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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/libspeex/lpc.c | |
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/libspeex/lpc.c')
-rw-r--r-- | lib/rbcodec/codecs/libspeex/lpc.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libspeex/lpc.c b/lib/rbcodec/codecs/libspeex/lpc.c new file mode 100644 index 0000000000..9845633a6c --- /dev/null +++ b/lib/rbcodec/codecs/libspeex/lpc.c | |||
@@ -0,0 +1,201 @@ | |||
1 | /* | ||
2 | Copyright 1992, 1993, 1994 by Jutta Degener and Carsten Bormann, | ||
3 | Technische Universitaet Berlin | ||
4 | |||
5 | Any use of this software is permitted provided that this notice is not | ||
6 | removed and that neither the authors nor the Technische Universitaet Berlin | ||
7 | are deemed to have made any representations as to the suitability of this | ||
8 | software for any purpose nor are held responsible for any defects of | ||
9 | this software. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. | ||
10 | |||
11 | As a matter of courtesy, the authors request to be informed about uses | ||
12 | this software has found, about bugs in this software, and about any | ||
13 | improvements that may be of general interest. | ||
14 | |||
15 | Berlin, 28.11.1994 | ||
16 | Jutta Degener | ||
17 | Carsten Bormann | ||
18 | |||
19 | |||
20 | Code modified by Jean-Marc Valin | ||
21 | |||
22 | Speex License: | ||
23 | |||
24 | Redistribution and use in source and binary forms, with or without | ||
25 | modification, are permitted provided that the following conditions | ||
26 | are met: | ||
27 | |||
28 | - Redistributions of source code must retain the above copyright | ||
29 | notice, this list of conditions and the following disclaimer. | ||
30 | |||
31 | - Redistributions in binary form must reproduce the above copyright | ||
32 | notice, this list of conditions and the following disclaimer in the | ||
33 | documentation and/or other materials provided with the distribution. | ||
34 | |||
35 | - Neither the name of the Xiph.org Foundation nor the names of its | ||
36 | contributors may be used to endorse or promote products derived from | ||
37 | this software without specific prior written permission. | ||
38 | |||
39 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | ||
40 | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | ||
41 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | ||
42 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR | ||
43 | CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | ||
44 | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | ||
45 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | ||
46 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF | ||
47 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING | ||
48 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | ||
49 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||
50 | */ | ||
51 | |||
52 | #ifdef HAVE_CONFIG_H | ||
53 | #include "config-speex.h" | ||
54 | #endif | ||
55 | |||
56 | #include "lpc.h" | ||
57 | |||
58 | #ifdef BFIN_ASM | ||
59 | #include "lpc_bfin.h" | ||
60 | #endif | ||
61 | |||
62 | /* LPC analysis | ||
63 | * | ||
64 | * The next two functions calculate linear prediction coefficients | ||
65 | * and/or the related reflection coefficients from the first P_MAX+1 | ||
66 | * values of the autocorrelation function. | ||
67 | */ | ||
68 | |||
69 | /* Invented by N. Levinson in 1947, modified by J. Durbin in 1959. | ||
70 | */ | ||
71 | |||
72 | /* returns minimum mean square error */ | ||
73 | spx_word32_t _spx_lpc( | ||
74 | spx_coef_t *lpc, /* out: [0...p-1] LPC coefficients */ | ||
75 | const spx_word16_t *ac, /* in: [0...p] autocorrelation values */ | ||
76 | int p | ||
77 | ) | ||
78 | { | ||
79 | int i, j; | ||
80 | spx_word16_t r; | ||
81 | spx_word16_t error = ac[0]; | ||
82 | |||
83 | if (ac[0] == 0) | ||
84 | { | ||
85 | for (i = 0; i < p; i++) | ||
86 | lpc[i] = 0; | ||
87 | return 0; | ||
88 | } | ||
89 | |||
90 | for (i = 0; i < p; i++) { | ||
91 | |||
92 | /* Sum up this iteration's reflection coefficient */ | ||
93 | spx_word32_t rr = NEG32(SHL32(EXTEND32(ac[i + 1]),13)); | ||
94 | for (j = 0; j < i; j++) | ||
95 | rr = SUB32(rr,MULT16_16(lpc[j],ac[i - j])); | ||
96 | #ifdef FIXED_POINT | ||
97 | r = DIV32_16(rr+PSHR32(error,1),ADD16(error,8)); | ||
98 | #else | ||
99 | r = rr/(error+.003*ac[0]); | ||
100 | #endif | ||
101 | /* Update LPC coefficients and total error */ | ||
102 | lpc[i] = r; | ||
103 | for (j = 0; j < i>>1; j++) | ||
104 | { | ||
105 | spx_word16_t tmp = lpc[j]; | ||
106 | lpc[j] = MAC16_16_P13(lpc[j],r,lpc[i-1-j]); | ||
107 | lpc[i-1-j] = MAC16_16_P13(lpc[i-1-j],r,tmp); | ||
108 | } | ||
109 | if (i & 1) | ||
110 | lpc[j] = MAC16_16_P13(lpc[j],lpc[j],r); | ||
111 | |||
112 | error = SUB16(error,MULT16_16_Q13(r,MULT16_16_Q13(error,r))); | ||
113 | } | ||
114 | return error; | ||
115 | } | ||
116 | |||
117 | |||
118 | #ifdef FIXED_POINT | ||
119 | |||
120 | /* Compute the autocorrelation | ||
121 | * ,--, | ||
122 | * ac(i) = > x(n) * x(n-i) for all n | ||
123 | * `--' | ||
124 | * for lags between 0 and lag-1, and x == 0 outside 0...n-1 | ||
125 | */ | ||
126 | |||
127 | #ifndef OVERRIDE_SPEEX_AUTOCORR | ||
128 | void _spx_autocorr( | ||
129 | const spx_word16_t *x, /* in: [0...n-1] samples x */ | ||
130 | spx_word16_t *ac, /* out: [0...lag-1] ac values */ | ||
131 | int lag, | ||
132 | int n | ||
133 | ) | ||
134 | { | ||
135 | spx_word32_t d; | ||
136 | int i, j; | ||
137 | spx_word32_t ac0=1; | ||
138 | int shift, ac_shift; | ||
139 | |||
140 | for (j=0;j<n;j++) | ||
141 | ac0 = ADD32(ac0,SHR32(MULT16_16(x[j],x[j]),8)); | ||
142 | ac0 = ADD32(ac0,n); | ||
143 | shift = 8; | ||
144 | while (shift && ac0<0x40000000) | ||
145 | { | ||
146 | shift--; | ||
147 | ac0 <<= 1; | ||
148 | } | ||
149 | ac_shift = 18; | ||
150 | while (ac_shift && ac0<0x40000000) | ||
151 | { | ||
152 | ac_shift--; | ||
153 | ac0 <<= 1; | ||
154 | } | ||
155 | |||
156 | |||
157 | for (i=0;i<lag;i++) | ||
158 | { | ||
159 | d=0; | ||
160 | for (j=i;j<n;j++) | ||
161 | { | ||
162 | d = ADD32(d,SHR32(MULT16_16(x[j],x[j-i]), shift)); | ||
163 | } | ||
164 | |||
165 | ac[i] = SHR32(d, ac_shift); | ||
166 | } | ||
167 | } | ||
168 | #endif | ||
169 | |||
170 | |||
171 | #else | ||
172 | |||
173 | |||
174 | |||
175 | /* Compute the autocorrelation | ||
176 | * ,--, | ||
177 | * ac(i) = > x(n) * x(n-i) for all n | ||
178 | * `--' | ||
179 | * for lags between 0 and lag-1, and x == 0 outside 0...n-1 | ||
180 | */ | ||
181 | void _spx_autocorr( | ||
182 | const spx_word16_t *x, /* in: [0...n-1] samples x */ | ||
183 | float *ac, /* out: [0...lag-1] ac values */ | ||
184 | int lag, | ||
185 | int n | ||
186 | ) | ||
187 | { | ||
188 | float d; | ||
189 | int i; | ||
190 | while (lag--) | ||
191 | { | ||
192 | for (i = lag, d = 0; i < n; i++) | ||
193 | d += x[i] * x[i-lag]; | ||
194 | ac[lag] = d; | ||
195 | } | ||
196 | ac[0] += 10; | ||
197 | } | ||
198 | |||
199 | #endif | ||
200 | |||
201 | |||