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[BUG] Export Can Hang Indefinitely When Video Has No Audio and Background Music Is Looped #1493
Description
When exporting a video that contains no original audio track, the export pipeline falls back to a music-only audio path.
If a background music track is longer than the video duration, or if "Loop Music" is enabled, the generated FFmpeg command may continue encoding indefinitely because the output is not constrained by the video duration.
This can result in:
- Infinite export operations
- Browser tab freezes
- Excessive memory consumption
- Potential Out-of-Memory (OOM) crashes
- Output videos significantly longer than the source video
Steps to Reproduce
- Import a video file that contains no audio stream.
- Add a background music track.
- Enable Loop Music OR use a music track longer than the video.
- Export the video.
- Observe the export process.
Expected Behavior
The exported video should end when the video stream ends.
Examples:
- 10-second video + 3-minute music track → 10-second export.
- 10-second video + looped music → 10-second export.
Actual Behavior
When the fallback music-only path is used:
- FFmpeg maps the music stream directly.
- The output duration becomes controlled by the audio stream.
- Looped music can cause export to continue indefinitely.
- Long music tracks can extend the final output far beyond the video duration.
- The final frame may remain frozen while audio continues playing.
Root Cause
The fallback branch used when the source video has no audio bypasses the audio-mixing path.
Generated commands resemble:
ffmpeg -i input.mp4 \
-stream_loop -1 \
-i music.mp3 \
-filter_complex "[0:v]...[vout];[1:a]volume=0.70[aout]" \
-map "[vout]" \
-map "[aout]" \
output.mp4Because the command does not include:
-shortestFFmpeg continues processing until the audio stream finishes.
For looped audio (-stream_loop -1) this can become effectively infinite.
Impact
Severity: High
Potential consequences:
- Infinite export jobs
- Browser crashes
- Memory exhaustion
- Corrupted user experience
- Unexpected output durations
Suggested Fix
Append:
-shortestto the final FFmpeg output arguments so encoding terminates when the video stream ends.
Example:
args.push("-shortest");before the output filename is appended.
Environment
- Browser: Any
- Platform: Web
- FFmpeg WASM Export Pipeline
- File:
src/lib/ffmpeg.ts
ASSIGN TO ME UNDER GSSOC2026
Activity
github-actions commentedon Jun 2, 2026
👋 Thanks for opening an issue, @Krishnx21!
Our maintainers will review this shortly 🚀
Before you start working
For GSSoC'26 contributors
If you're contributing under GirlScript Summer of Code 2026, please mention it in your comment when requesting assignment:
Architecture notes
Reframe is a static Next.js app with
output: "export". Key points:headers()innext.config.tswon't work — usevercel.jsoninsteadnot-found.tsxrequirespublic/404.html+vercel.jsonroutes configHappy contributing! ⭐ Star the repo if you find it useful!
Krishnx21 commentedon Jun 2, 2026
/ASSIGN/GSSOC2026
github-actions commentedon Jun 2, 2026
Hey @Krishnx21, this issue has been assigned to you! 🎉 Please make progress within 5 days or it will be automatically unassigned due to inactivity.
github-actions commentedon Jun 4, 2026
Hey @Krishnx21, just a friendly reminder that this issue has had no activity for 2 days. Please leave an update or let us know if you need help! ⏰
github-actions commentedon Jun 8, 2026
Hey @Krishnx21, final warning!⚠️ This issue has had no activity for 4 days and will be automatically unassigned in 24 hours if there is no update.
github-actions commentedon Jun 13, 2026
This issue has been unassigned from @Krishnx21 due to 5 days of inactivity and is open for anyone to pick up — comment
/assignto claim it!Saylee12R commentedon Jun 20, 2026
/assign
I'd like to work on this issue under GSSoC'26.
github-actions commentedon Jun 20, 2026
Hey @Saylee12R, this issue has been assigned to you! 🎉 Please make progress within 5 days or it will be automatically unassigned due to inactivity.
github-actions commentedon Jun 25, 2026
This issue has been unassigned from @Saylee12R due to 5 days of inactivity and is open for anyone to pick up — comment
/assignto claim it!