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   1 /*      MikMod sound library
   2         (c) 1998, 1999, 2000, 2001 Miodrag Vallat and others - see file AUTHORS
   3         for complete list.
   4
   5         This library is free software; you can redistribute it and/or modify
   6         it under the terms of the GNU Library General Public License as
   7         published by the Free Software Foundation; either version 2 of
   8         the License, or (at your option) any later version.
   9
  10         This program is distributed in the hope that it will be useful,
  11         but WITHOUT ANY WARRANTY; without even the implied warranty of
  12         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13         GNU Library General Public License for more details.
  14
  15         You should have received a copy of the GNU Library General Public
  16         License along with this library; if not, write to the Free Software
  17         Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18         02111-1307, USA.
  19 */
  20
  21 /*==============================================================================
  22
  23   $Id$
  24
  25   Routines for loading samples. The sample loader utilizes the routines
  26   provided by the "registered" sample loader.
  27
  28 ==============================================================================*/
  29
  30 #ifdef HAVE_CONFIG_H
  31 #include "config.h"
  32 #endif
  33
  34 #ifdef HAVE_UNISTD_H
  35 #include <unistd.h>
  36 #endif
  37
  38 #include "mikmod_internals.h"
  39
  40 static  int sl_rlength;
  41 static  SWORD sl_old;
  42 static  SWORD *sl_buffer=NULL;
  43 static  SAMPLOAD *musiclist=NULL,*sndfxlist=NULL;
  44
  45 /* size of the loader buffer in words */
  46 #define SLBUFSIZE 2048
  47
  48 /* IT-Compressed status structure */
  49 typedef struct ITPACK {
  50         UWORD bits;    /* current number of bits */
  51         UWORD bufbits; /* bits in buffer */
  52         SWORD last;    /* last output */
  53         UBYTE buf;     /* bit buffer */
  54 } ITPACK;
  55
  56 BOOL SL_Init(SAMPLOAD* s)
  57 {
  58         if(!sl_buffer)
  59                 if(!(sl_buffer=(SWORD*)MikMod_malloc(SLBUFSIZE*sizeof(SWORD)))) return 0;
  60
  61         sl_rlength = s->length;
  62         if(s->infmt & SF_16BITS) sl_rlength>>=1;
  63         sl_old = 0;
  64
  65         return 1;
  66 }
  67
  68 void SL_Exit(SAMPLOAD *s)
  69 {
  70         if(sl_rlength>0) _mm_fseek(s->reader,sl_rlength,SEEK_CUR);
  71
  72         MikMod_free(sl_buffer);
  73         sl_buffer=NULL;
  74 }
  75
  76 /* unpack a 8bit IT packed sample */
  77 static int read_itcompr8(ITPACK* status,MREADER *reader,SWORD *out,UWORD count,UWORD* incnt)
  78 {
  79         SWORD *dest=out,*end=out+count;
  80         UWORD x,y,needbits,havebits,new_count=0;
  81         UWORD bits = status->bits;
  82         UWORD bufbits = status->bufbits;
  83         SBYTE last = status->last;
  84         UBYTE buf = status->buf;
  85
  86         while (dest<end) {
  87                 needbits=new_count?3:bits;
  88                 x=havebits=0;
  89                 while (needbits) {
  90                         /* feed buffer */
  91                         if (!bufbits) {
  92                                 if((*incnt)--)
  93                                         buf=_mm_read_UBYTE(reader);
  94                                 else
  95                                         buf=0;
  96                                 bufbits=8;
  97                         }
  98                         /* get as many bits as necessary */
  99                         y = needbits<bufbits?needbits:bufbits;
 100                         x|= (buf & ((1<<y)- 1))<<havebits;
 101                         buf>>=y;
 102                         bufbits-=y;
 103                         needbits-=y;
 104                         havebits+=y;
 105                 }
 106                 if (new_count) {
 107                         new_count = 0;
 108                         if (++x >= bits)
 109                                 x++;
 110                         bits = x;
 111                         continue;
 112                 }
 113                 if (bits<7) {
 114                         if (x==(1<<(bits-1))) {
 115                                 new_count = 1;
 116                                 continue;
 117                         }
 118                 }
 119                 else if (bits<9) {
 120                         y = (0xff >> (9-bits)) - 4;
 121                         if ((x>y)&&(x<=y+8)) {
 122                                 if ((x-=y)>=bits)
 123                                         x++;
 124                                 bits = x;
 125                                 continue;
 126                         }
 127                 }
 128                 else if (bits<10) {
 129                         if (x>=0x100) {
 130                                 bits=x-0x100+1;
 131                                 continue;
 132                         }
 133                 } else {
 134                         /* error in compressed data... */
 135                         _mm_errno=MMERR_ITPACK_INVALID_DATA;
 136                         return 0;
 137                 }
 138
 139                 if (bits<8) /* extend sign */
 140                         x = ((SBYTE)(x <<(8-bits))) >> (8-bits);
 141                 *(dest++)= (last+=x) << 8; /* convert to 16 bit */
 142         }
 143         status->bits = bits;
 144         status->bufbits = bufbits;
 145         status->last = last;
 146         status->buf = buf;
 147         return (dest-out);
 148 }
 149
 150 /* unpack a 16bit IT packed sample */
 151 static int read_itcompr16(ITPACK *status,MREADER *reader,SWORD *out,UWORD count,UWORD* incnt)
 152 {
 153         SWORD *dest=out,*end=out+count;
 154         SLONG x,y,needbits,havebits,new_count=0;
 155         UWORD bits = status->bits;
 156         UWORD bufbits = status->bufbits;
 157         SWORD last = status->last;
 158         UBYTE buf = status->buf;
 159
 160         while (dest<end) {
 161                 needbits=new_count?4:bits;
 162                 x=havebits=0;
 163                 while (needbits) {
 164                         /* feed buffer */
 165                         if (!bufbits) {
 166                                 if((*incnt)--)
 167                                         buf=_mm_read_UBYTE(reader);
 168                                 else
 169                                         buf=0;
 170                                 bufbits=8;
 171                         }
 172                         /* get as many bits as necessary */
 173                         y=needbits<bufbits?needbits:bufbits;
 174                         x|=(buf &((1<<y)-1))<<havebits;
 175                         buf>>=y;
 176                         bufbits-=(UWORD)y;
 177                         needbits-=(UWORD)y;
 178                         havebits+=(UWORD)y;
 179                 }
 180                 if (new_count) {
 181                         new_count = 0;
 182                         if (++x >= bits)
 183                                 x++;
 184                         bits = (UWORD)x;
 185                         continue;
 186                 }
 187                 if (bits<7) {
 188                         if (x==(1<<(bits-1))) {
 189                                 new_count=1;
 190                                 continue;
 191                         }
 192                 }
 193                 else if (bits<17) {
 194                         y=(0xffff>>(17-bits))-8;
 195                         if ((x>y)&&(x<=y+16)) {
 196                                 if ((x-=y)>=bits)
 197                                         x++;
 198                                 bits = (UWORD)x;
 199                                 continue;
 200                         }
 201                 }
 202                 else if (bits<18) {
 203                         if (x>=0x10000) {
 204                                 bits=(UWORD)(x-0x10000+1);
 205                                 continue;
 206                         }
 207                 } else {
 208                          /* error in compressed data... */
 209                         _mm_errno=MMERR_ITPACK_INVALID_DATA;
 210                         return 0;
 211                 }
 212
 213                 if (bits<16) /* extend sign */
 214                         x = ((SWORD)(x<<(16-bits)))>>(16-bits);
 215                 *(dest++)=(last+=x);
 216         }
 217         status->bits = bits;
 218         status->bufbits = bufbits;
 219         status->last = last;
 220         status->buf = buf;
 221         return (dest-out);
 222 }
 223
 224 static int SL_LoadInternal(void* buffer,UWORD infmt,UWORD outfmt,int scalefactor,ULONG length,MREADER* reader,BOOL dither)
 225 {
 226         SBYTE *bptr = (SBYTE*)buffer;
 227         SWORD *wptr = (SWORD*)buffer;
 228         int stodo,t,u;
 229
 230         int result,c_block=0;   /* compression bytes until next block */
 231         ITPACK status;
 232         UWORD incnt = 0;
 233
 234         status.buf = 0;
 235         status.last = 0;
 236         status.bufbits = 0;
 237         status.bits = 0;
 238
 239         while(length) {
 240                 stodo=(length<SLBUFSIZE)?length:SLBUFSIZE;
 241
 242                 if(infmt&SF_ITPACKED) {
 243                         sl_rlength=0;
 244                         if (!c_block) {
 245                                 status.bits = (infmt & SF_16BITS) ? 17 : 9;
 246                                 status.last = status.bufbits = 0;
 247                                 incnt=_mm_read_I_UWORD(reader);
 248                                 c_block = (infmt & SF_16BITS) ? 0x4000 : 0x8000;
 249                                 if(infmt&SF_DELTA) sl_old=0;
 250                         }
 251                         if (infmt & SF_16BITS) {
 252                                 if(!(result=read_itcompr16(&status,reader,sl_buffer,stodo,&incnt)))
 253                                         return 1;
 254                         } else {
 255                                 if(!(result=read_itcompr8(&status,reader,sl_buffer,stodo,&incnt)))
 256                                         return 1;
 257                         }
 258                         if(result!=stodo) {
 259                                 _mm_errno=MMERR_ITPACK_INVALID_DATA;
 260                                 return 1;
 261                         }
 262                         c_block -= stodo;
 263                 } else {
 264                         if(infmt&SF_16BITS) {
 265                                 if(infmt&SF_BIG_ENDIAN)
 266                                         _mm_read_M_SWORDS(sl_buffer,stodo,reader);
 267                                 else
 268                                         _mm_read_I_SWORDS(sl_buffer,stodo,reader);
 269                         } else {
 270                                 SBYTE *src;
 271                                 SWORD *dest;
 272
 273                                 reader->Read(reader,sl_buffer,sizeof(SBYTE)*stodo);
 274                                 src = (SBYTE*)sl_buffer;
 275                                 dest  = sl_buffer;
 276                                 src += stodo;dest += stodo;
 277
 278                                 for(t=0;t<stodo;t++) {
 279                                         src--;dest--;
 280                                         *dest = (*src)<<8;
 281                                 }
 282                         }
 283                         sl_rlength-=stodo;
 284                 }
 285
 286                 if(infmt & SF_DELTA)
 287                         for(t=0;t<stodo;t++) {
 288                                 sl_buffer[t] += sl_old;
 289                                 sl_old = sl_buffer[t];
 290                         }
 291
 292                 if((infmt^outfmt) & SF_SIGNED)
 293                         for(t=0;t<stodo;t++)
 294                                 sl_buffer[t]^= 0x8000;
 295
 296                 if(scalefactor) {
 297                         int idx = 0;
 298                         SLONG scaleval;
 299
 300                         /* Sample Scaling... average values for better results. */
 301                         t= 0;
 302                         while(t<stodo && length) {
 303                                 scaleval = 0;
 304                                 for(u=scalefactor;u && t<stodo;u--,t++)
 305                                         scaleval+=sl_buffer[t];
 306                                 sl_buffer[idx++]=(UWORD)(scaleval/(scalefactor-u));
 307                                 length--;
 308                         }
 309                         stodo = idx;
 310                 } else
 311                         length -= stodo;
 312
 313                 if (dither) {
 314                         if((infmt & SF_STEREO) && !(outfmt & SF_STEREO)) {
 315                                 /* dither stereo to mono, average together every two samples */
 316                                 SLONG avgval;
 317                                 int idx = 0;
 318
 319                                 t=0;
 320                                 while(t<stodo && length) {
 321                                         avgval=sl_buffer[t++];
 322                                         avgval+=sl_buffer[t++];
 323                                         sl_buffer[idx++]=(SWORD)(avgval>>1);
 324                                         length-=2;
 325                                 }
 326                                 stodo = idx;
 327                         }
 328                 }
 329
 330                 if(outfmt & SF_16BITS) {
 331                         for(t=0;t<stodo;t++)
 332                                 *(wptr++)=sl_buffer[t];
 333                 } else {
 334                         for(t=0;t<stodo;t++)
 335                                 *(bptr++)=sl_buffer[t]>>8;
 336                 }
 337         }
 338         return 0;
 339 }
 340
 341 int SL_Load(void* buffer,SAMPLOAD *smp,ULONG length)
 342 {
 343         return SL_LoadInternal(buffer,smp->infmt,smp->outfmt,smp->scalefactor,
 344                                 length,smp->reader,0);
 345 }
 346
 347 /* Registers a sample for loading when SL_LoadSamples() is called. */
 348 SAMPLOAD* SL_RegisterSample(SAMPLE* s,int type,MREADER* reader)
 349 {
 350         SAMPLOAD *news,**samplist,*cruise;
 351
 352         if(type==MD_MUSIC) {
 353                 samplist = &musiclist;
 354                 cruise = musiclist;
 355         } else
 356           if (type==MD_SNDFX) {
 357                 samplist = &sndfxlist;
 358                 cruise = sndfxlist;
 359         } else
 360                 return NULL;
 361
 362         /* Allocate and add structure to the END of the list */
 363         if(!(news=(SAMPLOAD*)MikMod_malloc(sizeof(SAMPLOAD)))) return NULL;
 364
 365         if(cruise) {
 366                 while(cruise->next) cruise=cruise->next;
 367                 cruise->next = news;
 368         } else
 369                 *samplist = news;
 370
 371         news->infmt     = s->flags & SF_FORMATMASK;
 372         news->outfmt    = news->infmt;
 373         news->reader    = reader;
 374         news->sample    = s;
 375         news->length    = s->length;
 376         news->loopstart = s->loopstart;
 377         news->loopend   = s->loopend;
 378
 379         return news;
 380 }
 381
 382 static void FreeSampleList(SAMPLOAD* s)
 383 {
 384         SAMPLOAD *old;
 385
 386         while(s) {
 387                 old = s;
 388                 s = s->next;
 389                 MikMod_free(old);
 390         }
 391 }
 392
 393 /* Returns the total amount of memory required by the samplelist queue. */
 394 static ULONG SampleTotal(SAMPLOAD* samplist,int type)
 395 {
 396         int total = 0;
 397
 398         while(samplist) {
 399                 samplist->sample->flags=
 400                   (samplist->sample->flags&~SF_FORMATMASK)|samplist->outfmt;
 401                 total += MD_SampleLength(type,samplist->sample);
 402                 samplist=samplist->next;
 403         }
 404
 405         return total;
 406 }
 407
 408 static ULONG RealSpeed(SAMPLOAD *s)
 409 {
 410         return(s->sample->speed/(s->scalefactor?s->scalefactor:1));
 411 }
 412
 413 static int DitherSamples(SAMPLOAD* samplist,int type)
 414 {
 415         SAMPLOAD *c2smp=NULL;
 416         ULONG maxsize, speed;
 417         SAMPLOAD *s;
 418
 419         if(!samplist) return 0;
 420
 421         if((maxsize=MD_SampleSpace(type)*1024) != 0)
 422                 while(SampleTotal(samplist,type)>maxsize) {
 423                         /* First Pass - check for any 16 bit samples */
 424                         s = samplist;
 425                         while(s) {
 426                                 if(s->outfmt & SF_16BITS) {
 427                                         SL_Sample16to8(s);
 428                                         break;
 429                                 }
 430                                 s=s->next;
 431                         }
 432                         /* Second pass (if no 16bits found above) is to take the sample with
 433                            the highest speed and dither it by half. */
 434                         if(!s) {
 435                                 s = samplist;
 436                                 speed = 0;
 437                                 while(s) {
 438                                         if((s->sample->length) && (RealSpeed(s)>speed)) {
 439                                                 speed=RealSpeed(s);
 440                                                 c2smp=s;
 441                                         }
 442                                         s=s->next;
 443                                 }
 444                                 if (c2smp)
 445                                         SL_HalveSample(c2smp,2);
 446                         }
 447                 }
 448
 449         /* Samples dithered, now load them ! */
 450         s = samplist;
 451         while(s) {
 452                 /* sample has to be loaded ? -> increase number of samples, allocate
 453                    memory and load sample. */
 454                 if(s->sample->length) {
 455                         if(s->sample->seekpos)
 456                                 _mm_fseek(s->reader, s->sample->seekpos, SEEK_SET);
 457
 458                         /* Call the sample load routine of the driver module. It has to
 459                            return a 'handle' (>=0) that identifies the sample. */
 460                         s->sample->handle = MD_SampleLoad(s, type);
 461                         s->sample->flags  = (s->sample->flags & ~SF_FORMATMASK) | s->outfmt;
 462                         if(s->sample->handle<0) {
 463                                 FreeSampleList(samplist);
 464                                 if(_mm_errorhandler) _mm_errorhandler();
 465                                 return 1;
 466                         }
 467                 }
 468                 s = s->next;
 469         }
 470
 471         FreeSampleList(samplist);
 472         return 0;
 473 }
 474
 475 int SL_LoadSamples(void)
 476 {
 477         int rc;
 478
 479         _mm_critical = 0;
 480
 481         if((!musiclist)&&(!sndfxlist)) return 0;
 482         rc=DitherSamples(musiclist,MD_MUSIC)||DitherSamples(sndfxlist,MD_SNDFX);
 483         musiclist=sndfxlist=NULL;
 484
 485         return rc;
 486 }
 487
 488 void SL_Sample16to8(SAMPLOAD* s)
 489 {
 490         s->outfmt &= ~SF_16BITS;
 491         s->sample->flags = (s->sample->flags&~SF_FORMATMASK) | s->outfmt;
 492 }
 493
 494 void SL_Sample8to16(SAMPLOAD* s)
 495 {
 496         s->outfmt |= SF_16BITS;
 497         s->sample->flags = (s->sample->flags&~SF_FORMATMASK) | s->outfmt;
 498 }
 499
 500 void SL_SampleSigned(SAMPLOAD* s)
 501 {
 502         s->outfmt |= SF_SIGNED;
 503         s->sample->flags = (s->sample->flags&~SF_FORMATMASK) | s->outfmt;
 504 }
 505
 506 void SL_SampleUnsigned(SAMPLOAD* s)
 507 {
 508         s->outfmt &= ~SF_SIGNED;
 509         s->sample->flags = (s->sample->flags&~SF_FORMATMASK) | s->outfmt;
 510 }
 511
 512 void SL_HalveSample(SAMPLOAD* s,int factor)
 513 {
 514         s->scalefactor=factor>0?factor:2;
 515
 516         s->sample->divfactor = s->scalefactor;
 517         s->sample->length    = s->length / s->scalefactor;
 518         s->sample->loopstart = s->loopstart / s->scalefactor;
 519         s->sample->loopend   = s->loopend / s->scalefactor;
 520 }
 521
 522 /* ex:set ts=4: */