FreeCalypso > hg > gsm-codec-lib

annotate libgsmfrp/internal.h @ 183:452c1d5a6268

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
libgsmefr BFI w/o data: emit zero output after decoder reset In real-life usage, each EFR decoder session will most likely begin with lots of BFI frames before the first real frame arrives. However, because the spec-defined home state of the decoder is speech rather than CN, our regular logic for BFI w/o data would have to feed pseudorandom noise to the decoder (in the "fixed codebook excitation pulses" part), which is silly to do at the beginning of the decoder session right out of reset. Therefore, let's check reset_flag_old, and if we are still in the reset state, simply emit zero output.
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 03 Jan 2023 00:12:18 +0000
parents 3b64f255689a
children f081a6850fb5
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
3
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 * This header file is internal to libgsmfrp;
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 * here we define our state structure.
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 */
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 enum rx_state {
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 NO_DATA = 0,
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 SPEECH,
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 SPEECH_MUTING,
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 COMFORT_NOISE,
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 LOST_SID,
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 };
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 struct gsmfr_preproc_state {
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 enum rx_state rx_state;
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 int got_valid_sid;
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 gsm_frame speech_frame;
4
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents: 3
diff changeset
18 gsm_byte sid_prefix[5];
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents: 3
diff changeset
19 uint8_t sid_xmaxc[4];
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents: 3
diff changeset
20 uint32_t cn_random_lfsr;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents: 3
diff changeset
21 unsigned cn_random_6fold;
3
3cd5ad24b1d4 libgsmfrp: implement internal state
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22 };
4
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents: 3
diff changeset
23
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents: 3
diff changeset
24 /* we use the same LFSR PRNG for CN as ETSI EFR implementation */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents: 3
diff changeset
25 #define PN_INITIAL_SEED 0x70816958L /* Pseudo noise generator seed value */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents: 3
diff changeset
26
108
3b64f255689a libgsmfrp: factor out PRNG into its own module,
Mychaela Falconia <falcon@freecalypso.org>
parents: 4
diff changeset
27 /* internal functions */
4
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents: 3
diff changeset
28 extern void gsmfr_preproc_gen_cn(struct gsmfr_preproc_state *state,
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents: 3
diff changeset
29 gsm_byte *frame);
108
3b64f255689a libgsmfrp: factor out PRNG into its own module,
Mychaela Falconia <falcon@freecalypso.org>
parents: 4
diff changeset
30 extern uint16_t gsmfr_preproc_prng(struct gsmfr_preproc_state *state,
3b64f255689a libgsmfrp: factor out PRNG into its own module,
Mychaela Falconia <falcon@freecalypso.org>
parents: 4
diff changeset
31 uint16_t no_bits);