cvsd.c

linux下录音程序

		p->com.phase &= 3;
	}
	return done;
}

/* ---------------------------------------------------------------------- */

void
cvsdwrite(ft, buf, nsamp) 
ft_t ft;
LONG *buf, nsamp;
{
	struct cvsdpriv *p = (struct cvsdpriv *) ft->priv;
	int done = 0;
	float inval;

#ifdef DEBUG
	if (!dbg.f1) {
		if (!(dbg.f1 = fopen("dbg1", "w")))
			fail("debugging");
		fprintf(dbg.f1, "\"input\"\n");
	}
	if (!dbg.f2) {
		if (!(dbg.f2 = fopen("dbg2", "w")))
			fail("debugging");
		fprintf(dbg.f2, "\"recon\"\n");
	}
#endif
	for(;;) {
		/*
		 * check if the next input is due
		 */
		if (p->com.phase >= 4) {
			if (done >= nsamp)
				return;
			memmove(p->c.enc.input_filter+1, p->c.enc.input_filter,
				sizeof(p->c.enc.input_filter)-sizeof(float));
			p->c.enc.input_filter[0] = (*buf++) / 
				((float)LONG_MAX);
			done++;
		}
		p->com.phase &= 3;
		/* insert input filter here! */
		inval = float_conv(p->c.enc.input_filter, 
				   (p->cvsd_rate < 24000) ? 
				   (enc_filter_16[(p->com.phase >= 2)]) : 
				   (enc_filter_32[p->com.phase]), 
				   ENC_FILTERLEN);
		/*
		 * encode one bit
		 */
		p->com.overload = (((p->com.overload << 1) |
				    (inval >  p->c.enc.recon_int)) & 7);
		p->com.mla_int *= p->com.mla_tc0;
		if ((p->com.overload == 0) || (p->com.overload == 7))
			p->com.mla_int += p->com.mla_tc1;
		if (p->com.mla_int > p->com.v_max)
			p->com.v_max = p->com.mla_int;
		if (p->com.mla_int < p->com.v_min)
			p->com.v_min = p->com.mla_int;
		if (p->com.overload & 1) {
			p->c.enc.recon_int += p->com.mla_int;
			p->bit.shreg |= p->bit.mask;
		} else
			p->c.enc.recon_int -= p->com.mla_int;
		if ((++(p->bit.cnt)) >= 8) {
			putc(p->bit.shreg, ft->fp);
			p->bytes_written++;
			p->bit.shreg = p->bit.cnt = 0;
			p->bit.mask = p->swapbits ? 0x80 : 1;
		} else {
			if (p->swapbits)
				p->bit.mask >>= 1;
			else
				p->bit.mask <<= 1;
		}
		p->com.phase += p->com.phase_inc;
#ifdef DEBUG
		fprintf(dbg.f1, "%f %f\n", (double)dbg.cnt, (double)inval);
		fprintf(dbg.f2, "%f %f\n", (double)dbg.cnt, 
			(double)p->c.enc.recon_int);
		dbg.cnt++;
#endif	
	}
}

/* ---------------------------------------------------------------------- */
/*
 * DVMS file header
 */
struct dvms_header {
	char          Filename[14];
	unsigned      Id;
	unsigned      State;
	time_t        Unixtime;
	unsigned      Usender;
	unsigned      Ureceiver;
	ULONG	      Length;
	unsigned      Srate;
	unsigned      Days;
	unsigned      Custom1;
	unsigned      Custom2;
	char          Info[16];
	char          extend[64];
	unsigned      Crc;
};

#define DVMS_HEADER_LEN 120

/* ---------------------------------------------------------------------- */

static ULONG get32(p)
unsigned char **p;
{
	ULONG val = (((*p)[3]) << 24) | (((*p)[2]) << 16) | 
		(((*p)[1]) << 8) | (**p);
	(*p) += 4;
	return val;
}

static unsigned get16(p)
unsigned char **p;
{
	unsigned val = (((*p)[1]) << 8) | (**p);
	(*p) += 2;
	return val;
}

static void put32(p, val)
unsigned char **p;
ULONG val;
{
	*(*p)++ = val & 0xff;
	*(*p)++ = (val >> 8) & 0xff;
	*(*p)++ = (val >> 16) & 0xff;
	*(*p)++ = (val >> 24) & 0xff;
}

static void put16(p, val)
unsigned char **p;
unsigned val;
{
	*(*p)++ = val & 0xff;
	*(*p)++ = (val >> 8) & 0xff;
}

/* ---------------------------------------------------------------------- */

static void dvms_read_header(f, hdr)
FILE *f;
struct dvms_header *hdr;
{
	unsigned char hdrbuf[DVMS_HEADER_LEN];
	unsigned char *pch = hdrbuf;
	int i;
	unsigned sum;

	if (fread(hdrbuf, sizeof(hdrbuf), 1, f) != 1)
		fail("unable to read DVMS header\n");
	for(i = sizeof(hdrbuf), sum = 0; i > /*2*/3; i--) /* Deti bug */
		sum += *pch++;
	pch = hdrbuf;
	memcpy(hdr->Filename, pch, sizeof(hdr->Filename));
	pch += sizeof(hdr->Filename);
	hdr->Id = get16(&pch);
	hdr->State = get16(&pch);
	hdr->Unixtime = get32(&pch);
	hdr->Usender = get16(&pch);
	hdr->Ureceiver = get16(&pch);
	hdr->Length = get32(&pch);
	hdr->Srate = get16(&pch);
	hdr->Days = get16(&pch);
	hdr->Custom1 = get16(&pch);
	hdr->Custom2 = get16(&pch);
	memcpy(hdr->Info, pch, sizeof(hdr->Info));
	pch += sizeof(hdr->Info);
	memcpy(hdr->extend, pch, sizeof(hdr->extend));
	pch += sizeof(hdr->extend);
	hdr->Crc = get16(&pch);
	if (sum != hdr->Crc) 
		fail("DVMS header checksum error, read %u, calculated %u\n",
		     hdr->Crc, sum);
}

/* ---------------------------------------------------------------------- */

/*
 * note! file must be seekable
 */
static void dvms_write_header(f, hdr)
FILE *f;
struct dvms_header *hdr;
{
	unsigned char hdrbuf[DVMS_HEADER_LEN];
	unsigned char *pch = hdrbuf;
	unsigned char *pchs = hdrbuf;
	int i;
	unsigned sum;

	memcpy(pch, hdr->Filename, sizeof(hdr->Filename));
	pch += sizeof(hdr->Filename);
	put16(&pch, hdr->Id);
	put16(&pch, hdr->State);
	put32(&pch, hdr->Unixtime);
	put16(&pch, hdr->Usender);
	put16(&pch, hdr->Ureceiver);
	put32(&pch, hdr->Length);
	put16(&pch, hdr->Srate);
	put16(&pch, hdr->Days);
	put16(&pch, hdr->Custom1);
	put16(&pch, hdr->Custom2);
	memcpy(pch, hdr->Info, sizeof(hdr->Info));
	pch += sizeof(hdr->Info);
	memcpy(pch, hdr->extend, sizeof(hdr->extend));
	pch += sizeof(hdr->extend);
	for(i = sizeof(hdrbuf), sum = 0; i > /*2*/3; i--) /* Deti bug */
		sum += *pchs++;
	hdr->Crc = sum;
	put16(&pch, hdr->Crc);
	if (fseek(f, 0, SEEK_SET) < 0)
		fail("cannot write DVMS header, seek failed\n");
	if (fwrite(hdrbuf, sizeof(hdrbuf), 1, f) != 1)
		fail("cannot write DVMS header\n");
}

/* ---------------------------------------------------------------------- */

static void make_dvms_hdr(ft, hdr)
ft_t ft;
struct dvms_header *hdr;
{
	struct cvsdpriv *p = (struct cvsdpriv *) ft->priv;
	int len;

	memset(hdr->Filename, 0, sizeof(hdr->Filename));
	len = strlen(ft->filename);
	if (len >= sizeof(hdr->Filename))
		len = sizeof(hdr->Filename)-1;
	memcpy(hdr->Filename, ft->filename, len);
	hdr->Id = hdr->State = 0;
	hdr->Unixtime = time(NULL);
	hdr->Usender = hdr->Ureceiver = 0;
	hdr->Length = p->bytes_written;
	hdr->Srate = p->cvsd_rate/100;
	hdr->Days = hdr->Custom1 = hdr->Custom2 = 0;
	memset(hdr->Info, 0, sizeof(hdr->Info));
	len = strlen(ft->comment);
	if (len >= sizeof(hdr->Info))
		len = sizeof(hdr->Info)-1;
	memcpy(hdr->Info, ft->comment, len);
	memset(hdr->extend, 0, sizeof(hdr->extend));
}

/* ---------------------------------------------------------------------- */

void dvmsstartread(ft) 
ft_t ft;
{
	struct cvsdpriv *p = (struct cvsdpriv *) ft->priv;
	struct dvms_header hdr;

	dvms_read_header(ft->fp, &hdr);
	report("DVMS header of source file \"%s\":");
	report("  filename  \"%.14s\"",ft->filename);
        report("  id        0x%x", hdr.Filename);
	report("  state     0x%x", hdr.Id, hdr.State);
	report("  time      %s",ctime(&hdr.Unixtime)); /* ctime generates lf */
	report("  usender   %u", hdr.Usender);
	report("  ureceiver %u", hdr.Ureceiver);
	report("  length    %u", hdr.Length);
	report("  srate     %u", hdr.Srate);
	report("  days      %u", hdr.Days);
	report("  custom1   %u", hdr.Custom1);
	report("  custom2   %u", hdr.Custom2);
	report("  info      \"%.16s\"\n", hdr.Info);
	ft->info.rate = (hdr.Srate < 240) ? 16000 : 32000;
	report("DVMS rate %dbit/s using %dbit/s deviation %d%%\n", 
	       hdr.Srate*100, ft->info.rate, 
	       ((ft->info.rate - hdr.Srate*100) * 100) / ft->info.rate);
	cvsdstartread(ft);
	p->swapbits = 0;
}

/* ---------------------------------------------------------------------- */

void dvmsstartwrite(ft) 
ft_t ft;
{
	struct cvsdpriv *p = (struct cvsdpriv *) ft->priv;
	struct dvms_header hdr;
	
	cvsdstartwrite(ft);
	make_dvms_hdr(ft, &hdr);
	dvms_write_header(ft->fp, &hdr);
	if (!ft->seekable)
	       warn("Length in output .DVMS header will wrong since can't seek to fix it");
	p->swapbits = 0;
}

/* ---------------------------------------------------------------------- */

void
dvmsstopwrite(ft)
ft_t ft;
{
	struct dvms_header hdr;
	
	cvsdstopwrite(ft);
	if (!ft->seekable)
		return;
	if (fseek(ft->fp, 0L, 0) != 0)
		fail("Can't rewind output file to rewrite DVMS header.");
	make_dvms_hdr(ft, &hdr);
	dvms_write_header(ft->fp, &hdr);
}

/* ---------------------------------------------------------------------- */