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use crate::huff::write_huff;
use crate::impls::join;
use crate::split::split;
use crate::{decode::decode_block, Block, Frame, Pixel, Ref, View, P2};
use std::io::{BufReader, BufWriter, Read, Write};
use std::time::Instant;
#[derive(Debug, Clone)]
pub struct EncodeConfig {
pub threshold: f32,
pub max_block_size: usize,
pub min_block_size: usize,
pub attention_split: u32,
pub motion_split_f: f32,
pub keyframe_interval: usize,
}
pub fn encode(
config: EncodeConfig,
size: P2,
input: impl Read,
output: impl Write,
) -> std::io::Result<()> {
let mut input = BufReader::new(input);
let mut output = BufWriter::new(output);
let mut last_frame = Frame::new(size);
for frame_number in 0.. {
let mut frame = Frame::read(&mut input, size)?;
let mut config = config.clone();
if frame_number % config.keyframe_interval != 0 {
config.threshold = std::f32::INFINITY;
}
let t = Instant::now();
let b: Block = encode_block(&last_frame, &frame, View::all(size), &config);
let time_encode = t.elapsed();
let t = Instant::now();
decode_block(&last_frame, &mut frame, View::all(size), &b);
last_frame = frame;
let time_decode = t.elapsed();
if true {
let mut buf = vec![];
let mut bufw = std::io::Cursor::new(&mut buf);
b.write(&mut bufw)?;
drop(bufw);
let t = Instant::now();
let bits_raw = buf.len() * 8;
let bits_huff = write_huff(&buf, &mut output)?;
let time_huff = t.elapsed();
drop(buf);
eprintln!(
"frame {frame_number}: {:?}",
time_decode + time_huff + time_encode
);
eprintln!(
"\tencode {time_encode:?} ({:.2}%)",
(bits_raw as f32 / (size.area() * 24) as f32) * 100.0
);
eprintln!(
"\thuff {time_huff:?} ({:.2}%)",
(bits_huff as f32 / bits_raw as f32) * 100.0
);
eprintln!("\tdecode {time_decode:?}");
} else {
b.write(&mut output)?;
}
}
Ok(())
}
pub fn encode_block(last_frame: &Frame, frame: &Frame, view: View, config: &EncodeConfig) -> Block {
let view_area = view.size().area();
let thres = config.threshold * view_area as f32;
if view_area > config.max_block_size
|| (view_area > config.min_block_size
&& (total_contrast(frame, view) > config.attention_split
|| diff([last_frame, frame], view, Ref::default())
> (thres * config.motion_split_f) as u32))
{
let [av, bv] = split(view);
let (ab, bb) = join(
|| encode_block(last_frame, frame, av, config),
|| encode_block(last_frame, frame, bv, config),
);
return Block::Split(box ab, box bb);
}
let mut r = Ref::default();
let mut d = diff([last_frame, frame], view, r);
let target_average = average_color(frame, view);
for granularity in [1, 2, 3, 5, 7, 5, 3, 2, 1] {
let (nd, nrp) = optimize_ref(last_frame, frame, view, r, granularity, target_average);
if nd < d {
r = nrp;
d = nd;
} else {
break;
}
}
if d < thres as u32 {
return Block::Ref(r);
} else {
Block::Lit(frame.export(view))
}
}
pub fn optimize_ref(
last_frame: &Frame,
frame: &Frame,
view: View,
r: Ref,
g: i32,
target_average: Pixel,
) -> (u32, Ref) {
let g2 = g * 2;
[
Some(r.apply(|r| r.pos_off += P2 { x: g, y: 0 })),
Some(r.apply(|r| r.pos_off += P2 { x: g, y: g })),
Some(r.apply(|r| r.pos_off += P2 { x: 0, y: g })),
Some(r.apply(|r| r.pos_off += P2 { x: -g, y: g })),
Some(r.apply(|r| r.pos_off += P2 { x: -g, y: 0 })),
Some(r.apply(|r| r.pos_off += P2 { x: -g, y: -g })),
Some(r.apply(|r| r.pos_off += P2 { x: 0, y: -g })),
Some(r.apply(|r| r.pos_off += P2 { x: g, y: -g })),
Some(r.apply(|r| r.pos_off += P2 { x: g2, y: 0 })),
Some(r.apply(|r| r.pos_off += P2 { x: g2, y: g2 })),
Some(r.apply(|r| r.pos_off += P2 { x: 0, y: g2 })),
Some(r.apply(|r| r.pos_off += P2 { x: -g2, y: g2 })),
Some(r.apply(|r| r.pos_off += P2 { x: -g2, y: 0 })),
Some(r.apply(|r| r.pos_off += P2 { x: -g2, y: -g2 })),
Some(r.apply(|r| r.pos_off += P2 { x: 0, y: -g2 })),
Some(r.apply(|r| r.pos_off += P2 { x: g2, y: -g2 })),
{
let mut r = r;
let last_avr = average_color(last_frame, view);
let diff = target_average - last_avr;
r.color_off = diff;
if diff != Pixel::BLACK {
Some(r)
} else {
None
}
},
]
.into_iter()
.flatten()
.map(|r| (diff([last_frame, frame], view, r), r))
.min_by_key(|e| e.0)
.unwrap()
}
pub fn total_contrast(frame: &Frame, view: View) -> u32 {
let mut k = 0;
for y in view.a.y..view.b.y - 1 {
for x in view.a.x..view.b.x - 1 {
let p = P2 { x, y };
k += pixel_diff(frame[p], frame[p + P2::X]).pow(2);
k += pixel_diff(frame[p], frame[p + P2::Y]).pow(2);
}
}
k
}
pub fn average_color(frame: &Frame, view: View) -> Pixel {
let mut r = 0u32;
let mut g = 0u32;
let mut b = 0u32;
for y in view.a.y..view.b.y {
for x in view.a.x..view.b.x {
let p = frame[P2 { x, y }];
r += p.r as u32;
g += p.g as u32;
b += p.b as u32;
}
}
let area = view.size().area() as u32;
Pixel {
r: (r / area) as i16,
g: (g / area) as i16,
b: (b / area) as i16,
}
}
pub fn diff([frame1, frame2]: [&Frame; 2], view: View, rp: Ref) -> u32 {
let mut k = 0;
for y in view.a.y..view.b.y {
for x in view.a.x..view.b.x {
let pos = P2 { x, y };
let p1 = frame1[pos + rp.pos_off] + rp.color_off;
let p2 = frame2[pos];
k += pixel_diff(p1, p2)
}
}
k
}
#[inline(always)]
pub fn pixel_diff(p1: Pixel, p2: Pixel) -> u32 {
p1.r.abs_diff(p2.r) as u32 + p1.g.abs_diff(p2.g) as u32 + p1.b.abs_diff(p2.b) as u32
}
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