[Bug] FFmpeg virtual filesystem accumulates temp files between exports

[magic-peach]

Bug Description

Each export writes a temporary file to the FFmpeg WASM virtual filesystem using ffmpeg.writeFile(). However, after export, the temp file is not always deleted with ffmpeg.deleteFile(). This causes the virtual filesystem to accumulate files across multiple exports in the same session, wasting memory and potentially causing issues with file name conflicts.

Steps to Reproduce

1. Upload a video and export
2. Upload another video and export again
3. Repeat multiple times
4. Browser memory usage increases with each export

Expected Behavior

Temporary files should be deleted from the virtual filesystem after each export, both on success and failure.

File Reference

• src/lib/ffmpeg.ts — exportVideo() function, cleanup in finally block

[divyanshi-adhikari]

Hi @magic-peach, I’d like to work on this issue under GSSoC’26. Could you please assign it to me?

I was previously working on issue #81, which has now been closed via #260, so I’d be happy to contribute by working on this issue.

[mahema-14]

hey @magic-peach! I went through the issue ..the fix is just making sure ffmpeg.deleteFile() gets called in a finally block inside exportVideo() in ffmpeg.ts, so temp files are cleaned up whether the export succeeds or fails. already exploring the codebase, would love to take this up for GSSoC'26, please assign!
Thank you
@mahema-14

[sriram687]

Hi @magic-peach,

I’d like to work on this issue.

I reproduced the issue locally and observed increasing browser memory usage across repeated export operations (attached screenshot for reference). This appears to be caused by temporary FFmpeg WASM virtual filesystem files not being consistently cleaned up after export.

I plan to:

• ensure all temporary files created with ffmpeg.writeFile() are properly removed using ffmpeg.deleteFile()
• add reliable cleanup inside the finally block
• handle cleanup for both success and failure cases
• prevent virtual filesystem buildup, memory growth, and filename conflicts during long sessions

File:
src/lib/ffmpeg.ts — exportVideo() cleanup flow

Please assign this issue to me. Thanks! 🌟

BROWSER HEAP STORAGE INCREASES RISK PERFORMANCE SLOWS DOWN :