Please write ytdl_option in json for 'square-cropped thumbnail'

[yogijero]

Not a tech-savvy here, can anyone guide me how can i have square thumbnails for the music.
While doing directly with yt-dlp command,
yt-dlp -x --audio-format mp3 --embed-thumbnail -v --convert-thumbnail jpg --ppa "EmbedThumbnail+ffmpeg_o:-c:v mjpeg -vf crop=\"'if(gt(ih,iw),iw,ih)':'if(gt(iw,ih),ih,iw)'\"" --exec ffprobe
seems to work, but don't know how to convert it in json. Any help would be appreciated.

[PikuZheng]

For embedded yt-dlp option configuration, see https://github.com/yt-dlp/yt-dlp/blob/master/yt_dlp/YoutubeDL.py#L180 or discuss on yt-dlp project

[PikuZheng]

If you only want to embed the thumbnail in mp3, #188 (comment) fyi

[yogijero]

By Default, metube embeds the thumbnail, however it does that in 1280 × 720 pixels. I want it to be in 1:1 (square).
The above yt-dlp command does it but I do not know how to implement it in metube.