[ ] Feature request (request for a new functionality)
[x] Question
[ ] Other
What operating system do you use ?
Win10
List of actions to perform to reproduce the problem:
Copy and paste YouTube playlist URL
Choose destination and select "mp3" as the file format
Add to queue and proceed to download
What is the expected behaviour ?
Each song will be downloaded quickly in mp3 format, after pre-processing for a bit, of course.
What happens instead ?
After pre-processing, some videos (seemingly randomly) will proceed to download in webm format, before finally downloading as mp3. This multiplies the download time considerably. The webm will delete itself after either it or its corresponding mp3 are finished downloading, I don't know which.
As stated above, it's kind of weird how some videos will download as a webm despite me deliberately selecting "mp3". I'm not entirely sure whether it's a youtube-dl or a youtube-dl-gui issue. I'm not sure if it's a problem specifically with playlist downloading, either. But it does seem intentional, and if it's not an issue that can be fixed I'd like to know why, at least.
(Also, I once came across an issue where not every video in a playlist was downloaded, so it may be that playlist downloading is just buggy in general)
Edit: And now I'm coming across the issue in parentheses above again. And also, it's sometimes downloading m4a instead of webm? Weird.
axcore
commented
3 years ago 
DaforLynx
What is the purpose of your issue?
What operating system do you use ?
Win10
List of actions to perform to reproduce the problem:
What is the expected behaviour ?
Each song will be downloaded quickly in mp3 format, after pre-processing for a bit, of course.
What happens instead ?
After pre-processing, some videos (seemingly randomly) will proceed to download in webm format, before finally downloading as mp3. This multiplies the download time considerably. The webm will delete itself after either it or its corresponding mp3 are finished downloading, I don't know which.
As stated above, it's kind of weird how some videos will download as a webm despite me deliberately selecting "mp3". I'm not entirely sure whether it's a youtube-dl or a youtube-dl-gui issue. I'm not sure if it's a problem specifically with playlist downloading, either. But it does seem intentional, and if it's not an issue that can be fixed I'd like to know why, at least. (Also, I once came across an issue where not every video in a playlist was downloaded, so it may be that playlist downloading is just buggy in general)
Edit: And now I'm coming across the issue in parentheses above again. And also, it's sometimes downloading m4a instead of webm? Weird.