rvoip-codec-core 0.3.8

G.711 and optional G.729/Opus/AMR audio codec implementations for RVOIP
Documentation 
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//! Comfort-noise ISF quantiser tables for AMR-WB, from the TS 26.173 reference.
//!
//! A SID frame carries 35 bits, 28 of which are the spectrum. That buys a
//! five-way split of the sixteen ISFs at 6/6/6/5/5 bits -- against the speech
//! quantiser's 46 -- and no prediction at all: the noise quantiser is
//! memoryless, where the speech one carries a moving-average predictor across
//! frames. Comfort noise has to survive being decoded after an arbitrary gap,
//! so there is nothing to predict from.
//!
//! These are normative constants -- the codec cannot be conformant without
//! exactly these numbers -- and are generated by `tools/gen_isf_noise_tables.py`.

/// Long-term mean ISF vector for comfort noise, Q15.
///
/// Subtracted before quantisation and added back after. Distinct from the
/// speech quantiser's `MEAN_ISF`: a noise spectrum is not a speech spectrum,
/// and the two means differ in every coefficient.
pub const MEAN_ISF_NOISE: [i16; 16] = [
    478, 1100, 2213, 3267, 4219, 5222, 6198, 7240, 8229, 9153, 10098, 11108, 12144, 13184, 14165,
    3803,
];

/// Comfort-noise codebook, ISFs 0-1, 64 entries of 2. 6 bits.
pub const DICO1_NS: [i16; 128] = [
    -269, -673, -222, -537, -233, -430, -138, -451, -212, -331, -192, -241, -87, -231, -191, -128,
    -70, -106, -164, -6, 74, -179, 27, -33, -102, 74, -162, 115, -94, 172, -6, 130, -143, 234, 14,
    218, -65, 270, 88, 182, -124, 341, -44, 381, 38, 335, 117, 274, -112, 454, 74, 431, -5, 488,
    175, 384, -83, 561, 122, 529, 21, 601, 229, 481, 231, 303, 226, 608, 300, 372, 210, 187, 306,
    265, 328, 473, 382, 331, 371, 132, 139, 58, 365, 21, 250, -82, 443, 218, 483, 110, 426, 415,
    579, 222, 518, 333, 573, 448, 455, 529, 685, 329, 332, 580, 595, 593, 468, 645, 762, 517, 326,
    709, 485, 793, 130, 684, 671, 737, 354, 876, 88, 806, -65, 706, -35, 1016, 266, 1123,
];

/// Comfort-noise codebook, ISFs 2-4, 64 entries of 3. 6 bits.
pub const DICO2_NS: [i16; 192] = [
    -824, -884, -949, -805, -456, -418, -442, -438, -541, -217, -578, -793, -168, -444, -582, -287,
    -492, -274, -552, -297, -300, -163, -333, -358, -370, -232, -232, -175, -358, -159, -381, -21,
    -357, -184, -159, -162, -53, -191, -280, 18, -267, -215, -138, 61, -283, 71, -95, -294, 13,
    -156, -546, 0, -83, -79, 44, 97, -316, 178, -52, -213, 222, -261, -422, 237, -118, -44, 141,
    145, -132, 363, 81, -287, 213, 65, 34, -107, 94, -5, 91, -29, 126, -355, 51, -41, -219, -76,
    145, -63, 100, 244, -719, 44, 27, -572, -124, 155, -423, 133, 315, -917, 71, 224, -268, 318,
    131, -93, -190, 420, -97, 122, 491, -79, 317, 355, 130, 100, 325, 86, -293, 210, 133, 258, 161,
    176, -73, 465, 195, 300, 384, 348, 22, 221, 376, 183, 409, 377, 286, 202, 242, 213, 659, 257,
    565, 248, 344, 408, -76, 405, 440, 509, 612, 385, 379, 536, 607, 216, -56, 582, 192, 100, 517,
    567, -365, 448, 445, 728, 347, 10, 505, 357, 759, 636, 582, 658, 335, 517, 852, 378, 809, 572,
    -195, 878, 829, 529, 707, 987, 918, 726, 392, 1250, 997, 1063,
];

/// Comfort-noise codebook, ISFs 5-7, 64 entries of 3. 6 bits.
pub const DICO3_NS: [i16; 192] = [
    -805, -838, -774, -522, -627, -828, -477, -486, -603, -295, -481, -634, -366, -384, -393, -186,
    -414, -396, -237, -394, -106, -252, -202, -275, -61, -177, -442, -84, -198, -199, -179, -125,
    -31, -72, -47, -163, -298, -220, 215, -64, -168, 251, -133, 156, -59, -30, -2, 127, 54, 66,
    -61, -233, 21, 251, 209, -50, 32, 33, 194, 136, -117, -18, 475, 202, 46, 309, 256, 185, 53, 35,
    200, 390, 200, 263, 242, -216, 302, 294, 128, 358, 0, 19, 431, 287, 224, 447, 280, 367, 165,
    213, 397, 314, 319, 383, 379, 75, 277, 325, 462, 394, 505, 334, 251, 98, -213, 450, 153, 448,
    565, 226, 76, 470, 383, 502, 635, 390, 278, 237, 135, 620, 342, 401, 649, 331, 551, 518, 130,
    418, 592, 531, 306, 737, 729, 389, 580, 497, 557, 699, 296, 383, 874, 283, 624, 759, 126, 622,
    476, 559, 595, 472, 382, 770, 616, 719, 613, 745, 540, 639, 928, 517, 826, 801, 684, 811, 604,
    752, 786, 857, 933, 661, 350, 694, 450, 1061, 562, 911, 1051, 824, 813, 1104, 758, 1047, 882,
    1140, 917, 889, 1039, 1246, 1426, 1483, 1666, 1876,
];

/// Comfort-noise codebook, ISFs 8-11, 32 entries of 4. 5 bits.
pub const DICO4_NS: [i16; 128] = [
    -776, -854, -891, -920, -552, -610, -663, -741, -321, -370, -476, -565, 274, -160, -456, 201,
    265, 67, -160, -306, -8, -210, 79, 272, 163, 236, 307, 308, 578, 317, 64, 298, -9, 197, 342,
    620, 343, 232, 314, 622, 173, 149, 548, 527, 356, 370, 481, 376, 135, 444, 488, 556, 391, 471,
    487, 653, 228, 424, 576, 835, 422, 372, 722, 682, 295, 673, 693, 635, 539, 596, 590, 449, 475,
    618, 659, 818, 735, 517, 491, 673, 602, 346, 257, 877, 625, 635, 849, 720, 727, 818, 698, 595,
    653, 481, 690, 1139, 814, 762, 704, 908, 507, 747, 898, 936, 848, 855, 924, 785, 646, 1037,
    882, 795, 772, 845, 1024, 1151, 1133, 983, 818, 921, 940, 1068, 1252, 1302, 1588, 1767, 1718,
    1513,
];

/// Comfort-noise codebook, ISFs 12-15, 32 entries of 4. 5 bits.
pub const DICO5_NS: [i16; 128] = [
    -810, -879, -945, -254, 248, 184, 671, 128, 288, 703, 918, 99, 658, 558, 662, 219, 552, 585,
    910, 208, 559, 804, 759, 119, 606, 774, 921, -139, 782, 761, 748, 208, 756, 708, 983, 56, 544,
    864, 1010, 152, 737, 698, 987, 299, 771, 924, 879, 103, 536, 785, 961, 405, 667, 916, 801, 328,
    738, 705, 773, 439, 823, 871, 992, 355, 640, 1004, 1052, 369, 724, 822, 949, 597, 415, 655,
    729, 482, 1009, 896, 793, 363, 908, 803, 687, -25, 1016, 838, 1011, 189, 947, 1112, 942, 222,
    914, 1049, 981, 527, 956, 987, 1011, -120, 781, 1049, 1121, 92, 1178, 1053, 884, 47, 1123,
    1059, 1182, 118, 933, 972, 1277, 357, 1109, 918, 1101, 503, 1039, 1286, 1220, 317, 1351, 1207,
    1010, 326,
];