symphonia_codec_aac/aac/
common.rs

1// Symphonia
2// Copyright (c) 2019-2022 The Project Symphonia Developers.
3//
4// Previous Author: Kostya Shishkov <kostya.shiskov@gmail.com>
5//
6// This source file includes code originally written for the NihAV
7// project. With the author's permission, it has been relicensed for,
8// and ported to the Symphonia project.
9//
10// This Source Code Form is subject to the terms of the Mozilla Public
11// License, v. 2.0. If a copy of the MPL was not distributed with this
12// file, You can obtain one at https://mozilla.org/MPL/2.0/.
13
14pub const MAX_WINDOWS: usize = 8;
15pub const MAX_SFBS: usize = 64;
16
17pub const ONLY_LONG_SEQUENCE: u8 = 0;
18pub const LONG_START_SEQUENCE: u8 = 1;
19pub const EIGHT_SHORT_SEQUENCE: u8 = 2;
20pub const LONG_STOP_SEQUENCE: u8 = 3;
21
22pub const SWB_OFFSET_48K_LONG: [usize; 49 + 1] = [
23    0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 48, 56, 64, 72, 80, 88, 96, 108, 120, 132, 144, 160,
24    176, 196, 216, 240, 264, 292, 320, 352, 384, 416, 448, 480, 512, 544, 576, 608, 640, 672, 704,
25    736, 768, 800, 832, 864, 896, 928, 1024,
26];
27
28pub const SWB_OFFSET_48K_SHORT: [usize; 14 + 1] =
29    [0, 4, 8, 12, 16, 20, 28, 36, 44, 56, 68, 80, 96, 112, 128];
30
31pub const SWB_OFFSET_32K_LONG: [usize; 51 + 1] = [
32    0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 48, 56, 64, 72, 80, 88, 96, 108, 120, 132, 144, 160,
33    176, 196, 216, 240, 264, 292, 320, 352, 384, 416, 448, 480, 512, 544, 576, 608, 640, 672, 704,
34    736, 768, 800, 832, 864, 896, 928, 960, 992, 1024,
35];
36
37pub const SWB_OFFSET_8K_LONG: [usize; 40 + 1] = [
38    0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 172, 188, 204, 220, 236, 252, 268,
39    288, 308, 328, 348, 372, 396, 420, 448, 476, 508, 544, 580, 620, 664, 712, 764, 820, 880, 944,
40    1024,
41];
42
43pub const SWB_OFFSET_8K_SHORT: [usize; 15 + 1] =
44    [0, 4, 8, 12, 16, 20, 24, 28, 36, 44, 52, 60, 72, 88, 108, 128];
45
46pub const SWB_OFFSET_16K_LONG: [usize; 43 + 1] = [
47    0, 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 100, 112, 124, 136, 148, 160, 172, 184, 196, 212,
48    228, 244, 260, 280, 300, 320, 344, 368, 396, 424, 456, 492, 532, 572, 616, 664, 716, 772, 832,
49    896, 960, 1024,
50];
51
52pub const SWB_OFFSET_16K_SHORT: [usize; 15 + 1] =
53    [0, 4, 8, 12, 16, 20, 24, 28, 32, 40, 48, 60, 72, 88, 108, 128];
54
55pub const SWB_OFFSET_24K_LONG: [usize; 47 + 1] = [
56    0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 52, 60, 68, 76, 84, 92, 100, 108, 116, 124, 136,
57    148, 160, 172, 188, 204, 220, 240, 260, 284, 308, 336, 364, 396, 432, 468, 508, 552, 600, 652,
58    704, 768, 832, 896, 960, 1024,
59];
60
61pub const SWB_OFFSET_24K_SHORT: [usize; 15 + 1] =
62    [0, 4, 8, 12, 16, 20, 24, 28, 36, 44, 52, 64, 76, 92, 108, 128];
63
64pub const SWB_OFFSET_64K_LONG: [usize; 47 + 1] = [
65    0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 64, 72, 80, 88, 100, 112, 124, 140,
66    156, 172, 192, 216, 240, 268, 304, 344, 384, 424, 464, 504, 544, 584, 624, 664, 704, 744, 784,
67    824, 864, 904, 944, 984, 1024,
68];
69
70pub const SWB_OFFSET_64K_SHORT: [usize; 12 + 1] =
71    [0, 4, 8, 12, 16, 20, 24, 32, 40, 48, 64, 92, 128];
72
73pub const SWB_OFFSET_96K_LONG: [usize; 41 + 1] = [
74    0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 64, 72, 80, 88, 96, 108, 120, 132,
75    144, 156, 172, 188, 212, 240, 276, 320, 384, 448, 512, 576, 640, 704, 768, 832, 896, 960, 1024,
76];
77
78/// A Linear Congruential Generator (LCG) pseudo-random number generator from Numerical Recipes.
79#[derive(Clone)]
80pub struct Lcg {
81    state: u32,
82}
83
84impl Lcg {
85    pub fn new(state: u32) -> Self {
86        Lcg { state }
87    }
88
89    #[inline(always)]
90    pub fn next(&mut self) -> i32 {
91        // Numerical Recipes LCG parameters.
92        self.state = self.state.wrapping_mul(1664525).wrapping_add(1013904223);
93        self.state as i32
94    }
95}
96
97#[derive(Clone, Copy)]
98pub struct GASubbandInfo {
99    pub min_srate: u32,
100    pub long_bands: &'static [usize],
101    pub short_bands: &'static [usize],
102}
103
104impl GASubbandInfo {
105    pub fn find(srate: u32) -> GASubbandInfo {
106        for sbi in AAC_SUBBAND_INFO.iter() {
107            if srate >= sbi.min_srate {
108                return *sbi;
109            }
110        }
111        unreachable!()
112    }
113
114    pub fn find_idx(srate: u32) -> usize {
115        for (i, sbi) in AAC_SUBBAND_INFO.iter().enumerate() {
116            if srate >= sbi.min_srate {
117                return i;
118            }
119        }
120        unreachable!()
121    }
122}
123
124const AAC_SUBBAND_INFO: [GASubbandInfo; 12] = [
125    GASubbandInfo {
126        min_srate: 92017,
127        long_bands: &SWB_OFFSET_96K_LONG,
128        short_bands: &SWB_OFFSET_64K_SHORT,
129    }, //96K
130    GASubbandInfo {
131        min_srate: 75132,
132        long_bands: &SWB_OFFSET_96K_LONG,
133        short_bands: &SWB_OFFSET_64K_SHORT,
134    }, //88.2K
135    GASubbandInfo {
136        min_srate: 55426,
137        long_bands: &SWB_OFFSET_64K_LONG,
138        short_bands: &SWB_OFFSET_64K_SHORT,
139    }, //64K
140    GASubbandInfo {
141        min_srate: 46009,
142        long_bands: &SWB_OFFSET_48K_LONG,
143        short_bands: &SWB_OFFSET_48K_SHORT,
144    }, //48K
145    GASubbandInfo {
146        min_srate: 37566,
147        long_bands: &SWB_OFFSET_48K_LONG,
148        short_bands: &SWB_OFFSET_48K_SHORT,
149    }, //44.1K
150    GASubbandInfo {
151        min_srate: 27713,
152        long_bands: &SWB_OFFSET_32K_LONG,
153        short_bands: &SWB_OFFSET_48K_SHORT,
154    }, //32K
155    GASubbandInfo {
156        min_srate: 23004,
157        long_bands: &SWB_OFFSET_24K_LONG,
158        short_bands: &SWB_OFFSET_24K_SHORT,
159    }, //24K
160    GASubbandInfo {
161        min_srate: 18783,
162        long_bands: &SWB_OFFSET_24K_LONG,
163        short_bands: &SWB_OFFSET_24K_SHORT,
164    }, //22.05K
165    GASubbandInfo {
166        min_srate: 13856,
167        long_bands: &SWB_OFFSET_16K_LONG,
168        short_bands: &SWB_OFFSET_16K_SHORT,
169    }, //16K
170    GASubbandInfo {
171        min_srate: 11502,
172        long_bands: &SWB_OFFSET_16K_LONG,
173        short_bands: &SWB_OFFSET_16K_SHORT,
174    }, //12K
175    GASubbandInfo {
176        min_srate: 9391,
177        long_bands: &SWB_OFFSET_16K_LONG,
178        short_bands: &SWB_OFFSET_16K_SHORT,
179    }, //11.025K
180    GASubbandInfo {
181        min_srate: 0,
182        long_bands: &SWB_OFFSET_8K_LONG,
183        short_bands: &SWB_OFFSET_8K_SHORT,
184    }, //8K
185];
186
187macro_rules! validate {
188    ($a:expr) => {
189        if !$a {
190            log::error!("check failed at {}:{}", file!(), line!());
191            return symphonia_core::errors::decode_error("aac: invalid data");
192        }
193    };
194}
195
196pub(crate) use validate;
symphonia_codec_aac/aac/common.rs

symphonia_codec_aac/aac/
common.rs
