Avidemux Forum

Avidemux => Main version 2.6 => Topic started by: ABBrittain on October 15, 2012, 11:50:12 AM

Title: IDC Level in Mpeg4 AVC (X264)
Post by: ABBrittain on October 15, 2012, 11:50:12 AM
Can anyone explain what this parameter is and does please.
Title: Re: IDC Level in Mpeg4 AVC (X264)
Post by: Jan Gruuthuse on October 15, 2012, 02:30:31 PM
in my opinion these refer to: H.264/MPEG-4 AVC (http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC#Levels)
Title: Re: IDC Level in Mpeg4 AVC (X264)
Post by: ABBrittain on October 17, 2012, 11:02:31 AM
So the default setting of 3.1 should be ok? 
Title: Re: IDC Level in Mpeg4 AVC (X264)
Post by: Jan Gruuthuse on October 17, 2012, 02:12:55 PM
If you encode to specific hardware/media player (flat screen TV, ...) make some test videos couple of minutes with content you view often (football, action scenes, ...) and see what works best for you.
Quoteindicating a degree of required decoder performance for a profile
3.1 would not support 1080i/p, supports up to 720p 30 fps (1280Ãâ€"720@30.0), it is not always clearcut, more like a trial by error.
Title: Re: IDC Level in Mpeg4 AVC (X264)
Post by: nibbles on October 17, 2012, 03:14:29 PM
In general, 4.1 is the optimal level and is the unofficial standard for 720p or 1080p.  It can handle all the resolutions and frame rates.
Title: Re: IDC Level in Mpeg4 AVC (x264)
Post by: macduke on October 19, 2012, 09:22:58 AM
Some multimedia machines (ex.: WD) don't support IDC 5 and above.
In my opinion 4.1 or 4.2 is the best.
And don't forget "Max Ref. Frames": it's better to set not more than 5, for the same reasons as above.

Mac.
Title: Re: IDC Level in Mpeg4 AVC (X264)
Post by: ABBrittain on October 20, 2012, 09:14:54 AM
Thanks - I will make some test at 3.1/3.2/4.1/4.2 ansd check see which one of these works best for me.
Title: Re: IDC Level in Mpeg4 AVC (X264)
Post by: ABBrittain on November 13, 2012, 01:26:05 PM
Have been using 3.2 and eveything appears to be working. However I'm unable to make a direct comparision between 2.6 and 2.56-1 as not all the config options are active.

Any one know when the other config options will be active?
Title: Re: IDC Level in Mpeg4 AVC (X264)
Post by: Jan Gruuthuse on November 13, 2012, 01:41:09 PM
2.5 branch is frame based, 2.6 time based. More info can be found @ Avidemux versions (http://www.avidemux.org/admWiki/doku.php?id=versions:main)
Title: Re: IDC Level in Mpeg4 AVC (X264)
Post by: plasticassius on November 18, 2012, 08:04:00 AM
According to the wiki

http://www.avidemux.org/admWiki/doku.php?id=tutorial:h.264

Specifying an IDC Level does not mean that your stream actually complies to that level! Therefore it's highly commended to keep the IDC Level setting on Auto and let x264 detect the proper Level. However, Auto does not work. So, it doesn't make any difference what you set this parameter to, it just can't be Auto. See my other post:

http://avidemux.org/smuf/index.php/topic,11552.0.html