| 1 | use super::BlockMode; |
| 2 | |
| 3 | #[derive(Default)] |
| 4 | pub struct RateControl { |
| 5 | bitrate: u32, |
| 6 | bitpool: u32, |
| 7 | tb_num: u32, |
| 8 | tb_den: u32, |
| 9 | fpos: u32, |
| 10 | quality: u8, |
| 11 | lambda: f32, |
| 12 | first: bool, |
| 13 | } |
| 14 | |
| 15 | impl RateControl { |
| 16 | pub fn new() -> Self { |
| 17 | Self { |
| 18 | lambda: 1.0, |
| 19 | ..Default::default() |
| 20 | } |
| 21 | } |
| 22 | pub fn init(&mut self, tb_num: u32, tb_den: u32, bitrate: u32, quality: u8) { |
| 23 | self.tb_num = tb_num; |
| 24 | self.tb_den = tb_den; |
| 25 | self.bitrate = bitrate; |
| 26 | self.quality = quality; |
| 27 | |
| 28 | self.bitpool = self.bitrate; |
| 29 | self.fpos = 0; |
| 30 | self.first = true; |
| 31 | } |
| 32 | pub fn metric(&self, diff: u32, bits: usize) -> u32 { |
| 33 | diff.saturating_add((self.get_weight() * (bits as f32)) as u32) |
| 34 | } |
| 35 | fn get_weight(&self) -> f32 { |
| 36 | if (0..=100).contains(&self.quality) { |
| 37 | self.lambda * ((100 - self.quality) as f32) |
| 38 | } else { |
| 39 | self.lambda |
| 40 | } |
| 41 | } |
| 42 | pub fn expected_size(&self) -> u32 { |
| 43 | if self.bitrate != 0 { |
| 44 | (if !self.first { |
| 45 | let ticks = self.tb_den - self.fpos; |
| 46 | u64::from(self.bitpool) * u64::from(self.tb_num) / u64::from(ticks) |
| 47 | } else { |
| 48 | u64::from(self.bitrate) * 4 * u64::from(self.tb_num) / u64::from(self.tb_den) |
| 49 | }) as u32 |
| 50 | } else { |
| 51 | 0 |
| 52 | } |
| 53 | } |
| 54 | pub fn update_size(&mut self, real_size: usize) { |
| 55 | if self.bitrate != 0 { |
| 56 | let bits = (real_size * 8) as u32; |
| 57 | let tgt_size = self.expected_size(); |
| 58 | |
| 59 | self.fpos += self.tb_num; |
| 60 | while self.fpos >= self.tb_den { |
| 61 | self.fpos -= self.tb_den; |
| 62 | self.bitpool += self.bitrate; |
| 63 | } |
| 64 | self.bitpool = self.bitpool.saturating_sub(bits); |
| 65 | |
| 66 | if bits > tgt_size + tgt_size / 8 { |
| 67 | self.lambda += 0.1; |
| 68 | } |
| 69 | if bits < tgt_size - tgt_size / 8 { |
| 70 | self.lambda -= 0.1; |
| 71 | if self.lambda < 0.0 { |
| 72 | self.lambda = 0.0; |
| 73 | } |
| 74 | } |
| 75 | self.first = false; |
| 76 | } |
| 77 | } |
| 78 | pub fn pattern_run_threshold(&self) -> u8 { |
| 79 | match self.quality { |
| 80 | 1..=39 => 4, |
| 81 | 40..=59 => 3, |
| 82 | 60..=79 => 2, |
| 83 | 80..=89 => 1, |
| 84 | _ => 0, |
| 85 | } |
| 86 | } |
| 87 | pub fn get_quant_ranges(&self) -> [u8; 4] { |
| 88 | match self.quality { |
| 89 | 98..=100 => [ 0, 0, 0, 2 ], |
| 90 | 92..=97 => [ 2, 16, 4, 16 ], |
| 91 | 85..=91 => [ 5, 16, 7, 16 ], |
| 92 | 75..=84 => [ 8, 16, 10, 16 ], |
| 93 | 55..=74 => [ 11, 16, 12, 16 ], |
| 94 | 1..=54 => [ 12, 16, 13, 16 ], |
| 95 | _ => [ 0, 16, 0, 16 ], |
| 96 | } |
| 97 | } |
| 98 | pub fn modify_forbidden_btypes(&self, forbidden: &mut [bool; 12]) { |
| 99 | if self.quality > 98 { |
| 100 | forbidden[usize::from(BlockMode::Intra)] = true; |
| 101 | } |
| 102 | if self.quality > 0 { |
| 103 | if self.quality < 80 { |
| 104 | forbidden[usize::from(BlockMode::Run)] = true; |
| 105 | forbidden[usize::from(BlockMode::Residue)] = true; |
| 106 | } |
| 107 | if self.quality < 90 { |
| 108 | forbidden[usize::from(BlockMode::Raw)] = true; |
| 109 | } |
| 110 | } |
| 111 | } |
| 112 | } |