FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/pcm_tablegen.h
Date: 2025-09-01 20:07:09
Exec Total Coverage
Lines: 33 40 82.5%
Functions: 5 7 71.4%
Branches: 12 14 85.7%
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1 /*
2 * Header file for hardcoded PCM tables
3 *
4 * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
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_PCM_TABLEGEN_H
24 #define AVCODEC_PCM_TABLEGEN_H
25
26 #include <stdint.h>
27 #include "libavutil/attributes.h"
28
29 /* from g711.c by SUN microsystems (unrestricted use) */
30
31 #define SIGN_BIT (0x80) /* Sign bit for a A-law byte. */
32 #define QUANT_MASK (0xf) /* Quantization field mask. */
33 #define NSEGS (8) /* Number of A-law segments. */
34 #define SEG_SHIFT (4) /* Left shift for segment number. */
35 #define SEG_MASK (0x70) /* Segment field mask. */
36
37 #define BIAS (0x84) /* Bias for linear code. */
38
39 #define VIDC_SIGN_BIT (1)
40 #define VIDC_QUANT_MASK (0x1E)
41 #define VIDC_QUANT_SHIFT (1)
42 #define VIDC_SEG_SHIFT (5)
43 #define VIDC_SEG_MASK (0xE0)
44
45 #if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER
46 /* alaw2linear() - Convert an A-law value to 16-bit linear PCM */
47 8434 static av_cold int alaw2linear(unsigned char a_val)
48 {
49 int t;
50 int seg;
51
52 8434 a_val ^= 0x55;
53
54 8434 t = a_val & QUANT_MASK;
55 8434 seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
56
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 8434 if(seg) t= (t + t + 1 + 32) << (seg + 2);
57 1049 else t= (t + t + 1 ) << 3;
58
59
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 8434 return (a_val & SIGN_BIT) ? t : -t;
60 }
61 #endif
62
63 #if CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER
64 4092 static av_cold int ulaw2linear(unsigned char u_val)
65 {
66 int t;
67
68 /* Complement to obtain normal u-law value. */
69 4092 u_val = ~u_val;
70
71 /*
72 * Extract and bias the quantization bits. Then
73 * shift up by the segment number and subtract out the bias.
74 */
75 4092 t = ((u_val & QUANT_MASK) << 3) + BIAS;
76 4092 t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
77
78
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 4092 return (u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS);
79 }
80 #endif
81
82 #if CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
83 ✗ static av_cold int vidc2linear(unsigned char u_val)
84 {
85 int t;
86
87 /*
88 * Extract and bias the quantization bits. Then
89 * shift up by the segment number and subtract out the bias.
90 */
91 ✗ t = (((u_val & VIDC_QUANT_MASK) >> VIDC_QUANT_SHIFT) << 3) + BIAS;
92 ✗ t <<= ((unsigned)u_val & VIDC_SEG_MASK) >> VIDC_SEG_SHIFT;
93
94 ✗ return (u_val & VIDC_SIGN_BIT) ? (BIAS - t) : (t - BIAS);
95 }
96 #endif
97
98 #if CONFIG_HARDCODED_TABLES
99 #define pcm_alaw_tableinit()
100 #define pcm_ulaw_tableinit()
101 #define pcm_vidc_tableinit()
102 #include "libavcodec/pcm_tables.h"
103 #else
104 /* 16384 entries per table */
105 #if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER
106 static uint8_t linear_to_alaw[16384];
107 #endif
108 #if CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER
109 static uint8_t linear_to_ulaw[16384];
110 #endif
111 #if CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
112 static uint8_t linear_to_vidc[16384];
113 #endif
114
115 #if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER || \
116 CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER || \
117 CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
118 9 static av_cold void build_xlaw_table(uint8_t *linear_to_xlaw,
119 int (*xlaw2linear)(unsigned char),
120 int mask)
121 {
122 int i, j, v, v1, v2;
123
124 9 j = 1;
125 9 linear_to_xlaw[8192] = mask;
126
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 1152 for(i=0;i<127;i++) {
127 1143 v1 = xlaw2linear(i ^ mask);
128 1143 v2 = xlaw2linear((i + 1) ^ mask);
129 1143 v = (v1 + v2 + 4) >> 3;
130
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 72492 for(;j<v;j+=1) {
131 71349 linear_to_xlaw[8192 - j] = (i ^ (mask ^ 0x80));
132 71349 linear_to_xlaw[8192 + j] = (i ^ mask);
133 }
134 }
135
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 2379 for(;j<8192;j++) {
136 2370 linear_to_xlaw[8192 - j] = (127 ^ (mask ^ 0x80));
137 2370 linear_to_xlaw[8192 + j] = (127 ^ mask);
138 }
139 9 linear_to_xlaw[0] = linear_to_xlaw[1];
140 9 }
141 #endif
142
143 #if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER
144 7 static void pcm_alaw_tableinit(void)
145 {
146 7 build_xlaw_table(linear_to_alaw, alaw2linear, 0xd5);
147 7 }
148 #endif
149
150 #if CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER
151 2 static void pcm_ulaw_tableinit(void)
152 {
153 2 build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff);
154 2 }
155 #endif
156
157 #if CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
158 ✗ static void pcm_vidc_tableinit(void)
159 {
160 ✗ build_xlaw_table(linear_to_vidc, vidc2linear, 0xff);
161 ✗ }
162 #endif
163 #endif /* CONFIG_HARDCODED_TABLES */
164
165 #endif /* AVCODEC_PCM_TABLEGEN_H */
166