nice

dither-image.js

@@ -5,14 +5,18 @@ import {
 import Jimp from 'Jimp';
 
 
-function zeroes(n) {
+function repeat(val, n) {
     let arr = [];
     for (let i = 0; i < n; i++) {
-        arr.push(0);
+        arr.push(val);
     }
     return arr;
 }
 
+function zeroes(n) {
+    return repeat(0, n);
+}
+
 function toLinear(val) {
     // use a 2.4 gamma approximation
     // this is BT.1886 compatible
@@ -584,29 +588,60 @@ function decimate(input, palette, n) {
 
     // preface the reserved bits
     let buckets = reserved.slice().map((c) => [atariRGB[c]]).concat([input.slice()]);
+    if (input.length != 160) {
+        throw new Error('xxx bad input size');
+    }
 
+    /*
+    let buckets = [input.slice()];
+    if (reserved.length > 0) {
+        let pxPerReserved = input.length;
+        for (let c of reserved) {
+            for (let i = 0; i < pxPerReserved; i++) {
+                buckets[0].unshift(atariRGB[c]);
+            }
+        }
+        console.log(buckets[0].length, 'xxx');
+    }
+    */
+
+    let magicSort = (picker) => (a, b) => {
+        let bychannel = picker(b) - picker(a);
+        if (bychannel) return bychannel;
+
+        let byluma = b.luma() - a.luma();
+        return byluma;
+    };
     let medianCut = (bucket, range) => {
         if (bucket.length < 2) {
-            console.log(bucket);
             throw new Error('short bucket');
         }
         //console.log('medianCut', bucket, range);
         // Sort by the channel with the greatest range,
         // then cut the bucket in two at the median.
         if (range.g >= range.r && range.g >= range.b) {
-            bucket.sort((a, b) => b.g - a.g);
+            //bucket.sort((a, b) => b.g - a.g);
+            bucket.sort(magicSort((rgb) => rgb.g));
         } else if (range.r >= range.g && range.r >= range.b) {
-            bucket.sort((a, b) => b.r - a.r);
+            //bucket.sort((a, b) => b.r - a.r);
+            bucket.sort(magicSort((rgb) => rgb.r));
         } else if (range.b >= range.g && range.b >= range.r) {
-            bucket.sort((a, b) => b.b - a.b);
+            //bucket.sort((a, b) => b.b - a.b);
+            bucket.sort(magicSort((rgb) => rgb.b));
         }
         let half = bucket.length >> 1;
         //console.log('cutting', half, bucket.length);
-        return [bucket.slice(0, half), bucket.slice(half)];
+        let [bottom, top] = [bucket.slice(0, half), bucket.slice(half)];
+        //console.log({bottom, top});
+        return [bottom, top];
+        //return [bucket.slice(0, half), bucket.slice(half)];
     };
     while (buckets.length < n) {
         // Find the bucket with the greatest range in any channel
         let ranges = buckets.map((bucket) => {
+            if (bucket.length == 0) {
+                throw new Error('xxx empty bucket');
+            }
             let red   = bucket.map((rgb) => rgb.r);
             let green = bucket.map((rgb) => rgb.g);
             let blue  = bucket.map((rgb) => rgb.b);
@@ -622,21 +657,26 @@ function decimate(input, palette, n) {
         let greatest = 0;
         let index = -1;
         for (let i = 0; i < topRanges.length; i++) {
-            if (topRanges[i] >= greatest) {
+            //if (topRanges[i] >= greatest) {
+            if (topRanges[i] > greatest) {
                 greatest = topRanges[i];
                 index = i;
             }
         }
         if (index == -1) {
             // We just ran out of colors! Pad the buckets.
-            while (buckets.length < n) {
+            //while (buckets.length < n) {
-                buckets.push([new RGB(0, 0, 0)]);
+            //    buckets.push([new RGB(0, 0, 0)]);
-            }
+            //}
             break;
         }
         let [lo, hi] = medianCut(buckets[index], ranges[index]);
         buckets.splice(index, 1, lo, hi);
     }
+
+    if (buckets.length > n) {
+        throw new Error('xxx too many colors assigned');
+    }
     decimated = buckets.map((bucket) => {
         // Average the RGB colors in this chunk
         let rgb = bucket
@@ -723,10 +763,7 @@ function decimate(input, palette, n) {
         let index = dists.indexOf(closest);
         return palette[index];
     });
-    // hack
     decimated.sort((a, b) => a - b);
-    //console.log(decimated);
-    decimated[0] = 0;
 
     // Palette fits
     return dither(decimated);
@@ -742,11 +779,25 @@ async function loadImage(src) {
 
     let width = image.bitmap.width;
     let height = image.bitmap.height;
-    if (width != 160 || height != 160) {
+
+    let aspect = width / height;
+    let dar = 2 / 1.2;
+    if (aspect > ((320 / 1.2) / 192)) {
+        // wide
         width = 160;
-        height = 160;
+        height = Math.round((width * image.bitmap.height / image.bitmap.width) * dar);
-        image = image.resize(width, height);
+        if (height & 1) {
+            height++;
+        }
+    } else {
+        // tall
+        height = 192;
+        width = Math.round((height * image.bitmap.width / image.bitmap.height) / dar);
+        if (width & 1) {
+            width++;
+        }
     }
+    image = image.resize(width, height);
 
     let rgba = image.bitmap.data.slice();
     return {
@@ -783,13 +834,12 @@ async function convert(source) {
         rgba
     } = await loadImage(source);
 
-    if (width !== 160) {
+    if (width > 160) {
-        throw new Error(`expected 160px-compatible width, got ${width} pixels`);
+        throw new Error(`expected <160px width, got ${width} pixels`);
     }
 
-    if (height !== 160) {
+    if (height > 192) {
-        // @fixme support up to 240px
+        throw new Error(`expected <192px height, got ${height} pixels`);
-        throw new Error(`expected 160px height, got ${height} pixels`);
     }
 
     if (rgba.length != width * 4 * height) {
@@ -817,19 +867,33 @@ async function convert(source) {
         allColors.push(i);
     }
 
+    let left = [], right = [];
+    let padding = 0;
+    if (width < 160) {
+        padding = 160 - width;
+
+        let black = new RGB(0, 0, 0);
+        left = repeat(black, padding >> 1);
+        right = repeat(black, padding + 1 >> 1);
+    }
+
     let lines = [];
     for (let y = 0; y < height; y++) {
         let inputLine = input
             .slice(y * width, (y + 1) * width);
+
+        if (padding) {
+            inputLine = left.concat(inputLine, right);
+        }
         if (y > 0) {
             let error = lines[y - 1].error;
-            inputLine = inputLine.map((rgb, x) => rgb.add(error[x]));
+            inputLine = inputLine.map((rgb, x) => rgb.add(error[x]).clamp());
         }
         let line = decimate(inputLine, allColors, 4, y);
         lines.push(line);
     }
     return {
-        width,
+        width: width + padding,
         height,
         lines
     };
@@ -890,12 +954,14 @@ function genAssembly(width, height, nbits, lines) {
     return `.data
 .export frame1_top
 .export frame1_bottom
+
 .export frame1_palette1_even
 .export frame1_palette1_odd
 .export frame1_palette2_even
 .export frame1_palette2_odd
 .export frame1_palette3_even
 .export frame1_palette3_odd
+
 .export displaylist
 
 .segment "BUFFERS"
@@ -904,6 +970,10 @@ function genAssembly(width, height, nbits, lines) {
 frame1_top:
 ${byte2byte(frame.bitmap.slice(0, half))}
 
+.align 4096
+frame1_bottom:
+${byte2byte(frame.bitmap.slice(half))}
+
 .align 128
 frame1_palette1_even:
 ${byte2byte(even(frame.palette1))}
@@ -928,22 +998,19 @@ ${byte2byte(even(frame.palette3))}
 frame1_palette3_odd:
 ${byte2byte(odd(frame.palette3))}
 
-.align 4096
-frame1_bottom:
-${byte2byte(frame.bitmap.slice(half))}
 
 
 
 .align 1024
 displaylist:
-    ; 40 lines overscan
+    ; 24 lines overscan
-    .repeat 4
+    .repeat 2
         .byte $70 ; 8 blank lines
     .endrep
     ; include a DLI to mark us as frame 0
     .byte $f0 ; 8 blank lines
 
-    ; 160 lines graphics
+    ; ${height} lines graphics
     ; ANTIC mode e (160px 2bpp, 1 scan line per line)
     .byte $4e
     .addr frame1_top

dither4.s

@@ -28,12 +28,13 @@ sample_ptr = sample_ptrl
 scanline = $86
 frame_counter = $89
 
-height = 160
+;height = 160
+height = 192
 bytes_per_line = 40
 pages_per_frame = 32
 lines_per_frame = 262
 ;scanline_offset = 31 + (40 - 24) / 2
-scanline_offset = 46
+scanline_offset = 30
 scanline_max = (lines_per_frame - scanline_offset) / 2
 
 .data

video-bulk/atarifiy.sh

@@ -0,0 +1,62 @@
+set -e
+
+INFILE="$1"
+# additional params can be input to the extraction
+# for time or seek
+shift
+
+mkdir -p temp
+
+ffmpeg \
+    -i "$INFILE" \
+    -r 60000/1001 \
+    -vf 'scale=256:-2' \
+    -an \
+    "$@" \
+    -y "temp/$INFILE-%04d.png"
+
+ffmpeg \
+    -i "$INFILE" \
+    -vn \
+    -ac 1 \
+    -ar 15734 \
+    -acodec pcm_u8 \
+    "$@" \
+    -y "temp/$INFILE-audio.wav" || echo no audio
+
+for frame in "temp/$INFILE-"[0-9][0-9][0-9][0-9].png
+do
+    n="${frame#temp/$INFILE-}"
+    n="${n%.png}"
+    out="temp/$INFILE-dither-${n}"
+    last="${n:0-1}"
+    node ../dither-image.js "$frame" "$out" &
+    if (( last == 9 ))
+    then
+        echo "frame $n"
+        wait
+    fi
+done
+wait
+
+if [ -f "temp/$INFILE-audio.wav" ]
+then
+    ffmpeg \
+        -r 60000/1001 \
+        -i "temp/$INFILE-dither-%04d.png" \
+        -i "temp/$INFILE-audio.wav" \
+        -ac 2 \
+        -ar 48000 \
+        -vf 'pad=w=534' \
+        -pix_fmt yuv420p \
+        -movflags +faststart \
+        -y "$INFILE-dither.mp4"
+else
+    ffmpeg \
+        -r 60000/1001 \
+        -i "temp/$INFILE-dither-%04d.png" \
+        -vf 'pad=w=534' \
+        -pix_fmt yuv420p \
+        -movflags +faststart \
+        -y "$INFILE-dither.mp4"
+fi

video-cat/combine.sh

@@ -0,0 +1,10 @@
+ffmpeg \
+    -r 30000/1001 \
+    -i 'frames/dither-%04d.png' \
+    -i 'cats-audio.wav' \
+    -ac 2 \
+    -ar 48000 \
+    -vf 'pad=w=534' \
+    -pix_fmt yuv420p \
+    -movflags +faststart \
+    -y cats-dither.mp4

video-cat/extract.sh

@@ -0,0 +1,17 @@
+set -a
+
+mkdir -p frames
+
+ffmpeg \
+    -i 'cats computer fun.mp4' \
+    -vf 'scale=256:144' \
+    -an \
+    -y 'frames/cats-%04d.png'
+
+ffmpeg \
+    -i 'cats computer fun.mp4' \
+    -vn \
+    -ac 1 \
+    -ar 15734 \
+    -acodec pcm_u8 \
+    -y 'cats-audio.wav'

video-cat/video.sh

@@ -0,0 +1,15 @@
+set -e
+
+for frame in frames/cats-[0-9][0-9][0-9][0-9].png
+do
+    n="${frame#frames/cats-}"
+    n="${n%.png}"
+    out="frames/dither-${n}"
+    last="${n:0-1}"
+    node ../dither-image.js "$frame" "$out" &
+    if (( last == 9 ))
+    then
+        wait
+    fi
+done
+wait

video-doom/combine.sh

@@ -0,0 +1,10 @@
+ffmpeg \
+    -r 60000/1001 \
+    -i 'frames/dither-%04d.png' \
+    -i 'doom-audio.wav' \
+    -ac 2 \
+    -ar 48000 \
+    -vf 'pad=w=534' \
+    -pix_fmt yuv420p \
+    -movflags +faststart \
+    -y doom-dither.mp4

video-doom/extract.sh

@@ -0,0 +1,22 @@
+set -a
+
+mkdir -p frames
+
+TIME=37.5
+
+ffmpeg \
+    -i 'doom-speedrun.webm' \
+    -t $TIME \
+    -r 60000/1001 \
+    -vf 'scale=256:192' \
+    -an \
+    -y 'frames/doom-%04d.png'
+
+ffmpeg \
+    -i 'doom-speedrun.webm' \
+    -t $TIME \
+    -vn \
+    -ac 1 \
+    -ar 15734 \
+    -acodec pcm_u8 \
+    -y 'doom-audio.wav'

video-doom/video.sh

@@ -0,0 +1,15 @@
+set -e
+
+for frame in frames/doom-[0-9][0-9][0-9][0-9].png
+do
+    n="${frame#frames/doom-}"
+    n="${n%.png}"
+    out="frames/dither-${n}"
+    last="${n:0-1}"
+    node ../dither-image.js "$frame" "$out" &
+    if (( last == 9 ))
+    then
+        wait
+    fi
+done
+wait

video/combine.sh

@@ -4,7 +4,7 @@ ffmpeg \
     -i 'colamath-audio.wav' \
     -ac 2 \
     -ar 48000 \
-    -vf 'pad=w=640:h=360:x=52:y=20' \
+    -vf 'pad=w=534' \
     -pix_fmt yuv420p \
     -movflags +faststart \
     -y colamath-dither.mp4

video/extract.sh

@@ -4,7 +4,7 @@ mkdir -p frames
 
 ffmpeg \
     -i colamath-dv.avi \
-    -vf 'yadif=1,scale=160:200,crop=h=160' \
+    -vf 'yadif=1,scale=256:192' \
     -an \
     -y 'frames/colamath-%04d.png'