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author | Sean Bartell <wingedtachikoma@gmail.com> | 2011-06-25 21:32:25 -0400 |
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committer | Nils Wallménius <nils@rockbox.org> | 2012-04-25 22:13:20 +0200 |
commit | f40bfc9267b13b54e6379dfe7539447662879d24 (patch) | |
tree | 9b20069d5e62809ff434061ad730096836f916f2 /lib/rbcodec/codecs/libwmavoice/lsp.h | |
parent | a0009907de7a0107d49040d8a180f140e2eff299 (diff) | |
download | rockbox-f40bfc9267b13b54e6379dfe7539447662879d24.tar.gz rockbox-f40bfc9267b13b54e6379dfe7539447662879d24.zip |
Add codecs to librbcodec.
Change-Id: Id7f4717d51ed02d67cb9f9cb3c0ada4a81843f97
Reviewed-on: http://gerrit.rockbox.org/137
Reviewed-by: Nils Wallménius <nils@rockbox.org>
Tested-by: Nils Wallménius <nils@rockbox.org>
Diffstat (limited to 'lib/rbcodec/codecs/libwmavoice/lsp.h')
-rw-r--r-- | lib/rbcodec/codecs/libwmavoice/lsp.h | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libwmavoice/lsp.h b/lib/rbcodec/codecs/libwmavoice/lsp.h new file mode 100644 index 0000000000..5ee5c277bc --- /dev/null +++ b/lib/rbcodec/codecs/libwmavoice/lsp.h | |||
@@ -0,0 +1,120 @@ | |||
1 | /* | ||
2 | * LSP computing for ACELP-based codecs | ||
3 | * | ||
4 | * Copyright (c) 2008 Vladimir Voroshilov | ||
5 | * | ||
6 | * This file is part of FFmpeg. | ||
7 | * | ||
8 | * FFmpeg is free software; you can redistribute it and/or | ||
9 | * modify it under the terms of the GNU Lesser General Public | ||
10 | * License as published by the Free Software Foundation; either | ||
11 | * version 2.1 of the License, or (at your option) any later version. | ||
12 | * | ||
13 | * FFmpeg is distributed in the hope that it will be useful, | ||
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
16 | * Lesser General Public License for more details. | ||
17 | * | ||
18 | * You should have received a copy of the GNU Lesser General Public | ||
19 | * License along with FFmpeg; if not, write to the Free Software | ||
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
21 | */ | ||
22 | |||
23 | #ifndef AVCODEC_LSP_H | ||
24 | #define AVCODEC_LSP_H | ||
25 | |||
26 | #include <stdint.h> | ||
27 | |||
28 | /** | ||
29 | (I.F) means fixed-point value with F fractional and I integer bits | ||
30 | */ | ||
31 | |||
32 | /** | ||
33 | * \brief ensure a minimum distance between LSFs | ||
34 | * \param[in,out] lsfq LSF to check and adjust | ||
35 | * \param lsfq_min_distance minimum distance between LSFs | ||
36 | * \param lsfq_min minimum allowed LSF value | ||
37 | * \param lsfq_max maximum allowed LSF value | ||
38 | * \param lp_order LP filter order | ||
39 | */ | ||
40 | void ff_acelp_reorder_lsf(int16_t* lsfq, int lsfq_min_distance, int lsfq_min, int lsfq_max, int lp_order); | ||
41 | |||
42 | /** | ||
43 | * Adjust the quantized LSFs so they are increasing and not too close. | ||
44 | * | ||
45 | * This step is not mentioned in the AMR spec but is in the reference C decoder. | ||
46 | * Omitting this step creates audible distortion on the sinusoidal sweep | ||
47 | * test vectors in 3GPP TS 26.074. | ||
48 | * | ||
49 | * @param[in,out] lsf LSFs in Hertz | ||
50 | * @param min_spacing minimum distance between two consecutive lsf values | ||
51 | * @param size size of the lsf vector | ||
52 | */ | ||
53 | void ff_set_min_dist_lsf(float *lsf, double min_spacing, int size); | ||
54 | |||
55 | /** | ||
56 | * \brief Convert LSF to LSP | ||
57 | * \param[out] lsp LSP coefficients (-0x8000 <= (0.15) < 0x8000) | ||
58 | * \param lsf normalized LSF coefficients (0 <= (2.13) < 0x2000 * PI) | ||
59 | * \param lp_order LP filter order | ||
60 | * | ||
61 | * \remark It is safe to pass the same array into the lsf and lsp parameters. | ||
62 | */ | ||
63 | void ff_acelp_lsf2lsp(int16_t *lsp, const int16_t *lsf, int lp_order); | ||
64 | |||
65 | /** | ||
66 | * \brief LSP to LP conversion (3.2.6 of G.729) | ||
67 | * \param[out] lp decoded LP coefficients (-0x8000 <= (3.12) < 0x8000) | ||
68 | * \param lsp LSP coefficients (-0x8000 <= (0.15) < 0x8000) | ||
69 | * \param lp_half_order LP filter order, divided by 2 | ||
70 | */ | ||
71 | void ff_acelp_lsp2lpc(int16_t* lp, const int16_t* lsp, int lp_half_order); | ||
72 | |||
73 | /** | ||
74 | * \brief Interpolate LSP for the first subframe and convert LSP -> LP for both subframes (3.2.5 and 3.2.6 of G.729) | ||
75 | * \param[out] lp_1st decoded LP coefficients for first subframe (-0x8000 <= (3.12) < 0x8000) | ||
76 | * \param[out] lp_2nd decoded LP coefficients for second subframe (-0x8000 <= (3.12) < 0x8000) | ||
77 | * \param lsp_2nd LSP coefficients of the second subframe (-0x8000 <= (0.15) < 0x8000) | ||
78 | * \param lsp_prev LSP coefficients from the second subframe of the previous frame (-0x8000 <= (0.15) < 0x8000) | ||
79 | * \param lp_order LP filter order | ||
80 | */ | ||
81 | void ff_acelp_lp_decode(int16_t* lp_1st, int16_t* lp_2nd, const int16_t* lsp_2nd, const int16_t* lsp_prev, int lp_order); | ||
82 | |||
83 | |||
84 | #define MAX_LP_HALF_ORDER 8 | ||
85 | #define MAX_LP_ORDER (2*MAX_LP_HALF_ORDER) | ||
86 | |||
87 | /** | ||
88 | * Reconstruct LPC coefficients from the line spectral pair frequencies. | ||
89 | * | ||
90 | * @param lsp line spectral pairs in cosine domain | ||
91 | * @param lpc linear predictive coding coefficients | ||
92 | * @param lp_half_order half the number of the amount of LPCs to be | ||
93 | * reconstructed, need to be smaller or equal to MAX_LP_HALF_ORDER | ||
94 | * | ||
95 | * @note buffers should have a minimux size of 2*lp_half_order elements. | ||
96 | * | ||
97 | * TIA/EIA/IS-733 2.4.3.3.5 | ||
98 | */ | ||
99 | void ff_acelp_lspd2lpc(const double *lsp, float *lpc, int lp_half_order); | ||
100 | |||
101 | /** | ||
102 | * Sort values in ascending order. | ||
103 | * | ||
104 | * @note O(n) if data already sorted, O(n^2) - otherwise | ||
105 | */ | ||
106 | void ff_sort_nearly_sorted_floats(float *vals, int len); | ||
107 | |||
108 | /** | ||
109 | * Compute the Pa / (1 + z(-1)) or Qa / (1 - z(-1)) coefficients | ||
110 | * needed for LSP to LPC conversion. | ||
111 | * We only need to calculate the 6 first elements of the polynomial. | ||
112 | * | ||
113 | * @param lsp line spectral pairs in cosine domain | ||
114 | * @param[out] f polynomial input/output as a vector | ||
115 | * | ||
116 | * TIA/EIA/IS-733 2.4.3.3.5-1/2 | ||
117 | */ | ||
118 | void ff_lsp2polyf(const double *lsp, double *f, int lp_half_order); | ||
119 | |||
120 | #endif /* AVCODEC_LSP_H */ | ||