flightgear/3rdparty/iaxclient-2/lib/codec_ilbc.c
2022-11-12 21:36:02 +08:00

116 lines
2.4 KiB
C

/*
* iaxclient: a cross-platform IAX softphone library
*
* Copyrights:
* Copyright (C) 2003-2006, Horizon Wimba, Inc.
* Copyright (C) 2007, Wimba, Inc.
*
* Contributors:
* Steve Kann <stevek@stevek.com>
*
* This program is free software, distributed under the terms of
* the GNU Lesser (Library) General Public License.
*/
#include "codec_ilbc.h"
#include "iaxclient_lib.h"
#include "iLBC/iLBC_encode.h"
#include "iLBC/iLBC_decode.h"
static void destroy ( struct iaxc_audio_codec *c) {
free(c->encstate);
free(c->decstate);
free(c);
}
static int decode ( struct iaxc_audio_codec *c,
int *inlen, char *in, int *outlen, short *out ) {
float fbuf[240];
int i;
if(*inlen == 0) {
//fprintf(stderr, "ILBC Interpolate\n");
iLBC_decode(fbuf, NULL, c->decstate, 0);
for(i=0;i<240;i++)
out[i] = fbuf[i];
*outlen -= 240;
return 0;
}
/* need to decode minimum of 33 bytes to 160 byte output */
if( (*inlen < 50) || (*outlen < 240) ) {
fprintf(stderr, "codec_ilbc: inlen = %d outlen= %d\n",*inlen,*outlen);
return -1;
}
while( (*inlen >= 50) && (*outlen >= 240) ) {
iLBC_decode(fbuf, in, c->decstate, 1);
for(i=0;i<240;i++)
out[i] = fbuf[i];
out += 240;
*outlen -= 240;
in += 50;
*inlen -= 50;
}
return 0;
}
static int encode ( struct iaxc_audio_codec *c,
int *inlen, short *in, int *outlen, char *out ) {
float fbuf[240];
int i;
while( (*inlen >= 240) && (*outlen >= 50) ) {
for(i=0;i<240;i++)
fbuf[i] = in[i];
iLBC_encode(out,fbuf, c->encstate);
out += 50;
*outlen -= 50;
in += 240;
*inlen -= 240;
}
return 0;
}
struct iaxc_audio_codec *codec_audio_ilbc_new() {
struct iaxc_audio_codec *c = calloc(sizeof(struct iaxc_audio_codec),1);
if(!c) return c;
strcpy(c->name,"iLBC");
c->format = IAXC_FORMAT_ILBC;
c->encode = encode;
c->decode = decode;
c->destroy = destroy;
c->minimum_frame_size = 240;
c->encstate = calloc(sizeof(iLBC_Enc_Inst_t),1);
c->decstate = calloc(sizeof(iLBC_Dec_Inst_t),1);
/* leaks a bit on no-memory */
if(!(c->encstate && c->decstate))
return NULL;
/* the 30 parameters are used for the latest iLBC sources, in
* http://www.ietf.org/internet-drafts/draft-ietf-avt-ilbc-codec-05.txt
* as used in asterisk-CVS as of 14 Oct 2004 */
initEncode(c->encstate, 30);
initDecode(c->decstate, 30, 1); /* use enhancer */
return c;
}