[FFmpeg-user] libx264 options through FFmpeg

[Thomas Worth]

While I've historically used a standalone x264 binary to do encoding
by piping yuv420p from FFmpeg, I thought I'd try libx264 through
FFmpeg since it's certainly more convenient.

I've compiled the latest git of both FFmpeg and libx264. I've looked
through the help and I can't seem to find all of the x264 options I'm
looking for. The ones in question are the ones related to Blu-ray
encoding. They don't all seem to be implemented through FFmpeg.
However, there is a "-x264opts" option, which appears to take a
colon-delimited list of x264 options. Now the question is, why use the
built-in FFmpeg options (like -flags2, -me_method, -tune, -profile
etc) if I can just pass them via -x264opts? Is there a limitation to
this? Do I still need to use FFmpeg's versions of these options?

The Blu-ray options that appear to be missing from the FFmpeg
interface are options like --nal-hrd, --slices etc. I passed these
with -x264opts and it recognized them, although it mentioned this when
I used --nal-hrd with --vbv-maxrate and --vbv-bufsize:

"VBV parameters cannot be changed when NAL HRD is in use"

If I can safely pass all my options via -x264opts then I'll just use
that from now on and disregard FFmpeg's x264 interface.