Generic settings for converting files to H.264?

[sofakng]

Are there generic settings for ffmpeg/x264 to convert any given input file to H.264 and maintain as much original quality as possible?

For example, I don't want to upscale or change the framerate, etc. I just want to convert the file to H.264 and keep the file small.

Could I just use CRF 16 (or something similar) and have an estimate 95% of original quality? Do I need any other parameters to make sure nothing else is being changed during the re-encoding?

[Guest]

I just want to convert the file to H.264 and keep the file small. This makes your question essentially unanswerable. File size and quality are in tradeoff. Unless you quantify what you mean by small, your question is too vague.

If you are looking for a reliable single recipe for all sources, you are going to be disappointed, IMHO.

[Asmodian]

Could I just use CRF 16 (or something similar) and have an estimate 95% of original quality? Do I need any other parameters to make sure nothing else is being changed during the re-encoding?

This is more open ended than you might expect, the range of possible sources is so high that the answer to this question would be very complex.

One point is that if you use CRF 16 for everything you might end up with files larger than the original but also lower quality due to the generation problem.