What screen size should my Divx video be?

[David9799]

I want the best picture i can get so do i use 720x480? The same as a DVD? btw is there a way i can see what size the video is on a DVD?

[celtic_druid]

I'd crop the borders. Could run into issues with the AR though since I am not sure that DivX fully supports PAR resizing. Also if there are size constraints, then a larger resolution isn't always better in terms of quality.

[David9799]

So what size is best to use?

[steveryan]

There is no best, let your eyes be the judge - if the quality looks good to you then that's all that matters. Rip your DVD to the hard drive then use AutoGK to encode to Divx or Xvid. AutoGK will crop the borders for you and you can even keep the original audio, it's very easy to use.

[jagabo]

So what size is best to use?

There is no simpla answer to that question.

If you are using a player that supports the MPEG4 Picture Aspect Ratio (PAR) and you are willing to use whatever bitrate it takes to maintain the picture quality you want, then use the same size frame as the source and the same PAR. For DVD sources that would normally be 720x480 and 4:3 or 16:9 PAR. If your source has black bars (top and bottom) because it is wider than 16:9 (a 2.35:1 movie for example) then cropping the black bars (and setting the appropriate PAR) will be slightly more efficient.

If your player doesn't support PAR then you want to resize the frame so that the frame size matches the PAR. For example, a 4:3 movie could be resized to ~720x544 or 640x480. But again, you will have to be willing to use a high bitrate to maintain picture quality.

If you want to use low bitrates (say you want to put a 2 hour movie on a CD, so about 700 kbps) you have to find a compromise frame size. If the frame is too large the video will show lots of macroblocks. If the frame size is too small you lose overall resolution. The "best" compromise will vary depending on the video so there is no single answer. If this is what you're doing and you don't understand all the details you should use a program like AutoGK which will analyse the video and pick a good frame size for you.

Note that Divx doesn't really support PAR (both the encoder and the decoder) but you can add PAR information afterwards with MPEG4Modifier. Or you can simply encode with Xvid instead and set the PAR when you encode.

[GMaq]

Hi,
To actually answer the question you asked, Common sizes that give good quality (with cropped borders) are 512x384 for 4:3 Sources, 624x352 for 16:9 Sources and 704x304 for 2.35:1 Sources. Unless you are trying to squeeze it onto a CD I would suggest using a bitrate of 1000-1250kbps for 2-pass or 1-Pass Quality Based which will give you the best quality but an undetermined file size.

[celtic_druid]

That would be DAR. The PAR for 16:9 DAR is not 16:9. For instance the PAR for 720x480@16:9 would be something like 32:27.

[jagabo]

By PAR I meant Picture Aspect Ratio (which is why I spelled it out), basically the same thing as DAR, Display Aspect Ratio.

I know this is confusing because some programs/people use PAR to mean Pixel Aspect Ratio, the relative dimensions of individual pixels, or sometimes the relative dimension of the frame measured in pixels. I suppose I should use DAR instead since Gspot and the Xvid codec use that term.