| 1 | use nihav_core::codecs::*; |
| 2 | use nihav_core::io::bitreader::*; |
| 3 | use nihav_core::io::codebook::*; |
| 4 | |
| 5 | /// Bitstream reader. |
| 6 | #[derive(Debug,Clone)] |
| 7 | pub struct QdmBitReader<'a> { |
| 8 | cache: u32, |
| 9 | bits: u8, |
| 10 | pos: usize, |
| 11 | src: &'a [u8], |
| 12 | } |
| 13 | |
| 14 | #[allow(clippy::identity_op)] |
| 15 | #[allow(dead_code)] |
| 16 | impl<'a> QdmBitReader<'a> { |
| 17 | pub fn new(src: &'a [u8]) -> Self { |
| 18 | Self{ cache: 0, pos: 0, bits: 0, src } |
| 19 | } |
| 20 | pub fn tell(&self) -> usize { |
| 21 | self.pos * 8 - (self.bits as usize) |
| 22 | } |
| 23 | pub fn left(&self) -> isize { |
| 24 | ((self.src.len() as isize) - (self.pos as isize)) * 8 + (self.bits as isize) |
| 25 | } |
| 26 | fn refill(&mut self) { |
| 27 | while self.bits <= 24 { |
| 28 | let byte = if self.pos < self.src.len() { |
| 29 | self.pos += 1; |
| 30 | self.src[self.pos - 1] |
| 31 | } else { |
| 32 | self.pos += 1; |
| 33 | 0 |
| 34 | }; |
| 35 | self.cache |= u32::from(byte) << self.bits; |
| 36 | self.bits += 8; |
| 37 | } |
| 38 | } |
| 39 | fn read_cache(&mut self, nbits: u8) -> u32 { |
| 40 | ((1 << nbits) - 1) & self.cache |
| 41 | } |
| 42 | fn skip_cache(&mut self, nbits: u8) { |
| 43 | self.cache >>= nbits; |
| 44 | self.bits -= nbits; |
| 45 | } |
| 46 | fn reset_cache(&mut self) { |
| 47 | self.bits = 0; |
| 48 | self.cache = 0; |
| 49 | } |
| 50 | pub fn read(&mut self, nbits: u8) -> u32 { |
| 51 | if nbits == 0 { return 0; } |
| 52 | if nbits > 32 { return 0; } |
| 53 | if self.bits < nbits { |
| 54 | self.refill(); |
| 55 | } |
| 56 | let res = self.read_cache(nbits); |
| 57 | self.skip_cache(nbits); |
| 58 | res |
| 59 | } |
| 60 | pub fn read_bool(&mut self) -> bool { |
| 61 | if self.bits < 1 { |
| 62 | self.refill(); |
| 63 | } |
| 64 | let res = self.read_cache(1); |
| 65 | self.skip_cache(1); |
| 66 | res == 1 |
| 67 | } |
| 68 | pub fn peek(&mut self, nbits: u8) -> u32 { |
| 69 | if nbits > 32 { return 0 } |
| 70 | if self.bits < nbits { self.refill(); } |
| 71 | self.read_cache(nbits) |
| 72 | } |
| 73 | pub fn skip(&mut self, nbits: u32) { |
| 74 | if u32::from(self.bits) >= nbits { |
| 75 | self.skip_cache(nbits as u8); |
| 76 | return; |
| 77 | } |
| 78 | let mut skip_bits = nbits - u32::from(self.bits); |
| 79 | self.reset_cache(); |
| 80 | self.pos += ((skip_bits / 32) * 4) as usize; |
| 81 | skip_bits &= 0x1F; |
| 82 | self.refill(); |
| 83 | if skip_bits > 0 { |
| 84 | self.skip_cache(skip_bits as u8); |
| 85 | } |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | impl<'a, S: Copy> CodebookReader<S> for QdmBitReader<'a> { |
| 90 | #[allow(unused_variables)] |
| 91 | fn read_cb(&mut self, cb: &Codebook<S>) -> CodebookResult<S> { |
| 92 | let mut esc = true; |
| 93 | let mut idx = 0; |
| 94 | let mut lut_bits = cb.lut_bits; |
| 95 | while esc { |
| 96 | let lut_idx = (self.peek(lut_bits) as usize) + idx; |
| 97 | if cb.table[lut_idx] == TABLE_FILL_VALUE { return Err(CodebookError::InvalidCode); } |
| 98 | let bits = cb.table[lut_idx] & 0x7F; |
| 99 | esc = (cb.table[lut_idx] & 0x80) != 0; |
| 100 | idx = (cb.table[lut_idx] >> 8) as usize; |
| 101 | let skip_bits = if esc { u32::from(lut_bits) } else { bits }; |
| 102 | self.skip(skip_bits); |
| 103 | lut_bits = bits as u8; |
| 104 | } |
| 105 | Ok(cb.syms[idx]) |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | |
| 110 | pub fn to_signed(val: i32) -> i32 { |
| 111 | if (val & 1) != 0 { |
| 112 | (val + 1) >> 1 |
| 113 | } else { |
| 114 | -(val >> 1) |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | pub trait QdmcCodeReader { |
| 119 | fn read_code(&mut self, cb: &Codebook<u8>) -> DecoderResult<u32>; |
| 120 | fn read_code_long(&mut self, cb: &Codebook<u8>) -> DecoderResult<u32>; |
| 121 | } |
| 122 | |
| 123 | impl<'a> QdmcCodeReader for BitReader<'a> { |
| 124 | fn read_code(&mut self, cb: &Codebook<u8>) -> DecoderResult<u32> { |
| 125 | let idx = self.read_cb(cb)?; |
| 126 | if idx > 0 { |
| 127 | Ok(u32::from(idx - 1)) |
| 128 | } else { |
| 129 | let len = (self.read(3)? as u8) + 1; |
| 130 | let val = self.read(len)?; |
| 131 | Ok(val) |
| 132 | } |
| 133 | } |
| 134 | fn read_code_long(&mut self, cb: &Codebook<u8>) -> DecoderResult<u32> { |
| 135 | let idx = self.read_code(cb)? as usize; |
| 136 | validate!(idx < ESCAPE_PREFIX.len()); |
| 137 | let add = self.read((idx >> 2) as u8)?; |
| 138 | Ok(ESCAPE_PREFIX[idx] + add) |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | impl<'a> QdmcCodeReader for QdmBitReader<'a> { |
| 143 | fn read_code(&mut self, cb: &Codebook<u8>) -> DecoderResult<u32> { |
| 144 | let idx = self.read_cb(cb)?; |
| 145 | if idx > 0 { |
| 146 | Ok(u32::from(idx - 1)) |
| 147 | } else { |
| 148 | let len = (self.read(3) as u8) + 1; |
| 149 | let val = self.read(len); |
| 150 | Ok(val) |
| 151 | } |
| 152 | } |
| 153 | fn read_code_long(&mut self, cb: &Codebook<u8>) -> DecoderResult<u32> { |
| 154 | let idx = self.read_code(cb)? as usize; |
| 155 | validate!(idx < ESCAPE_PREFIX.len()); |
| 156 | let add = self.read((idx >> 2) as u8); |
| 157 | Ok(ESCAPE_PREFIX[idx] + add) |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | const ESCAPE_PREFIX: [u32; 65] = [ |
| 162 | 0x00000, 0x00001, 0x00002, 0x00003, 0x00004, 0x00006, 0x00008, 0x0000A, |
| 163 | 0x0000C, 0x00010, 0x00014, 0x00018, 0x0001C, 0x00024, 0x0002C, 0x00034, |
| 164 | 0x0003C, 0x0004C, 0x0005C, 0x0006C, 0x0007C, 0x0009C, 0x000BC, 0x000DC, |
| 165 | 0x000FC, 0x0013C, 0x0017C, 0x001BC, 0x001FC, 0x0027C, 0x002FC, 0x0037C, |
| 166 | 0x003FC, 0x004FC, 0x005FC, 0x006FC, 0x007FC, 0x009FC, 0x00BFC, 0x00DFC, |
| 167 | 0x00FFC, 0x013FC, 0x017FC, 0x01BFC, 0x01FFC, 0x027FC, 0x02FFC, 0x037FC, |
| 168 | 0x03FFC, 0x04FFC, 0x05FFC, 0x06FFC, 0x07FFC, 0x09FFC, 0x0BFFC, 0x0DFFC, |
| 169 | 0x0FFFC, 0x13FFC, 0x17FFC, 0x1BFFC, 0x1FFFC, 0x27FFC, 0x2FFFC, 0x37FFC, |
| 170 | 0x3FFFC |
| 171 | ]; |
| 172 | |
| 173 | pub struct RNG { |
| 174 | pub seed: u32, |
| 175 | } |
| 176 | |
| 177 | impl RNG { |
| 178 | pub fn new() -> Self { Self { seed: 0 } } |
| 179 | pub fn next(&mut self) -> u32 { |
| 180 | self.seed = self.seed.wrapping_mul(0x343FD).wrapping_add(0x269EC3); |
| 181 | self.seed |
| 182 | } |
| 183 | pub fn next_float(&mut self) -> f32 { |
| 184 | self.next(); |
| 185 | ((((self.seed >> 16) & 0x7FFF) as f32) - 16384.0) / 16384.0 |
| 186 | } |
| 187 | } |
| 188 | |
| 189 | #[derive(Clone,Copy)] |
| 190 | pub struct Tone { |
| 191 | pub ch: u8, |
| 192 | pub phase: u8, |
| 193 | pub offset: u8, |
| 194 | pub freq: u16, |
| 195 | pub amp_idx: u8, |
| 196 | } |
| 197 | |
| 198 | pub const MAX_TONES: usize = 8192; |
| 199 | |