[handbrake] How do i ensure HP@L4.1 compliance

[Mutant_Fruit]

I just started using handbrake recently and I've been trying to figure out what encoding options I can use without exceeding HP@L4.1, which is what my hardware player (an xtreamer) claims support for. I made a test encode which ended up not playing and when i checked using mediainfo it said that it was MP@L5.0.

I haven't been able to find a table anywhere which states what options I can use, only tables listing maximum bitrates and resolutions.

Thanks!

[odditory]

handbrake forum.

[nurbs]

Never use more than 4 reference frames for 1080p or more than 9 for 720p.

[Mutant_Fruit]

Well i was torn between putting this post here and in the actual x264 encoder forum, maybe there would've been better.

Ignore handbrake for a moment (there was actually no point in me mentioning it), what x264 *options* would push me over HP@L4.1 or what options can I pass x264 to ensure it keeps me in spec.


Never use more than 4 reference frames for 1080p or more than 9 for 720p.

I didn't know that. Do bframes affect things to? What about bpyramid? I can't find good documentation on this kind of stuff :(

[nurbs]

You can look up the restrictions of level 4.1 in the H.264 article on wikipedia. Basically it's resolution and framerate (macroblocks per second), number of reference frames depending on resolution (DPB size) and VBV maxrate.

As long as you use sources that aren't higher resolution and framerate than 1080p30 the only thing you have to worry about are the reference frames. It can't hurt to set VBV parameters, but in normal backup scenarios the bitrate you encode to is so low that you won't run into problems. The number of b-frames and b-pyramid shoudn't have any effect on level compliance.

In x264 using --level 4.1 will lower the number of reference frames depending on the source resolution so the level isn't exceeded if you are using only the presets and tunings, but IIRC if you manually specify the reference frames, say --ref 16, this will override the --level command.