comparison libgsmefr/dec_rtp_in.c @ 542:f2d0f2f15d5f

libgsmefr: add wrapper for TW-TS-001 RTP input
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 28 Sep 2024 06:38:08 +0000
parents libgsmfr2/full_dec_wrap.c@f681fb758041
children
comparison
equal deleted inserted replaced
541:23656d874524 542:f2d0f2f15d5f
1 /*
2 * This module implements a wrapper around the main processing functions
3 * of our full decoder, handling RTP input per TW-TS-001.
4 */
5
6 #include <stdint.h>
7 #include "gsm_efr.h"
8
9 int EFR_decode_rtp(struct EFR_decoder_state *st, const uint8_t *rtp_pl,
10 unsigned rtp_pl_len, int16_t *pcm)
11 {
12 switch (rtp_pl_len) {
13 case 0:
14 /* BFI-no-data, but not an invalid RTP input per se */
15 EFR_decode_bfi_nodata(st, 0, pcm);
16 return 0;
17 case 1:
18 if ((rtp_pl[0] & 0xF6) != 0xE6)
19 goto bad_rtp_input;
20 /* TW-TS-001 No_Data frame */
21 EFR_decode_bfi_nodata(st, rtp_pl[0] & 1, pcm);
22 return 0;
23 case EFR_RTP_FRAME_LEN:
24 if ((rtp_pl[0] & 0xF0) != 0xC0)
25 goto bad_rtp_input;
26 /* basic RTP format */
27 EFR_decode_frame(st, rtp_pl, 0, 0, pcm);
28 return 0;
29 case EFR_RTP_FRAME_LEN+1:
30 if ((rtp_pl[0] & 0xF4) != 0xE0)
31 goto bad_rtp_input;
32 if ((rtp_pl[1] & 0xF0) != 0xC0)
33 goto bad_rtp_input;
34 /* extended RTP format (TW-TS-001) */
35 EFR_decode_frame(st, rtp_pl + 1, (rtp_pl[0] & 2) >> 1,
36 rtp_pl[0] & 1, pcm);
37 return 0;
38 default:
39 bad_rtp_input:
40 /*
41 * Treat it like BFI-no-data, and tell the caller
42 * that we received an invalid RTP payload.
43 */
44 EFR_decode_bfi_nodata(st, 0, pcm);
45 return -1;
46 }
47 }