non square pixels?

[talz13]

I'm trying to save on file size by capturing at 320x480 (1/2 width frames). is there a way to specify the setting of a 2:1 pixel aspect ratio in the .prx profile itself? I know that you can specify it in the windows media encoder program, but i'm trying to get this profile to work with another software that uses windows media profiles.

[underwurlde]

Interesting...

What exactly are you trying to do with the resulting movie file.... just play it on a PC or eventually burn it onto a DVD?

The reason I ask is if you are just playing it back on a PC, I would just ignore anything relating to PAR / DAR! The bit you need to know you already have, i.e. convert / encode / copy etc using 320x480.

If you then play it back in windows media player, sure it will be squished, but hey who uses that! Use something proper like ZoomPlayer or DivX Player where you can set the playback aspect ratio!

Aspect ratios got me in a hole once and the program which caused me infinite confusion was Media Player! Like I said, the upshot was to basically ignore aspect ratios.....

I guess i'm not helping much but you never know!


Regards,

Andy.

[talz13]

that could possibly work... this is involved in a project that will be capturing video and converting in real time, and the resulting videos will be burned to cd and viewed at other computers. I can't say much more than that. But suffice it to say, most of the clients will only have (and know how to work) windows media player. I don't think using an add-on player will be the solution that we're looking for (but i didn't think of other players that could play with the PAR like that )

[underwurlde]

OK, fair enough!

So you have an original that is 320x480 that you want played back with an AR of 1.33:1 (If you use this AR, will also suit DVD authouring...)

I guess that you are starting with an MPEG1 / MPEG2 and want to keep it so...

I would therefore recompress (using VirtualDub MPEG v1.5.10) your half width source to one of the following H/V pixel sizes...

640x480 = does not loose any of the original data but may end up bigger
512x384
448x336
384x288
320x240 = probably best but will loose half the vertical quality. Smallest

Windows Media player will then play back with the correct (initial) AR of 1.33:1. Experiment with the above for best results...

While in the resizing process, you could also try encoding using different compression codecs etc. in an attempt to reduce file size (if using alternate codecs is not a problem to your end users).

I have found that Media Player picks up on the AR from the basic H/V pixel frame sizes. (I THINK!) I did look into the use of embedded DAR / PAR within the movie file header but did not get very far - it, as I have said, seems to be basically the pixel frame size but I would invite correction!

Andy.