mikmod: playercode/sloader.c comparison

comparison playercode/sloader.c @ 6:d14fd386d182

Initial entry of mikmod into the CVS tree.

author	darius
date	Fri, 23 Jan 1998 16:05:09 +0000
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-:42e11dc15457
+:d14fd386d182
+/*
+--> Sample Loaders and Sample Processing
+Name: sloader.c
+Description:
+Routines for loading samples.  The sample loader utilizes the routines
+provided by the "registered" sample loader.  See SAMPLELOADER in
+MIKMOD.H for the sample loader structure.
+Portability:
+All systems - all compilers
+*/
+#include "mikmod.h"
+static int   sl_rlength;
+static SWORD sl_old;
+static SWORD *sl_buffer = NULL;
+static SAMPLOAD *musiclist = NULL,
+*sndfxlist = NULL;
+BOOL SL_Init(SAMPLOAD *s)        // returns 0 on error!
+{
+if(sl_buffer==NULL)
+if((sl_buffer=_mm_malloc(4100)) == NULL) return 0;
+sl_rlength = s->length;
+if(s->infmt & SF_16BITS) sl_rlength>>=1;
+sl_old = 0;
+return 1;
+}
+void SL_Exit(SAMPLOAD *s)
+{
+if(sl_rlength > 0) _mm_fseek(s->fp,sl_rlength,SEEK_CUR);
+}
+void SL_Reset(void)
+{
+sl_old = 0;
+}
+void SL_Load(void *buffer, SAMPLOAD *smp, int length)
+{
+UWORD infmt = smp->infmt, outfmt = smp->outfmt;
+SBYTE *bptr = (SBYTE *)buffer;
+SWORD *wptr = (SWORD *)buffer;
+int   stodo;
+int   t, u;
+while(length)
+{   stodo = (length<2048) ? length : 2048;
+if(infmt & SF_16BITS)
+{   if(infmt & SF_BIG_ENDIAN)
+_mm_read_M_SWORDS(sl_buffer,stodo,smp->fp);
+else
+_mm_read_I_SWORDS(sl_buffer,stodo,smp->fp);
+} else
+{   SBYTE  *s;
+SWORD  *d;
+fread(sl_buffer,sizeof(SBYTE),stodo,smp->fp);
+s  = (SBYTE *)sl_buffer;
+d  = sl_buffer;
+s += stodo;
+d += stodo;
+for(t=0; t<stodo; t++)
+{   s--;
+d--;
+*d = (*s)<<8;
+}
+}
+if(infmt & SF_DELTA)
+{   for(t=0; t<stodo; t++)
+{   sl_buffer[t] += sl_old;
+sl_old = sl_buffer[t];
+}
+}
+if((infmt^outfmt) & SF_SIGNED)
+{   for(t=0; t<stodo; t++)
+sl_buffer[t] ^= 0x8000;
+}
+if(smp->scalefactor)
+{   int   idx = 0;
+SLONG scaleval;
+// Sample Scaling... average values for better results.
+t = 0;
+while(t<stodo && length)
+{   scaleval = 0;
+for(u=smp->scalefactor; u && t<stodo; u--, t++)
+scaleval += sl_buffer[t];
+sl_buffer[idx++] = scaleval / (smp->scalefactor-u);
+length--;
+}
+sl_rlength -= stodo;
+stodo = idx;
+} else
+{   length -= stodo;
+sl_rlength -= stodo;
+}
+if(outfmt & SF_16BITS)
+{   for(t=0; t<stodo; t++) *(wptr++) = sl_buffer[t];
+} else
+{   for(t=0; t<stodo; t++) *(bptr++) = sl_buffer[t]>>8;
+}
+}
+}
+void SL_LoadStream(void *buffer, UWORD infmt, UWORD outfmt, int length, FILE *fp)
+// This is like SL_Load, but does not perform sample scaling, and does not
+// require calls to SL_Init / SL_Exit.
+{
+SBYTE *bptr = (SBYTE *)buffer;
+SWORD *wptr = (SWORD *)buffer;
+int   stodo;
+int   t;
+// compute number of samples to load
+if(sl_buffer==NULL)
+if((sl_buffer=_mm_malloc(4100)) == NULL) return;
+while(length)
+{   stodo = (length<2048) ? length : 2048;
+if(infmt & SF_16BITS)
+{   if(infmt & SF_BIG_ENDIAN)
+_mm_read_M_SWORDS(sl_buffer,stodo,fp);
+else
+_mm_read_I_SWORDS(sl_buffer,stodo,fp);
+} else
+{   SBYTE  *s;
+SWORD  *d;
+fread(sl_buffer,sizeof(SBYTE),stodo,fp);
+s  = (SBYTE *)sl_buffer;
+d  = sl_buffer;
+s += stodo;
+d += stodo;
+for(t=0; t<stodo; t++)
+{   s--;
+d--;
+*d = (*s)<<8;
+}
+}
+if(infmt & SF_DELTA)
+{   for(t=0; t<stodo; t++)
+{   sl_buffer[t] += sl_old;
+sl_old = sl_buffer[t];
+}
+}
+if((infmt^outfmt) & SF_SIGNED)
+{   for(t=0; t<stodo; t++)
+sl_buffer[t] ^= 0x8000;
+}
+length -= stodo;
+if((infmt & SF_STEREO) && !(outfmt & SF_STEREO))
+{   // Dither stereo to mono .. average together every two samples
+SLONG avgval;
+int   idx = 0;
+t = 0;
+while(t<stodo && length)
+{   avgval  = sl_buffer[t++];
+avgval += sl_buffer[t++];
+sl_buffer[idx++] = avgval >> 1;
+length-=2;
+}
+stodo = idx;
+}
+if(outfmt & SF_16BITS)
+{   for(t=0; t<stodo; t++) *(wptr++) = sl_buffer[t];
+} else
+{   for(t=0; t<stodo; t++) *(bptr++) = sl_buffer[t]>>8;
+}
+}
+}
+SAMPLOAD *SL_RegisterSample(SAMPLE *s, int type, FILE *fp)    // Returns 1 on error!
+// Registers a sample for loading when SL_LoadSamples() is called.
+//   type  -  type of sample to be loaded ..
+//             MD_MUSIC, MD_SNDFX
+{
+SAMPLOAD *news, **samplist, *cruise;
+if(type==MD_MUSIC)
+{   samplist = & musiclist;
+cruise = musiclist;
+} else
+{   samplist = &sndfxlist;
+cruise = sndfxlist;
+}
+// Allocate and add structure to the END of the list
+if((news=(SAMPLOAD *)_mm_calloc(1,sizeof(SAMPLOAD))) == NULL) return NULL;
+if(cruise!=NULL)
+{   while(cruise->next!=NULL)  cruise = cruise->next;
+cruise->next = news;
+} else
+*samplist = news;
+news->infmt     = s->flags & 31;
+news->outfmt    = news->infmt;
+news->fp        = fp;
+news->sample    = s;
+news->length    = s->length;
+news->loopstart = s->loopstart;
+news->loopend   = s->loopend;
+return news;
+}
+static void FreeSampleList(SAMPLOAD *s)
+{
+SAMPLOAD *old;
+while(s!=NULL)
+{   old = s;
+s = s->next;
+free(old);
+}
+}
+static ULONG SampleTotal(SAMPLOAD *samplist, int type)
+// Returns the total amount of memory required by the samplelist queue.
+{
+int total = 0;
+while(samplist!=NULL)
+{   samplist->sample->flags = (samplist->sample->flags&~31) | samplist->outfmt;
+total += MD_SampleLength(type,samplist->sample);
+samplist = samplist->next;
+}
+return total;
+}
+static ULONG RealSpeed(SAMPLOAD *s)
+{
+return(s->sample->speed / ((s->scalefactor==0) ? 1 : s->scalefactor));
+}
+static BOOL DitherSamples(SAMPLOAD *samplist, int type)
+{
+SAMPLOAD  *c2smp;
+ULONG     maxsize, speed;
+SAMPLOAD  *s;
+if(samplist==NULL) return 0;
+// make sure the samples will fit inside available RAM
+if((maxsize = MD_SampleSpace(type)*1024) != 0)
+{   while(SampleTotal(samplist, type) > maxsize)
+{   // First Pass - check for any 16 bit samples
+s = samplist;
+while(s!=NULL)
+{   if(s->outfmt & SF_16BITS)
+{   SL_Sample16to8(s);
+break;
+}
+s = s->next;
+}
+// Second pass (if no 16bits found above) is to take the sample
+// with the highest speed and dither it by half.
+if(s==NULL)
+{   s = samplist;
+speed = 0;
+while(s!=NULL)
+{   if((s->sample->length) && (RealSpeed(s) > speed))
+{   speed = RealSpeed(s);
+c2smp = s;
+}
+s = s->next;
+}
+SL_HalveSample(c2smp);
+}
+}
+}
+// Samples dithered, now load them!
+// ================================
+s = samplist;
+while(s != NULL)
+{   // sample has to be loaded ? -> increase number of
+// samples, allocate memory and load sample.
+if(s->sample->length)
+{   if(s->sample->seekpos)
+_mm_fseek(s->fp, s->sample->seekpos, SEEK_SET);
+// Call the sample load routine of the driver module.
+// It has to return a 'handle' (>=0) that identifies
+// the sample.
+s->sample->handle = MD_SampleLoad(s, type, s->fp);
+s->sample->flags  = (s->sample->flags & ~31) | s->outfmt;
+if(s->sample->handle < 0)
+{   FreeSampleList(samplist);
+if(_mm_errorhandler!=NULL) _mm_errorhandler();
+return 1;
+}
+}
+s = s->next;
+}
+FreeSampleList(samplist);
+return 0;
+}
+BOOL SL_LoadSamples(void)      // Returns 1 on error!
+{
+BOOL ok;
+_mm_critical = 0;
+if((musiclist==NULL) && (sndfxlist==NULL)) return 0;
+//    MikMod_Exit();
+//    exit(1);
+ok = DitherSamples(musiclist,MD_MUSIC) || DitherSamples(sndfxlist,MD_SNDFX);
+musiclist = sndfxlist = NULL;
+return ok;
+}
+void SL_Sample16to8(SAMPLOAD *s)
+{
+s->outfmt &= ~SF_16BITS;
+s->sample->flags = (s->sample->flags&~31) | s->outfmt;
+}
+void SL_Sample8to16(SAMPLOAD *s)
+{
+s->outfmt |= SF_16BITS;
+s->sample->flags = (s->sample->flags&~31) | s->outfmt;
+}
+void SL_SampleSigned(SAMPLOAD *s)
+{
+s->outfmt |= SF_SIGNED;
+s->sample->flags = (s->sample->flags&~31) | s->outfmt;
+}
+void SL_SampleUnsigned(SAMPLOAD *s)
+{
+s->outfmt &= ~SF_SIGNED;
+s->sample->flags = (s->sample->flags&~31) | s->outfmt;
+}
+void SL_HalveSample(SAMPLOAD *s)
+{
+if(s->scalefactor)
+s->scalefactor++;
+else
+s->scalefactor = 2;
+s->sample->divfactor = s->scalefactor;
+s->sample->length    = s->length / s->scalefactor;
+s->sample->loopstart = s->loopstart / s->scalefactor;
+s->sample->loopend   = s->loopend / s->scalefactor;
+}

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comparison playercode/sloader.c @ 6:d14fd386d182