/*
 * 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_i.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#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!!!! */
	uint32_t nsamples;
};

static void maudwriteheader(ft_t);

/*
 * Do anything required before you start reading samples.
 * Read file header. 
 *	Find out sampling rate, 
 *	size and encoding of samples, 
 *	mono/stereo/quad.
 */
int st_maudstartread(ft_t ft) 
{
	struct maudstuff * p = (struct maudstuff *) ft->priv;
	
	char buf[12];
	char *chunk_buf;
	
	unsigned short bitpersam;
	uint32_t nom;
	unsigned short denom;
	unsigned short chaninf;
	
	uint32_t chunksize;
	uint32_t trash32;
	int rc;

	/* Needed for rawread() */
	rc = st_rawstartread(ft);
	if (rc)
	    return rc;

	/* maud is in big endian format.  Swap whats read in
	 * on little endian machines.
	 */
	if (ST_IS_LITTLEENDIAN)
	{
		ft->swap = ft->swap ? 0 : 1;
	}
	
	/* read FORM chunk */
	if (st_reads(ft, buf, 4) == ST_EOF || strncmp(buf, "FORM", 4) != 0)
	{
		st_fail_errno(ft,ST_EHDR,"MAUD: header does not begin with magic word 'FORM'");
		return (ST_EOF);
	}
	
	st_readdw(ft, &trash32); /* totalsize */
	
	if (st_reads(ft, buf, 4) == ST_EOF || strncmp(buf, "MAUD", 4) != 0)
	{
		st_fail_errno(ft,ST_EHDR,"MAUD: 'FORM' chunk does not specify 'MAUD' as type");
		return(ST_EOF);
	}
	
	/* read chunks until 'BODY' (or end) */
	
	while (st_reads(ft, buf, 4) == ST_SUCCESS && strncmp(buf,"MDAT",4) != 0) {
		
		/*
		buf[4] = 0;
		st_report("chunk %s",buf);
		*/
		
		if (strncmp(buf,"MHDR",4) == 0) {
			
			st_readdw(ft, &chunksize);
			if (chunksize != 8*4) 
			{
			    st_fail_errno(ft,ST_EHDR,"MAUD: MHDR chunk has bad size");
			    return(ST_EOF);
			}
			
			/* fseek(ft->fp,12,SEEK_CUR); */

			/* number of samples stored in MDAT */
			st_readdw(ft, &(p->nsamples));

			/* number of bits per sample as stored in MDAT */
			st_readw(ft, &bitpersam);

			/* number of bits per sample after decompression */
			st_readw(ft, (unsigned short *)&trash32);

			st_readdw(ft, &nom);         /* clock source frequency */
			st_readw(ft, &denom);       /* clock devide           */
			if (denom == 0) 
			{
			    st_fail_errno(ft,ST_EHDR,"MAUD: frequency denominator == 0, failed");
			    return (ST_EOF);
			}
			
			ft->info.rate = nom / denom;
			
			st_readw(ft, &chaninf); /* channel information */
			switch (chaninf) {
			case 0:
				ft->info.channels = 1;
				break;
			case 1:
				ft->info.channels = 2;
				break;
			default:
				st_fail_errno(ft,ST_EFMT,"MAUD: unsupported number of channels in file");
				return (ST_EOF);
			}
			
			st_readw(ft, &chaninf); /* number of channels (mono: 1, stereo: 2, ...) */
			if (chaninf != ft->info.channels) 
			{
				st_fail_errno(ft,ST_EFMT,"MAUD: unsupported number of channels in file");
			    return(ST_EOF);
			}
			
			st_readw(ft, &chaninf); /* compression type */
			
			st_readdw(ft, &trash32); /* rest of chunk, unused yet */
			st_readdw(ft, &trash32);
			st_readdw(ft, &trash32);
			
			if (bitpersam == 8 && chaninf == 0) {
				ft->info.size = ST_SIZE_BYTE;
				ft->info.encoding = ST_ENCODING_UNSIGNED;
			}
			else if (bitpersam == 8 && chaninf == 2) {
				ft->info.size = ST_SIZE_BYTE;
				ft->info.encoding = ST_ENCODING_ALAW;
			}
			else if (bitpersam == 8 && chaninf == 3) {
				ft->info.size = ST_SIZE_BYTE;
				ft->info.encoding = ST_ENCODING_ULAW;
			}
			else if (bitpersam == 16 && chaninf == 0) {
				ft->info.size = ST_SIZE_WORD;
				ft->info.encoding = ST_ENCODING_SIGN2;
			}
			else 
			{
				st_fail_errno(ft,ST_EFMT,"MAUD: unsupported compression type detected");
				return(ST_EOF);
			}
			
			ft->comment = 0;
			
			continue;
		}
		
		if (strncmp(buf,"ANNO",4) == 0) {
			st_readdw(ft, &chunksize);
			if (chunksize & 1)
				chunksize++;
			chunk_buf = (char *) malloc(chunksize + 1);
			if (!chunk_buf)
			{
			    st_fail_errno(ft,ST_ENOMEM,"Couldn't alloc resources");
			    return(ST_EOF);
			}
			if (fread(chunk_buf,1,(int)chunksize,ft->fp) 
					!= chunksize)
			{
				st_fail_errno(ft,ST_EOF,"MAUD: Unexpected EOF in ANNO header");
				return(ST_EOF);
			}
			chunk_buf[chunksize] = '\0';
			st_report("%s",chunk_buf);
			free(chunk_buf);
			
			continue;
		}
		
		/* some other kind of chunk */
		st_readdw(ft, &chunksize);
		if (chunksize & 1)
			chunksize++;
		fseek(ft->fp,chunksize,SEEK_CUR);
		continue;
		
	}
	
	if (strncmp(buf,"MDAT",4) != 0) 
	{
	    st_fail_errno(ft,ST_EFMT,"MAUD: MDAT chunk not found");
	    return(ST_EOF);
	}
	st_readdw(ft, &(p->nsamples));
	return(ST_SUCCESS);
}

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

st_ssize_t st_maudread(ft_t ft, st_sample_t *buf, st_ssize_t len) 
{
	return (st_rawread(ft, buf, len));
}

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

int st_maudstartwrite(ft_t ft) 
{
	struct maudstuff * p = (struct maudstuff *) ft->priv;
	int rc;

	/* Needed for rawwrite() */
	rc = st_rawstartwrite(ft);
	if (rc)
	    return rc;

	/* maud is in big endian format.  Swap whats read in
	 * on little endian machines.
	 */
	if (ST_IS_LITTLEENDIAN)
	{
		ft->swap = ft->swap ? 0 : 1;
	}
	
	/* If you have to seek around the output file */
	if (! ft->seekable) 
	{
	    st_fail_errno(ft,ST_EOF,"Output .maud file must be a file, not a pipe");
	    return (ST_EOF);
	}
	
	if (ft->info.channels != 1 && ft->info.channels != 2) {
		st_fail_errno(ft,ST_EFMT,"MAUD: unsupported number of channels, unable to store");
		return(ST_EOF);
	}
	if (ft->info.size == ST_SIZE_WORD) ft->info.encoding = ST_ENCODING_SIGN2;
	if (ft->info.encoding == ST_ENCODING_ULAW || 
	    ft->info.encoding == ST_ENCODING_ALAW) ft->info.size = ST_SIZE_BYTE;
	if (ft->info.size == ST_SIZE_BYTE && 
	    ft->info.encoding == ST_ENCODING_SIGN2) 
	    ft->info.encoding = ST_ENCODING_UNSIGNED;
	
	p->nsamples = 0x7f000000L;
	maudwriteheader(ft);
	p->nsamples = 0;
	return (ST_SUCCESS);
}

st_ssize_t st_maudwrite(ft_t ft, st_sample_t *buf, st_ssize_t len) 
{
	struct maudstuff * p = (struct maudstuff *) ft->priv;
	
	p->nsamples += len;
	
	return st_rawwrite(ft, buf, len);
}

int st_maudstopwrite(ft_t ft) 
{
        int rc;

	/* Flush out remaining samples*/
	rc = st_rawstopwrite(ft);
	if (rc)
	    return rc;

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

#define MAUDHEADERSIZE (4+(4+4+32)+(4+4+32)+(4+4))
static void maudwriteheader(ft_t ft)
{
	struct maudstuff * p = (struct maudstuff *) ft->priv;
	
	st_writes(ft, "FORM");
	st_writedw(ft, (p->nsamples*ft->info.size) + MAUDHEADERSIZE);  /* size of file */
	st_writes(ft, "MAUD"); /* File type */
	
	st_writes(ft, "MHDR");
	st_writedw(ft,  8*4); /* number of bytes to follow */
	st_writedw(ft, p->nsamples);  /* number of samples stored in MDAT */
	
	switch (ft->info.encoding) {
		
	case ST_ENCODING_UNSIGNED:
		st_writew(ft, (int) 8); /* number of bits per sample as stored in MDAT */
		st_writew(ft, (int) 8); /* number of bits per sample after decompression */
		break;
		
	case ST_ENCODING_SIGN2:
		st_writew(ft, (int) 16); /* number of bits per sample as stored in MDAT */
		st_writew(ft, (int) 16); /* number of bits per sample after decompression */
		break;
		
	case ST_ENCODING_ALAW:
	case ST_ENCODING_ULAW:
		st_writew(ft, (int) 8); /* number of bits per sample as stored in MDAT */
		st_writew(ft, (int) 16); /* number of bits per sample after decompression */
		break;
		
	}
	
	st_writedw(ft, ft->info.rate); /* clock source frequency */
	st_writew(ft, (int) 1); /* clock devide */
	
	if (ft->info.channels == 1) {
		st_writew(ft, (int) 0); /* channel information */
		st_writew(ft, (int) 1); /* number of channels (mono: 1, stereo: 2, ...) */
	}
	else {
		st_writew(ft, (int) 1);
		st_writew(ft, (int) 2);
	}
	
	switch (ft->info.encoding) {
		
	case ST_ENCODING_UNSIGNED:
	case ST_ENCODING_SIGN2:
		st_writew(ft, (int) 0); /* no compression */
		break;
		
	case ST_ENCODING_ULAW:
		st_writew(ft, (int) 3);
		break;
		
	case ST_ENCODING_ALAW:
		st_writew(ft, (int) 2);
		break;
		
	}
	
	st_writedw(ft, 0); /* reserved */
	st_writedw(ft, 0); /* reserved */
	st_writedw(ft, 0); /* reserved */
	
	st_writes(ft, "ANNO");
	st_writedw(ft, 30); /* length of block */
	st_writes(ft, "file create by Sound eXchange ");
	
	st_writes(ft, "MDAT");
	st_writedw(ft, p->nsamples * ft->info.size ); /* samples in file */
}