diff --git a/Makefile b/Makefile
index cf80fb4..87a10af 100644
--- a/Makefile
+++ b/Makefile
@@ -7,8 +7,6 @@ all : sample0.xex sample1.xex sample2.xex sample3.xex sample4.xex sample5.xex sa
 
 %.s : %.jpg dither-image.js gif.sh mp4.sh
 	node dither-image.js $< $@
-	./gif.sh $@
-	./mp4.sh $@
 
 chickens.s : chickens.wav pack-wav.js
 	node pack-wav.js $< $@
@@ -37,9 +35,6 @@ clean :
 	rm -f sample[0-6].o
 	rm -f sample[0-6].xex
 	rm -f sample[0-6].s.png
-	rm -f sample[0-6].s.[0-9].png
-	rm -f sample[0-6].s.palette.png
-	rm -f sample[0-6].s.gif
 	rm -f *.xex
 	rm -f chickens.s
 	rm -f chickens.o
diff --git a/dither-image.js b/dither-image.js
index 4aa7252..d8ae0c4 100644
--- a/dither-image.js
+++ b/dither-image.js
@@ -504,7 +504,8 @@ function decimate(input, palette, n, inputError) {
             }
         }
         decimated = decimated.filter((color, i) => {
-            if (i == 0) {
+            if (palette[i] == 0) {
+                // solid black
                 return true;
             }
             if (i == pick) {
@@ -567,7 +568,7 @@ function imageToLinearRGB(rgba) {
  * @param {string} source path to source image file
  * @returns {{width: number, height: number, lines: {palette: Array, output: Uint8Array}[]}}
  */
-async function convert(source, nbits, reps) {
+async function convert(source, nbits) {
 
     let {
         width,
@@ -592,15 +593,6 @@ async function convert(source, nbits, reps) {
         throw new Error('inconsistent data size');
     }
 
-    if (reps > 1) {
-        height *= reps;
-        let rgba2 = new Uint8Array(rgba.length * reps);
-        for (let i = 0; i < reps; i++) {
-            rgba2.set(rgba, rgba.length * i);
-        }
-        rgba = rgba2;
-    }
-
     let input = imageToLinearRGB(rgba);
 
     if (input.length != width * height) {
@@ -662,31 +654,26 @@ function odd(arr) {
     return arr.filter((_item, index) => (index & 1));
 }
 
-function genAssembly(width, height, nbits, lines, reps) {
-    let linesEach = height / reps;
+function genAssembly(width, height, nbits, lines) {
     let stride = width * nbits / 8;
-    let half = stride * linesEach / 2;
-    let frames = [];
-
-    for (let i = 0; i < reps; i ++) {
-        let frame = frames[i] = {
-            palette1: new Uint8Array(linesEach),
-            palette2: new Uint8Array(linesEach),
-            palette3: new Uint8Array(linesEach),
-            bitmap: new Uint8Array(stride * linesEach),
-        };
-        for (let y = 0; y < linesEach; y++) {
-            let base = linesEach * i;
-            frame.palette1[y] = lines[y + base].palette[1];
-            frame.palette2[y] = lines[y + base].palette[2];
-            frame.palette3[y] = lines[y + base].palette[3];
-            indexedToBitmap(
-                width,
-                nbits,
-                lines[y + base].output,
-                frame.bitmap.subarray(y * stride, (y + 1) * stride)
-            );
-        }
+    let half = stride * height / 2;
+    let frame = {
+        palette1: new Uint8Array(height),
+        palette2: new Uint8Array(height),
+        palette3: new Uint8Array(height),
+        bitmap: new Uint8Array(stride * height),
+    };
+    for (let y = 0; y < height; y++) {
+        let base = 0;
+        frame.palette1[y] = lines[y + base].palette[1];
+        frame.palette2[y] = lines[y + base].palette[2];
+        frame.palette3[y] = lines[y + base].palette[3];
+        indexedToBitmap(
+            width,
+            nbits,
+            lines[y + base].output,
+            frame.bitmap.subarray(y * stride, (y + 1) * stride)
+        );
     }
 
     return `.data
@@ -704,35 +691,35 @@ function genAssembly(width, height, nbits, lines, reps) {
 
 .align 4096
 frame1_top:
-${byte2byte(frames[0].bitmap.slice(0, half))}
+${byte2byte(frame.bitmap.slice(0, half))}
 
 .align 128
 frame1_palette1_even:
-${byte2byte(even(frames[0].palette1))}
+${byte2byte(even(frame.palette1))}
 
 .align 128
 frame1_palette1_odd:
-${byte2byte(odd(frames[0].palette1))}
+${byte2byte(odd(frame.palette1))}
 
 .align 128
 frame1_palette2_even:
-${byte2byte(even(frames[0].palette2))}
+${byte2byte(even(frame.palette2))}
 
 .align 128
 frame1_palette2_odd:
-${byte2byte(odd(frames[0].palette2))}
+${byte2byte(odd(frame.palette2))}
 
 .align 128
 frame1_palette3_even:
-${byte2byte(even(frames[0].palette3))}
+${byte2byte(even(frame.palette3))}
 
 .align 128
 frame1_palette3_odd:
-${byte2byte(odd(frames[0].palette3))}
+${byte2byte(odd(frame.palette3))}
 
 .align 4096
 frame1_bottom:
-${byte2byte(frames[0].bitmap.slice(half))}
+${byte2byte(frame.bitmap.slice(half))}
 
 
 
@@ -749,12 +736,12 @@ displaylist:
     ; ANTIC mode e (160px 2bpp, 1 scan line per line)
     .byte $4e
     .addr frame1_top
-    .repeat ${linesEach / 2 - 1}
+    .repeat ${height / 2 - 1}
         .byte $0e
     .endrep
     .byte $4e
     .addr frame1_bottom
-    .repeat ${linesEach / 2 - 1}
+    .repeat ${height / 2 - 1}
         .byte $0e
     .endrep
 
@@ -811,18 +798,13 @@ async function main() {
     }
 
     let nbits = 2;
-    let reps = 1;
 
-    let {width, height, lines} = await convert(process.argv[2], nbits, reps);
+    let {width, height, lines} = await convert(process.argv[2], nbits);
 
-    let asm = genAssembly(width, height, nbits, lines, reps);
+    let asm = genAssembly(width, height, nbits, lines);
     writeFileSync(process.argv[3], asm, "utf-8");
 
-    let heightPerFrame = height / reps;
-    for (let i = 0; i < reps; i++) {
-        let slice = lines.slice(i * heightPerFrame, (i + 1) * heightPerFrame);
-        await saveImage(width, heightPerFrame, slice, `${process.argv[3]}.${i}.png`);
-    }
+    await saveImage(width, height, lines, `${process.argv[3]}.png`);
 
     process.exit(0);
 }