BD Rebuilder vs. CloneBD

[drfsupercenter]

Hey everyone, remember me?

I used to be a regular here as a teenager, before Blu-ray existed and shortly after.

Well, I'm back, as I wasn't sure where else to ask this question.

I've been using jdobbs' great program https://www.videohelp.com/software/B...r]BD Rebuilder for the past few years to shrink dual-layer Blu-ray discs to BD25 format so I can burn backup copies on cheaper media (BD-R DL is still absurdly cost-prohibitive despite being 15 years old)

Well, it appears the makers of CloneDVD have made an updated version called CloneBD that can do similar tasks, copying non-copy-protected Blu-ray discs to ISO files and also shrinking them from dual layer to single layer. The website mentions it can use H265/HEVC compression.

Has anyone used both programs on the same source material and compared the output quality? BD Rebuilder works, functionally, for what I am doing - but even the "very slow" best quality option only does a one-pass average-bitrate encode using x264/x265, with no option to do dual or multi-pass encoding. I am not sure if CloneBD does this either, but it at least mentions HEVC which is something I don't believe BDRB can do.

Thanks in advance

[admin]

Welcome back!

BD Rebuilder does encode to HEVC using x265, as does CloneBD. I would be surprised if either was just using constant bitrate encoding, most likely it's doing one-pass CRF. The only downside for CRF is the file size can be unpredictable (so you may have to be a bit more conservative in order to get it to fit into a BD25), but the quality is predictable (given that the CRF value is the quality value). If both produce the same file size encode, the quality should be near identical with either method.

[drfsupercenter]

I haven't tried CloneBD yet since it's payware, but BD-RB only does one-pass for sure. It has two options, ABR or CRF. The default seemed to be ABR but I changed it because pretty much anyone agrees that's the worse mode to use.

I just find it strange that BD-RB doesn't have any support for multi-pass mode. Is that not a thing with H264/HEVC? I haven't really dabbled in encoding since the XVID days, but you could absolutely get better results if you did two-pass very slow mode.

In fact, "average bitrate" sounds like exactly what I used to do, except I would have a target size I gave the encoder, e.g. "make this movie fit in 700MB" and let it run. Bitrate/filesize are basically the same calculation.

[admin]

People are using 2-pass encoding less and less because of how slow it is, and also because ensuring an encoding having a certain file size is less important than the encoding having a certain quality. This is where CRF comes in, where you can say set it to "18" and you can be fairly certain it will always give you a consistent level of quality.