[Marsu42]

I'm currently trancoding a video archive to save space. The videos are AVC with vastly different bitrates from 1.5 to 15 MBps, usually with little motion.

With my former, extremely old PC (Core1 Quad) using x265 was a no-go. With my more currrent PC (Haswell Dual) I could switch if there is a clear advantage. Yes, I know, your boxes are waaaaaaaay faster.

I'm downsizing to 720p to save some further space and because my usual monitor isn't full hd anyway.

=> QUESTION: Is there a low source bitrate threshold like 3-5 MBps that could result in _worse_ transcoding quality AVC=>HEVC than AVC=>AVC? Or is HEVC encoding too similar to AVC so it doesn't make a difference? Or does HEVC result in significantly enhanced quality in transcoding in any case?

I'm thinking of the different artifact types, which is why transcoding different image formats like dct-jpeg and wavelet-jpeg2000 isn't a good idea with low quality sources.