rvoip-codec-core 0.2.2

G.711 and optional G.729A/G.729AB audio codec implementation for RVOIP
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196

//! Lookup table utilities for codec optimizations

/// Pre-computed μ-law decoding table (8-bit μ-law to 16-bit linear)
pub static MULAW_DECODE_TABLE: [i16; 256] = [
    16004, 14980, 13956, 12932, 11908, 10884, 9860, 8836, 7812, 6788, 5764, 4740, 3716, 2692, 1668,
    644, 8068, 7556, 7044, 6532, 6020, 5508, 4996, 4484, 3972, 3460, 2948, 2436, 1924, 1412, 900,
    388, 4100, 3844, 3588, 3332, 3076, 2820, 2564, 2308, 2052, 1796, 1540, 1284, 1028, 772, 516,
    260, 2116, 1988, 1860, 1732, 1604, 1476, 1348, 1220, 1092, 964, 836, 708, 580, 452, 324, 196,
    1124, 1060, 996, 932, 868, 804, 740, 676, 612, 548, 484, 420, 356, 292, 228, 164, 628, 596,
    564, 532, 500, 468, 436, 404, 372, 340, 308, 276, 244, 212, 180, 148, 380, 364, 348, 332, 316,
    300, 284, 268, 252, 236, 220, 204, 188, 172, 156, 140, 252, 244, 236, 228, 220, 212, 204, 196,
    188, 180, 172, 164, 156, 148, 140, 132, -16004, -14980, -13956, -12932, -11908, -10884, -9860,
    -8836, -7812, -6788, -5764, -4740, -3716, -2692, -1668, -644, -8068, -7556, -7044, -6532,
    -6020, -5508, -4996, -4484, -3972, -3460, -2948, -2436, -1924, -1412, -900, -388, -4100, -3844,
    -3588, -3332, -3076, -2820, -2564, -2308, -2052, -1796, -1540, -1284, -1028, -772, -516, -260,
    -2116, -1988, -1860, -1732, -1604, -1476, -1348, -1220, -1092, -964, -836, -708, -580, -452,
    -324, -196, -1124, -1060, -996, -932, -868, -804, -740, -676, -612, -548, -484, -420, -356,
    -292, -228, -164, -628, -596, -564, -532, -500, -468, -436, -404, -372, -340, -308, -276, -244,
    -212, -180, -148, -380, -364, -348, -332, -316, -300, -284, -268, -252, -236, -220, -204, -188,
    -172, -156, -140, -252, -244, -236, -228, -220, -212, -204, -196, -188, -180, -172, -164, -156,
    -148, -140, -132,
];

/// Pre-computed A-law decoding table (8-bit A-law to 16-bit linear)
pub static ALAW_DECODE_TABLE: [i16; 256] = [
    15880, 14856, 13832, 12808, 11784, 10760, 9736, 8712, 7688, 6664, 5640, 4616, 3592, 2568, 1544,
    520, 7944, 7432, 6920, 6408, 5896, 5384, 4872, 4360, 3848, 3336, 2824, 2312, 1800, 1288, 776,
    264, 3976, 3720, 3464, 3208, 2952, 2696, 2440, 2184, 1928, 1672, 1416, 1160, 904, 648, 392,
    136, 1992, 1864, 1736, 1608, 1480, 1352, 1224, 1096, 968, 840, 712, 584, 456, 328, 200, 72,
    1000, 936, 872, 808, 744, 680, 616, 552, 488, 424, 360, 296, 232, 168, 104, 40, 504, 472, 440,
    408, 376, 344, 312, 280, 248, 216, 184, 152, 120, 88, 56, 24, 256, 240, 224, 208, 192, 176,
    160, 144, 128, 112, 96, 80, 64, 48, 32, 16, 248, 232, 216, 200, 184, 168, 152, 136, 120, 104,
    88, 72, 56, 40, 24, 8, -15880, -14856, -13832, -12808, -11784, -10760, -9736, -8712, -7688,
    -6664, -5640, -4616, -3592, -2568, -1544, -520, -7944, -7432, -6920, -6408, -5896, -5384,
    -4872, -4360, -3848, -3336, -2824, -2312, -1800, -1288, -776, -264, -3976, -3720, -3464, -3208,
    -2952, -2696, -2440, -2184, -1928, -1672, -1416, -1160, -904, -648, -392, -136, -1992, -1864,
    -1736, -1608, -1480, -1352, -1224, -1096, -968, -840, -712, -584, -456, -328, -200, -72, -1000,
    -936, -872, -808, -744, -680, -616, -552, -488, -424, -360, -296, -232, -168, -104, -40, -504,
    -472, -440, -408, -376, -344, -312, -280, -248, -216, -184, -152, -120, -88, -56, -24, -256,
    -240, -224, -208, -192, -176, -160, -144, -128, -112, -96, -80, -64, -48, -32, -16, -248, -232,
    -216, -200, -184, -168, -152, -136, -120, -104, -88, -72, -56, -40, -24, -8,
];

/// Fast μ-law encoding using direct computation
pub fn encode_mulaw_table(sample: i16) -> u8 {
    crate::utils::simd::linear_to_mulaw_scalar(sample)
}

/// Fast μ-law decoding using lookup table
pub fn decode_mulaw_table(encoded: u8) -> i16 {
    MULAW_DECODE_TABLE[encoded as usize]
}

/// Fast A-law encoding using direct computation
pub fn encode_alaw_table(sample: i16) -> u8 {
    crate::utils::simd::linear_to_alaw_scalar(sample)
}

/// Fast A-law decoding using lookup table
pub fn decode_alaw_table(encoded: u8) -> i16 {
    ALAW_DECODE_TABLE[encoded as usize]
}

/// Batch μ-law encoding using lookup tables
pub fn encode_mulaw_batch(samples: &[i16], output: &mut [u8]) {
    for (i, &sample) in samples.iter().enumerate() {
        output[i] = encode_mulaw_table(sample);
    }
}

/// Batch μ-law decoding using lookup tables
pub fn decode_mulaw_batch(encoded: &[u8], output: &mut [i16]) {
    for (i, &byte) in encoded.iter().enumerate() {
        output[i] = decode_mulaw_table(byte);
    }
}

/// Batch A-law encoding using lookup tables
pub fn encode_alaw_batch(samples: &[i16], output: &mut [u8]) {
    for (i, &sample) in samples.iter().enumerate() {
        output[i] = encode_alaw_table(sample);
    }
}

/// Batch A-law decoding using lookup tables
pub fn decode_alaw_batch(encoded: &[u8], output: &mut [i16]) {
    for (i, &byte) in encoded.iter().enumerate() {
        output[i] = decode_alaw_table(byte);
    }
}

/// Initialize all lookup tables
pub fn init_tables() {
    // Static arrays are already initialized at compile time
    tracing::debug!("Codec lookup tables already initialized (1KB total)");
}

/// Get memory usage of lookup tables
pub fn get_table_memory_usage() -> usize {
    // Only decode tables:
    // μ-law: 256 * 2 = 512 bytes
    // A-law: 256 * 2 = 512 bytes
    // Total: 1024 bytes (1KB)
    let mulaw_decode_size = std::mem::size_of::<[i16; 256]>();
    let alaw_decode_size = std::mem::size_of::<[i16; 256]>();

    mulaw_decode_size + alaw_decode_size
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_table_initialization() {
        // Test that static arrays are available
        assert_eq!(MULAW_DECODE_TABLE.len(), 256);
        assert_eq!(ALAW_DECODE_TABLE.len(), 256);

        // Test first and last values are reasonable
        assert_ne!(MULAW_DECODE_TABLE[0], 0);
        assert_ne!(MULAW_DECODE_TABLE[255], 0);
        assert_ne!(ALAW_DECODE_TABLE[0], 0);
        assert_ne!(ALAW_DECODE_TABLE[255], 0);
    }

    #[test]
    fn test_table_vs_scalar() {
        // Test decode tables only (they're small and fast)
        let test_encoded = vec![0, 127, 128, 255];

        for encoded in test_encoded {
            // Test μ-law decode
            let table_result = decode_mulaw_table(encoded);
            let scalar_result = crate::utils::simd::mulaw_to_linear_scalar(encoded);
            assert_eq!(
                table_result, scalar_result,
                "μ-law decode table mismatch for encoded {}",
                encoded
            );

            // Test A-law decode
            let table_result = decode_alaw_table(encoded);
            let scalar_result = crate::utils::simd::alaw_to_linear_scalar(encoded);
            assert_eq!(
                table_result, scalar_result,
                "A-law decode table mismatch for encoded {}",
                encoded
            );
        }
    }

    #[test]
    fn test_batch_operations() {
        // Test decode batch operations only (they're fast)
        let encoded = vec![0u8, 127, 128, 255];
        let mut decoded = vec![0i16; encoded.len()];

        // Test μ-law batch decode
        decode_mulaw_batch(&encoded, &mut decoded);

        // Verify we got some non-zero results
        assert_ne!(decoded[1], 0);
        assert_ne!(decoded[2], 0);
        assert_ne!(decoded[3], 0);

        // Test A-law batch decode
        decode_alaw_batch(&encoded, &mut decoded);

        // Verify we got some non-zero results
        assert_ne!(decoded[1], 0);
        assert_ne!(decoded[2], 0);
        assert_ne!(decoded[3], 0);
    }

    #[test]
    fn test_memory_usage() {
        let usage = get_table_memory_usage();

        // Expected: 2 * 256 * 2 bytes = 1024 bytes
        assert_eq!(usage, 1024);
    }

    #[test]
    fn test_edge_cases() {
        // Test boundary values for decode operations only
        let edge_cases = vec![0u8, 127, 128, 255];

        for encoded in edge_cases {
            // Decoders return `i16`; the value range is guaranteed by
            // the type. We only need to assert they don't panic.
            let _ = decode_mulaw_table(encoded);
            let _ = decode_alaw_table(encoded);
        }
    }
}