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comparison libgsmefr/bfi_nodata.c @ 160:eefef9f6d533

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libgsmefr: randomize d1035pf params in no-data BFI case
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 15 Dec 2022 07:23:18 +0000
parents 7152cc7d1ca3
children 452c1d5a6268
comparison
equal deleted inserted replaced
159:aa4cdab30dc8 160:eefef9f6d533
1 /* 1 /*
2 * In the expected usage mode of our libgsmefr decoder as part of "soft TRAU" 2 * In the expected usage mode of our libgsmefr decoder as part of "soft TRAU"
3 * uplink implementation, there will be times when the radio subsystem tells 3 * uplink implementation, there will be times when the radio subsystem tells
4 * us that a frame has been lost, but we don't have any errored bits to feed 4 * us that a frame has been lost, but we don't have any errored bits to feed
5 * to the decoder as ETSI canon calls for. We could of course call 5 * to the decoder as ETSI canon calls for. Specifically, the canonical EFR
6 * EFR_decode_frame() with a dummy frame of all zeros and BFI=1, but the 6 * decoder will use the "fixed codebook excitation pulses" part of errored
7 * EFR_decode_bfi_nodata() function provided in this module accomplishes 7 * frames when a BFI comes in after speech, although not when BFI comes in
8 * the same effect more efficiently. 8 * after SID. Our solution in EFR_decode_bfi_nodata(): we look in the
9 * decoder state to see if we are in speech mode, and if we are, we fill
10 * the needed parameters with a PRNG.
9 */ 11 */
10 12
11 #include <string.h> 13 #include <string.h>
12 #include "gsm_efr.h" 14 #include "gsm_efr.h"
15 #include "typedef.h"
16 #include "namespace.h"
17 #include "cnst.h"
18 #include "dtx.h"
19 #include "dec_state.h"
20
21 static void random_1035(Word32 *lfsr, Word16 *param_1035)
22 {
23 Word16 *p = param_1035;
24 Word16 i;
25
26 /* 5 params of bit width 4 */
27 for (i = 0; i < 5; i++)
28 *p++ = pseudonoise(lfsr, 4);
29 /* another 5 params of bit width 3 */
30 for (i = 0; i < 5; i++)
31 *p++ = pseudonoise(lfsr, 3);
32 }
33
34 static void random_bad_frame(struct EFR_decoder_state *st, Word16 *params)
35 {
36 Word32 *lfsr = &st->L_pn_seed_nodata;
37
38 random_1035(lfsr, params + 7);
39 random_1035(lfsr, params + 20);
40 random_1035(lfsr, params + 33);
41 random_1035(lfsr, params + 46);
42 }
13 43
14 void EFR_decode_bfi_nodata(struct EFR_decoder_state *st, int taf, 44 void EFR_decode_bfi_nodata(struct EFR_decoder_state *st, int taf,
15 int16_t *pcm_out) 45 int16_t *pcm_out)
16 { 46 {
17 int16_t params[EFR_NUM_PARAMS]; 47 int16_t params[EFR_NUM_PARAMS];
18 48
19 memset(params, 0, sizeof(int16_t) * EFR_NUM_PARAMS); 49 memset(params, 0, sizeof(int16_t) * EFR_NUM_PARAMS);
50 if (st->rxdtx_ctrl & RX_SP_FLAG)
51 random_bad_frame(st, params);
20 EFR_decode_params(st, params, 1, 0, taf, pcm_out); 52 EFR_decode_params(st, params, 1, 0, taf, pcm_out);
21 } 53 }