(YouTube) Audio file corrupted when you download at best quality

[diorandan]

bug description

I noticed how when exporting and downloading audio from YouTube using the best format (.m4a because YouTube uses that format), it extends the audio file 2 times the original length. It doesn’t repeat the audio though, only silence.

reproduction steps

1. Go to YouTube and find a short video you want to download (I downloaded an unreleased song).
2. Go to cobalt.tools > settings > audio
3. Click “best” under “audio format” and turn on “prefer better quality” under “youtube audio quality”.
4. Go to “save”, click “audio”, paste your YouTube link and press the “>>” button to download your file.
5. The file you’re downloading should be in .m4a format. Check the audio length, it extends twice the original length (e.g. your video was 4 minutes 11 seconds, the file should be around 8 minutes 22 seconds).

screenshots

links

platform information

Safari on iPhone 15 iOS 18.4.1

additional context

No response