PAR and not aspect ratio in x264 2.6.0 8323

[Jan Gruuthuse]

When applying aspect ratio and re-encoding in x264 something strange happens? Or did I misunderstand this feature?
1:1
4:3
16:9
Each clip approximate 7 MB!
original clip 720p 16:9 : test.mkv
Re-encoded 1:1 aspect ratio: test11.mp4
Re-encoded 4:3 aspect ratio: test43.mp4
Re-encoded 16:9 aspect ratio: test169.mp4

[KoolAidMan]

Looks to be working properly. The aspect ratio is not of the video itself, but rather of the individual pixels.

The predefined aspect ratios will work properly if you have a 720x480 resolution video and would like the aspect ratio to be either 4:3, or 16:9 for NTSC. They will also work if you have a 720x576 resolution video and would like the aspect ratio to be either 4:3 or 16:9 for PAL.

[Jan Gruuthuse]

Thanks for pointing this out. That figures. Got caught out by Predifined Aspect Ratio Forgetting it was still under Pixel Aspect Ratio (PAR)

[qwerty84]

The predefined aspect ratios will work properly if you have a 720x480 resolution video and would like the aspect ratio to be either 4:3, or 16:9 for NTSC. They will also work if you have a 720x576 resolution video and would like the aspect ratio to be either 4:3 or 16:9 for PAL.

The predefined aspect ratios are wrong.
For 4:3 PAL the correct pixel aspect ratio is 12:11 and for 16:9 PAL the correct P.A.R. is 16:11.

For example if you have a 720x576 PAL image with a Display Aspect Ratio of 4:3 and you use a PAR of 16:15 then you get an image of (720x576)*(16/15)= 768x576. 

768/576 = 4/3 = 1.333333...
BUT. What about the Nominal analogue blanking ? (the two vertical black stripes)

The black stripes on the left and right of the video are not part of the 4:3 image.
So with a P.A.R. of 12:11 you have : (720x576)*(12/11)= 785x576