Handbrake - size % of original file?

[T0tum]

Is there a way to let Handbrake encode to a certain % of input file size?

Iam trying to batch convert large number of flv files into mp4's, but due to huge bitrate variation in files, quality factor "RF" is not working out for me. Some files with bitrate around 500Kbps (using constant quality 15) result in 400 - 650Kbps, others with bitrate over 1000Kbps result in anywhere between 600 and 800Kbps. Basically, some files get oversized, others get compressed to around 50%.

I cant seem to find a trade off using constant quality factor. Setting bitrate manually is too time consuming due to the amount of files iam converting.

[ndjamena]

I'm afraid MediaInfo/FFProbe + CMD Batch File + HandbrakeCLI.exe is the closest you'll ever get to that.

[jman98]

I'm not claiming to be an expert as I don't use Handbrake so if I'm wrong then others can correct me, but I think if you set constant quality it overrides your bit rate setting and uses whatever it needs to reach the quality setting, which will be different for every film. So basically by setting constant quality it's not using your bit rate target at all.

[fritzi93]

So basically by setting constant quality it's not using your bit rate target at all.

In a nutshell. It's one or the other, no?
Now, I don't use Handbrake either, but I don't see how you can combine bitrate target (or target file size) and quality-based encoding.
Seems to me that Handbrake is working properly. Each file is allocated the bits needed to get the quality specified.

[LigH.de]

Encoding with a rather equal quality distribution and a target file size means to run two passes. The first pass will gather required information to run a second pass to match a target bitrate while controlling the bitrate to have a rather equal quality loss over the whole playtime.

If you are going to use x264 as encoder, it will in fact calculate the CRF value in the first pass which is required in the second pass to approach the target filesize.

But of course, two-pass encoding will be more time consuming than single-pass CRF encoding. And every movie will have a different degree of quality loss, despite a similar target size.

[iceblitzed]

Ive used handbrake before and I don't think there is a way to do what you want to do.
What I can recommend though is raising the crf value to 18 to help the compression and retain good quality.

[ndjamena]

What I can recommend though is raising the crf value to 18 to help the compression and retain good quality.

That's a point.