diff --git a/src/main/ffmpeg.ts b/src/main/ffmpeg.ts
index a6656693..d3a195ff 100644
--- a/src/main/ffmpeg.ts
+++ b/src/main/ffmpeg.ts
@@ -11,6 +11,7 @@ import { platform, arch, isWindows, isMac, isLinux } from './util.js';
 import { CaptureFormat, Html5ifyMode, Waveform } from '../../types.js';
 import isDev from './isDev.js';
 import logger from './logger.js';
+import { parseFfmpegProgressLine } from './progress.js';
 
 
 const runningFfmpegs = new Set<ExecaChildProcess<Buffer>>();
@@ -55,9 +56,9 @@ export function abortFfmpegs() {
 
 function handleProgress(
   process: { stderr: Readable | null },
-  durationIn: number | undefined,
+  duration: number | undefined,
   onProgress: (a: number) => void,
-  customMatcher: (a: string) => void = () => undefined,
+  customMatcher?: (a: string) => void,
 ) {
   if (!onProgress) return;
   if (process.stderr == null) return;
@@ -68,44 +69,10 @@ function handleProgress(
     // console.log('progress', line);
 
     try {
-      // eslint-disable-next-line unicorn/better-regex
-      let match = line.match(/frame=\s*[^\s]+\s+fps=\s*[^\s]+\s+q=\s*[^\s]+\s+(?:size|Lsize)=\s*[^\s]+\s+time=\s*([^\s]+)\s+/);
-      // Audio only looks like this: "line size=  233422kB time=01:45:50.68 bitrate= 301.1kbits/s speed= 353x    "
-      // eslint-disable-next-line unicorn/better-regex
-      if (!match) match = line.match(/(?:size|Lsize)=\s*[^\s]+\s+time=\s*([^\s]+)\s+/);
-      if (!match) {
-        customMatcher(line);
-        return;
+      const progress = parseFfmpegProgressLine({ line, customMatcher, duration });
+      if (progress != null) {
+        onProgress(progress);
       }
-
-      const timeStr = match[1];
-      // console.log(timeStr);
-      const match2 = timeStr!.match(/^(-?)(\d+):(\d+):(\d+)\.(\d+)$/);
-      if (!match2) throw new Error(`Invalid time from ffmpeg progress ${timeStr}`);
-
-      const sign = match2[1];
-
-      if (sign === '-') {
-        // For some reason, ffmpeg sometimes gives a negative progress, e.g. "-00:00:06.46"
-        // let's just ignore that
-        return;
-      }
-
-      const h = parseInt(match2[2]!, 10);
-      const m = parseInt(match2[3]!, 10);
-      const s = parseInt(match2[4]!, 10);
-      const cs = parseInt(match2[5]!, 10);
-      const time = (((h * 60) + m) * 60 + s) + cs / 100;
-      // console.log(time);
-
-      const progressTime = Math.max(0, time);
-      // console.log(progressTime);
-
-      if (durationIn == null) return;
-      const duration = Math.max(0, durationIn);
-      if (duration === 0) return;
-      const progress = Math.min(progressTime / duration, 1); // sometimes progressTime will be greater than cutDuration
-      onProgress(progress);
     } catch (err) {
       logger.error('Failed to parse ffmpeg progress line:', err instanceof Error ? err.message : err);
     }
diff --git a/src/main/pathToFileURL.test.ts b/src/main/pathToFileURL.test.ts
index 212b1e39..8826d0e7 100644
--- a/src/main/pathToFileURL.test.ts
+++ b/src/main/pathToFileURL.test.ts
@@ -1,4 +1,3 @@
-// eslint-disable-line unicorn/filename-case
 // eslint-disable-next-line import/no-extraneous-dependencies
 import { test, expect, describe } from 'vitest';
 
diff --git a/src/main/progress.test.ts b/src/main/progress.test.ts
new file mode 100644
index 00000000..04c1c7d3
--- /dev/null
+++ b/src/main/progress.test.ts
@@ -0,0 +1,18 @@
+// eslint-disable-next-line import/no-extraneous-dependencies
+import { describe, expect, test } from 'vitest';
+import { parseFfmpegProgressLine } from './progress';
+
+describe('parseFfmpegProgressLine', () => {
+  test('parse video', () => {
+    const str = 'frame= 2285 fps=135 q=4.0 Lsize=N/A time=00:01:31.36 bitrate=N/A speed=5.38x    ';
+    expect(parseFfmpegProgressLine({ line: str, duration: 60 + 31.36 })).toBe(1);
+  });
+  test('parse audio 0', () => {
+    const str = 'size=       0kB time=00:00:00.00 bitrate=N/A speed=N/A    ';
+    expect(parseFfmpegProgressLine({ line: str, duration: 1 })).toBe(0);
+  });
+  test('parse audio 32.02', () => {
+    const str = 'size=     501kB time=00:00:32.02 bitrate= 128.2kbits/s speed=2.29e+03x    ';
+    expect(parseFfmpegProgressLine({ line: str, duration: 32.02 })).toBe(1);
+  });
+});
diff --git a/src/main/progress.ts b/src/main/progress.ts
new file mode 100644
index 00000000..4b2a968b
--- /dev/null
+++ b/src/main/progress.ts
@@ -0,0 +1,46 @@
+// eslint-disable-next-line import/prefer-default-export
+export function parseFfmpegProgressLine({ line, customMatcher, duration: durationIn }: {
+  line: string,
+  customMatcher?: ((a: string) => void) | undefined,
+  duration: number | undefined,
+}) {
+  let match = line.match(/frame=\s*\S+\s+fps=\s*\S+\s+q=\s*\S+\s+(?:size|Lsize)=\s*\S+\s+time=\s*(\S+)\s+/);
+  if (!match) {
+    // Audio only looks like this: "size=  233422kB time=01:45:50.68 bitrate= 301.1kbits/s speed= 353x    "
+    match = line.match(/(?:size|Lsize)=\s*\S+\s+time=\s*(\S+)\s+/);
+  }
+  if (!match) {
+    customMatcher?.(line);
+    return undefined;
+  }
+
+  if (durationIn == null) return undefined;
+  const duration = Math.max(0, durationIn);
+  if (duration === 0) return undefined;
+
+  const timeStr = match[1];
+  // console.log(timeStr);
+  const match2 = timeStr!.match(/^(-?)(\d+):(\d+):(\d+)\.(\d+)$/);
+  if (!match2) throw new Error(`Invalid time from ffmpeg progress ${timeStr}`);
+
+  const sign = match2[1];
+
+  if (sign === '-') {
+    // For some reason, ffmpeg sometimes gives a negative progress, e.g. "-00:00:06.46"
+    // let's just ignore those lines
+    return undefined;
+  }
+
+  const h = parseInt(match2[2]!, 10);
+  const m = parseInt(match2[3]!, 10);
+  const s = parseInt(match2[4]!, 10);
+  const cs = parseInt(match2[5]!, 10);
+  const time = (((h * 60) + m) * 60 + s) + cs / 100;
+  // console.log(time);
+
+  const progressTime = Math.max(0, time);
+  // console.log(progressTime);
+
+  const progress = Math.min(progressTime / duration, 1); // sometimes progressTime will be greater than cutDuration
+  return progress;
+}