNELFLAG_FORCELOOP) ? 0 : totallength);
 359                         looping = loopstart < totallength;
 360
 361                         // do the actual paint now (may skip work if silent)
 362                         paint = paintbuffer;
 363                         istartframe = 0;
 364                         for (wantframes = totalmixframes;wantframes > 0;posd += count * speedd, wantframes -= count)
 365                         {
 366                                 // check if this is a delayed sound
 367                                 if (posd < 0)
 368                                 {
 369                                         // for a delayed sound we have to eat into the delay first
 370                                         count = (int)floor(-posd / speedd) + 1;
 371                                         count = bound(1, count, wantframes);
 372                                         // let the for loop iterator apply the skip
 373                                         continue;
 374                                 }
 375
 376                                 // compute a fetch size that won't overflow our buffer
 377                                 count = wantframes;
 378                                 for (;;)
 379                                 {
 380                                         istartframe = (int)floor(posd);
 381                                         iendframe = (int)floor(posd + (count-1) * speedd);
 382                                         ilengthframes = count > 1 ? (iendframe - istartframe + 2) : 2;
 383                                         if (ilengthframes <= S_FETCHBUFFERSIZE)
 384                                                 break;
 385                                         // reduce count by 25% and try again
 386                                         count -= count >> 2;
 387                                 }
 388
 389                                 // zero whole fetch buffer for safety
 390                                 // (floating point noise from uninitialized memory = HORRIBLE)
 391                                 // otherwise we would only need to clear the excess
 392                                 if (!silent)
 393                                         memset(fetchsampleframes, 0, ilengthframes*sfx->format.channels*sizeof(fetchsampleframes[0]));
 394
 395                                 // if looping, do multiple fetches
 396                                 fetched = 0;
 397                                 for (;;)
 398                                 {
 399                                         fetch = min(ilengthframes - fetched, totallength - istartframe);
 400                                         if (fetch > 0)
 401                                         {
 402                                                 if (!silent)
 403                                                         sfx->fetcher->getsamplesfloat(ch, sfx, istartframe, fetch, fetchsampleframes + fetched*sfx->format.channels);
 404                                                 istartframe += fetch;
 405                                                 fetched += fetch;
 406                                         }
 407                                         if (istartframe == totallength && looping && fetched < ilengthframes)
 408                                         {
 409                                                 // loop and fetch some more
 410                                                 posd += loopstart - totallength;
 411                                                 istartframe = loopstart;
 412                                         }
 413                                         else
 414                                         {
 415                                                 break;
 416                                         }
 417                                 }
 418
 419                                 // set up our fixedpoint resampling variables (float to int conversions are expensive so do not do one per sampleframe)
 420                                 fetchsampleframe = fetchsampleframes;
 421                                 indexfrac = (int)floor((posd - floor(posd)) * 65536.0);
 422                                 indexfracstep = (int)floor(speedd * 65536.0);
 423                                 if (!silent)
 424                                 {
 425                                         if (sfx->format.channels == 2)
 426                                         {
 427                                                 // music is stereo
 428 #if SND_LISTENERS != 8
 429 #error the following code only supports up to 8 channels, update it
 430 #endif
 431                                                 if (snd_speakerlayout.channels > 2)
 432                                                 {
 433                                                         // surround mixing
 434                                                         for (i = 0;i < count;i++, paint++)
 435                                                         {
 436                                                                 lerp[1] = indexfrac * (1.0f / 65536.0f);
 437                                                                 lerp[0] = 1.0f - lerp[1];
 438                                                                 sample[0] = fetchsampleframe[0] * lerp[0] + fetchsampleframe[2] * lerp[1];
 439                                                                 sample[1] = fetchsampleframe[1] * lerp[0] + fetchsampleframe[3] * lerp[1];
 440                                                                 sample[2] = (sample[0] + sample[1]) * 0.5f;
 441                                                                 paint->sample[0] += sample[0] * vol[0];
 442                                                                 paint->sample[1] += sample[1] * vol[1];
 443                                                                 paint->sample[2] += sample[0] * vol[2];
 444                                                                 paint->sample[3] += sample[1] * vol[3];
 445                                                                 paint->sample[4] += sample[2] * vol[4];
 446                                                                 paint->sample[5] += sample[2] * vol[5];
 447                                                                 paint->sample[6] += sample[0] * vol[6];
 448                                                                 paint->sample[7] += sample[1] * vol[7];
 449                                                                 indexfrac += indexfracstep;
 450                                                                 fetchsampleframe += 2 * (indexfrac >> 16);
 451                                                                 indexfrac &= 0xFFFF;
 452                                                         }
 453                                                 }
 454                                                 else
 455                                                 {
 456                                                         // stereo mixing
 457                                                         for (i = 0;i < count;i++, paint++)
 458                                                         {
 459                                                                 lerp[1] = indexfrac * (1.0f / 65536.0f);
 460                                                                 lerp[0] = 1.0f - lerp[1];
 461                                                                 sample[0] = fetchsampleframe[0] * lerp[0] + fetchsampleframe[2] * lerp[1];
 462                                                                 sample[1] = fetchsampleframe[1] * lerp[0] + fetchsampleframe[3] * lerp[1];
 463                                                                 paint->sample[0] += sample[0] * vol[0];
 464                                                                 paint->sample[1] += sample[1] * vol[1];
 465                                                                 indexfrac += indexfracstep;
 466                                                                 fetchsampleframe += 2 * (indexfrac >> 16);
 467                                                                 indexfrac &= 0xFFFF;
 468                                                         }
 469                                                 }
 470                                         }
 471                                         else if (sfx->format.channels == 1)
 472                                         {
 473                                                 // most sounds are mono
 474 #if SND_LISTENERS != 8
 475 #error the following code only supports up to 8 channels, update it
 476 #endif
 477                                                 if (snd_speakerlayout.channels > 2)
 478                                                 {
 479                                                         // surround mixing
 480                                                         for (i = 0;i < count;i++, paint++)
 481                                                         {
 482                                                                 lerp[1] = indexfrac * (1.0f / 65536.0f);
 483                                                                 lerp[0] = 1.0f - lerp[1];
 484                                                                 sample[0] = fetchsampleframe[0] * lerp[0] + fetchsampleframe[1] * lerp[1];
 485                                                                 paint->sample[0] += sample[0] * vol[0];
 486                                                                 paint->sample[1] += sample[0] * vol[1];
 487                                                                 paint->sample[2] += sample[0] * vol[2];
 488                                                                 paint->sample[3] += sample[0] * vol[3];
 489                                                                 paint->sample[4] += sample[0] * vol[4];
 490                                                                 paint->sample[5] += sample[0] * vol[5];
 491                                                                 paint->sample[6] += sample[0] * vol[6];
 492                                                                 paint->sample[7] += sample[0] * vol[7];
 493                                                                 indexfrac += indexfracstep;
 494                                                                 fetchsampleframe += (indexfrac >> 16);
 495                                                                 indexfrac &= 0xFFFF;
 496                                                         }
 497                                                 }
 498                                                 else
 499                                                 {
 500                                                         // stereo mixing
 501                                                         for (i = 0;i < count;i++, paint++)
 502                                                         {
 503                                                                 lerp[1] = indexfrac * (1.0f / 65536.0f);
 504                                                                 lerp[0] = 1.0f - lerp[1];
 505                                                                 sample[0] = fetchsampleframe[0] * lerp[0] + fetchsampleframe[1] * lerp[1];
 506                                                                 paint->sample[0] += sample[0] * vol[0];
 507                                                                 paint->sample[1] += sample[0] * vol[1];
 508                                                                 indexfrac += indexfracstep;
 509                                                                 fetchsampleframe += (indexfrac >> 16);
 510                                                                 indexfrac &= 0xFFFF;
 511                                                         }
 512                                                 }
 513                                         }
 514                                 }
 515                         }
 516                         ch->position = posd;
 517                         if (!looping && istartframe == totallength)
 518                                 S_StopChannel(ch - channels, false, false);
 519                 }
 520
 521                 S_SoftClipPaintBuffer(paintbuffer, totalmixframes, snd_renderbuffer->format.width, snd_renderbuffer->format.channels);
 522
 523                 if (!snd_usethreadedmixing)
 524                         S_CaptureAVISound(paintbuffer, totalmixframes);
 525
 526                 S_ConvertPaintBuffer(paintbuffer, outbytes, totalmixframes, snd_renderbuffer->format.width, snd_renderbuffer->format.channels);
 527
 528                 // advance the output pointer
 529                 outbytes += totalmixframes * snd_renderbuffer->format.width * snd_renderbuffer->format.channels;
 530                 bufferframes -= totalmixframes;
 531         }
 532 }