128 lines
2.9 KiB
C
128 lines
2.9 KiB
C
/*
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* iaxclient: a cross-platform IAX softphone library
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*
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* Copyrights:
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* Copyright (C) 2003-2006, Horizon Wimba, Inc.
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* Copyright (C) 2007, Wimba, Inc.
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*
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* Contributors:
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* Steve Kann <stevek@stevek.com>
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*
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* This program is free software, distributed under the terms of
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* the GNU Lesser (Library) General Public License.
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*/
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#include "codec_gsm.h"
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#include "iaxclient_lib.h"
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#include "gsm.h"
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struct state {
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gsm gsmstate;
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plc_state_t plc;
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};
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static void destroy ( struct iaxc_audio_codec *c) {
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struct state * encstate = (struct state *) c->encstate;
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struct state * decstate = (struct state *) c->decstate;
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gsm_destroy(encstate->gsmstate);
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gsm_destroy(decstate->gsmstate);
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free(c->encstate);
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free(c->decstate);
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free(c);
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}
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static int decode ( struct iaxc_audio_codec *c,
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int *inlen, unsigned char *in, int *outlen, short *out ) {
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struct state * decstate = (struct state *) c->decstate;
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/* use generic interpolation */
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if(*inlen == 0) {
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int interp_len = 160;
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if(*outlen < interp_len) interp_len = *outlen;
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plc_fillin(&decstate->plc,out,interp_len);
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*outlen -= interp_len;
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return 0;
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}
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/* need to decode minimum of 33 bytes to 160 byte output */
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while( (*inlen >= 33) && (*outlen >= 160) ) {
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if(gsm_decode(decstate->gsmstate, in, out))
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{
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fprintf(stderr, "codec_gsm: gsm_decode returned error\n");
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return -1;
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}
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/* push decoded data to interpolation buffer */
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plc_rx(&decstate->plc,out,160);
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/* we used 33 bytes of input, and 160 bytes of output */
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*inlen -= 33;
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in += 33;
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*outlen -= 160;
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out += 160;
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}
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return 0;
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}
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static int encode ( struct iaxc_audio_codec *c,
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int *inlen, short *in, int *outlen, unsigned char *out ) {
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struct state * encstate = (struct state *) c->encstate;
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/* need to encode minimum of 160 bytes to 33 byte output */
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while( (*inlen >= 160) && (*outlen >= 33) ) {
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gsm_encode(encstate->gsmstate, in, out);
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/* we used 160 bytes of input, and 33 bytes of output */
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*inlen -= 160;
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in += 160;
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*outlen -= 33;
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out += 33;
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}
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return 0;
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}
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struct iaxc_audio_codec *codec_audio_gsm_new() {
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struct state * encstate;
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struct state * decstate;
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struct iaxc_audio_codec *c = (struct iaxc_audio_codec *)calloc(sizeof(struct iaxc_audio_codec),1);
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if(!c) return c;
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strcpy(c->name,"gsm 06.10");
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c->format = IAXC_FORMAT_GSM;
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c->encode = encode;
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c->decode = decode;
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c->destroy = destroy;
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c->minimum_frame_size = 160;
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c->encstate = calloc(sizeof(struct state),1);
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c->decstate = calloc(sizeof(struct state),1);
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/* leaks a bit on no-memory */
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if(!(c->encstate && c->decstate))
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return NULL;
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encstate = (struct state *) c->encstate;
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decstate = (struct state *) c->decstate;
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encstate->gsmstate = gsm_create();
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decstate->gsmstate = gsm_create();
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if(!(encstate->gsmstate && decstate->gsmstate))
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return NULL;
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return c;
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}
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