sffile.c

MIDI解码程序(用VC编写)

/*================================================================
 * process sample data list
 *================================================================*/

static int process_sdta(int size, SFInfo *sf, struct timidity_file *fd)
{
	while (size > 0) {
		SFChunk chunk;

		/* read a sub chunk */
		if(READCHUNK(&chunk, fd) <= 0)
		    return -1;
		size -= 8;

		ctl->cmsg(CMSG_INFO, VERB_DEBUG, " %c%c%c%c:",
			  chunk.id[0], chunk.id[1], chunk.id[2], chunk.id[3]);
		switch (chunkid(chunk.id)) {
		case SNAM_ID:
			/* sample name list */
			load_sample_names(chunk.size, sf, fd);
			break;
		case SMPL_ID:
			/* sample data starts from here */
			sf->samplepos = tf_tell(fd);
			sf->samplesize = chunk.size;
			FSKIP(chunk.size, fd);
			break;
		default:
			FSKIP(chunk.size, fd);
			break;
		}
		size -= chunk.size;
	}
	return 0;
}


/*================================================================
 * process preset data list
 *================================================================*/

static int process_pdta(int size, SFInfo *sf, struct timidity_file *fd)
{
	while (size > 0) {
		SFChunk chunk;

		/* read a subchunk */
		if(READCHUNK(&chunk, fd) <= 0)
		    return -1;
		size -= 8;

		ctl->cmsg(CMSG_INFO, VERB_DEBUG, " %c%c%c%c:",
			  chunk.id[0], chunk.id[1], chunk.id[2], chunk.id[3]);
		switch (chunkid(chunk.id)) {
		case PHDR_ID:
			load_preset_header(chunk.size, sf, fd);
			break;
		case PBAG_ID:
			load_bag(chunk.size, &prbags, fd);
			break;
		case PGEN_ID:
			load_gen(chunk.size, &prbags, fd);
			break;
		case INST_ID:
			load_inst_header(chunk.size, sf, fd);
			break;
		case IBAG_ID:
			load_bag(chunk.size, &inbags, fd);
			break;
		case IGEN_ID:
			load_gen(chunk.size, &inbags, fd);
			break;
		case SHDR_ID:
			load_sample_info(chunk.size, sf, fd);
			break;
		case PMOD_ID: /* ignored */
		case IMOD_ID: /* ingored */
		default:
			FSKIP(chunk.size, fd);
			break;
		}
		size -= chunk.size;
	}
	return 0;
}


/*----------------------------------------------------------------
 * store sample name list; sf1 only
 *----------------------------------------------------------------*/

static void load_sample_names(int size, SFInfo *sf, struct timidity_file *fd)
{
	int i, nsamples;
	if (sf->version > 1) {
		ctl->cmsg(CMSG_WARNING, VERB_NORMAL,
			  "%s: *** version 2 has obsolete format??",
			  current_filename);
		FSKIP(size, fd);
		return;
	}

	/* each sample name has a fixed lentgh (20 bytes) */
	nsamples = size / 20;
	if (sf->sample == NULL) {
		sf->nsamples = nsamples;
		sf->sample = NEW(SFSampleInfo, sf->nsamples);
	} else if (sf->nsamples != nsamples) {
		ctl->cmsg(CMSG_WARNING, VERB_NORMAL,
			  "%s: *** different # of samples ?? (%d : %d)\n",
			  current_filename, sf->nsamples, nsamples);
		FSKIP(size, fd);
		return;
	}
		
	/* read each name from file */
	for (i = 0; i < sf->nsamples; i++) {
		READSTR(sf->sample[i].name, fd);
	}
}


/*----------------------------------------------------------------
 * preset header list
 *----------------------------------------------------------------*/

static void load_preset_header(int size, SFInfo *sf, struct timidity_file *fd)
{
	int i;

	sf->npresets = size / 38;
	sf->preset = NEW(SFPresetHdr, sf->npresets);
	for (i = 0; i < sf->npresets; i++) {
		READSTR(sf->preset[i].hdr.name, fd);
		READW(&sf->preset[i].preset, fd);
		READW(&sf->preset[i].bank, fd);
		READW(&sf->preset[i].hdr.bagNdx, fd);
		SKIPDW(fd); /* lib; ignored*/
		SKIPDW(fd); /* genre; ignored */
		SKIPDW(fd); /* morph; ignored */
		/* initialize layer table; it'll be parsed later */
		sf->preset[i].hdr.nlayers = 0;
		sf->preset[i].hdr.layer = NULL;

		ctl->cmsg(CMSG_INFO, VERB_DEBUG,
			  "  Preset %d (%s) index=%d bank=%d preset=%d",
			  i, sf->preset[i].hdr.name,
			  sf->preset[i].hdr.bagNdx,
			  sf->preset[i].bank,
			  sf->preset[i].preset + progbase);
	}
}


/*----------------------------------------------------------------
 * instrument header list
 *----------------------------------------------------------------*/

static void load_inst_header(int size, SFInfo *sf, struct timidity_file *fd)
{
	int i;

	sf->ninsts = size / 22;
	sf->inst = NEW(SFInstHdr, sf->ninsts);
	for (i = 0; i < sf->ninsts; i++) {
		READSTR(sf->inst[i].hdr.name, fd);
		READW(&sf->inst[i].hdr.bagNdx, fd);
		/* iniitialize layer table; it'll be parsed later */
		sf->inst[i].hdr.nlayers = 0;
		sf->inst[i].hdr.layer = NULL;

		ctl->cmsg(CMSG_INFO, VERB_DEBUG,
			  "  InstHdr %d (%s) bagNdx=%d",
			  i, sf->inst[i].hdr.name, sf->inst[i].hdr.bagNdx);
	}
}


/*----------------------------------------------------------------
 * load preset/instrument bag list on the private table
 *----------------------------------------------------------------*/

static void load_bag(int size, SFBags *bagp, struct timidity_file *fd)
{
	int i;

	size /= 4;
	bagp->bag = NEW(uint16, size);
	for (i = 0; i < size; i++) {
		READW(&bagp->bag[i], fd);
		SKIPW(fd); /* mod; ignored */
	}
	bagp->nbags = size;
}


/*----------------------------------------------------------------
 * load preset/instrument generator list on the private table
 *----------------------------------------------------------------*/

static void load_gen(int size, SFBags *bagp, struct timidity_file *fd)
{
	int i;

	size /= 4;
	bagp->gen = NEW(SFGenRec, size);
	for (i = 0; i < size; i++) {
		READW((uint16 *)&bagp->gen[i].oper, fd);
		READW((uint16 *)&bagp->gen[i].amount, fd);
	}
	bagp->ngens = size;
}


/*----------------------------------------------------------------
 * load sample info list
 *----------------------------------------------------------------*/

static void load_sample_info(int size, SFInfo *sf, struct timidity_file *fd)
{
	int i;
	int in_rom;

	/* the record size depends on the soundfont version */
	if (sf->version > 1) {
		/* SF2 includes sample name and other infos */
		sf->nsamples = size / 46;
		sf->sample = NEW(SFSampleInfo, sf->nsamples);
	} else  {
		/* SBK; sample name may be read already */
		int nsamples = size / 16;
		if (sf->sample == NULL) {
			sf->nsamples = nsamples;
			sf->sample = NEW(SFSampleInfo, sf->nsamples);
		} else if (sf->nsamples != nsamples) {
#if 0
			fprintf(stderr, "*** different # of infos ?? (%d : %d)\n",
			       sf->nsamples, nsamples);
			FSKIP(size, fd);
			return;
#endif
			/* overwrite it */
			sf->nsamples = nsamples;
		}
	}

	in_rom = 1;  /* data may start from ROM samples */
	for (i = 0; i < sf->nsamples; i++) {
		if (sf->version > 1) /* SF2 only */
			READSTR(sf->sample[i].name, fd);
		READDW((uint32 *)&sf->sample[i].startsample, fd);
		READDW((uint32 *)&sf->sample[i].endsample, fd);
		READDW((uint32 *)&sf->sample[i].startloop, fd);
		READDW((uint32 *)&sf->sample[i].endloop, fd);
		if (sf->version > 1) { /* SF2 only */
			READDW((uint32 *)&sf->sample[i].samplerate, fd);
			READB(sf->sample[i].originalPitch, fd);
			READB(sf->sample[i].pitchCorrection, fd);
			READW(&sf->sample[i].samplelink, fd);
			READW(&sf->sample[i].sampletype, fd);
		} else { /* for SBK; set missing infos */
			sf->sample[i].samplerate = 44100;
			sf->sample[i].originalPitch = 60;
			sf->sample[i].pitchCorrection = 0;
			sf->sample[i].samplelink = 0;
			/* the first RAM data starts from address 0 */
			if (sf->sample[i].startsample == 0)
				in_rom = 0;
			if (in_rom)
				sf->sample[i].sampletype = 0x8001;
			else
				sf->sample[i].sampletype = 1;
		}
	}
}


/*================================================================
 * convert from bags to layers
 *================================================================*/

static void convert_layers(SFInfo *sf)
{
	int i;

	if (prbags.bag == NULL || prbags.gen == NULL ||
	    inbags.bag == NULL || inbags.gen == NULL) {
		ctl->cmsg(CMSG_WARNING, VERB_NORMAL,
			  "%s: *** illegal bags / gens", current_filename);
		return;
	}

	for (i = 0; i < sf->npresets - 1; i++) {
		generate_layers(&sf->preset[i].hdr,
				&sf->preset[i+1].hdr,
				&prbags);
	}
	for (i = 0; i < sf->ninsts - 1; i++) {
		generate_layers(&sf->inst[i].hdr,
				&sf->inst[i+1].hdr,
				&inbags);
	}
}


/*----------------------------------------------------------------
 * generate layer lists from stored bags
 *----------------------------------------------------------------*/

static void generate_layers(SFHeader *hdr, SFHeader *next, SFBags *bags)
{
	int i;
	SFGenLayer *layp;
	
	hdr->nlayers = next->bagNdx - hdr->bagNdx;
	if (hdr->nlayers < 0) {
		ctl->cmsg(CMSG_WARNING, VERB_NORMAL,
			  "%s: illegal layer numbers %d",
			  current_filename, hdr->nlayers);
		return;
	}
	if (hdr->nlayers == 0)
		return;
	hdr->layer = (SFGenLayer*)safe_malloc(sizeof(SFGenLayer) * hdr->nlayers);
	layp = hdr->layer;
	for (layp = hdr->layer, i = hdr->bagNdx; i < next->bagNdx; layp++, i++) {
		int genNdx = bags->bag[i];
		layp->nlists = bags->bag[i+1] - genNdx;
		if (layp->nlists < 0) {
			ctl->cmsg(CMSG_WARNING, VERB_NORMAL,
				  "%s: illegal list numbers %d",
				  current_filename, layp->nlists);
			return;
		}
		layp->list = (SFGenRec*)safe_malloc(sizeof(SFGenRec) * layp->nlists);
		memcpy(layp->list, &bags->gen[genNdx],
		       sizeof(SFGenRec) * layp->nlists);
	}
}

/*----------------------------------------------------------------
 * free a layer
 *----------------------------------------------------------------*/

static void free_layer(SFHeader *hdr)
{
	int i;
	for (i = 0; i < hdr->nlayers; i++) {
		SFGenLayer *layp = &hdr->layer[i];
		if (layp->nlists > 0)
			free(layp->list);
	}
	if (hdr->nlayers > 0)
		free(hdr->layer);
}

/* add blank loop for each data */
int auto_add_blank = 0;
void correct_samples(SFInfo *sf)
{
	int i;
	SFSampleInfo *sp;
	int prev_end;

	prev_end = 0;
	for (sp = sf->sample, i = 0; i < sf->nsamples; i++, sp++) {
		/* correct sample positions for SBK file */
		if (sf->version == 1) {
			sp->startloop++;
			sp->endloop += 2;
		}

		/* calculate sample data size */
		if (sp->sampletype & 0x8000)
			sp->size = 0;
		else if (sp->startsample < prev_end && sp->startsample != 0)
			sp->size = 0;
		else {
			sp->size = -1;
			if (!auto_add_blank && i != sf->nsamples-1)
				sp->size = sp[1].startsample - sp->startsample;
			if (sp->size < 0)
				sp->size = sp->endsample - sp->startsample + 48;		}
		prev_end = sp->endsample;

		/* calculate short-shot loop size */
		if (auto_add_blank || i == sf->nsamples-1)
			sp->loopshot = 48;
		else {
			sp->loopshot = sp[1].startsample - sp->endsample;
			if (sp->loopshot < 0 || sp->loopshot > 48)
				sp->loopshot = 48;
		}
	}
}