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/* $OpenBSD: headers.c,v 1.13 2010/04/06 20:07:01 ratchov Exp $ */
/*
* Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/param.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "aparams.h"
#include "conf.h"
#include "wav.h"
/*
* Encoding IDs used in .wav headers.
*/
#define WAV_ENC_PCM 1
#define WAV_ENC_ALAW 6
#define WAV_ENC_ULAW 7
struct wavriff {
char magic[4];
uint32_t size;
char type[4];
} __packed;
struct wavchunk {
char id[4];
uint32_t size;
} __packed;
struct wavfmt {
uint16_t fmt;
uint16_t nch;
uint32_t rate;
uint32_t byterate;
uint16_t blkalign;
uint16_t bits;
} __packed;
char wav_id_riff[4] = { 'R', 'I', 'F', 'F' };
char wav_id_wave[4] = { 'W', 'A', 'V', 'E' };
char wav_id_data[4] = { 'd', 'a', 't', 'a' };
char wav_id_fmt[4] = { 'f', 'm', 't', ' ' };
int
wav_readfmt(int fd, unsigned csize, struct aparams *par, short **map)
{
struct wavfmt fmt;
unsigned nch, cmax, rate, bits, enc;
if (csize < sizeof(fmt)) {
warnx("bogus format chunk");
return 0;
}
if (read(fd, &fmt, sizeof(fmt)) != sizeof(fmt)) {
warn("riff_read: chunk");
return 0;
}
enc = letoh16(fmt.fmt);
switch (enc) {
case WAV_ENC_PCM:
*map = NULL;
break;
case WAV_ENC_ALAW:
*map = wav_alawmap;
break;
case WAV_ENC_ULAW:
*map = wav_ulawmap;
break;
default:
errx(1, "%u: unsupported encoding in .wav file", enc);
}
nch = letoh16(fmt.nch);
if (nch == 0) {
warnx("zero number of channels");
return 0;
}
cmax = par->cmin + nch - 1;
if (cmax >= NCHAN_MAX) {
warnx("%u:%u: bad range", par->cmin, cmax);
return 0;
}
rate = letoh32(fmt.rate);
if (rate < RATE_MIN || rate > RATE_MAX) {
warnx("%u: bad sample rate", rate);
return 0;
}
bits = letoh16(fmt.bits);
if (bits == 0 || bits > 32) {
warnx("%u: bad number of bits", bits);
return 0;
}
if (enc == WAV_ENC_PCM) {
par->bps = (bits + 7) / 8;
par->bits = bits;
par->le = 1;
par->sig = (bits <= 8) ? 0 : 1; /* ask microsoft why... */
} else {
if (bits != 8) {
warnx("%u: mulaw/alaw encoding not 8-bit", bits);
return 0;
}
par->bits = 8 * sizeof(short);
par->bps = sizeof(short);
par->le = NATIVE_LE;
par->sig = 1;
}
par->msb = 1;
par->cmax = cmax;
par->rate = rate;
return 1;
}
int
wav_readhdr(int fd, struct aparams *par, off_t *startpos, off_t *datasz, short **map)
{
struct wavriff riff;
struct wavchunk chunk;
unsigned csize, rsize, pos = 0;
int fmt_done = 0;
if (lseek(fd, 0, SEEK_SET) < 0) {
warn("lseek: 0");
return 0;
}
if (read(fd, &riff, sizeof(riff)) != sizeof(riff)) {
warn("wav_readhdr: header");
return 0;
}
if (memcmp(&riff.magic, &wav_id_riff, 4) != 0 ||
memcmp(&riff.type, &wav_id_wave, 4)) {
warnx("not a wave file");
return 0;
}
rsize = letoh32(riff.size);
while (pos + sizeof(struct wavchunk) <= rsize) {
if (read(fd, &chunk, sizeof(chunk)) != sizeof(chunk)) {
warn("wav_readhdr: chunk");
return 0;
}
csize = letoh32(chunk.size);
if (memcmp(chunk.id, wav_id_fmt, 4) == 0) {
if (!wav_readfmt(fd, csize, par, map))
return 0;
fmt_done = 1;
} else if (memcmp(chunk.id, wav_id_data, 4) == 0) {
*startpos = pos;
*datasz = csize;
break;
} else {
#ifdef DEBUG
if (debug_level >= 1)
warnx("ignoring chuck <%.4s>\n", chunk.id);
#endif
}
/*
* next chunk
*/
pos += sizeof(struct wavchunk) + csize;
if (lseek(fd, sizeof(riff) + pos, SEEK_SET) < 0) {
warn("lseek");
return 0;
}
}
if (!fmt_done) {
warnx("missing format chunk");
return 0;
}
return 1;
}
/*
* Write header and seek to start position
*/
int
wav_writehdr(int fd, struct aparams *par, off_t *startpos, off_t datasz)
{
unsigned nch = par->cmax - par->cmin + 1;
struct {
struct wavriff riff;
struct wavchunk fmt_hdr;
struct wavfmt fmt;
struct wavchunk data_hdr;
} hdr;
/*
* Check that encoding is supported by .wav file format.
*/
if (par->bits > 8 && !par->le) {
warnx("samples must be little endian");
return 0;
}
if (8 * par->bps - par->bits >= 8) {
warnx("padding must be less than 8 bits");
return 0;
}
if ((par->bits <= 8 && par->sig) || (par->bits > 8 && !par->sig)) {
warnx("samples with more (less) than 8 bits must be signed "
"(unsigned)");
return 0;
}
if (8 * par->bps != par->bits && !par->msb) {
warnx("samples must be MSB justified");
return 0;
}
memcpy(hdr.riff.magic, wav_id_riff, 4);
memcpy(hdr.riff.type, wav_id_wave, 4);
hdr.riff.size = htole32(datasz + sizeof(hdr) - sizeof(hdr.riff));
memcpy(hdr.fmt_hdr.id, wav_id_fmt, 4);
hdr.fmt_hdr.size = htole32(sizeof(hdr.fmt));
hdr.fmt.fmt = htole16(1);
hdr.fmt.nch = htole16(nch);
hdr.fmt.rate = htole32(par->rate);
hdr.fmt.byterate = htole32(par->rate * par->bps * nch);
hdr.fmt.bits = htole16(par->bits);
hdr.fmt.blkalign = 0;
memcpy(hdr.data_hdr.id, wav_id_data, 4);
hdr.data_hdr.size = htole32(datasz);
if (lseek(fd, 0, SEEK_SET) < 0) {
warn("wav_writehdr: lseek");
return 0;
}
if (write(fd, &hdr, sizeof(hdr)) != sizeof(hdr)) {
warn("wav_writehdr: write");
return 0;
}
*startpos = sizeof(hdr);
return 1;
}
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