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Diffstat (limited to 'apps/codecs/libFLAC/bitmath.c')
-rw-r--r-- | apps/codecs/libFLAC/bitmath.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/apps/codecs/libFLAC/bitmath.c b/apps/codecs/libFLAC/bitmath.c new file mode 100644 index 0000000000..2bc509b414 --- /dev/null +++ b/apps/codecs/libFLAC/bitmath.c | |||
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1 | /* libFLAC - Free Lossless Audio Codec library | ||
2 | * Copyright (C) 2001,2002,2003,2004,2005 Josh Coalson | ||
3 | * | ||
4 | * Redistribution and use in source and binary forms, with or without | ||
5 | * modification, are permitted provided that the following conditions | ||
6 | * are met: | ||
7 | * | ||
8 | * - Redistributions of source code must retain the above copyright | ||
9 | * notice, this list of conditions and the following disclaimer. | ||
10 | * | ||
11 | * - Redistributions in binary form must reproduce the above copyright | ||
12 | * notice, this list of conditions and the following disclaimer in the | ||
13 | * documentation and/or other materials provided with the distribution. | ||
14 | * | ||
15 | * - Neither the name of the Xiph.org Foundation nor the names of its | ||
16 | * contributors may be used to endorse or promote products derived from | ||
17 | * this software without specific prior written permission. | ||
18 | * | ||
19 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | ||
20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | ||
21 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | ||
22 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR | ||
23 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | ||
24 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | ||
25 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | ||
26 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF | ||
27 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING | ||
28 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | ||
29 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||
30 | */ | ||
31 | |||
32 | #include "private/bitmath.h" | ||
33 | #include "FLAC/assert.h" | ||
34 | |||
35 | /* An example of what FLAC__bitmath_ilog2() computes: | ||
36 | * | ||
37 | * ilog2( 0) = assertion failure | ||
38 | * ilog2( 1) = 0 | ||
39 | * ilog2( 2) = 1 | ||
40 | * ilog2( 3) = 1 | ||
41 | * ilog2( 4) = 2 | ||
42 | * ilog2( 5) = 2 | ||
43 | * ilog2( 6) = 2 | ||
44 | * ilog2( 7) = 2 | ||
45 | * ilog2( 8) = 3 | ||
46 | * ilog2( 9) = 3 | ||
47 | * ilog2(10) = 3 | ||
48 | * ilog2(11) = 3 | ||
49 | * ilog2(12) = 3 | ||
50 | * ilog2(13) = 3 | ||
51 | * ilog2(14) = 3 | ||
52 | * ilog2(15) = 3 | ||
53 | * ilog2(16) = 4 | ||
54 | * ilog2(17) = 4 | ||
55 | * ilog2(18) = 4 | ||
56 | */ | ||
57 | unsigned FLAC__bitmath_ilog2(FLAC__uint32 v) | ||
58 | { | ||
59 | unsigned l = 0; | ||
60 | FLAC__ASSERT(v > 0); | ||
61 | while(v >>= 1) | ||
62 | l++; | ||
63 | return l; | ||
64 | } | ||
65 | |||
66 | unsigned FLAC__bitmath_ilog2_wide(FLAC__uint64 v) | ||
67 | { | ||
68 | unsigned l = 0; | ||
69 | FLAC__ASSERT(v > 0); | ||
70 | while(v >>= 1) | ||
71 | l++; | ||
72 | return l; | ||
73 | } | ||
74 | |||
75 | /* An example of what FLAC__bitmath_silog2() computes: | ||
76 | * | ||
77 | * silog2(-10) = 5 | ||
78 | * silog2(- 9) = 5 | ||
79 | * silog2(- 8) = 4 | ||
80 | * silog2(- 7) = 4 | ||
81 | * silog2(- 6) = 4 | ||
82 | * silog2(- 5) = 4 | ||
83 | * silog2(- 4) = 3 | ||
84 | * silog2(- 3) = 3 | ||
85 | * silog2(- 2) = 2 | ||
86 | * silog2(- 1) = 2 | ||
87 | * silog2( 0) = 0 | ||
88 | * silog2( 1) = 2 | ||
89 | * silog2( 2) = 3 | ||
90 | * silog2( 3) = 3 | ||
91 | * silog2( 4) = 4 | ||
92 | * silog2( 5) = 4 | ||
93 | * silog2( 6) = 4 | ||
94 | * silog2( 7) = 4 | ||
95 | * silog2( 8) = 5 | ||
96 | * silog2( 9) = 5 | ||
97 | * silog2( 10) = 5 | ||
98 | */ | ||
99 | unsigned FLAC__bitmath_silog2(int v) | ||
100 | { | ||
101 | while(1) { | ||
102 | if(v == 0) { | ||
103 | return 0; | ||
104 | } | ||
105 | else if(v > 0) { | ||
106 | unsigned l = 0; | ||
107 | while(v) { | ||
108 | l++; | ||
109 | v >>= 1; | ||
110 | } | ||
111 | return l+1; | ||
112 | } | ||
113 | else if(v == -1) { | ||
114 | return 2; | ||
115 | } | ||
116 | else { | ||
117 | v++; | ||
118 | v = -v; | ||
119 | } | ||
120 | } | ||
121 | } | ||
122 | |||
123 | unsigned FLAC__bitmath_silog2_wide(FLAC__int64 v) | ||
124 | { | ||
125 | while(1) { | ||
126 | if(v == 0) { | ||
127 | return 0; | ||
128 | } | ||
129 | else if(v > 0) { | ||
130 | unsigned l = 0; | ||
131 | while(v) { | ||
132 | l++; | ||
133 | v >>= 1; | ||
134 | } | ||
135 | return l+1; | ||
136 | } | ||
137 | else if(v == -1) { | ||
138 | return 2; | ||
139 | } | ||
140 | else { | ||
141 | v++; | ||
142 | v = -v; | ||
143 | } | ||
144 | } | ||
145 | } | ||