load_it.c

wince下著名的视频播放器源码

	/* 2.16 : IT 2.14p3 with resonant filters */
	/* 2.15 : IT 2.14p3 (improved compression) */
	if((mh->cwt<=0x219)&&(mh->cwt>=0x217))
		of.modtype=strdup(IT_Version[mh->cmwt<0x214?4:5]);
	else if (mh->cwt>=0x215)
		of.modtype=strdup(IT_Version[mh->cmwt<0x214?2:3]);
	else {
		of.modtype     = strdup(IT_Version[mh->cmwt<0x214?0:1]);
		of.modtype[mh->cmwt<0x214?15:26] = (mh->cwt>>8)+'0';
		of.modtype[mh->cmwt<0x214?17:28] = ((mh->cwt>>4)&0xf)+'0';
		of.modtype[mh->cmwt<0x214?18:29] = ((mh->cwt)&0xf)+'0';
	}

	if(mh->flags&8)
		of.flags |= UF_XMPERIODS | UF_LINEAR;

	if((mh->cwt>=0x106)&&(mh->flags&16))
		old_effect=S3MIT_OLDSTYLE;
	else
		old_effect=0;

	/* set panning positions */
	if (mh->flags & 1)
		for(t=0;t<64;t++) {
			mh->pantable[t]&=0x7f;
			if(mh->pantable[t]<64)
				of.panning[t]=mh->pantable[t]<<2;
			else if(mh->pantable[t]==64)
				of.panning[t]=255;
			else if(mh->pantable[t]==100)
				of.panning[t]=PAN_SURROUND;
			else if(mh->pantable[t]==127)
				of.panning[t]=PAN_CENTER;
			else {
				_mm_errno=MMERR_LOADING_HEADER;
				return 0;
			}
		}
	else
		for(t=0;t<64;t++)
			of.panning[t]=PAN_CENTER;

	/* set channel volumes */
	memcpy(of.chanvol,mh->voltable,64);

	/* read the order data */
	if(!AllocPositions(mh->ordnum)) return 0;
	if(!(origpositions=_mm_calloc(mh->ordnum,sizeof(UWORD)))) return 0;

	for(t=0;t<mh->ordnum;t++) {
		origpositions[t]=_mm_read_UBYTE(modreader);
		if((origpositions[t]>mh->patnum)&&(origpositions[t]<254))
			origpositions[t]=255;
	}

	if(_mm_eof(modreader)) {
		_mm_errno = MMERR_LOADING_HEADER;
		return 0;
	}

	poslookupcnt=mh->ordnum;
	S3MIT_CreateOrders(curious);

	if(!(paraptr=(ULONG*)_mm_malloc((mh->insnum+mh->smpnum+of.numpat)*
	                               sizeof(ULONG)))) return 0;

	/* read the instrument, sample, and pattern parapointers */
	_mm_read_I_ULONGS(paraptr,mh->insnum+mh->smpnum+of.numpat,modreader);

	if(_mm_eof(modreader)) {
		_mm_errno = MMERR_LOADING_HEADER;
		return 0;
	}

	/* Check for and load midi information for resonant filters */
	if(mh->cmwt>=0x216) {
		if(mh->special&8) {
			IT_LoadMidiConfiguration(modreader);
			if(_mm_eof(modreader)) {
				_mm_errno = MMERR_LOADING_HEADER;
				return 0;
			}
		} else
			IT_LoadMidiConfiguration(NULL);
		filters=1;
	}

	/* Check for and load song comment */
	if((mh->special&1)&&(mh->cwt>=0x104)&&(mh->msglength)) {
		_mm_fseek(modreader,(long)(mh->msgoffset),SEEK_SET);
		if(!ReadComment(mh->msglength)) return 0;
	}

	if(!(mh->flags&4)) of.numins=of.numsmp;
	if(!AllocSamples()) return 0;

	if(!AllocLinear()) return 0;

	/* Load all samples */
	q = of.samples;
	for(t=0;t<mh->smpnum;t++) {
		ITSAMPLE s;

		/* seek to sample position */
		_mm_fseek(modreader,(long)(paraptr[mh->insnum+t]+4),SEEK_SET);

		/* load sample info */
		_mm_read_string(s.filename,12,modreader);
		s.zerobyte    = _mm_read_UBYTE(modreader);
		s.globvol     = _mm_read_UBYTE(modreader);
		s.flag        = _mm_read_UBYTE(modreader);
		s.volume      = _mm_read_UBYTE(modreader);
		_mm_read_string(s.sampname,26,modreader);
		s.convert     = _mm_read_UBYTE(modreader);
		s.panning     = _mm_read_UBYTE(modreader);
		s.length      = _mm_read_I_ULONG(modreader);
		s.loopbeg     = _mm_read_I_ULONG(modreader);
		s.loopend     = _mm_read_I_ULONG(modreader);
		s.c5spd       = _mm_read_I_ULONG(modreader);
		s.susbegin    = _mm_read_I_ULONG(modreader);
		s.susend      = _mm_read_I_ULONG(modreader);
		s.sampoffset  = _mm_read_I_ULONG(modreader);
		s.vibspeed    = _mm_read_UBYTE(modreader);
		s.vibdepth    = _mm_read_UBYTE(modreader);
		s.vibrate     = _mm_read_UBYTE(modreader);
		s.vibwave     = _mm_read_UBYTE(modreader);

		/* Generate an error if c5spd is > 512k, or samplelength > 256 megs
		   (nothing would EVER be that high) */

		if(_mm_eof(modreader)||(s.c5spd>0x7ffffL)||(s.length>0xfffffffUL)) {
			_mm_errno = MMERR_LOADING_SAMPLEINFO;
			return 0;
		}

		/* Reality check for sample loop information */
		if((s.flag&16)&&
		   ((s.loopbeg>0xfffffffUL)||(s.loopend>0xfffffffUL))) {
			_mm_errno = MMERR_LOADING_SAMPLEINFO;
			return 0;
		}

		q->samplename = DupStr(s.sampname,26,0);
		q->speed      = s.c5spd / 2;
		q->panning    = ((s.panning&127)==64)?255:(s.panning&127)<<2;
		q->length     = s.length;
		q->loopstart  = s.loopbeg;
		q->loopend    = s.loopend;
		q->volume     = s.volume;
		q->globvol    = s.globvol;
		q->seekpos    = s.sampoffset;

		/* Convert speed to XM linear finetune */
		if(of.flags&UF_LINEAR)
			q->speed=speed_to_finetune(s.c5spd,t);

		if(s.panning&128) q->flags|=SF_OWNPAN;

		if(s.vibrate) {
			q->vibflags |= AV_IT;
			q->vibtype   = s.vibwave;
			q->vibsweep  = s.vibrate * 2;
			q->vibdepth  = s.vibdepth;
			q->vibrate   = s.vibspeed;
		}

		if(s.flag&2) q->flags|=SF_16BITS;
		if((s.flag&8)&&(mh->cwt>=0x214)) {
			q->flags|=SF_ITPACKED;
			compressed=1;
		}
		if(s.flag&16) q->flags|=SF_LOOP;
		if(s.flag&64) q->flags|=SF_BIDI;

		if(mh->cwt>=0x200) {
			if(s.convert&1) q->flags|=SF_SIGNED;
			if(s.convert&4) q->flags|=SF_DELTA;   
		}
		q++;
	}

	/* Load instruments if instrument mode flag enabled */
	if(mh->flags&4) {
		if(!AllocInstruments()) return 0;
		d=of.instruments;
		of.flags|=UF_NNA|UF_INST;

		for(t=0;t<mh->insnum;t++) {
			ITINSTHEADER ih;

			/* seek to instrument position */
			_mm_fseek(modreader,paraptr[t]+4,SEEK_SET);

			/* load instrument info */
			_mm_read_string(ih.filename,12,modreader);
			ih.zerobyte  = _mm_read_UBYTE(modreader);
			if(mh->cwt<0x200) {
				/* load IT 1.xx inst header */
				ih.volflg    = _mm_read_UBYTE(modreader);
				ih.volbeg    = _mm_read_UBYTE(modreader);
				ih.volend    = _mm_read_UBYTE(modreader);
				ih.volsusbeg = _mm_read_UBYTE(modreader);
				ih.volsusend = _mm_read_UBYTE(modreader);
				_mm_read_I_UWORD(modreader);
				ih.fadeout   = _mm_read_I_UWORD(modreader);
				ih.nna       = _mm_read_UBYTE(modreader);
				ih.dnc       = _mm_read_UBYTE(modreader);
			} else {
				/* Read IT200+ header */
				ih.nna       = _mm_read_UBYTE(modreader);
				ih.dct       = _mm_read_UBYTE(modreader);
				ih.dca       = _mm_read_UBYTE(modreader);
				ih.fadeout   = _mm_read_I_UWORD(modreader);
				ih.ppsep     = _mm_read_UBYTE(modreader);
				ih.ppcenter  = _mm_read_UBYTE(modreader);
				ih.globvol   = _mm_read_UBYTE(modreader);
				ih.chanpan   = _mm_read_UBYTE(modreader);
				ih.rvolvar   = _mm_read_UBYTE(modreader);
				ih.rpanvar   = _mm_read_UBYTE(modreader);
			}

			ih.trkvers   = _mm_read_I_UWORD(modreader);
			ih.numsmp    = _mm_read_UBYTE(modreader);
			_mm_read_UBYTE(modreader);
			_mm_read_string(ih.name,26,modreader);
			_mm_read_UBYTES(ih.blank01,6,modreader);
			_mm_read_I_UWORDS(ih.samptable,ITNOTECNT,modreader);
			if(mh->cwt<0x200) {
				/* load IT 1xx volume envelope */
				_mm_read_UBYTES(ih.volenv,200,modreader);
				for(lp=0;lp<ITENVCNT;lp++) {
					ih.oldvoltick[lp] = _mm_read_UBYTE(modreader);
					ih.volnode[lp]    = _mm_read_UBYTE(modreader);
				} 
			} else {
				/* load IT 2xx volume, pan and pitch envelopes */
#if defined __STDC__ || defined _MSC_VER || defined MPW_C
#define IT_LoadEnvelope(name,type) 										\
				ih. name##flg   =_mm_read_UBYTE(modreader);				\
				ih. name##pts   =_mm_read_UBYTE(modreader);				\
				ih. name##beg   =_mm_read_UBYTE(modreader);				\
				ih. name##end   =_mm_read_UBYTE(modreader);				\
				ih. name##susbeg=_mm_read_UBYTE(modreader);				\
				ih. name##susend=_mm_read_UBYTE(modreader);				\
				for(lp=0;lp<ITENVCNT;lp++) {							\
					ih. name##node[lp]=_mm_read_##type (modreader);		\
					ih. name##tick[lp]=_mm_read_I_UWORD(modreader);		\
				}														\
				_mm_read_UBYTE(modreader)
#else
#define IT_LoadEnvelope(name,type) 										\
				ih. name/**/flg   =_mm_read_UBYTE(modreader);			\
				ih. name/**/pts   =_mm_read_UBYTE(modreader);			\
				ih. name/**/beg   =_mm_read_UBYTE(modreader);			\
				ih. name/**/end   =_mm_read_UBYTE(modreader);			\
				ih. name/**/susbeg=_mm_read_UBYTE(modreader);			\
				ih. name/**/susend=_mm_read_UBYTE(modreader);			\
				for(lp=0;lp<ITENVCNT;lp++) {							\
					ih. name/**/node[lp]=_mm_read_/**/type (modreader);	\
					ih. name/**/tick[lp]=_mm_read_I_UWORD(modreader);	\
				}														\
				_mm_read_UBYTE(modreader)
#endif

				IT_LoadEnvelope(vol,UBYTE);
				IT_LoadEnvelope(pan,SBYTE);
				IT_LoadEnvelope(pit,SBYTE);
#undef IT_LoadEnvelope
			}
 
			if(_mm_eof(modreader)) {
				_mm_errno = MMERR_LOADING_SAMPLEINFO;
				return 0;
			}

			d->volflg|=EF_VOLENV;
			d->insname = DupStr(ih.name,26,0);
			d->nnatype = ih.nna & NNA_MASK;

			if(mh->cwt<0x200) {
				d->volfade=ih.fadeout<< 6;
				if(ih.dnc) {
					d->dct=DCT_NOTE;
					d->dca=DCA_CUT;
				}

				if(ih.volflg&1) d->volflg|=EF_ON;
				if(ih.volflg&2) d->volflg|=EF_LOOP;
				if(ih.volflg&4) d->volflg|=EF_SUSTAIN;      

				/* XM conversion of IT envelope Array */
				d->volbeg    = ih.volbeg;   
				d->volend    = ih.volend;
				d->volsusbeg = ih.volsusbeg;
				d->volsusend = ih.volsusend;

				if(ih.volflg&1) {
					for(u=0;u<ITENVCNT;u++)
						if(ih.oldvoltick[d->volpts]!=0xff) {
							d->volenv[d->volpts].val=(ih.volnode[d->volpts]<<2);
							d->volenv[d->volpts].pos=ih.oldvoltick[d->volpts];
							d->volpts++;
						} else
							break;
				}  
			} else {
				d->panning=((ih.chanpan&127)==64)?255:(ih.chanpan&127)<<2;
				if(!(ih.chanpan&128)) d->flags|=IF_OWNPAN;

				if(!(ih.ppsep & 128)) {
					d->pitpansep=ih.ppsep<<2;
					d->pitpancenter=ih.ppcenter;
					d->flags|=IF_PITCHPAN;
				}
				d->globvol=ih.globvol>>1;
				d->volfade=ih.fadeout<<5;
				d->dct    =ih.dct;
				d->dca    =ih.dca;

				if(mh->cwt>=0x204) {
					d->rvolvar = ih.rvolvar;
					d->rpanvar = ih.rpanvar;
				}

#if defined __STDC__ || defined _MSC_VER || defined MPW_C
#define IT_ProcessEnvelope(name) 										\
				if(ih. name##flg&1) d-> name##flg|=EF_ON;				\
				if(ih. name##flg&2) d-> name##flg|=EF_LOOP;				\
				if(ih. name##flg&4) d-> name##flg|=EF_SUSTAIN;			\
				d-> name##pts=ih. name##pts;							\
				d-> name##beg=ih. name##beg;							\
				d-> name##end=ih. name##end;							\
				d-> name##susbeg=ih. name##susbeg;						\
				d-> name##susend=ih. name##susend;						\
																		\
				for(u=0;u<ih. name##pts;u++)							\
					d-> name##env[u].pos=ih. name##tick[u];				\
																		\
				if((d-> name##flg&EF_ON)&&(d-> name##pts<2))			\
					d-> name##flg&=~EF_ON
#else
#define IT_ProcessEnvelope(name) 									\
				if(ih. name/**/flg&1) d-> name/**/flg|=EF_ON;		\
				if(ih. name/**/flg&2) d-> name/**/flg|=EF_LOOP;		\
				if(ih. name/**/flg&4) d-> name/**/flg|=EF_SUSTAIN;	\
				d-> name/**/pts=ih. name/**/pts;					\
				d-> name/**/beg=ih. name/**/beg;					\
				d-> name/**/end=ih. name/**/end;					\
				d-> name/**/susbeg=ih. name/**/susbeg;				\
				d-> name/**/susend=ih. name/**/susend;				\
																	\
				for(u=0;u<ih. name/**/pts;u++)						\
					d-> name/**/env[u].pos=ih. name/**/tick[u];		\
																	\
				if((d-> name/**/flg&EF_ON)&&(d-> name/**/pts<2))	\
					d-> name/**/flg&=~EF_ON
#endif

				IT_ProcessEnvelope(vol);
				for(u=0;u<ih.volpts;u++)
					d->volenv[u].val=(ih.volnode[u]<<2);

				IT_ProcessEnvelope(pan);
				for(u=0;u<ih.panpts;u++)
					d->panenv[u].val=
					  ih.pannode[u]==32?255:(ih.pannode[u]+32)<<2;

				IT_ProcessEnvelope(pit);
				for(u=0;u<ih.pitpts;u++)
					d->pitenv[u].val=ih.pitnode[u]+32;
#undef IT_ProcessEnvelope

				if(ih.pitflg&0x80) {
					/* filter envelopes not supported yet */
					d->pitflg&=~EF_ON;
					ih.pitpts=ih.pitbeg=ih.pitend=0;
#ifdef MIKMOD_DEBUG
					{
						static int warn=0;
						
						if(!warn)
							fprintf(stderr, "\rFilter envelopes not supported yet\n");
						warn=1;
					}
#endif
				}
			}

			for(u=0;u<ITNOTECNT;u++) {
				d->samplenote[u]=(ih.samptable[u]&255);
				d->samplenumber[u]=
				  (ih.samptable[u]>>8)?((ih.samptable[u]>>8)-1):0xffff;
				if(d->samplenumber[u]>=of.numsmp)
					d->samplenote[u]=255;
				else if (of.flags&UF_LINEAR) {
					int note=(int)d->samplenote[u]+noteindex[d->samplenumber[u]];
					d->samplenote[u]=(note<0)?0:(note>255?255:note);
				}
			}

			d++;                  
		}
	} else if(of.flags & UF_LINEAR) {
		if(!AllocInstruments()) return 0;
		d=of.instruments;
		of.flags|=UF_INST;

		for(t=0;t<mh->smpnum;t++,d++)
			for(u=0;u<ITNOTECNT;u++) {
				if(d->samplenumber[u]>=of.numsmp)
					d->samplenote[u]=255;
				else {
					int note=(int)d->samplenote[u]+noteindex[d->samplenumber[u]];
					d->samplenote[u]=(note<0)?0:(note>255?255:note);
				}
			}
	}

	/* Figure out how many channels this song actually uses */
	of.numchn=0;
	memset(remap,-1,UF_MAXCHAN*sizeof(UBYTE));
	for(t=0;t<of.numpat;t++) {
		UWORD packlen;

		/* seek to pattern position */
		if(paraptr[mh->insnum+mh->smpnum+t]) { /* 0 -> empty 64 row pattern */
			_mm_fseek(modreader,((long)paraptr[mh->insnum+mh->smpnum+t]),SEEK_SET);
			_mm_read_I_UWORD(modreader);
			/* read pattern length (# of rows)
			   Impulse Tracker never creates patterns with less than 32 rows,
			   but some other trackers do, so we only check for more than 256
			   rows */
			packlen=_mm_read_I_UWORD(modreader);
			if(packlen>256) {
				_mm_errno=MMERR_LOADING_PATTERN;
				return 0;
			}
			_mm_read_I_ULONG(modreader);
			if(IT_GetNumChannels(packlen)) return 0;
		}
	}

	/* give each of them a different number */
	for(t=0;t<UF_MAXCHAN;t++) 
		if(!remap[t])
			remap[t]=of.numchn++;

	of.numtrk = of.numpat*of.numchn;
	if(of.numvoices)
		if (of.numvoices<of.numchn) of.numvoices=of.numchn;

	if(!AllocPatterns()) return 0;
	if(!AllocTracks()) return 0;

	for(t=0;t<of.numpat;t++) {
		UWORD packlen;

		/* seek to pattern position */
		if(!paraptr[mh->insnum+mh->smpnum+t]) { /* 0 -> empty 64 row pattern */
			of.pattrows[t]=64;
			for(u=0;u<of.numchn;u++) {
				int k;

				UniReset();
				for(k=0;k<64;k++) UniNewline();
				of.tracks[numtrk++]=UniDup();
			}
		} else {
			_mm_fseek(modreader,((long)paraptr[mh->insnum+mh->smpnum+t]),SEEK_SET);
			packlen=_mm_read_I_UWORD(modreader);
			of.pattrows[t]=_mm_read_I_UWORD(modreader);
			_mm_read_I_ULONG(modreader);
			if(!IT_ReadPattern(of.pattrows[t])) return 0;
		}
	}

	return 1;
}

CHAR *IT_LoadTitle(void)
{
	CHAR s[26];

	_mm_fseek(modreader,4,SEEK_SET);
	if(!_mm_read_UBYTES(s,26,modreader)) return NULL;
   
	return(DupStr(s,26,0));
}

/*========== Loader information */

MIKMODAPI MLOADER load_it={
	NULL,
	"IT",
	"IT (Impulse Tracker)",
	IT_Init,
	IT_Test,
	IT_Load,
	IT_Cleanup,
	IT_LoadTitle
};

/* ex:set ts=4: */