x264 (r1123): level 4.1 and options ¿problem with megui?

[daimroc]

When I use megui to configure x264, if I select level 4.1 to enconde then I can't select P4x4 partion, because it is incompatible with the 4.1 level.

However, if I use the command line to use x264, If I use the option --partitions all and I don't stablish the level parameter, when the code starts, I can see an info in which it says that it is used the 4.1 level.

If I put the five posible partitions manually, i get the same result, I use all the partitions and the level 4.1.

So my doubt is if there are limitations in the partitions that I can use in level 4.1 or not.

Someone could say me what difference are between level 4.1 and level 5.1? What options are not compatible with level 4.1? There are any documentation about it?.

PD: I edit the post because of the probes that I made (see below posts). Ithink that all partitions are compatible with level 4.1 and perhpas the problem is that megui don't allows to select partition P4x4 if the level 4.1 is selected. is this true?




Thanks.
Daimroc.

[LoRd_MuldeR]

Someone could say me what difference are between level 4.1 and level 5.1? What options are not compatible with level 4.1? There are any documentation about it?.

http://en.wikipedia.org/wiki/H.264#Profiles

http://en.wikipedia.org/wiki/H.264#Levels

[daimroc]

Thanks. It's an interesting information. But I can see that the difference are in max bitrate and resolution, but It doesn't say any about the options of the coder.

I would like to know which options are compatible with level 4.1 and what options are not.

Because I have a dobut, I put in the options of the coder that I want to use all partitions. However it says me that It's used level 4.1. Really do I use all partitions or not? If we considerate that it really exists some limititation in the parititions in level 4.1. Perhaps this lmitation doesn't exist.




Thanks.
Daimroc.

[LoRd_MuldeR]

...but It doesn't say any about the options of the coder.

Because these are not limited by Levels, but by Profiles ;)

With H.264 you always have Profile@Level, for example High@5.1 or Main@4.1.

[daimroc]

Well, I have done a probe using a video with a resolution of 4096x2048, that is a resolution that it is only compatible with level 5.1 and in this case the codec says that it is used level 5.1.

So I think that the codec use de minimun level that it is needed to encode with the desire options.

I think that all partitions are compatible with level 4.1 and the problem is with megui, that not allows to select p4x4 partion if it is selected the level 4.1.

Really is it tue?




Thanks.
Daimroc.

[LoRd_MuldeR]

So I think that the codec use de minimun level that it is needed to encode with the desire options.

The encoder (x264 in this case) doesn't "use" any Profile or Level. x264 simply uses the settings you tell it to use.

At the end x264 detects and prints the lowest profile/level with which the resulting stream complies.

If you want your stream to comply with a specific profile and/or level, you must choose your encoder settings accordingly!

[daimroc]

I do another probe, in this case I use the option --partitions all but I don't use the option --8x8dct that it is need to the partition i8x8.

In this case the codec doesn't report any problem. In this case the option --8x8dct is activated automatically or it doesn't use the i8x8 partition?




Thaks.
Daimroc.

[LoRd_MuldeR]

The --8x8dct option enables "8x8 vs. 4x4 Transform Adaptivity", which is a "High Profile" feature. Hence the resulting stream will comply with "High" profile, but not with "Main" or "Baseline" profile.

However that option is not related to Levels, I think...

[Dark Shikari]

When I use megui to configure x264, if I select level 4.1 to enconde then I can't select P4x4 partion, because it is incompatible with the 4.1 level.This is because MeGUI's interface is wrong. I have told the MeGUI developers repeatedly to fix this but they haven't.

[Sharktooth]

sorry, lack of time. ill see what i can do in the next days.

[Sharktooth]

fixed in megui rev. 1076.
next build will include the fixes to the x264 configuration window and AVC Levels checks.

[daimroc]

Thank you very much, Sharktooth, for the update.




Daimroc.