shithub: sox

ref: 1c4b3fa8155b442d2b108e7adb0df3358c88d3f8
dir: /src/sf.c/

/*
 * 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 IRCAM SoundFile format handler.
 * 
 * Derived from: Sound Tools skeleton handler file.
 */

#include "st.h"
#include "sfircam.h"

#ifndef SIZEOF_BSD_HEADER
#define SIZEOF_BSD_HEADER 1024
#endif

#include <string.h>
#include <stdlib.h>

/* Private data for SF file */
typedef struct sfstuff {
	struct sfinfo info;
	/* needed for seek */
	LONG dataStart;
} *sf_t;

/*
 * Read the codes from the sound file, allocate space for the comment and
 * assign its pointer to the comment field in ft.
 */
static void readcodes(ft, sfhead)
ft_t ft;
SFHEADER *sfhead;
{
	char *commentbuf = NULL, *sfcharp, *newline;
	short bsize, finished = 0;
	SFCODE *sfcodep;

	sfcodep = (SFCODE *) &sfcodes(sfhead);
	do {
		sfcharp = (char *) sfcodep + sizeof(SFCODE);
		if (ft->swap) {
			sfcodep->bsize = st_swapl(sfcodep->bsize);
			sfcodep->code = st_swapl(sfcodep->code);
		}
		bsize = sfcodep->bsize - sizeof(SFCODE);
		switch(sfcodep->code) {
		case SF_END:
			finished = 1;
			break;
		case SF_COMMENT:
			if((commentbuf = (char *) malloc(bsize + 1)) != NULL) {
				memcpy(commentbuf, sfcharp, bsize);
				st_report("IRCAM comment: %s", sfcharp);
				commentbuf[bsize] = '\0';
				if((newline = strchr(commentbuf, '\n')) != NULL)
					*newline = '\0';
			}
			break;
		}
		sfcodep = (SFCODE *) (sfcharp + bsize);
	} while(!finished);
	if(commentbuf != NULL)	/* handles out of memory condition as well */
		ft->comment = commentbuf;
}

int st_sfseek(ft,offset) 
ft_t ft;
LONG offset;
{
	sf_t sf = (sf_t ) ft->priv;

	return st_seek(ft,offset*ft->info.size + sf->dataStart,SEEK_SET);

}

/*
 * 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_sfstartread(ft) 
ft_t ft;
{
	sf_t sf = (sf_t) ft->priv;
	SFHEADER sfhead;
	int rc;
	int samplesize = 0;	

	if (fread(&sfhead, 1, sizeof(sfhead), ft->fp) != sizeof(sfhead))
	{
		st_fail("unexpected EOF in SF header");
		return(ST_EOF);
	}
	memcpy(&sf->info, &sfhead.sfinfo, sizeof(struct sfinfo));
	if (ft->swap) {
		sf->info.sf_srate = st_swapf(sf->info.sf_srate);
		sf->info.sf_packmode = st_swapl(sf->info.sf_packmode);
		sf->info.sf_chans = st_swapl(sf->info.sf_chans);
	}
	if ((sfmagic1(&sfhead) != SF_MAGIC1) ||
	    (sfmagic2(&sfhead) != SF_MAGIC2))
		st_fail(
"SF %s file: can't read, it is byte-swapped or it is not an IRCAM SoundFile", 
			ft->filename);


	/*
	 * If your format specifies or your file header contains
	 * any of the following information. 
	 */
	ft->info.rate = sf->info.sf_srate;
	switch(sf->info.sf_packmode) {
		case SF_SHORT:
			ft->info.size = ST_SIZE_WORD;
			ft->info.encoding = ST_ENCODING_SIGN2;
			samplesize = ft->info.size;
			break;
		case SF_FLOAT:
			ft->info.size = ST_SIZE_FLOAT;
			ft->info.encoding = ST_ENCODING_SIGN2;
			samplesize = sizeof(float);
			break;
		default:
			st_fail("Soundfile input: unknown format 0x%x\n",
				sf->info.sf_packmode);
			return(ST_EOF);
	}
	ft->info.channels = (int) sf->info.sf_chans;

	if (ft->info.channels == -1)
	    ft->info.channels = 1;

	/* Read codes and print as comments. */
	readcodes(ft, &sfhead);

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

/* Need length for seeking */
	if(ft->seekable){
		ft->length = st_filelength(ft)/samplesize;
		sf->dataStart = ftell(ft->fp);
	} else {
		ft->length = 0;
	}
	
	return(rc);
}

int st_sfstartwrite(ft) 
ft_t ft;
{
	sf_t sf = (sf_t) ft->priv;
	SFHEADER sfhead;
	SFCODE *sfcodep;
	char *sfcharp;
	int rc;

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

	sf->info.magic_union._magic_bytes.sf_magic1 = SF_MAGIC1;
	sf->info.magic_union._magic_bytes.sf_magic2 = SF_MAGIC2;
	sf->info.magic_union._magic_bytes.sf_param = 0;

	/* This file handler can handle both big and little endian data */
	if (ST_IS_LITTLEENDIAN)
	    sf->info.magic_union._magic_bytes.sf_machine = SF_VAX;
	else
	    sf->info.magic_union._magic_bytes.sf_machine = SF_SUN;

	sf->info.sf_srate = ft->info.rate;
	if (ft->info.size == ST_SIZE_FLOAT) {
		sf->info.sf_packmode = SF_FLOAT;
	} else {
		sf->info.sf_packmode = SF_SHORT;
		/* Default to signed words */
		ft->info.size = ST_SIZE_WORD;
		ft->info.encoding = ST_ENCODING_SIGN2;
	}

	sf->info.sf_chans = ft->info.channels;

	/* Clean out structure so unused areas will remain constain  */
	/* between different coverts and not rely on memory contents */
	memset (&sfhead, 0, sizeof(SFHEADER));
	memcpy(&sfhead.sfinfo, &sf->info, sizeof(struct sfinfo));
	sfcodep = (SFCODE *) &sfcodes(&sfhead);
	sfcodep->code = SF_COMMENT;
	sfcodep->bsize = strlen(ft->comment) + sizeof(SFCODE);
	while (sfcodep->bsize % 4)
		sfcodep->bsize++;
	sfcharp = (char *) sfcodep;
	strcpy(sfcharp + sizeof(SFCODE), ft->comment);
	sfcodep = (SFCODE *) (sfcharp + sfcodep->bsize);
	sfcodep->code = SF_END;
	sfcodep->bsize = sizeof(SFCODE);
	sfcharp = (char *) sfcodep + sizeof(SFCODE);
	while(sfcharp < (char *) &sfhead + SIZEOF_BSD_HEADER)
		*sfcharp++ = '\0';
	fwrite(&sfhead, 1, sizeof(SFHEADER), ft->fp);

	return(ST_SUCCESS);
}

/* Read and write are supplied by raw.c */