How can i download thumbnails in png/jpg format?

[aviv926]

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Question

Hello, I try to download the thumbnails files in png/jpg format but they are always downloaded by default in webp format.
I'm inserting this code in cmd:

youtube-dl --write-thumbnail [URL playlist]

The files are downloaded directly to the computer in webp format

I tried to add -f:

youtube-dl -f --write-thumbnail [URL playlist]
But it still wouldn't let me choose the format I wanted.

I know there's an commend called:

--write-all-thumbnails
But I don't understand why you can't choose to download in jpg/png format
At the end of the day, it's the same quality.

For example:
https://i.ytimg.com/vi_webp/HOYDj769s6k/maxresdefault.webp

https://i.ytimg.com/vi/HOYDj769s6k/maxresdefault.jpg

It's the same picture with a different extension.

I've seen a report on it before and it's closed, but I didn't understand the solution.

Can someone explain to me where I'm wrong?

[aviv926]

Anyone who can help?

[ghost]

If you are talking about YouTube's thumbnails, it seems that if you specify a user-agent which doesn't handle webp, you can get maxresdefault.jpg.

$ youtube-dl HOYDj769s6k --get-thumbnail
https://i.ytimg.com/vi_webp/HOYDj769s6k/maxresdefault.webp
$ youtube-dl HOYDj769s6k --get-thumbnail --user-agent curl/7.54.0
https://i.ytimg.com/vi/HOYDj769s6k/maxresdefault.jpg

[nicolaasjan]

If you are talking about YouTube's thumbnails, it seems that if you specify a user-agent which doesn't handle webp, you can get maxresdefault.jpg.

I just tried that and noticed that in that case the quality of the image is much worse...
A lot of jpeg artefacts.

[nicolaasjan]

you can always use dWebP from the Google's WebM project #1 #2, or ffmpeg (which I think is already used in ytdl anyway..), to convert the thumbnail to whatever format that works best for you.

With FFmpeg (Unix commands):

To .jpg:
for i in *.webp; do ffmpeg -i "${i}" -q:v 1 -bsf:v mjpeg2jpeg "${i%.webp}.jpg"; done

To .png:
for i in *.webp; do ffmpeg -i "${i}" "${i%.webp}.png"; done

[aviv926]

you can always use dWebP from the Google's WebM project #1 #2, or ffmpeg (which I think is already used in ytdl anyway..), to convert the thumbnail to whatever format that works best for you.

you can always use dWebP from the Google's WebM project #1 #2, or ffmpeg (which I think is already used in ytdl anyway..), to convert the thumbnail to whatever format that works best for you.

With FFmpeg (Unix commands):

To .jpg: for i in *.webp; do ffmpeg -i "${i}" -q:v 1 -bsf:v mjpeg2jpeg "${i%.webp}.jpg"; done

To .png: for i in *.webp; do ffmpeg -i "${i}" "${i%.webp}.png"; done

Thanks guys!

I'll check it out.
Suggestion I Considered an Increase:
Add an option to choose which format to download thumbnails as can be done with video
I mean it:
youtube-dl -f 'bestvideo + bestaudio / bestvideo + bestaudio' --merge-output-format mp4 [URL]

And turn it into something like this:

youtube-dl.exe --write-thumbnail [ext = jpg/png] --skip-download --output "%(title)s.%(ext)s" [URL HERE]

[nicolaasjan]

Suggestion I Considered an Increase: Add an option to choose which format to download thumbnails as can be done with video I mean it: youtube-dl -f 'bestvideo + bestaudio / bestvideo + bestaudio' --merge-output-format mp4 [URL]

And turn it into something like this:

youtube-dl.exe --write-thumbnail [ext = jpg/png] --skip-download --output "%(title)s.%(ext)s" [URL HERE]

There is already an option to do this in the yt-dlp fork of this repo. :)
(the development of the youtube-dl repo has come to a standstill since the beginning of June...
See: #29965)

--convert-thumbnails FORMAT
Convert the thumbnails to another format
(currently supported: jpg|png)

So try e.g.:

yt-dlp.exe --skip-download --write-thumbnail --convert-thumbnails jpg https://www.youtube.com/watch?v=Y2T4caGlK80

To convert to highest quality .jpg, append:
--ppa "ThumbnailsConvertor:-q:v 1"
to your command as well (this only works in yt-dlp; not nessessary for .png).

So:

yt-dlp.exe --skip-download --write-thumbnail --convert-thumbnails jpg --ppa "ThumbnailsConvertor:-q:v 1" https://www.youtube.com/watch?v=Y2T4caGlK80

[aviv926]

yt-dlp.exe --skip-download --write-thumbnail --convert-thumbnails jpg

Thank you very much bro you helped me!
I did not even know that yt-dlp exists.
Thanks

[Uhter]

So:
yt-dlp.exe --skip-download --write-thumbnail --convert-thumbnails jpg --ppa "ThumbnailsConvertor:-q:v 1" https://www.youtube.com/watch?v=Y2T4caGlK80

Thank you @nicolaasjan, this command is perfect.
I made an alias with it ;)

[nicolaasjan]

So:
yt-dlp.exe --skip-download --write-thumbnail --convert-thumbnails jpg --ppa "ThumbnailsConvertor:-q:v 1" https://www.youtube.com/watch?v=Y2T4caGlK80

Thank you @nicolaasjan, this command is perfect. I made an alias with it ;)

👍️
However, later I found out that even better quality jpg can be achieved with:
--convert-thumbnails jpg --ppa "ThumbnailsConvertor:-qmin 1 -q:v 1"

See top answer at Stack Overflow:

Use -qscale:v (or the alias -q:v) as an output option.

• Normal range for JPEG is 2-31 with 31 being the worst quality.
• The scale is linear with double the qscale being roughly half the bitrate.
• Recommend trying values of 2-5.
• You can use a value of 1 but you must add the -qmin 1 output option (because the default is -qmin 2).

That gives a ~128KB image instead of a ~80KB image for the video in my example. 🙂

[Uhter]

Perfect !
Thanks again :)