view libgsmfr2/pp_good.c @ 301:019eed8b1948

doc/FR1-library-history: new article
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 15 Apr 2024 18:36:21 +0000
parents 573afa985df6
children 96c4ed5529bf
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/*
 * In this module we implement preprocessing of received good frames.
 */

#include <stdint.h>
#include <string.h>
#include "tw_gsmfr.h"
#include "pp_state.h"
#include "pp_internal.h"

void gsmfr_preproc_good_frame(struct gsmfr_preproc_state *st, uint8_t *frame)
{
	int sid;

	/* always set correct magic */
	frame[0] = 0xD0 | frame[0] & 0x0F;
	/* now classify by SID */
	sid = gsmfr_preproc_sid_classify(frame);
	switch (sid) {
	case 0:		/* good speech frame */
		st->rx_state = SPEECH;
		memcpy(&st->speech_frame, frame, GSMFR_RTP_FRAME_LEN);
		return;
	case 1:		/* invalid SID frame */
		/* state-dependent handling, similar to BFI */
		gsmfr_preproc_invalid_sid(st, frame);
		return;
	case 2:		/* valid SID frame */
		st->rx_state = COMFORT_NOISE;
		gsmfr_preproc_sid2cn(st, frame);
		return;
	}
}