ref: 7e6e33818acc4623d440ed1d6371760cf84d6ad3
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.
*/
/*
* libSoX IRCAM SoundFile format handler.
*
* Derived from: libSoX skeleton handler file.
*/
#include "sox_i.h"
#include "sfircam.h"
#include <string.h>
#include <stdlib.h>
/* Private data for SF file */
typedef struct sfstuff {
struct sfinfo info;
/* needed for seek */
sox_size_t 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(sox_format_t * ft, SFHEADER *sfhead)
{
char *commentbuf = NULL, *sfcharp;
sox_size_t bsize;
sox_bool finished = sox_false;
SFCODE *sfcodep;
sfcodep = (SFCODE *) (&sfhead->sfinfo + 1);
do {
sfcharp = (char *) sfcodep + sizeof(SFCODE);
if (ft->encoding.reverse_bytes) {
sfcodep->bsize = sox_swapdw(sfcodep->bsize);
sfcodep->code = sox_swapdw(sfcodep->code);
}
bsize = sfcodep->bsize - sizeof(SFCODE);
switch(sfcodep->code) {
case SF_END:
finished = sox_true;
break;
case SF_COMMENT:
commentbuf = (char *) xmalloc(bsize + 1);
memcpy(commentbuf, sfcharp, bsize);
commentbuf[bsize] = '\0';
break;
}
sfcodep = (SFCODE *) (sfcharp + bsize);
} while(!finished);
append_comments(&ft->comments, commentbuf);
free(commentbuf);
}
static int seek(sox_format_t * ft, sox_size_t offset)
{
sox_size_t new_offset, channel_block, alignment;
sf_t sf = (sf_t ) ft->priv;
new_offset = offset * (ft->encoding.bits_per_sample >> 3);
/* Make sure request aligns to a channel block (ie left+right) */
channel_block = ft->signal.channels * (ft->encoding.bits_per_sample >> 3);
alignment = new_offset % channel_block;
/* Most common mistaken is to compute something like
* "skip everthing upto and including this sample" so
* advance to next sample block in this case.
*/
if (alignment != 0)
new_offset += (channel_block - alignment);
new_offset += sf->dataStart;
return sox_seeki(ft, (sox_ssize_t)new_offset, 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.
*/
static int startread(sox_format_t * ft)
{
sf_t sf = (sf_t) ft->priv;
SFHEADER sfhead;
int rc;
int samplesize = 0;
if (sox_readbuf(ft, &sfhead, sizeof(sfhead)) != sizeof(sfhead))
{
sox_fail("unexpected EOF in SF header");
return(SOX_EOF);
}
memcpy(&sf->info, &sfhead.sfinfo, sizeof(struct sfinfo));
if (ft->encoding.reverse_bytes) {
sox_swapf(&sf->info.sf_srate);
sf->info.sf_packmode = sox_swapdw(sf->info.sf_packmode);
sf->info.sf_chans = sox_swapdw(sf->info.sf_chans);
}
if ((sfmagic1(&sfhead) != SF_MAGIC1) ||
(sfmagic2(&sfhead) != SF_MAGIC2)) {
sox_fail_errno(ft, SOX_EHDR, "sf: can't find IRCAM identifier");
return SOX_EOF;
}
/*
* If your format specifies or your file header contains
* any of the following information.
*/
ft->signal.rate = sf->info.sf_srate;
switch(sf->info.sf_packmode) {
case SF_SHORT:
ft->encoding.bits_per_sample = 16;
ft->encoding.encoding = SOX_ENCODING_SIGN2;
samplesize = 2;
break;
case SF_FLOAT:
ft->encoding.bits_per_sample = 16;
ft->encoding.encoding = SOX_ENCODING_FLOAT;
samplesize = sizeof(float);
break;
default:
sox_fail("Soundfile input: unknown format 0x%x",
sf->info.sf_packmode);
return(SOX_EOF);
}
ft->signal.channels = (int) sf->info.sf_chans;
if (ft->signal.channels == 0)
ft->signal.channels = 1;
/* Read codes and print as comments. */
readcodes(ft, &sfhead);
/* Needed for rawread() */
rc = sox_rawstartread(ft);
/* Need length for seeking */
if(ft->seekable){
ft->length = sox_filelength(ft)/samplesize;
sf->dataStart = sox_tell(ft);
} else {
ft->length = 0;
}
return(rc);
}
static int startwrite(sox_format_t * ft)
{
sf_t sf = (sf_t) ft->priv;
SFHEADER sfhead;
SFCODE *sfcodep;
char *sfcharp;
int rc;
char * comment = cat_comments(ft->comments);
/* Needed for rawwrite() */
rc = sox_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 (SOX_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->signal.rate;
if (ft->encoding.bits_per_sample == 32 &&
ft->encoding.encoding == SOX_ENCODING_FLOAT) {
sf->info.sf_packmode = SF_FLOAT;
} else {
sf->info.sf_packmode = SF_SHORT;
/* Default to signed words */
ft->encoding.bits_per_sample = 16;
ft->encoding.encoding = SOX_ENCODING_SIGN2;
}
sf->info.sf_chans = ft->signal.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 *) (&sfhead.filler[SF_INFO_LEN+1]);
sfcodep->code = SF_COMMENT;
sfcodep->bsize = strlen(comment) + sizeof(SFCODE);
while (sfcodep->bsize % 4)
sfcodep->bsize++;
sfcharp = (char *) sfcodep;
strcpy(sfcharp + sizeof(SFCODE), comment);
free(comment);
sfcodep = (SFCODE *) (sfcharp + sfcodep->bsize);
sfcodep->code = SF_END;
sfcodep->bsize = sizeof(SFCODE);
sfcharp = (char *) sfcodep + sizeof(SFCODE);
sox_writebuf(ft, &sfhead, sizeof(SFHEADER));
return(SOX_SUCCESS);
}
SOX_FORMAT_HANDLER(sf)
{
static char const * const names[] = {"sf", "ircam", NULL};
static unsigned const encodings[] = {
SOX_ENCODING_SIGN2, 16, 0,
SOX_ENCODING_FLOAT, 32, 0,
0};
static sox_format_handler_t const handler = {
SOX_LIB_VERSION_CODE,
"Institut de Recherche et Coordination Acoustique/Musique Sound Description Interchange Format",
names, 0,
startread, sox_rawread, sox_rawstopread,
startwrite, sox_rawwrite, sox_rawstopwrite,
seek, encodings, NULL
};
return &handler;
}