comparison libgsmfr2/pp_internal.h @ 256:a33edf624061

libgsmfr2: start with API definition and port of libgsmfrp code
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 12 Apr 2024 20:49:53 +0000
parents libgsmfrp/internal.h@6ac547f0b903
children 573afa985df6
comparison
equal deleted inserted replaced
255:07f936338de1 256:a33edf624061
1 /*
2 * This header file is internal to libgsmfr2;
3 * here we define our state structure for the Rx DTX preprocessor component.
4 */
5
6 enum rx_dtx_st {
7 NO_DATA = 0,
8 SPEECH,
9 SPEECH_MUTING,
10 COMFORT_NOISE,
11 LOST_SID,
12 CN_MUTING,
13 };
14
15 struct gsmfr_preproc_state {
16 enum rx_dtx_st rx_state;
17 uint8_t speech_frame[GSMFR_RTP_FRAME_LEN];
18 uint8_t sid_prefix[5];
19 uint8_t sid_xmaxc;
20 uint32_t cn_random_lfsr;
21 unsigned cn_random_6fold;
22 };
23
24 /* we use the same LFSR PRNG for CN as ETSI EFR implementation */
25 #define PN_INITIAL_SEED 0x70816958L /* Pseudo noise generator seed value */
26
27 /* internal functions */
28 extern void gsmfr_preproc_gen_cn(struct gsmfr_preproc_state *state,
29 uint8_t *frame);
30 extern void gsmfr_preproc_sid2cn(struct gsmfr_preproc_state *state,
31 uint8_t *frame);
32 extern void gsmfr_preproc_invalid_sid(struct gsmfr_preproc_state *state,
33 uint8_t *frame);
34 extern uint16_t gsmfr_preproc_prng(struct gsmfr_preproc_state *state,
35 uint16_t no_bits);
36 extern uint8_t gsmfr_preproc_xmaxc_mean(const uint8_t *frame);