shithub: sox

ref: c61a5fec6258b484fc7e5fbd2a088eff1c4571be
dir: /src/maud.c/

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/*
 * July 5, 1991
 * Copyright 1991 Lance Norskog And Sundry Contributors
 * This source code is freely redistributable and may be used for
 * any purpose.  This copyright notice must be maintained. 
 * Lance Norskog And Sundry Contributors are not responsible for 
 * the consequences of using this software.
 */

/*
 * Sound Tools MAUD file format driver, by Lutz Vieweg 1993
 *
 * supports: mono and stereo, linear, a-law and u-law reading and writing
 *
 * March 3, 1999 - cbagwell
 *   Changed to use rawread for reading.
 *
 */

#include "st.h"
#include "libst.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>	/* For SEEK_* defines if not found in stdio */
#endif

/* Private data for MAUD file */
struct maudstuff { /* max. 100 bytes!!!! */
	ULONG nsamples;
};

void maudwriteheader(P1(ft_t));
LONG rawread(P3(ft_t, LONG *, LONG));
void rawwrite(P3(ft_t, LONG *, LONG));

/*
 * Do anything required before you start reading samples.
 * Read file header. 
 *	Find out sampling rate, 
 *	size and style of samples, 
 *	mono/stereo/quad.
 */
void maudstartread(ft) 
ft_t ft;
{
	struct maudstuff * p = (struct maudstuff *) ft->priv;
	
	char buf[12];
	char *chunk_buf;
	
	unsigned short bitpersam;
	ULONG nom;
	unsigned short denom;
	unsigned short chaninf;
	
	ULONG chunksize;

	int littlendian = 1;
	char *endptr;

	/* Needed for rawread() */
	rawstartread(ft);

	endptr = (char *) &littlendian;
	/* maud is in big endian format.  Swap whats read in
	 * on little endian machines.
	 */
	if (*endptr)
	{
		ft->swap = ft->swap ? 0 : 1;
	}
	
	/* read FORM chunk */
	if (fread(buf, 1, 4, ft->fp) != 4 || strncmp(buf, "FORM", 4) != 0)
		fail("MAUD: header does not begin with magic word 'FORM'");
	
	rlong(ft); /* totalsize */
	
	if (fread(buf, 1, 4, ft->fp) != 4 || strncmp(buf, "MAUD", 4) != 0)
		fail("MAUD: 'FORM' chunk does not specify 'MAUD' as type");
	
	/* read chunks until 'BODY' (or end) */
	
	while (fread(buf,1,4,ft->fp) == 4 && strncmp(buf,"MDAT",4) != 0) {
		
		/*
		buf[4] = 0;
		report("chunk %s",buf);
		*/
		
		if (strncmp(buf,"MHDR",4) == 0) {
			
			chunksize = rlong(ft);
			if (chunksize != 8*4) fail ("MAUD: MHDR chunk has bad size");
			
			/* fseek(ft->fp,12,SEEK_CUR); */
			
			p->nsamples = rlong(ft); /* number of samples stored in MDAT */
			bitpersam = rshort(ft);  /* number of bits per sample as stored in MDAT */
			rshort(ft);              /* number of bits per sample after decompression */
			nom = rlong(ft);         /* clock source frequency */
			denom = rshort(ft);       /* clock devide           */
			if (denom == 0) fail("MAUD: frequency denominator == 0, failed");
			
			ft->info.rate = nom / denom;
			
			chaninf = rshort(ft); /* channel information */
			switch (chaninf) {
			case 0:
				ft->info.channels = 1;
				break;
			case 1:
				ft->info.channels = 2;
				break;
			default:
				fail("MAUD: unsupported number of channels in file");
				break;
			}
			
			chaninf = rshort(ft); /* number of channels (mono: 1, stereo: 2, ...) */
			if (chaninf != ft->info.channels) fail("MAUD: unsupported number of channels in file");
			
			chaninf = rshort(ft); /* compression type */
			
			rlong(ft); /* rest of chunk, unused yet */
			rlong(ft);
			rlong(ft);
			
			if (bitpersam == 8 && chaninf == 0) {
				ft->info.size = BYTE;
				ft->info.style = UNSIGNED;
			}
			else if (bitpersam == 8 && chaninf == 2) {
				ft->info.size = BYTE;
				ft->info.style = ALAW;
			}
			else if (bitpersam == 8 && chaninf == 3) {
				ft->info.size = BYTE;
				ft->info.style = ULAW;
			}
			else if (bitpersam == 16 && chaninf == 0) {
				ft->info.size = WORD;
				ft->info.style = SIGN2;
			}
			else fail("MAUD: unsupported compression type detected");
			
			ft->comment = 0;
			
			continue;
		}
		
		if (strncmp(buf,"ANNO",4) == 0) {
			chunksize = rlong(ft);
			if (chunksize & 1)
				chunksize++;
			chunk_buf = (char *) malloc(chunksize + 1);
			if (fread(chunk_buf,1,(int)chunksize,ft->fp) 
					!= chunksize)
				fail("MAUD: Unexpected EOF in ANNO header");
			chunk_buf[chunksize] = '\0';
			report ("%s",chunk_buf);
			free(chunk_buf);
			
			continue;
		}
		
		/* some other kind of chunk */
		chunksize = rlong(ft);
		if (chunksize & 1)
			chunksize++;
		fseek(ft->fp,chunksize,SEEK_CUR);
		continue;
		
	}
	
	if (strncmp(buf,"MDAT",4) != 0) fail("MAUD: MDAT chunk not found");
	p->nsamples = rlong(ft);
}

/*
 * Read up to len samples from file.
 * Convert to signed longs.
 * Place in buf[].
 * Return number of samples read.
 */

LONG maudread(ft, buf, len) 
ft_t ft;
LONG *buf, len;
{
	return (rawread(ft, buf, len));
}

/*
 * Do anything required when you stop reading samples.  
 * Don't close input file! 
 */
void maudstopread(ft) 
ft_t ft;
{
	/* Needed because of rawread() */
	rawstopread(ft);
}

void maudstartwrite(ft) 
ft_t ft;
{
	struct maudstuff * p = (struct maudstuff *) ft->priv;

	int littlendian = 1;
	char *endptr;

	/* Needed for rawwrite() */
	rawstartwrite(ft);

	endptr = (char *) &littlendian;
	/* maud is in big endian format.  Swap whats read in
	 * on little endian machines.
	 */
	if (*endptr)
	{
		ft->swap = ft->swap ? 0 : 1;
	}
	
	/* If you have to seek around the output file */
	if (! ft->seekable) fail("Output .maud file must be a file, not a pipe");
	
	if (ft->info.channels != 1 && ft->info.channels != 2) {
		fail("MAUD: unsupported number of channels, unable to store");
	}
	if (ft->info.size == WORD) ft->info.style = SIGN2;
	if (ft->info.style == ULAW || ft->info.style == ALAW) ft->info.size = BYTE;
	if (ft->info.size == BYTE && ft->info.style == SIGN2) ft->info.style = UNSIGNED;
	
	p->nsamples = 0x7f000000L;
	maudwriteheader(ft);
	p->nsamples = 0;
}

void maudwrite(ft, buf, len) 
ft_t ft;
LONG *buf, len;
{
	struct maudstuff * p = (struct maudstuff *) ft->priv;
	
	p->nsamples += len;
	
	rawwrite(ft, buf, len);
}

void maudstopwrite(ft) 
ft_t ft;
{
	/* Flush out remaining samples*/
	rawstopwrite(ft);

	/* All samples are already written out. */
	
	if (fseek(ft->fp, 0L, 0) != 0) fail("can't rewind output file to rewrite MAUD header");
	
	maudwriteheader(ft);
}

#define MAUDHEADERSIZE (4+(4+4+32)+(4+4+32)+(4+4))
void maudwriteheader(ft)
ft_t ft;
{
	struct maudstuff * p = (struct maudstuff *) ft->priv;
	
	fputs ("FORM", ft->fp);
	wlong(ft, (p->nsamples*ft->info.size) + MAUDHEADERSIZE);  /* size of file */
	fputs("MAUD", ft->fp); /* File type */
	
	fputs ("MHDR", ft->fp);
	wlong(ft, (LONG) 8*4); /* number of bytes to follow */
	wlong(ft, (LONG) (p->nsamples ));  /* number of samples stored in MDAT */
	
	switch (ft->info.style) {
		
	case UNSIGNED:
		wshort(ft, (int) 8); /* number of bits per sample as stored in MDAT */
		wshort(ft, (int) 8); /* number of bits per sample after decompression */
		break;
		
	case SIGN2:
		wshort(ft, (int) 16); /* number of bits per sample as stored in MDAT */
		wshort(ft, (int) 16); /* number of bits per sample after decompression */
		break;
		
	case ALAW:
	case ULAW:
		wshort(ft, (int) 8); /* number of bits per sample as stored in MDAT */
		wshort(ft, (int) 16); /* number of bits per sample after decompression */
		break;
		
	}
	
	wlong(ft, (LONG) ft->info.rate); /* clock source frequency */
	wshort(ft, (int) 1); /* clock devide */
	
	if (ft->info.channels == 1) {
		wshort(ft, (int) 0); /* channel information */
		wshort(ft, (int) 1); /* number of channels (mono: 1, stereo: 2, ...) */
	}
	else {
		wshort(ft, (int) 1);
		wshort(ft, (int) 2);
	}
	
	switch (ft->info.style) {
		
	case UNSIGNED:
	case SIGN2:
		wshort(ft, (int) 0); /* no compression */
		break;
		
	case ULAW:
		wshort(ft, (int) 3);
		break;
		
	case ALAW:
		wshort(ft, (int) 2);
		break;
		
	}
	
	wlong(ft, (LONG) 0); /* reserved */
	wlong(ft, (LONG) 0); /* reserved */
	wlong(ft, (LONG) 0); /* reserved */
	
	fputs ("ANNO", ft->fp);
	wlong(ft, (LONG) 32); /* length of block */
	fputs ("file written by SOX MAUD-export ", ft->fp);
	
	fputs ("MDAT", ft->fp);
	wlong(ft, p->nsamples * ft->info.size ); /* samples in file */
}