Avisynth Script for letterboxed mp4 to mpg?

[Robert Simandl]

Hey everybody,

I've been out of the game for a while now, and suddenly have a weird mp4 file I'd like to convert to a DVD.

It's weird in that even though it was made from film, its frame rate is 29.97. And it's letterboxed within a 4:3 aspect ratio. Yep, black bars at the top and bottom are hard coded into it.

I've always used VirtualDub to split off the audio from avi files, but it doesn't seem to recognize mp4 files. First question is, what's the best way to get the audio from this file separated out so I can covert it to AC3?

Second question is, I'd like to chop off the black bars at the top and bottom, and encode as a 16:9 mpeg-2 .m2v file so I can author a DVD-R.

Can someone recommend an Avisynth script to do that (output will be loaded into the HC encoder)?

Thanks!

[manono]

I use the free AoA Audio extractor to get the audio out (as a WAV file). But there are lots of ways.

If it's really from film you can either IVTC it or maybe decimate it to remove dupe frames and return it to 23.976fps. If it's been resized you may be screwed. The usual NTSC 4:3 to 16:9 conversion from a 720x480 source script goes something like this:

Crop(0,60,0,-60)
LanczosResize(720,480)

Depending on the distrubution of the black bars, the '60's might be a bit more or less, but still adding up to '120'. If it's PAL, the '60's become '72's and the '480' becomes '576'.