fileio.c

e1c0df5d-c8bc-48a5-bc02-a2b7c51c0dbf是做mp3的源代码

#include "fileio.h"

int get_cf_parms()
{
	unsigned long pstart;
	unsigned int reserved, fatcount, rootentries;				// various fat parameters, neccessary
	unsigned char numfats;							// to locate files, browse directory etc.

	if (CFIdentify())							// get CHS from cf card
	return 1;

	numfats = CFReadSector(0);
	if (numfats)								// read MBR
	return 5+numfats;

	pstart = (((((unsigned int) secbuf[0x1c0] & 0xc0) << 2) + secbuf[0x1c1])* heads * sectors_per_track) +
		(secbuf[0x1bf] * sectors_per_track) + (secbuf[0x1c0] & 0x3f) -1;

	if (CFReadSector(pstart))						// read first fat sector
	return 3;

	fatstart = pstart + ((((unsigned int) secbuf[0x0f]) << 8) + secbuf[0x0e]);
	fatcount = (((unsigned int) secbuf[0x17]) << 8) + secbuf[0x16];		// # of sectors per fat
	numfats  = secbuf[0x10];						// # of copies of fat
	rootentries = ((((unsigned int) secbuf[0x12]) << 8) + secbuf[0x11]);	// # of root dir entries
	secpercluster = (secbuf[0x0d]);

	rootdir = fatstart + ((unsigned long) fatcount * numfats);		// start of root dir
	data = rootdir + (rootentries >> 4);					// start of data area (Cluster area)

	return(0);
}

unsigned int get_next_cluster(unsigned int lastcl)
{
//	unsigned int res;
	lastcl += 2;
//	res = CFReadSector((unsigned long) fatstart + (lastcl >> 8));
//	if (res) return 0xffff;
	if (CFReadSector((unsigned long) fatstart + (lastcl >> 8))) return 0xffff;
	return (unsigned int) secbuf[(((unsigned int) lastcl & 0xff) << 1)] - 2
	+ (((unsigned int) secbuf[(((unsigned int) lastcl & 0xff) << 1)+1]) << 8);	// fetch next cluster
}

unsigned int get_next_direntry(unsigned int dircluster, unsigned int num, char dir, unsigned char type, unsigned char get_id3)
{
	register unsigned int direntry, numsave;
	register unsigned int res;
	register unsigned char i;
	unsigned char *p;
	unsigned long sect, lastsec;

	numsave = num;
	sect = lastsec = 0;

	attrib = 1;

	do
	{
		wdt_reset();
		num += dir;
		if (dircluster == 0)					// is this the root directory?
		{
			sect = rootdir + (num >> 4);			// yes, right after fat
		}
		else
		{
			sect = data + ((unsigned long) dircluster * secpercluster) + (num >> 4);	// no, add offset
		}
		if (sect != lastsec)
		{
			res = CFReadSector(sect);
			lastsec = sect;
		}
		direntry = (num << 5) - ((num >> 4) * 512);		// start of directory entry
		attrib = secbuf[direntry+11];				// get file attribute;
		if ((secbuf[direntry] == 0) && (dir > 0)) break;	// end of dir
		if ((type == TYPE_DIR) && !(attrib & 0x10)) continue;	// we're looking for a directory -> continue
		if ((attrib & 0x10) && (secbuf[direntry]=='.') && (secbuf[direntry+1]==' ')) continue;	// current directory -> continue
		if ((attrib != 0x0f) && ((secbuf[direntry] != 0xe5) && (secbuf[direntry] != 0x00)))	// valid file!
		{
			p = filename;					// set stringbuffer pointer to filename
			for (i=0;i<11;i++)				// 8+3, 11 characters
			{
				*p++ = secbuf[direntry+i];
				if (i==7) *p++ = '.';			// add the dot
			}
			*p='\0';					// terminate string
			
			filecluster = (((unsigned int) secbuf[direntry+27]) << 8) + secbuf[direntry+26];
			if (filecluster != 0) filecluster -= 2;
			dirfilesize = (unsigned long) (((unsigned long) secbuf[direntry+31] << 24)
					+ (((unsigned long) secbuf[direntry+30]) << 16)
					+ (((unsigned long) secbuf[direntry+29]) << 8)
					+ (((unsigned long) secbuf[direntry+28])));

			if (!(attrib & 0x10) && (filecluster == 0 && dirfilesize == 0)) continue;	// empty file -> continue
			if (!(strncmp_P(filename+9, PSTR("MP3"), 3) == 0) && type==TYPE_MP3) continue;	// file extension doesn't 
			if (!(strncmp_P(filename+9, PSTR("M3U"), 3) == 0) && type==TYPE_M3U) continue;	// match requested type


			get_lfn(num);					// get long file name
			if ((attrib & 0x10) && (filecluster == 0) && (dirfilesize == 0))	// parent directory
				strncpy_P(filename, PSTR("<dir up>"), 10);
			else if (attrib & 0x10)							// mark as folder
				strncpy_P(artalb, PSTR("<folder>"), 9);
			else if (get_id3)							// mp3 file, get ID3 info
				get_id3_info(filecluster);

//			lcd_clrscr();
//			lcd_upd = LCDUPDATEFREQ;
			return num;
		}
	} while (((num > 0) && (dir < 0)) || ((num < 512) && (dir > 0)));

	beep(60,100);
	return 0xffff;
//	return num;

}

unsigned char get_next_playlist_entry(unsigned char playlistid, char dir)
{
	unsigned char ibuf[6];
	unsigned char *p;
	register unsigned int readcl;
	register int i;
	register unsigned char ii;
	register char readsect;
	
	wdt_reset();
	if ((dir < 0) && playlistptr > 1) playlistptr--;		// remove trailing linefeed if direction is rewind
	readcl = playlistcl;
	i = playlistptr / ((unsigned int) secpercluster * 512);		// determine right cluster for playlistptr
	for (ii = 0;ii < i; ii++)
		readcl = get_next_cluster(readcl);		// fetch cluster...

	readsect = (playlistptr - ((unsigned int) secpercluster * 512 * i)) / 512;	// determine sector inside cluster
	
	CFReadSector(data + (unsigned long) readcl * secpercluster + readsect);
	
	i = playlistptr - ((unsigned int) secpercluster * 512 * i) - (readsect * 512);
	artalb[0] = '\0';
	if (dir > 0) p = artalb;
	else
	{
		artalb[49] = '\0';
		p = artalb+48;
	}
		
	
	while (((dir > 0) && (playlistptr < playlistlength)) || ((dir < 0) && (playlistptr > 0)))
	{
		wdt_reset();
		lcd_upd = 0;
		if (secbuf[i] == 0x0a)
		{
			if (dir > 0)
			{
				*p++ = '\0';
				break;
			}
			else
			{
				memmove(artalb, p, artalb+49-p+1);
				break;
			}
		}
		if ((p-artalb) < 49)
		{
			if (dir > 0) *p++ = secbuf[i];
			else *p-- = secbuf[i];
		}
		else
			if (dir > 0) playlistptr++;
			else playlistptr--;
		if (dir > 0)
		{
			i++;
			if (i == 512)
			{
				i = 0;
				playlistptr++;
				readsect++;
				if (readsect == secpercluster)
				{
					readsect = 0;
					readcl = get_next_cluster(readcl);
				}
				wdt_reset();
				CFReadSector(data + (unsigned long) readcl * secpercluster + readsect);
			}
		}
		else
		{
			i--;
			if (i < 0)
			{
				i = 511;
				playlistptr--;
				readsect--;
				if (readsect < 0)
				{
					readsect = secpercluster - 1;
					readcl = filecluster;
					for (ii = 0; ii<(playlistptr / ((unsigned int) secpercluster * 512)); ii++)
						readcl = get_next_cluster(readcl);
				}
				wdt_reset();
				CFReadSector(data + (unsigned long) readcl * secpercluster + readsect);
			}
		}
	}
	if (dir > 0)
		playlistptr += strlen(artalb)+1;
	else
		playlistptr -= strlen(artalb)+1;
	
	if ((p-artalb) > 48) artalb[49] = '\0';

	if (strlen(artalb) == 0)
		return 0xff;
	
	readcl = 0;
	lcd_clrscr();

	cli();				// finding song may take som time, so no interrupts until then (i.e., disable timer)
	while (strncmp(filename, artalb, 48) && (readcl != 0xffff))
	{
		readcl = get_next_direntry(dircluster, readcl, 1, TYPE_MP3, NOID3);
	}
	sei();
	
	if (readcl != 0xffff)
	{
		get_id3_info(filecluster);
		return 0;
	}
	else
		return 0xfe;

	return 0;	
	
}

unsigned char get_lfn(unsigned int dirid)
{
	register unsigned long sect, lastsec;
	register unsigned int res, lfnentry;
	register unsigned char i;
	unsigned char *p;

	p = filename;
	lastsec = (0);

	while ((dirid > 0) && (p < (&filename[0] + 48)))
	{
		dirid--;
		if (dircluster == 0)		// is this the root directory?
		{
			sect = rootdir + (dirid >> 4);		// yes, right after fat
		}
		else
		{
			sect = data + ((unsigned long) dircluster * secpercluster) + (dirid >> 4);	// no, add offset
		}
		if (sect != lastsec)
		{
			lastsec = sect;
			res = CFReadSector(sect);
		}
		lfnentry = (dirid << 5) - ((dirid >> 4) * 512);
		if (secbuf[lfnentry+11] = 0x0f)
		{
			if (secbuf[lfnentry] & 0x40) dirid = 0;		// last lfn entry
			for (i=1;i<32;i+=2)
			{
				if (p > (&filename[0]+48)) continue;
				if (i==11) i += 3;			// attribute, type, checksum
				if (i==26) i += 2;			// cluster
				*p++ = secbuf[lfnentry+i];

			}
		}
		else return(0xff);						// this is not an lfs entry
	}
//	*p='\0';
	return 0;

}

void get_id3_info(unsigned int cl)
{
	unsigned long tagsize, offset;
	unsigned int cluster;
	char id, length;
	unsigned char *p, *p2;
	register int i;
	char charbuf[30];

	artalb[0]='\0';
	artalbpos = titlepos = 0;
	artalbdir = titledir = 1;
	scrolltimer = SCROLLSPEED;
	lcd_upd = 0;
	tagsize = 0;
	wdt_reset();
	id = CFReadSector(data + (unsigned long) cl * secpercluster);// read next sector
	if (secbuf[0]=='I' && secbuf[1]=='D' && secbuf[2]=='3')
	{
		filename[0]='\0';								// clear filename, we've got a ID3 tag!
		tagsize = ((unsigned long ) secbuf[6]) << 21 | ((unsigned long) secbuf[7]) << 14
		| ((unsigned long) secbuf[8]) << 7 | secbuf[9];
		offset = 10;
		while ((offset < 502) && (id != -1))
		{
			charbuf[0]='\0';
			id = parse_tag(&offset, charbuf);
			if (strlen(charbuf) > 0)
			{
				p2 = NULL;
				switch (id)
				{
					case 1:
						p2 = artalb;
					case 3:
						if (p2== NULL) p2 = filename;
						
						if (strlen(p2)==0) { strncpy(p2, charbuf, 30);}
						else
						{
							length = strlen(charbuf)+3;
							if ((strlen(p2)+length)>49)
								length = 46-strlen(p2);
							memmove(p2+length, p2, strlen(p2));
							memcpy(p2, charbuf, length-3);
							strncpy_P(p2+length-3, PSTR(" - "), 3);
						}
						*(p2+49)='\0';
						break;
	
					case 2:
						p2 = artalb;
					case 4:
						if (p2 == NULL) p2 = filename;
						
						if (strlen(p2)==0) {strncpy(p2, charbuf, 30);}
						else
						{
//							length = 30;
//							if (strlen(p2)+strlen(charbuf)>46)
//								length = 46-strlen(p2);
							if (strlen(p2)>0) strlcat_P(p2, PSTR(" - "), 50);
							strlcat(p2, charbuf, 50);
						}
						*(p2+49)='\0';
						break;
				}
			}
		}
	}
	cluster = cl;
	if (tagsize > 512)
	{
		for (i = 0;i < (tagsize / 512);i++)
		{
			cluster = get_next_cluster(cluster);
		}
	}
	tagsize = tagsize % 512;
	id = CFReadSector(data + (unsigned long) cluster * secpercluster);	// read next sector
	id =6 * ((secbuf[tagsize+2] >> 4) -1) + 3 * (1-((secbuf[tagsize+1] >> 3) & 0x01))+ (3- ((secbuf[tagsize+1] >> 1) & 0x03));
	file_bitrate = PRG_RDB(&bitrate[id]);
	if (file_bitrate < 12)
		file_bitrate = 16;

}



char parse_tag(unsigned long * offs, unsigned char * buffer)
{
	unsigned long tsize;
	char encoding, numid;
	char div;
	register int i;
	char *p;
	static char valid_tags[] PROGMEM = "TPE1TALBTRCKTIT2";

	wdt_reset();
	numid = 0;
	p=valid_tags;
	for (i=0; i<4; i++)
	{
		if (strncmp_P(&secbuf[*offs], p, 4) == 0)
		{
			numid = i+1;
			break;
		}
		p+=4;
	}
	*offs += 4;
	tsize = ((unsigned long) secbuf[*offs]) << 21 | ((unsigned long) secbuf[*offs+1]) << 14 |
		 ((unsigned long) secbuf[*offs+2]) << 7 | (unsigned long) secbuf[*offs+3];
	if (tsize == 0) return -1;			// length zero -> last frame
	*offs += 6;		// jump over flags...
	if (numid != 0)
	{
		encoding = secbuf[*offs];
		if (encoding == 0)
		{*offs += 1; tsize -= 1; div = 1; }
		else
		{*offs += 3; tsize -= 3; div = 2; }
		for (i=0; i<tsize; i++)
		{
			if (i>29)
			{
					buffer[29]='\0';
					i=tsize;
			}
			buffer[i/div]=secbuf[*offs+i];
			if (encoding != 0) i++;
		}
		if (i<=29) buffer[i/div]='\0';
	}
	*offs += tsize;
	return numid;
}