Alc/mixer.c

   1 /**
   2  * OpenAL cross platform audio library
   3  * Copyright (C) 1999-2007 by authors.
   4  * This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Library General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library 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.  See the GNU
  12  *  Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  *  License along with this library; if not, write to the
  16  *  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  *  Boston, MA  02111-1307, USA.
  18  * Or go to http://www.gnu.org/copyleft/lgpl.html
  19  */
  20
  21 #include "config.h"
  22
  23 #include <math.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <ctype.h>
  27 #include <assert.h>
  28
  29 #include "alMain.h"
  30 #include "AL/al.h"
  31 #include "AL/alc.h"
  32 #include "alSource.h"
  33 #include "alBuffer.h"
  34 #include "alListener.h"
  35 #include "alAuxEffectSlot.h"
  36 #include "alu.h"
  37 #include "bs2b.h"
  38
  39
  40 static inline ALfloat Sample_ALbyte(ALbyte val)
  41 { return val * (1.0f/127.0f); }
  42
  43 static inline ALfloat Sample_ALshort(ALshort val)
  44 { return val * (1.0f/32767.0f); }
  45
  46 static inline ALfloat Sample_ALfloat(ALfloat val)
  47 { return val; }
  48
  49 #define DECL_TEMPLATE(T)                                                      \
  50 static void Load_##T(ALfloat *dst, const T *src, ALuint srcstep, ALuint samples)\
  51 {                                                                             \
  52     ALuint i;                                                                 \
  53     for(i = 0;i < samples;i++)                                                \
  54         dst[i] = Sample_##T(src[i*srcstep]);                                  \
  55 }
  56
  57 DECL_TEMPLATE(ALbyte)
  58 DECL_TEMPLATE(ALshort)
  59 DECL_TEMPLATE(ALfloat)
  60
  61 #undef DECL_TEMPLATE
  62
  63 static void LoadData(ALfloat *dst, const ALvoid *src, ALuint srcstep, enum FmtType srctype, ALuint samples)
  64 {
  65     switch(srctype)
  66     {
  67         case FmtByte:
  68             Load_ALbyte(dst, src, srcstep, samples);
  69             break;
  70         case FmtShort:
  71             Load_ALshort(dst, src, srcstep, samples);
  72             break;
  73         case FmtFloat:
  74             Load_ALfloat(dst, src, srcstep, samples);
  75             break;
  76     }
  77 }
  78
  79 static void SilenceData(ALfloat *dst, ALuint samples)
  80 {
  81     ALuint i;
  82     for(i = 0;i < samples;i++)
  83         dst[i] = 0.0f;
  84 }
  85
  86
  87 static void DoFilter(ALfilterState *filter, ALfloat *restrict dst, const ALfloat *restrict src,
  88                      ALuint numsamples)
  89 {
  90     ALuint i;
  91     for(i = 0;i < numsamples;i++)
  92         dst[i] = ALfilterState_processSingle(filter, src[i]);
  93 }
  94
  95
  96 ALvoid MixSource(ALactivesource *src, ALCdevice *Device, ALuint SamplesToDo)
  97 {
  98     ALsource *Source = src->Source;
  99     ALbufferlistitem *BufferListItem;
 100     ALuint DataPosInt, DataPosFrac;
 101     ALboolean Looping;
 102     ALuint increment;
 103     enum Resampler Resampler;
 104     ALenum State;
 105     ALuint OutPos;
 106     ALuint NumChannels;
 107     ALuint SampleSize;
 108     ALint64 DataSize64;
 109     ALuint chan, j;
 110
 111     /* Get source info */
 112     State          = Source->state;
 113     BufferListItem = Source->current_buffer;
 114     DataPosInt     = Source->position;
 115     DataPosFrac    = Source->position_fraction;
 116     Looping        = Source->Looping;
 117     increment      = src->Step;
 118     Resampler      = (increment==FRACTIONONE) ? PointResampler : Source->Resampler;
 119     NumChannels    = Source->NumChannels;
 120     SampleSize     = Source->SampleSize;
 121
 122     /* Get current buffer queue item */
 123
 124     OutPos = 0;
 125     do {
 126         const ALuint BufferPrePadding = ResamplerPrePadding[Resampler];
 127         const ALuint BufferPadding = ResamplerPadding[Resampler];
 128         ALuint SrcBufferSize, DstBufferSize;
 129
 130         /* Figure out how many buffer samples will be needed */
 131         DataSize64  = SamplesToDo-OutPos;
 132         DataSize64 *= increment;
 133         DataSize64 += DataPosFrac+FRACTIONMASK;
 134         DataSize64 >>= FRACTIONBITS;
 135         DataSize64 += BufferPadding+BufferPrePadding;
 136
 137         SrcBufferSize = (ALuint)mini64(DataSize64, BUFFERSIZE);
 138
 139         /* Figure out how many samples we can actually mix from this. */
 140         DataSize64  = SrcBufferSize;
 141         DataSize64 -= BufferPadding+BufferPrePadding;
 142         DataSize64 <<= FRACTIONBITS;
 143         DataSize64 -= DataPosFrac;
 144
 145         DstBufferSize = (ALuint)((DataSize64+(increment-1)) / increment);
 146         DstBufferSize = minu(DstBufferSize, (SamplesToDo-OutPos));
 147
 148         /* Some mixers like having a multiple of 4, so try to give that unless
 149          * this is the last update. */
 150         if(OutPos+DstBufferSize < SamplesToDo)
 151             DstBufferSize &= ~3;
 152
 153         for(chan = 0;chan < NumChannels;chan++)
 154         {
 155             ALfloat *SrcData = Device->SampleData1;
 156             ALfloat *ResampledData = Device->SampleData2;
 157             ALuint SrcDataSize = 0;
 158
 159             if(Source->SourceType == AL_STATIC)
 160             {
 161                 const ALbuffer *ALBuffer = Source->queue->buffer;
 162                 const ALubyte *Data = ALBuffer->data;
 163                 ALuint DataSize;
 164                 ALuint pos;
 165
 166                 /* If current pos is beyond the loop range, do not loop */
 167                 if(Looping == AL_FALSE || DataPosInt >= (ALuint)ALBuffer->LoopEnd)
 168                 {
 169                     Looping = AL_FALSE;
 170
 171                     if(DataPosInt >= BufferPrePadding)
 172                         pos = DataPosInt - BufferPrePadding;
 173                     else
 174                     {
 175                         DataSize = BufferPrePadding - DataPosInt;
 176                         DataSize = minu(SrcBufferSize - SrcDataSize, DataSize);
 177
 178                         SilenceData(&SrcData[SrcDataSize], DataSize);
 179                         SrcDataSize += DataSize;
 180
 181                         pos = 0;
 182                     }
 183
 184                     /* Copy what's left to play in the source buffer, and clear the
 185                      * rest of the temp buffer */
 186                     DataSize = minu(SrcBufferSize - SrcDataSize, ALBuffer->SampleLen - pos);
 187
 188                     LoadData(&SrcData[SrcDataSize], &Data[(pos*NumChannels + chan)*SampleSize],
 189                              NumChannels, ALBuffer->FmtType, DataSize);
 190                     SrcDataSize += DataSize;
 191
 192                     SilenceData(&SrcData[SrcDataSize], SrcBufferSize - SrcDataSize);
 193                     SrcDataSize += SrcBufferSize - SrcDataSize;
 194                 }
 195                 else
 196                 {
 197                     ALuint LoopStart = ALBuffer->LoopStart;
 198                     ALuint LoopEnd   = ALBuffer->LoopEnd;
 199
 200                     if(DataPosInt >= LoopStart)
 201                     {
 202                         pos = DataPosInt-LoopStart;
 203                         while(pos < BufferPrePadding)
 204                             pos += LoopEnd-LoopStart;
 205                         pos -= BufferPrePadding;
 206                         pos += LoopStart;
 207                     }
 208                     else if(DataPosInt >= BufferPrePadding)
 209                         pos = DataPosInt - BufferPrePadding;
 210                     else
 211                     {
 212                         DataSize = BufferPrePadding - DataPosInt;
 213                         DataSize = minu(SrcBufferSize - SrcDataSize, DataSize);
 214
 215                         SilenceData(&SrcData[SrcDataSize], DataSize);
 216                         SrcDataSize += DataSize;
 217
 218                         pos = 0;
 219                     }
 220
 221                     /* Copy what's left of this loop iteration, then copy repeats
 222                      * of the loop section */
 223                     DataSize = LoopEnd - pos;
 224                     DataSize = minu(SrcBufferSize - SrcDataSize, DataSize);
 225
 226                     LoadData(&SrcData[SrcDataSize], &Data[(pos*NumChannels + chan)*SampleSize],
 227                              NumChannels, ALBuffer->FmtType, DataSize);
 228                     SrcDataSize += DataSize;
 229
 230                     DataSize = LoopEnd-LoopStart;
 231                     while(SrcBufferSize > SrcDataSize)
 232                     {
 233                         DataSize = minu(SrcBufferSize - SrcDataSize, DataSize);
 234
 235                         LoadData(&SrcData[SrcDataSize], &Data[(LoopStart*NumChannels + chan)*SampleSize],
 236                                  NumChannels, ALBuffer->FmtType, DataSize);
 237                         SrcDataSize += DataSize;
 238                     }
 239                 }
 240             }
 241             else
 242             {
 243                 /* Crawl the buffer queue to fill in the temp buffer */
 244                 ALbufferlistitem *tmpiter = BufferListItem;
 245                 ALuint pos;
 246
 247                 if(DataPosInt >= BufferPrePadding)
 248                     pos = DataPosInt - BufferPrePadding;
 249                 else
 250                 {
 251                     pos = BufferPrePadding - DataPosInt;
 252                     while(pos > 0)
 253                     {
 254                         ALbufferlistitem *prev;
 255                         if((prev=tmpiter->prev) != NULL)
 256                             tmpiter = prev;
 257                         else if(Looping)
 258                         {
 259                             while(tmpiter->next)
 260                                 tmpiter = tmpiter->next;
 261                         }
 262                         else
 263                         {
 264                             ALuint DataSize = minu(SrcBufferSize - SrcDataSize, pos);
 265
 266                             SilenceData(&SrcData[SrcDataSize], DataSize);
 267                             SrcDataSize += DataSize;
 268
 269                             pos = 0;
 270                             break;
 271                         }
 272
 273                         if(tmpiter->buffer)
 274                         {
 275                             if((ALuint)tmpiter->buffer->SampleLen > pos)
 276                             {
 277                                 pos = tmpiter->buffer->SampleLen - pos;
 278                                 break;
 279                             }
 280                             pos -= tmpiter->buffer->SampleLen;
 281                         }
 282                     }
 283                 }
 284
 285                 while(tmpiter && SrcBufferSize > SrcDataSize)
 286                 {
 287                     const ALbuffer *ALBuffer;
 288                     if((ALBuffer=tmpiter->buffer) != NULL)
 289                     {
 290                         const ALubyte *Data = ALBuffer->data;
 291                         ALuint DataSize = ALBuffer->SampleLen;
 292
 293                         /* Skip the data already played */
 294                         if(DataSize <= pos)
 295                             pos -= DataSize;
 296                         else
 297                         {
 298                             Data += (pos*NumChannels + chan)*SampleSize;
 299                             DataSize -= pos;
 300                             pos -= pos;
 301
 302                             DataSize = minu(SrcBufferSize - SrcDataSize, DataSize);
 303                             LoadData(&SrcData[SrcDataSize], Data, NumChannels,
 304                                      ALBuffer->FmtType, DataSize);
 305                             SrcDataSize += DataSize;
 306                         }
 307                     }
 308                     tmpiter = tmpiter->next;
 309                     if(!tmpiter && Looping)
 310                         tmpiter = Source->queue;
 311                     else if(!tmpiter)
 312                     {
 313                         SilenceData(&SrcData[SrcDataSize], SrcBufferSize - SrcDataSize);
 314                         SrcDataSize += SrcBufferSize - SrcDataSize;
 315                     }
 316                 }
 317             }
 318
 319             /* Now resample, then filter and mix to the appropriate outputs. */
 320             src->Resample(&SrcData[BufferPrePadding], DataPosFrac,
 321                           increment, ResampledData, DstBufferSize);
 322
 323             {
 324                 DirectParams *directparms = &src->Direct;
 325
 326                 DoFilter(&directparms->LpFilter[chan], SrcData, ResampledData,
 327                          DstBufferSize);
 328                 src->DryMix(directparms, SrcData, chan, OutPos, DstBufferSize);
 329             }
 330
 331             for(j = 0;j < Device->NumAuxSends;j++)
 332             {
 333                 SendParams *sendparms = &src->Send[j];
 334                 if(!sendparms->OutBuffer)
 335                     continue;
 336
 337                 DoFilter(&sendparms->LpFilter[chan], SrcData, ResampledData,
 338                          DstBufferSize);
 339                 src->WetMix(sendparms, SrcData, OutPos, DstBufferSize);
 340             }
 341         }
 342         /* Update positions */
 343         for(j = 0;j < DstBufferSize;j++)
 344         {
 345             DataPosFrac += increment;
 346             DataPosInt  += DataPosFrac>>FRACTIONBITS;
 347             DataPosFrac &= FRACTIONMASK;
 348         }
 349         OutPos += DstBufferSize;
 350
 351         /* Handle looping sources */
 352         while(1)
 353         {
 354             const ALbuffer *ALBuffer;
 355             ALuint DataSize = 0;
 356             ALuint LoopStart = 0;
 357             ALuint LoopEnd = 0;
 358
 359             if((ALBuffer=BufferListItem->buffer) != NULL)
 360             {
 361                 DataSize = ALBuffer->SampleLen;
 362                 LoopStart = ALBuffer->LoopStart;
 363                 LoopEnd = ALBuffer->LoopEnd;
 364                 if(LoopEnd > DataPosInt)
 365                     break;
 366             }
 367
 368             if(Looping && Source->SourceType == AL_STATIC)
 369             {
 370                 assert(LoopEnd > LoopStart);
 371                 DataPosInt = ((DataPosInt-LoopStart)%(LoopEnd-LoopStart)) + LoopStart;
 372                 break;
 373             }
 374
 375             if(DataSize > DataPosInt)
 376                 break;
 377
 378             if(BufferListItem->next)
 379                 BufferListItem = BufferListItem->next;
 380             else if(Looping)
 381                 BufferListItem = Source->queue;
 382             else
 383             {
 384                 State = AL_STOPPED;
 385                 BufferListItem = NULL;
 386                 DataPosInt = 0;
 387                 DataPosFrac = 0;
 388                 break;
 389             }
 390
 391             DataPosInt -= DataSize;
 392         }
 393     } while(State == AL_PLAYING && OutPos < SamplesToDo);
 394
 395     /* Update source info */
 396     Source->state             = State;
 397     Source->current_buffer    = BufferListItem;
 398     Source->position          = DataPosInt;
 399     Source->position_fraction = DataPosFrac;
 400     src->Direct.Offset += OutPos;
 401     src->Direct.Counter = maxu(src->Direct.Counter, OutPos) - OutPos;
 402 }