--prefer-free-formats doesn't work

[Kcchouette]

$ youtube-dl -F https://www.youtube.com/watch?v=zt-LbzrS2lI
[youtube] Setting language
[youtube] zt-LbzrS2lI: Downloading webpage
[youtube] zt-LbzrS2lI: Downloading video info webpage
[youtube] zt-LbzrS2lI: Extracting video information
[info] Available formats for zt-LbzrS2lI:
format code extension resolution  note 
171         webm      audio only  DASH webm audio , audio@ 48k (worst)
140         m4a       audio only  DASH audio , audio@128k
160         mp4       192p        DASH video 
133         mp4       240p        DASH video 
134         mp4       360p        DASH video 
135         mp4       480p        DASH video 
136         mp4       720p        DASH video 
17          3gp       176x144     
36          3gp       320x240     
5           flv       400x240     
18          mp4       640x360     
43          webm      640x360     
22          mp4       1280x720    (best)

Normally, if I add the option --prefer-free-formats, youtube-dl must choose the webm format (43 webm 640x360)

But in this case :

$ youtube-dl https://www.youtube.com/watch?v=zt-LbzrS2lI --prefer-free-formats
[youtube] Setting language
[youtube] zt-LbzrS2lI: Downloading webpage
[youtube] zt-LbzrS2lI: Downloading video info webpage
[youtube] zt-LbzrS2lI: Extracting video information
[download] Destination: NORMAN - ACCRO À TON SMARTPHONE -zt-LbzrS2lI.mp4

Thanks
Jeremy

[xanadu]

It prefers the best quality, then free formats ...

[Kcchouette]

Ok :-/

Thanks

[phihag]

As @xanadu said, this behavior is correct - format 22 (mp4) is of much better quality than the best webm format. If you want to have webm first regardless of quality, pass in -f webm/best.

[Kcchouette]

In the case of a ogg format too, is youtube-dl LINK -f webm/best -f ogg/best correct ?

[phihag]

If you pass in multiple -f options, the latest one overrides the whole (that's useful for configuration files, for example). If you want webm first, then ogg, and after that anything else, pass in -f webm/ogg/best.

[Kcchouette]

Thanks