Extraction is not the same as transcoding
An MP4 normally contains compressed audio such as AAC. Producing MP3 requires decoding that track and encoding it again because MP3 is a different codec.
Choose bitrate based on content
Speech can often tolerate a lower bitrate than music. Higher bitrates increase size and cannot restore detail missing from the source.
Do not expect video metadata to become music metadata
Title/artist tags may not be present or meaningful in a camera video. Review metadata after export when organizing a music library.
Keep the source
The video remains unchanged. The MP3 is a derivative for playback or sharing.
Official marketplace references
Requirements can change. Review the source before publishing an important listing.
Mediabunny browser media toolkit documentation ↗