shithub: sox

ref: 32736bb3b3a40125b6985844dc1efe280f02dd45
dir: /src/wve.c/

/*
 * Psion wve format, based on the au format file. Hacked by
 * Richard Caley (R.Caley@ed.ac.uk)
 */

#include "st.h"
#include "g72x.h"
#include "string.h"

/* Magic numbers used in Psion audio files */
#define PSION_MAGIC     "ALawSoundFile**"
#define PSION_VERSION   ((short)3856)
#define PSION_INV_VERSION   ((short)4111)
#define PSION_HDRSIZE	32

typedef struct wvepriv
    {
    ULONG length;
    short padding;
    short repeats;
/* For seeking */
	LONG dataStart;
    } *wve_t;

static void wvewriteheader(ft_t ft);

int st_wveseek(ft,offset) 
ft_t ft;
LONG offset;
{
	wve_t wve = (wve_t ) ft->priv;

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

int st_wvestartread(ft) 
ft_t ft;
{
	wve_t p = (wve_t ) ft->priv;
	char magic[16];
	short version;
	int rc;

	ULONG trash;

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

	/* WVE is in big endian format.  Swap whats read in
	 * on little endian machines.
	 */
	if (ST_IS_LITTLEENDIAN)
	{
		ft->swap = ft->swap ? 0 : 1;
	}

	/* Check the magic word (null-terminated) */
        st_reads(ft, magic, 16);
	if (strncmp(magic, PSION_MAGIC, 15)==0) {
		st_report("Found Psion magic word");
	}
	else
	{
		st_fail_errno(ft,ST_EHDR,"Psion header doesn't start with magic word\nTry the '.al' file type with '-t al -r 8000 filename'");
		return (ST_EOF);
	}

        st_readw(ft, &version);

	/* Check for what type endian machine its read on */
	if (version == PSION_INV_VERSION)
	{
		/* This is probably left over from a time before
		 * testing for endianess was standardized.  Leaving since
		 * it doesn't hurt.
		 */
		ft->swap = ft->swap ? 0 : 1;
		st_report("Found inverted PSION magic word.  Swapping bytes.");
	}
	else if (version == PSION_VERSION)
	{
	    st_report("Found PSION magic word");
	}
	else
	{
	    st_fail_errno(ft,ST_EHDR,"Wrong version in Psion header");
	    return(ST_EOF);
	}

     	st_readdw(ft, &(p->length));

	st_readw(ft, &(p->padding));

	st_readw(ft, &(p->repeats));

 	(void)st_readw(ft, (unsigned short *)&trash);
  	(void)st_readw(ft, (unsigned short *)&trash);
	(void)st_readw(ft, (unsigned short *)&trash);
    
	ft->info.encoding = ST_ENCODING_ALAW;
	ft->info.size = ST_SIZE_BYTE;

	ft->info.rate = 8000;

	ft->info.channels = 1;

	p->dataStart = ftell(ft->fp);
	ft->length = p->length/ft->info.size;

	return (ST_SUCCESS);
}

/* When writing, the header is supposed to contain the number of
   data bytes written, unless it is written to a pipe.
   Since we don't know how many bytes will follow until we're done,
   we first write the header with an unspecified number of bytes,
   and at the end we rewind the file and write the header again
   with the right size.  This only works if the file is seekable;
   if it is not, the unspecified size remains in the header
   (this is illegal). */

int st_wvestartwrite(ft) 
ft_t ft;
{
	wve_t p = (wve_t ) ft->priv;
	int rc;

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

	/* wve is in big endian format.  Swap whats read in
	 * on little endian machines.
	 */
	if (ST_IS_LITTLEENDIAN)
	{
		ft->swap = ft->swap ? 0 : 1;
	}

	p->length = 0;
	if (p->repeats == 0)
	    p->repeats = 1;

	ft->info.encoding = ST_ENCODING_ALAW;
	ft->info.size = ST_SIZE_BYTE;
	ft->info.rate = 8000;

	wvewriteheader(ft);
	return ST_SUCCESS;
}

LONG st_wveread(ft, buf, samp)
ft_t ft;
LONG *buf, samp;
{
	return st_rawread(ft, buf, samp);
}

LONG st_wvewrite(ft, buf, samp)
ft_t ft;
LONG *buf, samp;
{
	wve_t p = (wve_t ) ft->priv;
	p->length += samp * ft->info.size;
	return st_rawwrite(ft, buf, samp);
}

int st_wvestopwrite(ft)
ft_t ft;
{
	if (!ft->seekable)
	{
	    st_warn("Header will be have invalid file length since file is not seekable");
	    return ST_SUCCESS;
	}

	if (fseek(ft->fp, 0L, 0) != 0)
	{
		st_fail_errno(ft,errno,"Can't rewind output file to rewrite Psion header.");
		return(ST_EOF);
	}
	wvewriteheader(ft);

	/* Needed for rawwrite() */
	return st_rawstopwrite(ft);
}

static void wvewriteheader(ft)
ft_t ft;
{

    char magic[16];
    short version;
    short zero;
    wve_t p = (wve_t ) ft->priv;

    strcpy(magic,PSION_MAGIC);
    version=PSION_VERSION;
    zero=0;

    st_writes(ft, magic);
    /* Null terminate string */
    st_writeb(ft, 0);

    st_writew(ft, version);
    st_writedw(ft, p->length);
    st_writew(ft, p->padding);
    st_writew(ft, p->repeats);

    st_writew(ft, zero);
    st_writew(ft, zero);
    st_writew(ft, zero);
}