1 files changed, 127 insertions, 0 deletions
diff --git a/lvc/codec/src/encode.rs b/lvc/codec/src/encode.rs
new file mode 100644
index 0000000..030e882
--- /dev/null
+++ b/lvc/codec/src/encode.rs
@@ -0,0 +1,127 @@
+use crate::diff::{diff, pixel_diff};
+use crate::split::split;
+use crate::{Block, Frame, Pixel, Ref, View, P2};
+
+#[derive(Debug, Clone)]
+pub struct EncodeConfig {
+    pub threshold: f32,
+    pub max_block_size: usize,
+    pub attention_split: u32,
+}
+
+pub fn encode(last_frame: &Frame, frame: &Frame, view: View, config: &EncodeConfig) -> Block {
+    let view_area = view.size().area();
+    if view_area > config.max_block_size
+        || (view_area > 64 && attention(frame, view) > config.attention_split)
+    {
+        let [av, bv] = split(view);
+        let (ab, bb) = rayon::join(
+            || Box::new(encode(last_frame, frame, av, config)),
+            || Box::new(encode(last_frame, frame, bv, config)),
+        );
+        return Block::Split(ab, bb);
+    }
+
+    let mut r = Ref::default();
+    let mut d = diff([last_frame, frame], view, r);
+
+    // let att = 1. - attention(frame, view) as f32 * 0.000001;
+    // let thres = (config.threshold as f32 * att.clamp(0.2, 1.0)) as u32;
+    let thres = (config.threshold * view_area as f32) as u32;
+
+    let target_average = average_color(frame, view);
+
+    for granularity in [2, 1, 2, 1, 2, 1, 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 {
+        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 attention(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,
+    }
+}