FreeCalypso > hg > gsm-codec-lib
annotate libgsmefr/syn_filt.c @ 183:452c1d5a6268
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 | bb71c5414e71 |
children |
rev | line source |
---|---|
53
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
1 /************************************************************************* |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
2 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
3 * FUNCTION: Syn_filt: |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
4 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
5 * PURPOSE: Perform synthesis filtering through 1/A(z). |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
6 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
7 *************************************************************************/ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
8 |
92
bb71c5414e71
libgsmefr: syn_filt.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents:
53
diff
changeset
|
9 #include "gsm_efr.h" |
53
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
10 #include "typedef.h" |
92
bb71c5414e71
libgsmefr: syn_filt.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents:
53
diff
changeset
|
11 #include "namespace.h" |
53
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
12 #include "basic_op.h" |
92
bb71c5414e71
libgsmefr: syn_filt.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents:
53
diff
changeset
|
13 #include "no_count.h" |
bb71c5414e71
libgsmefr: syn_filt.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents:
53
diff
changeset
|
14 #include "sig_proc.h" |
53
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
15 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
16 /* m = LPC order == 10 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
17 #define m 10 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
18 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
19 void Syn_filt ( |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
20 Word16 a[], /* (i) : a[m+1] prediction coefficients (m=10) */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
21 Word16 x[], /* (i) : input signal */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
22 Word16 y[], /* (o) : output signal */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
23 Word16 lg, /* (i) : size of filtering */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
24 Word16 mem[], /* (i/o) : memory associated with this filtering. */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
25 Word16 update /* (i) : 0=no update, 1=update of memory. */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
26 ) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
27 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
28 Word16 i, j; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
29 Word32 s; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
30 Word16 tmp[80]; /* This is usually done by memory allocation (lg+m) */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
31 Word16 *yy; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
32 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
33 /* Copy mem[] to yy[] */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
34 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
35 yy = tmp; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
36 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
37 for (i = 0; i < m; i++) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
38 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
39 *yy++ = mem[i]; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
40 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
41 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
42 /* Do the filtering. */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
43 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
44 for (i = 0; i < lg; i++) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
45 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
46 s = L_mult (x[i], a[0]); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
47 for (j = 1; j <= m; j++) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
48 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
49 s = L_msu (s, a[j], yy[-j]); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
50 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
51 s = L_shl (s, 3); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
52 *yy++ = round (s); move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
53 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
54 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
55 for (i = 0; i < lg; i++) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
56 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
57 y[i] = tmp[i + m]; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
58 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
59 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
60 /* Update of memory if update==1 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
61 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
62 test (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
63 if (update != 0) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
64 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
65 for (i = 0; i < m; i++) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
66 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
67 mem[i] = y[lg - m + i]; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
68 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
69 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
70 return; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
71 } |