exporting mpeg-2-dvd, but keep getting 640×480 ?

[Steve Roberts]

If you have DVDsp, you have Compressor.

Render (composition>Make Movie) a Quicktime Animation movie in AE, then drag that into Compressor and make the MPEG-2 there, using a 2-pass VBR preset, probably the 90-minute one.

[Michael Greenawalt]

thx for the response…

so VBR rather than CBR for authoring DVDs? i thought that i had read that using a Constant rate was more the standard for DVDs.

What’s the major diff between them in the exports? file size? quality?

– michael

[Steve Roberts]

2-pass VBR is better quality, and file size. On the first pass, the encoder reads the clip to see where you have rustling trees (high bitrate) and talking head on bluescreen (low bitrate). On the second pass, it encodes appropriately, ensuring quality on the messy stuff and low bitrate (file size) on the smooth stuff.

Hey, don’t take my word for it. Do some tests. 🙂

[Michael Greenawalt]

ok thx again for the advice, my deadline is making it hard to do any tests, so i appreciate the info.

take care, all hail the cow.

– michael

[Darby Edelen]

[michael greenawalt] “all getting the same 640×480 result. I need a 720×480 for dvd studio pro. “

For some reason, QT Player reports 4:3 NTSC MPEG-2s as 640×480 and 16:9 NTSC MPEG-2s as 720×404. If you import these into DVDSP the dimensions will be read as 720×480.

Darby Edelen
Designer
Left Coast Digital
Santa Cruz, CA

[Michael Greenawalt]

Aha!!!! QT is just reporting is wrong.

Darby you rule, thx so much!!

– michael

[Scott Bush]

I always thought this was due to pixel aspect – so a 720×480 frame with DV pixels is 640×480 in square pixels (like in QT player) – for some formats it will even say “640×480 (720×480)” – not sure if my theory is right, but I know this is normal behavior for QT.

[Erik Pontius]

CBR applies, well… a constant bit rate across the entire duration of the video. This is wonderful for short videos say less than 30-45 mins, in which the resulting file size won’t exceed that of a single layer DVD-R disc.
For longer pieces, doing a 2-pass VBR can create a better balance between the compression used and file size in order to get the resulting files to fit on the disc and still have good quality. 2-pass is more efficient by essentially taking notes on the first pass where areas that have low movement (say a nice steady tripod shot of a bowl of fruit on a table) where it can use a lot of compression with less artifacting and areas where there are lots of changes and movement (say a big action scene or explosion) where it needs to apply less compression to minimize the artifacting.

Erik