Question about encoding anamorphic x264

[nhope]

I have a question about encoding anamorphic video.

Can I halve the size of HDV from 1440 x 1080i anamorphic (PAR 1.333) to 720 x 540p anamorphic (PAR 1.333) and encode this as anamorphic x264 such that media players will play it back correctly at 16:9 and not treat the pixels as square (4:3 playback)?

How would I set that up in AviSynth/x264/MeGUI?

(I just tried this with "clever anamorphic encoding" in MeGUI but the result plays back 4:3 in VLC)

Thanks!

Edit: Apologies for putting this in the wrong forum.

[morphinapg]

My program ASXGui can set this up for you.

http://forum.doom9.org/showthread.php?t=136147

Just import your 1440x1080i file in ASXGui, set the custom resize to 720 x 540, and override aspect ratio to 16:9

You probably also want to enable deinterlace. If your source video is film, you should also enable convert frame rate and set it to 23.976

Example of those settings:

http://i31.tinypic.com/de4odv.jpg

[nhope]

That looks good morphinapg. I will check it out. What is that override doing under the hood in terms of x264 command line options?

[morphinapg]

That looks good morphinapg. I will check it out. What is that override doing under the hood in terms of x264 command line options?

in this case it's adding the option --sar 4:3 which adjusts the pixel-aspect ratio of the encode to 1.333, which to this resolution changes the display aspect to 16:9

My program will probably actually add the option as --sar 960:720 but x264 automatically reduces this to 4:3 so it doesn't matter.

[jmartinr]

Can I halve the size of HDV from 1440 x 1080i anamorphic (PAR 1.333) to 720 x 540p anamorphic (PAR 1.333) and encode this as anamorphic x264 such that media players will play it back correctly at 16:9 and not treat the pixels as square (4:3 playback)?

I've looked into it a bit more now. You can use MeGui. You have to make sure --sar 4:3 is on the x264 command line.

Then in the end you can use dumpster (get it from Apple somewhere under legacy windows stuff), to adjust some values in the MP4 to get the AR right in Flash Player. Under "moov", "trak", "tkhd" you put the PAR in the matrix upperleft and put the old values in "width" and "height" (or else QuickTime will use the PAR twice).