x264 warning question

[jhd]

I am transcoding video using x264 from the command line, and I'm getting these warning:

x264 [warning]: frame MB size (40x23) > level limit (396)
x264 [warning]: MB rate (27572) > level limit (11880)

I found next to nothing on this by searching. Anyone know what these two warnings mean? Do they really matter?

[mitsubishi]

You should post your command line also.
It looks like you have set a level and then not adhered to it
http://forum.doom9.org/showthread.php?p=678891

[DarkZell666]

Indeed, you violated some constraints imposed by the --level x.x option.

You are encoding to 640*368 but you specified a "--level x.x" (which is either level 1.3 or level 2) which doesn't allow such a high resolution. This explains both warnings.

Are you trying to encode for ipod or psp by any chance ?
If so, reduce the resolution to something like 320*y (you won't be able to go higher because of the level you specified).

If not, then it doesn't matter, but you can also safely remove the --level option.

[jhd]

Thanks for the help. Here is my command:

x264 --progress -A i4x4 --trellis 1 --crf 26 --subme 6 --no-psnr --qpmin 12 --qpmax 51 -B 1000 --me hex --threads 2 --level 13 --fps 30000/1001 --pass 1 --stats script/../config/../files/temp/fire-short.mov.log -o script/../config/../files/temp/fire-short.mov.ff.video.mp4 - 640x360

(pass two is similar, and input is piped from a rgb to yuv converter.)

Does the --level option actually change the outputted file, or does it just provide warnings? I will be doing some transcoding for ipod - do I need the level option to output to ipod?

[DarkZell666]

I've never used the --level option, but I doubt x264 is able to do anything for the resolution (it doesn't downscale automatically, lol), so the output is just as you asked it to be ^^

Better leave it in so you'll know what's going wrong :)

But see, if ipod actually does handle the 640*Y resolution, then it surely supports a higher level than 1.3 (unless the resolution is the only exception to the rule), in which case the ipod supports a batard level somewhere between 2.0 and 2.1 xD

[bond]

Does the --level option actually change the outputted file, or does it just provide warnings? I will be doing some transcoding for ipod - do I need the level option to output to ipod?the level option only changes the output in the sense that it signals the set level in the file
additionally it signals whether your encode will be compliant to the level set, but will do nothing to make your encode compliant to the level