appears to work now

This reverts commit debdd36ce0.

.gitignore

@@ -12,4 +12,9 @@ sample*.s
 chickens.wav
 chickens.s
 dubstep.wav
-dubstep.wav.*
+dubstep.wav.*
+video-rickroll/frames
+video-doom/frames
+video-cat/frames
+video-bulk/frames
+video/frames

Makefile

@@ -1,21 +1,44 @@
-all : sample0.xex \
+all : rickroll.xex
-	sample1.xex sample2.xex sample3.xex sample4.xex sample5.xex sample6.xex \
-	fruit.xex mapclock.xex sailboat.xex sunset.xex train404.xex \
-	potato.xex selfie.xex kitty.xex meme.xex
 
 # sample5.s from sample5.jpg
 
 # reminder: $< is input
 #           $@ is output
 
-%.s : %.jpg dither-image.js
+%.s : %.jpg dither-image.js gif.sh mp4.sh
 	node dither-image.js $< $@
 
+chickens.s : chickens.wav pack-wav.js
+	node pack-wav.js $< $@
+
+dubstep.wav.s : dubstep.wav pack-wav.js
+	node pack-wav.js $< $@
+
+dubstep.wav : Dubstep_Loop_by_WinnieTheMoog.ogg
+	ffmpeg -i "Dubstep_Loop_by_WinnieTheMoog.ogg" \
+	  -t 2.0 \
+	  -acodec pcm_u8 \
+	  -ac 1 \
+	  -ar 15704 \
+	  -y $@
+
+never-gonna-give-you-up.wav.s : never-gonna-give-you-up.wav pack-wav.js
+	node pack-wav.js $< $@
+
+never-gonna-give-you-up.wav : never-gonna-give-you-up.mp4
+	ffmpeg -i "never-gonna-give-you-up.mp4" \
+	  -vn \
+	  -t 2.0 \
+	  -acodec pcm_u8 \
+	  -ac 1 \
+	  -ar 15704 \
+	  -y $@
+
 %.o : %.s
 	ca65 -v -t atari -o $@ $<
 
-%.xex : %.o dither4.o atari-asm-xex.cfg
+%.xex : %.o dither4.o never-gonna-give-you-up.wav.o atari-asm-xex.cfg
-	ld65 -v -C ./atari-asm-xex.cfg -o $@ dither4.o $<
+	ld65 -v -C ./atari-asm-xex.cfg -o $@ dither4.o never-gonna-give-you-up.wav.o $<
 
 clean :
 	rm -f *.o
@@ -24,3 +47,14 @@ clean :
 	rm -f fruit.s mapclock.s sailboat.s sunset.s train404.s
 	rm -f potato.s selfie.s kitty.s meme.s
 	rm -f *.xex
+	rm -f chickens.s
+	rm -f chickens.o
+	rm -f dubstep.wav
+	rm -f dubstep.wav.[so]
+	rm -f never-gonna-give-you-up.wav
+	rm -f never-gonna-give-you-up.wav.[so]
+
+test : all
+	atari800 rickroll.xex
+
+.dummy: clean test sample0.s sample1.s sample2.s sample3.s sample4.s sample5.s sample6.s chickens.s rickroll.s

dither-image.js

@@ -1067,7 +1067,7 @@ async function saveImage(width, height, lines, dest) {
             resolve(image);
         });
     });
-    await image.resize(Math.round(width2 * 2 / 1.2), height * 2);
+    await image.resize(Math.round(width2 * 2), height * 2);
     await image.writeAsync(dest);
 }
 

dither4.s

@@ -26,6 +26,7 @@ sample_ptrl = $84
 sample_ptrh = $85
 sample_ptr = sample_ptrl
 scanline = $86
+audiotemp = $87
 frame_counter = $89
 
 ;height = 160
@@ -39,6 +40,9 @@ scanline_max = (lines_per_frame - scanline_offset) / 2
 
 .data
 
+.import audio_samples
+.import audio_samples_end
+
 .import frame1_top
 .import frame1_bottom
 .import frame1_palette1_even
@@ -49,11 +53,41 @@ scanline_max = (lines_per_frame - scanline_offset) / 2
 .import frame1_palette3_odd
 .import displaylist
 
+audio_high_byte:
+    .scope
+        .macro byteseq val
+            .repeat 16
+                .byte val | $10
+            .endrep
+        .endmacro
+        byteseq $0
+        byteseq $1
+        byteseq $2
+        byteseq $3
+        byteseq $4
+        byteseq $5
+        byteseq $7
+        byteseq $8
+        byteseq $9
+        byteseq $a
+        byteseq $b
+        byteseq $c
+        byteseq $d
+        byteseq $e
+        byteseq $f
+    .endscope
+
 .code
 
 .export start
 
 .proc start
+    ; Set up the audio sample buffer
+    lda #.lobyte(audio_samples)
+    sta sample_ptrl
+    lda #.hibyte(audio_samples)
+    sta sample_ptrh
+
     ; Disable display DMA
     lda #$00
     sta DMACTL
@@ -98,8 +132,6 @@ wait_loop:
     .macro inner_scanline frame_offset, line_offset
         ; Y should be VCOUNT at entry
         ; it'll fire on unused lines, but harmlessly
-        ;ldy scanline ; 3 cyc
-        ;inc scanline ; 5 cyc
 
         ; 23-26 cycles before break
         ; Leisurely memory fetches
@@ -109,6 +141,7 @@ wait_loop:
         lda frame1_palette3_even + frame_offset + line_offset - scanline_offset / 2,y ; 4/5
         tay                                                                           ; 2
         pla                                                                           ; 3
+
         ; Wait for horizontal blank
         sta WSYNC                                                                     ; 4
 
@@ -119,6 +152,59 @@ wait_loop:
         sty COLPF2 ; 4
     .endmacro
 
+    .macro audio_play_raw
+        ;ldy VCOUNT ; set on entry
+        lda (sample_ptr),y ; 5/6 cyc
+        sta AUDC1          ; 4 cyc
+    .endmacro
+
+    .macro audio_prep
+        ; Y is VCOUNT at entry
+        lda (sample_ptr),y ; 5/6 cyc
+        sta audiotemp      ; 3 cyc
+    .endmacro
+
+    ; call with A pre-loaded to audiotemp
+    .macro audio_play_lo
+        ;lda audiotemp ; 3 cyc
+        and #$0f ; 2 cyc
+        ora #$10 ; 2 cyc
+        sta AUDC1 ; 4 cyc
+    .endmacro
+
+    ; clobbers Y
+    .macro audio_play_hi ; 12 cycles
+        ldy audiotemp ; 3 cyc
+        lda audio_high_byte,y ; 5 cyc
+        sta AUDC1 ; 4 cyc
+    .endmacro
+
+    .macro audio_inc
+        ; 22 cycles
+        lda sample_ptrl ; 3 cyc
+        clc             ; 2 cyc
+        adc #131        ; 2 cyc
+        sta sample_ptrl ; 3 cyc
+        lda sample_ptrh ; 3 cyc
+        adc #0          ; 2 cyc
+        sta sample_ptrh ; 3 cyc
+        cmp #.hibyte(audio_samples_end) ; 2 cyc
+        bmi audio_cont                  ; 2 cyc
+
+        sta WSYNC
+
+        ; 10 cycles, optional
+        lda #.lobyte(audio_samples)     ; 2
+        sta sample_ptrl                 ; 3
+        lda #.hibyte(audio_samples)     ; 2
+        sta sample_ptrh                 ; 3
+
+        sta WSYNC
+        ldy VCOUNT             ; 4 cycles
+
+        audio_cont:
+    .endmacro
+
     .macro run_frame frame_offset
     .scope
         ; each scanline is 228 color clocks
@@ -129,13 +215,21 @@ wait_loop:
         sty scanline ; 3 cycles
         inner_scanline frame_offset, 0 ; 23-26 cycles before break, 12 cycles after
 
+        ldy scanline ; 3 cycles
+        audio_prep
+        audio_play_lo
+
         ldy scanline   ; 3 cycles
         inner_scanline frame_offset, 128 ; 23-26 cycles before break, 12 cycles after
 
+        audio_play_hi
+
         ; pair cleanup: 6 cycles
         ldy VCOUNT             ; 4 cycles
         bne each_scanline_pair ; 2 cycles
 
+        audio_inc      ; 22-32 cycles
+
         ; frame cleanup: 11 cycles
         lda frame_counter ; 3 cycles
         eor #1            ; 2 cycles

pack-wav.js

@@ -14,31 +14,44 @@ function byte2byte(arr) {
     return lines.join('\n');
 }
 
-function to4bit(val8) {
+class Dither {
-    let val = (val8 + 7) >> 4;
+    constructor() {
-    if (val > 15) {
+        this.err = 0;
-        return 15;
+    }
+
+    to4bit(val8) {
+        let val = (val8 / 255) - this.err;
+        if (val < 0) {
+            val = 0;
+        }
+        if (val > 1) {
+            val = 1;
+        }
+        let val4 = Math.round(val * 15);
+        let dithered = (val4 / 15);
+        this.err = (dithered - val);
+        return val4;
     }
-    return val;
 }
 
 function pack(audio) {
     let packed = [];
-    /*
+    let dither = new Dither();
     for (let i = 0; i < audio.length; i += 2) {
         // little-endian 4-bit samples
-        let low = to4bit(audio[i]);
+        let low = dither.to4bit(audio[i]);
-        let high = to4bit(audio[i + 1]);
+        let high = dither.to4bit(audio[i + 1]);
         let byte = low | (high << 4);
         packed.push(byte);
     }
-    */
+    /*
     // raw push bytes
     for (let i = 0; i < audio.length; i += 2) {
         let val = to4bit(audio[i]);
         let byte = val | 0x10;
         packed.push(byte);
     }
+    */
     return packed;
 }
 

package-lock.json

@@ -6,6 +6,7 @@
     "": {
       "dependencies": {
         "jimp": "^0.16.2",
+        "wav": "^1.0.2",
         "wavefile": "^11.0.0"
       },
       "devDependencies": {
@@ -708,6 +709,22 @@
         "ieee754": "^1.1.13"
       }
     },
+    "node_modules/buffer-alloc": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/buffer-alloc/-/buffer-alloc-1.2.0.tgz",
+      "integrity": "sha512-CFsHQgjtW1UChdXgbyJGtnm+O/uLQeZdtbDo8mfUgYXCHSM1wgrVxXm6bSyrUuErEb+4sYVGCzASBRot7zyrow==",
+      "license": "MIT",
+      "dependencies": {
+        "buffer-alloc-unsafe": "^1.1.0",
+        "buffer-fill": "^1.0.0"
+      }
+    },
+    "node_modules/buffer-alloc-unsafe": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/buffer-alloc-unsafe/-/buffer-alloc-unsafe-1.1.0.tgz",
+      "integrity": "sha512-TEM2iMIEQdJ2yjPJoSIsldnleVaAk1oW3DBVUykyOLsEsFmEc9kn+SFFPz+gl54KQNxlDnAwCXosOS9Okx2xAg==",
+      "license": "MIT"
+    },
     "node_modules/buffer-equal": {
       "version": "0.0.1",
       "resolved": "https://registry.npmjs.org/buffer-equal/-/buffer-equal-0.0.1.tgz",
@@ -716,6 +733,18 @@
         "node": ">=0.4.0"
       }
     },
+    "node_modules/buffer-fill": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/buffer-fill/-/buffer-fill-1.0.0.tgz",
+      "integrity": "sha512-T7zexNBwiiaCOGDg9xNX9PBmjrubblRkENuptryuI64URkXDFum9il/JGL8Lm8wYfAXpredVXXZz7eMHilimiQ==",
+      "license": "MIT"
+    },
+    "node_modules/buffer-from": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/buffer-from/-/buffer-from-1.1.2.tgz",
+      "integrity": "sha512-E+XQCRwSbaaiChtv6k6Dwgc+bx+Bs6vuKJHHl5kox/BaKbhiXzqQOwK4cO22yElGp2OCmjwVhT3HmxgyPGnJfQ==",
+      "license": "MIT"
+    },
     "node_modules/callsites": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/callsites/-/callsites-3.1.0.tgz",
@@ -765,6 +794,12 @@
       "integrity": "sha512-/Srv4dswyQNBfohGpz9o6Yb3Gz3SrUDqBH5rTuhGR7ahtlbYKnVxw2bCFMRljaA7EXHaXZ8wsHdodFvbkhKmqg==",
       "dev": true
     },
+    "node_modules/core-util-is": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.3.tgz",
+      "integrity": "sha512-ZQBvi1DcpJ4GDqanjucZ2Hj3wEO5pZDS89BWbkcrvdxksJorwUDDZamX9ldFkp9aw2lmBDLgkObEA4DWNJ9FYQ==",
+      "license": "MIT"
+    },
     "node_modules/cross-spawn": {
       "version": "7.0.3",
       "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.3.tgz",
@@ -1216,8 +1251,7 @@
     "node_modules/inherits": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.4.tgz",
-      "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==",
+      "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ=="
-      "dev": true
     },
     "node_modules/is-extglob": {
       "version": "2.1.1",
@@ -1254,6 +1288,12 @@
         "node": ">=8"
       }
     },
+    "node_modules/isarray": {
+      "version": "0.0.1",
+      "resolved": "https://registry.npmjs.org/isarray/-/isarray-0.0.1.tgz",
+      "integrity": "sha512-D2S+3GLxWH+uhrNEcoh/fnmYeP8E8/zHl644d/jdA0g2uyXvy3sb0qxotE+ne0LtccHknQzWwZEzhak7oJ0COQ==",
+      "license": "MIT"
+    },
     "node_modules/isexe": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/isexe/-/isexe-2.0.0.tgz",
@@ -1621,6 +1661,18 @@
         }
       ]
     },
+    "node_modules/readable-stream": {
+      "version": "1.1.14",
+      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-1.1.14.tgz",
+      "integrity": "sha512-+MeVjFf4L44XUkhM1eYbD8fyEsxcV81pqMSR5gblfcLCHfZvbrqy4/qYHE+/R5HoBUT11WV5O08Cr1n3YXkWVQ==",
+      "license": "MIT",
+      "dependencies": {
+        "core-util-is": "~1.0.0",
+        "inherits": "~2.0.1",
+        "isarray": "0.0.1",
+        "string_decoder": "~0.10.x"
+      }
+    },
     "node_modules/regenerator-runtime": {
       "version": "0.13.11",
       "resolved": "https://registry.npmjs.org/regenerator-runtime/-/regenerator-runtime-0.13.11.tgz",
@@ -1709,6 +1761,36 @@
         "node": ">=8"
       }
     },
+    "node_modules/stream-parser": {
+      "version": "0.3.1",
+      "resolved": "https://registry.npmjs.org/stream-parser/-/stream-parser-0.3.1.tgz",
+      "integrity": "sha512-bJ/HgKq41nlKvlhccD5kaCr/P+Hu0wPNKPJOH7en+YrJu/9EgqUF+88w5Jb6KNcjOFMhfX4B2asfeAtIGuHObQ==",
+      "license": "MIT",
+      "dependencies": {
+        "debug": "2"
+      }
+    },
+    "node_modules/stream-parser/node_modules/debug": {
+      "version": "2.6.9",
+      "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+      "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+      "license": "MIT",
+      "dependencies": {
+        "ms": "2.0.0"
+      }
+    },
+    "node_modules/stream-parser/node_modules/ms": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
+      "integrity": "sha512-Tpp60P6IUJDTuOq/5Z8cdskzJujfwqfOTkrwIwj7IRISpnkJnT6SyJ4PCPnGMoFjC9ddhal5KVIYtAt97ix05A==",
+      "license": "MIT"
+    },
+    "node_modules/string_decoder": {
+      "version": "0.10.31",
+      "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-0.10.31.tgz",
+      "integrity": "sha512-ev2QzSzWPYmy9GuqfIVildA4OdcGLeFZQrq5ys6RtiuF+RQQiZWr8TZNyAcuVXyQRYfEO+MsoB/1BuQVhOJuoQ==",
+      "license": "MIT"
+    },
     "node_modules/strip-ansi": {
       "version": "6.0.1",
       "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-6.0.1.tgz",
@@ -1805,6 +1887,34 @@
         "pako": "^1.0.5"
       }
     },
+    "node_modules/wav": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/wav/-/wav-1.0.2.tgz",
+      "integrity": "sha512-viHtz3cDd/Tcr/HbNqzQCofKdF6kWUymH9LGDdskfWFoIy/HJ+RTihgjEcHfnsy1PO4e9B+y4HwgTwMrByquhg==",
+      "license": "MIT",
+      "dependencies": {
+        "buffer-alloc": "^1.1.0",
+        "buffer-from": "^1.0.0",
+        "debug": "^2.2.0",
+        "readable-stream": "^1.1.14",
+        "stream-parser": "^0.3.1"
+      }
+    },
+    "node_modules/wav/node_modules/debug": {
+      "version": "2.6.9",
+      "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+      "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+      "license": "MIT",
+      "dependencies": {
+        "ms": "2.0.0"
+      }
+    },
+    "node_modules/wav/node_modules/ms": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
+      "integrity": "sha512-Tpp60P6IUJDTuOq/5Z8cdskzJujfwqfOTkrwIwj7IRISpnkJnT6SyJ4PCPnGMoFjC9ddhal5KVIYtAt97ix05A==",
+      "license": "MIT"
+    },
     "node_modules/wavefile": {
       "version": "11.0.0",
       "resolved": "https://registry.npmjs.org/wavefile/-/wavefile-11.0.0.tgz",
@@ -2411,11 +2521,35 @@
         "ieee754": "^1.1.13"
       }
     },
+    "buffer-alloc": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/buffer-alloc/-/buffer-alloc-1.2.0.tgz",
+      "integrity": "sha512-CFsHQgjtW1UChdXgbyJGtnm+O/uLQeZdtbDo8mfUgYXCHSM1wgrVxXm6bSyrUuErEb+4sYVGCzASBRot7zyrow==",
+      "requires": {
+        "buffer-alloc-unsafe": "^1.1.0",
+        "buffer-fill": "^1.0.0"
+      }
+    },
+    "buffer-alloc-unsafe": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/buffer-alloc-unsafe/-/buffer-alloc-unsafe-1.1.0.tgz",
+      "integrity": "sha512-TEM2iMIEQdJ2yjPJoSIsldnleVaAk1oW3DBVUykyOLsEsFmEc9kn+SFFPz+gl54KQNxlDnAwCXosOS9Okx2xAg=="
+    },
     "buffer-equal": {
       "version": "0.0.1",
       "resolved": "https://registry.npmjs.org/buffer-equal/-/buffer-equal-0.0.1.tgz",
       "integrity": "sha512-RgSV6InVQ9ODPdLWJ5UAqBqJBOg370Nz6ZQtRzpt6nUjc8v0St97uJ4PYC6NztqIScrAXafKM3mZPMygSe1ggA=="
     },
+    "buffer-fill": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/buffer-fill/-/buffer-fill-1.0.0.tgz",
+      "integrity": "sha512-T7zexNBwiiaCOGDg9xNX9PBmjrubblRkENuptryuI64URkXDFum9il/JGL8Lm8wYfAXpredVXXZz7eMHilimiQ=="
+    },
+    "buffer-from": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/buffer-from/-/buffer-from-1.1.2.tgz",
+      "integrity": "sha512-E+XQCRwSbaaiChtv6k6Dwgc+bx+Bs6vuKJHHl5kox/BaKbhiXzqQOwK4cO22yElGp2OCmjwVhT3HmxgyPGnJfQ=="
+    },
     "callsites": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/callsites/-/callsites-3.1.0.tgz",
@@ -2453,6 +2587,11 @@
       "integrity": "sha512-/Srv4dswyQNBfohGpz9o6Yb3Gz3SrUDqBH5rTuhGR7ahtlbYKnVxw2bCFMRljaA7EXHaXZ8wsHdodFvbkhKmqg==",
       "dev": true
     },
+    "core-util-is": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.3.tgz",
+      "integrity": "sha512-ZQBvi1DcpJ4GDqanjucZ2Hj3wEO5pZDS89BWbkcrvdxksJorwUDDZamX9ldFkp9aw2lmBDLgkObEA4DWNJ9FYQ=="
+    },
     "cross-spawn": {
       "version": "7.0.3",
       "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.3.tgz",
@@ -2792,8 +2931,7 @@
     "inherits": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.4.tgz",
-      "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==",
+      "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ=="
-      "dev": true
     },
     "is-extglob": {
       "version": "2.1.1",
@@ -2821,6 +2959,11 @@
       "integrity": "sha512-Fd4gABb+ycGAmKou8eMftCupSir5lRxqf4aD/vd0cD2qc4HL07OjCeuHMr8Ro4CoMaeCKDB0/ECBOVWjTwUvPQ==",
       "dev": true
     },
+    "isarray": {
+      "version": "0.0.1",
+      "resolved": "https://registry.npmjs.org/isarray/-/isarray-0.0.1.tgz",
+      "integrity": "sha512-D2S+3GLxWH+uhrNEcoh/fnmYeP8E8/zHl644d/jdA0g2uyXvy3sb0qxotE+ne0LtccHknQzWwZEzhak7oJ0COQ=="
+    },
     "isexe": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/isexe/-/isexe-2.0.0.tgz",
@@ -3101,6 +3244,17 @@
       "integrity": "sha512-NuaNSa6flKT5JaSYQzJok04JzTL1CA6aGhv5rfLW3PgqA+M2ChpZQnAC8h8i4ZFkBS8X5RqkDBHA7r4hej3K9A==",
       "dev": true
     },
+    "readable-stream": {
+      "version": "1.1.14",
+      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-1.1.14.tgz",
+      "integrity": "sha512-+MeVjFf4L44XUkhM1eYbD8fyEsxcV81pqMSR5gblfcLCHfZvbrqy4/qYHE+/R5HoBUT11WV5O08Cr1n3YXkWVQ==",
+      "requires": {
+        "core-util-is": "~1.0.0",
+        "inherits": "~2.0.1",
+        "isarray": "0.0.1",
+        "string_decoder": "~0.10.x"
+      }
+    },
     "regenerator-runtime": {
       "version": "0.13.11",
       "resolved": "https://registry.npmjs.org/regenerator-runtime/-/regenerator-runtime-0.13.11.tgz",
@@ -3156,6 +3310,34 @@
       "integrity": "sha512-7++dFhtcx3353uBaq8DDR4NuxBetBzC7ZQOhmTQInHEd6bSrXdiEyzCvG07Z44UYdLShWUyXt5M/yhz8ekcb1A==",
       "dev": true
     },
+    "stream-parser": {
+      "version": "0.3.1",
+      "resolved": "https://registry.npmjs.org/stream-parser/-/stream-parser-0.3.1.tgz",
+      "integrity": "sha512-bJ/HgKq41nlKvlhccD5kaCr/P+Hu0wPNKPJOH7en+YrJu/9EgqUF+88w5Jb6KNcjOFMhfX4B2asfeAtIGuHObQ==",
+      "requires": {
+        "debug": "2"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "2.6.9",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+          "requires": {
+            "ms": "2.0.0"
+          }
+        },
+        "ms": {
+          "version": "2.0.0",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
+          "integrity": "sha512-Tpp60P6IUJDTuOq/5Z8cdskzJujfwqfOTkrwIwj7IRISpnkJnT6SyJ4PCPnGMoFjC9ddhal5KVIYtAt97ix05A=="
+        }
+      }
+    },
+    "string_decoder": {
+      "version": "0.10.31",
+      "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-0.10.31.tgz",
+      "integrity": "sha512-ev2QzSzWPYmy9GuqfIVildA4OdcGLeFZQrq5ys6RtiuF+RQQiZWr8TZNyAcuVXyQRYfEO+MsoB/1BuQVhOJuoQ=="
+    },
     "strip-ansi": {
       "version": "6.0.1",
       "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-6.0.1.tgz",
@@ -3228,6 +3410,33 @@
         "pako": "^1.0.5"
       }
     },
+    "wav": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/wav/-/wav-1.0.2.tgz",
+      "integrity": "sha512-viHtz3cDd/Tcr/HbNqzQCofKdF6kWUymH9LGDdskfWFoIy/HJ+RTihgjEcHfnsy1PO4e9B+y4HwgTwMrByquhg==",
+      "requires": {
+        "buffer-alloc": "^1.1.0",
+        "buffer-from": "^1.0.0",
+        "debug": "^2.2.0",
+        "readable-stream": "^1.1.14",
+        "stream-parser": "^0.3.1"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "2.6.9",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+          "requires": {
+            "ms": "2.0.0"
+          }
+        },
+        "ms": {
+          "version": "2.0.0",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
+          "integrity": "sha512-Tpp60P6IUJDTuOq/5Z8cdskzJujfwqfOTkrwIwj7IRISpnkJnT6SyJ4PCPnGMoFjC9ddhal5KVIYtAt97ix05A=="
+        }
+      }
+    },
     "wavefile": {
       "version": "11.0.0",
       "resolved": "https://registry.npmjs.org/wavefile/-/wavefile-11.0.0.tgz",

package.json

@@ -2,6 +2,7 @@
   "type": "module",
   "dependencies": {
     "jimp": "^0.16.2",
+    "wav": "^1.0.2",
     "wavefile": "^11.0.0"
   },
   "devDependencies": {

video-rickroll/combine.sh

@@ -0,0 +1,10 @@
+ffmpeg \
+    -r 60000/1001 \
+    -i 'frames/dither-%05d.png' \
+    -i 'rickroll-audio.wav' \
+    -ac 2 \
+    -ar 48000 \
+    -vf 'scale=534x384,setsar=1' \
+    -pix_fmt yuv420p \
+    -movflags +faststart \
+    -y rickroll-dither.mp4

video-rickroll/extract.sh

@@ -0,0 +1,17 @@
+set -a
+
+mkdir -p frames
+
+ffmpeg \
+    -i rickroll.mp4 \
+    -vf 'scale=320:230,framerate=60000/1001' \
+    -an \
+    -y 'frames/rickroll-%05d.png'
+
+ffmpeg \
+    -i rickroll.mp4 \
+    -vn \
+    -ac 1 \
+    -ar 15734 \
+    -acodec pcm_u8 \
+    -y 'rickroll-audio.wav'

video-rickroll/video.sh

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