2023-06-28 22:52:09 +00:00
|
|
|
<!DOCTYPE html>
|
|
|
|
|
<html>
|
|
|
|
|
<head>
|
|
|
|
|
<meta charset="utf-8">
|
|
|
|
|
<title>Block video encoding test</title>
|
|
|
|
|
<style type="text/css">
|
|
|
|
|
.stretchy {
|
|
|
|
|
width:267px;
|
2023-07-03 03:58:19 +00:00
|
|
|
height: 160px;
|
2023-06-28 22:52:09 +00:00
|
|
|
object-fit: fill;
|
|
|
|
|
image-rendering: pixelated;
|
|
|
|
|
}
|
|
|
|
|
</style>
|
|
|
|
|
</head>
|
|
|
|
|
<body>
|
|
|
|
|
<h1>Block video encoding test</h1>
|
|
|
|
|
|
|
|
|
|
<h2>Source video</h2>
|
|
|
|
|
<div>
|
|
|
|
|
<video id="source" src="llamigos.webm" class="stretchy" muted controls playsinline></video>
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
<h2>Work canvas</h2>
|
|
|
|
|
<div>
|
2023-07-03 03:58:19 +00:00
|
|
|
<canvas id="work" width="80" height="160" class="stretchy"></canvas>
|
2023-06-28 22:52:09 +00:00
|
|
|
</div>
|
2023-07-03 04:47:06 +00:00
|
|
|
<div>
|
|
|
|
|
<span id="block-count">n/a</span> blocks per frame
|
|
|
|
|
</div>
|
2023-06-28 22:52:09 +00:00
|
|
|
|
|
|
|
|
<script type="text/javascript">
|
|
|
|
|
let width = 80;
|
2023-07-03 03:58:19 +00:00
|
|
|
let height = 160;
|
|
|
|
|
|
|
|
|
|
let blockWidth = 2;
|
|
|
|
|
let blockHeight = 8;
|
|
|
|
|
|
|
|
|
|
let widthBlocks = width / blockWidth;
|
|
|
|
|
let heightBlocks = height / blockHeight;
|
2023-06-28 22:52:09 +00:00
|
|
|
|
|
|
|
|
function fromSRGB(val) {
|
|
|
|
|
if (val <= 0.04045) {
|
2023-07-03 03:58:19 +00:00
|
|
|
return val / 12.92;
|
2023-06-28 22:52:09 +00:00
|
|
|
}
|
2023-07-03 03:58:19 +00:00
|
|
|
return ((val + 0.055) / 1.055) ** 2.4;
|
2023-06-28 22:52:09 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
function toSRGB(val) {
|
|
|
|
|
if (val <= 0.0031308) {
|
2023-07-03 03:58:19 +00:00
|
|
|
return val * 12.92;
|
2023-06-28 22:52:09 +00:00
|
|
|
}
|
2023-07-03 03:58:19 +00:00
|
|
|
return (val * 1.055) ** (1.0 / 2.4) - 0.055;
|
2023-06-28 22:52:09 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
function luma(r, g, b) {
|
|
|
|
|
return r * 0.299 + g * 0.586 + b * 0.114;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
function update() {
|
|
|
|
|
let ctx = work.getContext('2d');
|
2023-07-03 03:58:19 +00:00
|
|
|
let pixels = new Uint8Array(width * height);
|
|
|
|
|
|
|
|
|
|
// Extract the luma
|
2023-06-28 22:52:09 +00:00
|
|
|
ctx.drawImage(source, 0, 0);
|
|
|
|
|
let bits = ctx.getImageData(0, 0, width, height);
|
|
|
|
|
let data = bits.data;
|
|
|
|
|
for (let y = 0; y < height; y++) {
|
|
|
|
|
for (let x = 0; x < width; x++) {
|
2023-07-03 03:58:19 +00:00
|
|
|
let i = y * width + x;
|
2023-06-28 22:52:09 +00:00
|
|
|
|
2023-07-03 03:58:19 +00:00
|
|
|
let r = fromSRGB(data[i * 4] / 255);
|
|
|
|
|
let g = fromSRGB(data[i * 4 + 1] / 255);
|
|
|
|
|
let b = fromSRGB(data[i * 4 + 2] / 255);
|
|
|
|
|
|
|
|
|
|
let grayLinear = luma(r, g, b);
|
|
|
|
|
let gray = toSRGB(grayLinear);
|
|
|
|
|
let gray16 = Math.round(gray * 15);
|
|
|
|
|
pixels[i] = gray16;
|
|
|
|
|
}
|
|
|
|
|
}
|
2023-06-28 22:52:09 +00:00
|
|
|
|
2023-07-03 03:58:19 +00:00
|
|
|
let blocks = [];
|
2023-07-03 04:47:06 +00:00
|
|
|
let chars = new Uint16Array(widthBlocks * heightBlocks);
|
|
|
|
|
for (let n = 0, y = 0; y < heightBlocks; y++) {
|
|
|
|
|
for (let x = 0; x < widthBlocks; x++, n++) {
|
|
|
|
|
let i = y * widthBlocks + x;
|
|
|
|
|
blocks[i] = new Uint8Array(blockWidth * blockHeight);
|
|
|
|
|
chars[n] = i;
|
|
|
|
|
for (let yy = 0; yy < blockHeight; yy++) {
|
|
|
|
|
for (let xx = 0; xx < blockWidth; xx++) {
|
|
|
|
|
let ii = yy * blockWidth + xx;
|
|
|
|
|
blocks[i][ii] = pixels[(y * blockHeight + yy) * width + (x * blockWidth + xx)];
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// Now we have 800 blocks for 80x160 image
|
|
|
|
|
// But we can only use 128 + their mirror images
|
|
|
|
|
//
|
|
|
|
|
// First pass: sort.
|
|
|
|
|
let zero = "0".charCodeAt(0);
|
|
|
|
|
// Convert the 4bpp pixel indices into hex strings
|
|
|
|
|
let blockMap = {};
|
|
|
|
|
let keys = [];
|
|
|
|
|
for (let i = 0; i < blocks.length; i++) {
|
|
|
|
|
let key = blocks[i].map((n) => n.toString(16)).join('');
|
|
|
|
|
console.log(key);
|
|
|
|
|
if (!blockMap[key]) {
|
|
|
|
|
blockMap[key] = blocks[i];
|
|
|
|
|
keys.push(blockMap[key]);
|
2023-07-03 03:58:19 +00:00
|
|
|
}
|
|
|
|
|
}
|
2023-07-03 04:47:06 +00:00
|
|
|
let span = document.querySelector('#block-count');
|
|
|
|
|
span.textContent = `${keys.length}`;
|
|
|
|
|
|
2023-06-28 22:52:09 +00:00
|
|
|
|
2023-07-03 03:58:19 +00:00
|
|
|
for (let y = 0; y < height; y++) {
|
|
|
|
|
for (let x = 0; x < width; x++) {
|
|
|
|
|
let i = y * width + x;
|
|
|
|
|
let gray16 = pixels[i];
|
|
|
|
|
let gray256 = Math.round(gray16 * 255 / 15);
|
|
|
|
|
data[i * 4] = gray256;
|
|
|
|
|
data[i * 4 + 1] = gray256;
|
|
|
|
|
data[i * 4 + 2] = gray256;
|
2023-06-28 22:52:09 +00:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
ctx.putImageData(bits, 0, 0);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
let timer = null;
|
|
|
|
|
source.addEventListener('playing', () => {
|
|
|
|
|
if (!timer) {
|
|
|
|
|
timer = setInterval(update, 1000 / 24);
|
|
|
|
|
}
|
|
|
|
|
update();
|
|
|
|
|
});
|
|
|
|
|
source.addEventListener('pause', () => {
|
|
|
|
|
if (timer) {
|
|
|
|
|
clearInterval(timer);
|
|
|
|
|
timer = null;
|
|
|
|
|
}
|
|
|
|
|
});
|
|
|
|
|
</script>
|
|
|
|
|
</body>
|
|
|
|
|
</html>
|
