diff --git a/ffmpeg.js b/ffmpeg.js
new file mode 100644
index 0000000..eb47ed1
--- /dev/null
+++ b/ffmpeg.js
@@ -0,0 +1,19 @@
+const fs = require('fs-extra');
+
+const getFfmpegCommonArgs = ({ enableFfmpegLog }) => (enableFfmpegLog ? [] : ['-hide_banner', '-loglevel', 'error']);
+
+const getCutFromArgs = ({ cutFrom }) => (cutFrom ? ['-ss', cutFrom] : []);
+
+const getCutToArgs = ({ cutTo, cutFrom, framePtsFactor }) => (cutTo ? ['-t', (cutTo - cutFrom) * framePtsFactor] : []);
+
+async function createConcatFile(segments, concatFilePath) {
+  // https://superuser.com/questions/787064/filename-quoting-in-ffmpeg-concat
+  await fs.writeFile(concatFilePath, segments.map((seg) => `file '${seg.replace(/'/g, "'\\''")}'`).join('\n'));
+}
+
+module.exports = {
+  getFfmpegCommonArgs,
+  getCutFromArgs,
+  getCutToArgs,
+  createConcatFile,
+};
diff --git a/index.js b/index.js
index 075dfe4..6996afc 100644
--- a/index.js
+++ b/index.js
@@ -21,7 +21,6 @@ const checkTransition = (transition) => assert(transition == null || typeof tran
 
 const assertFileExists = async (path) => assert(await fs.exists(path), `File does not exist ${path}`);
 
-
 module.exports = async (config = {}) => {
   const {
     // Testing options:
@@ -353,7 +352,7 @@ module.exports = async (config = {}) => {
       const toClipNumFrames = getTransitionToClip() && Math.round(getTransitionToClip().duration * fps);
       const fromClipProgress = fromClipFrameCount / fromClipNumFrames;
       const toClipProgress = getTransitionToClip() && toClipFrameCount / toClipNumFrames;
-      const frameData1 = await frameSource1.readNextFrame(fromClipProgress);
+      const frameSource1Data = await frameSource1.readNextFrame(fromClipProgress);
 
       const clipTransition = getTransitionFromClip().transition;
 
@@ -371,7 +370,7 @@ module.exports = async (config = {}) => {
         if (totalFrameCount % 10 === 0) process.stdout.write(`${String(percentDone).padStart(3, ' ')}% `);
       }
 
-      if (!frameData1 || transitionFrameAt >= transitionNumFramesSafe - 1) {
+      if (!frameSource1Data || transitionFrameAt >= transitionNumFramesSafe - 1) {
       // if (!frameData1 || transitionFrameAt >= transitionNumFramesSafe) {
         console.log('Done with transition, switching to next clip');
         transitionFromClipId += 1;
@@ -393,25 +392,25 @@ module.exports = async (config = {}) => {
         if (frameSource2 && transitionFrameAt >= 0) {
           if (verbose) console.log('Transition', 'frame', transitionFrameAt, '/', transitionNumFramesSafe, clipTransition.name, `${clipTransition.duration}s`);
 
-          const frameData2 = await frameSource2.readNextFrame(toClipProgress);
+          const frameSource2Data = await frameSource2.readNextFrame(toClipProgress);
           toClipFrameCount += 1;
 
-          if (frameData2) {
+          if (frameSource2Data) {
             const progress = transitionFrameAt / transitionNumFramesSafe;
             const easedProgress = clipTransition.easingFunction(progress);
 
             if (verbose) console.time('runTransitionOnFrame');
-            outFrameData = runTransitionOnFrame({ fromFrame: frameData1, toFrame: frameData2, progress: easedProgress, transitionName: clipTransition.name, transitionParams: clipTransition.params });
+            outFrameData = runTransitionOnFrame({ fromFrame: frameSource1Data, toFrame: frameSource2Data, progress: easedProgress, transitionName: clipTransition.name, transitionParams: clipTransition.params });
             if (verbose) console.timeEnd('runTransitionOnFrame');
           } else {
             console.warn('Got no frame data from clip 2!');
             // We have reached end of clip2 but transition is not complete
             // Pass thru
             // TODO improve, maybe cut it short
-            outFrameData = frameData1;
+            outFrameData = frameSource1Data;
           }
         } else {
-          outFrameData = frameData1;
+          outFrameData = frameSource1Data;
         }
 
         // If we don't await we get EINVAL when dealing with high resolution files (big writes)
diff --git a/sources/videoFrameSource.js b/sources/videoFrameSource.js
index f697ac0..0d4b938 100644
--- a/sources/videoFrameSource.js
+++ b/sources/videoFrameSource.js
@@ -1,6 +1,8 @@
 const execa = require('execa');
 const assert = require('assert');
 
+const { getFfmpegCommonArgs } = require('../ffmpeg');
+
 module.exports = async ({ width, height, channels, framerateStr, verbose, ffmpegPath, enableFfmpegLog, params }) => {
   const targetSize = width * height * channels;
 
@@ -29,7 +31,7 @@ module.exports = async ({ width, height, channels, framerateStr, verbose, ffmpeg
   // Testing: ffmpeg -i 'vid.mov' -t 1 -vcodec rawvideo -pix_fmt rgba -f image2pipe - | ffmpeg -f rawvideo -vcodec rawvideo -pix_fmt rgba -s 2166x1650 -i - -vf format=yuv420p -vcodec libx264 -y out.mp4
   // https://trac.ffmpeg.org/wiki/ChangingFrameRate
   const args = [
-    ...(enableFfmpegLog ? [] : ['-hide_banner', '-loglevel', 'error']),
+    ...getFfmpegCommonArgs({ enableFfmpegLog }),
     ...(cutFrom ? ['-ss', cutFrom] : []),
     '-i', path,
     ...(cutTo ? ['-t', (cutTo - cutFrom) * framePtsFactor] : []),