Recommended crf value for transparent re-encode of 1920x1080 avc video

[wiseant]

Hi

My friend uploaded a video: https://icedrive.net/0/67YsFqxg7q
It took me over an hour to download it [907 MB]

Here is the media info: [I used a gif because the text file was poorly formatted when I tried posting it here]

[Attachment 62416 - Click to enlarge]


Here is a resized screenshot:

[Attachment 62417 - Click to enlarge]
Anyway, as far as I am concerned this is bitrate overkill.
He has another video that is about 2.5 GB - it would take over 3 1/2 hours to download from that site.

What x264 crf value would be close to transparent for a re-encode?

I'm sure that the bitrate could be reduced to 30 to 40% of the original - which would make it a lot faster to upload / download

TIA

[jagabo]

"Transparent" varies from person to person and depends, how a video is watched, and what encoder/settings are used. But x264 at at crf=18, slow preset, is decent for normal viewing. That gave a 184 MB file (without audio). Took about 3 minutes to encode (i9 9900K).

[davexnet]

"Transparent" varies from person to person and depends, how a video is watched, and what encoder/settings are used. But x264 at at crf=18, slow preset, is decent for normal viewing. That gave a 184 MB file (without audio). Took about 3 minutes to encode (i9 9900K).

I tried it also, the result looked pretty good. On my AMD FX4300 (roughly equivalent to the old i3's) it took about 20 minutes

[wiseant]

@jagabo
@davexnet

Much appreciated. So video of 900 MB down to 184 MB = 20% of original size - wow
I"ll have to try that at crf=18 slow preset
BTW - how long did it take to download?
Thanks

[davexnet]

@jagabo
@davexnet

Much appreciated. So video of 900 MB down to 184 MB = 20% of original size - wow
I"ll have to try that at crf=18 slow preset
BTW - how long did it take to download?
Thanks

Less than 60 second. According to https://speedtest.xfinity.com/
I'm getting about 232 mbps

[wiseant]

@davexnet

Thanks
I just downloaded it again - took 2 minutes - I wonder why the first download took so long . . .

[jagabo]

BTW - how long did it take to download?

About 2 minutes for me. 60 Mb/s connection.

[4kblurayguru]

Anywhere between 17-28
Try one then increase or decrease by 6 until you find one acceptable quality/file size.
You can try 30 seconds instead of the entire length.
You can also drop the resolution to 720p or 480p or 360p for smaller size.