720x480 DV to 352x480 MPEG-2

[donbarzini]

Is it possible to convert a NTSC DV file from 720x480 to an MPEG-2 file that is 352x480? I tried several ways but the video seems to be a diaganal lined mess when playing in either Quicktime or Windows Media Player on a PC. The conversion from 720x480 DV to 720x480 MPEG-2 is always flawless. I need to convert these 720x480 files to 1/2 D1 352x480, any suggestions?

[galactica]

Is it possible to convert a NTSC DV file from 720x480 to an MPEG-2 file that is 352x480? I tried several ways but the video seems to be a diaganal lined mess when playing in either Quicktime or Windows Media Player on a PC. The conversion from 720x480 DV to 720x480 MPEG-2 is always flawless. I need to convert these 720x480 files to 1/2 D1 352x480, any suggestions?

If there's one thing i have leared, is that Its possible to do just about everything. Does that answer your question? we will have to find out.

1. How is it that you tried to do this reduction in size? what program did you use?

thats as good a place to start as any

[donbarzini]

I own FCP 4 and tried Compressor at 720x480 and that worked fine. Compressor does not allow you to do any other sizing with MPEG-2, 720x480 is the default. A friend of mine owns Bitvice so I brought my DV file to his system and the 720x480 conversion to MPEG-2 worked fine. When we tried to convert my original 720x480 DV file to a 352x480 MPEG-2 file, it was a mess (garbled diagnal lines, like bad reception). Bitvice converts the original DV to a .m2v file and a .AIF file. Without even muxing the 2 files (audio & video) with Bitvice Helper, the .m2v was as I described, a mess. So my conclusion is that the muxing has nothing to do with the problem.

[galactica]

I concurr, however know NOTING about Final Cut Pro, so im out of my leage here.
Ill msg a friend how knows a bit about it and see what he thinks.

[galactica]

This is what he said

1. 1. you are doing an odd reductoin in size, thereby making the outcome a non standard resolution. try keeping both length and width proportional to the origional source.

2. Typically a mpeg2 isnt reduced in size b/c an mpeg2 is used for DVD video which is 720x480. so You needs to reduce the video size within FCP b4 you export to mpeg2. The mpeg2 will still be 720x480, but your video will be the size you wants, except there will be black around it.

[brett]

g -- in NTSC land, there are four allowable DVD resolutions for mpeg2 per spec: 720x480, 704x480, 352x480, 352x240. (the last one also works with mpeg1). those are all technically "dvd video." so, 352x480 actually IS a "standard" dvd rez. play it on any dvd player and you will see a full size, full screen picture.

(in PAL land, the spec dvd rez's are 720x576, 704x576, 352x576, 352x240 for mpeg2. and 352x288 for mpeg1.)

you DO NOT have to reduce the resolution of the fcp source movie b4 using bitvice. bitvice will downscale it just fine -- and you can use a nice low bitrate because you are encoding one-half of the source movie's information.

d -- are you using a fcp reference movie as the input for bitvice? i've had trouble with that too -- getting the horizontal garbage as my result, which i think you described above. export a full quality dv movie and encode that and see what happens -- that seems to always give me a clean bitvice encode.

also, check the boards/post your problem at bitvice:

http://innobits.se/forum/

[AntnyMD]

352x480 is a part of the DVD NTSC spec, and it is the standard for CVD (the original SVCD).

I would recommend doing the resize (a DV to DV conversion) in Final Cut Pro, then use a different encoder to compress to mpeg 2. The Quicktime MPEG2 encoder is not so hot anyway (though theres a new version due soon in DVD Studio Pro 2).

[donbarzini]

brett,

yes, I am using an FCP reference movie. What I will do is export the entire 30 second clip not as a reference and burn it to a DVD. I'll bring it to my friend again and see what happens. I appreciate the advice. It seems logical that the reference file may not want to be downscaled, that could be the problem.

[brett]

hey, here's another tip to try: use a reference movie but delete its timecode track.

http://innobits.se/forum/viewtopic.php?t=310&highlight=reference


and here's one guy's fcp/resizing workflow (last post):

http://innobits.se/forum/viewtopic.php?t=209&highlight=resize

[galactica]

g -- in NTSC land, there are four allowable DVD resolutions for mpeg2 per spec: 720x480, 704x480, 352x480, 352x240. (the last one also works with mpeg1). those are all technically "dvd video." so, 352x480 actually IS a "standard" dvd rez. play it on any dvd player and you will see a full size, full screen picture.

(in PAL land, the spec dvd rez's are 720x576, 704x576, 352x576, 352x240 for mpeg2. and 352x288 for mpeg1.)

you DO NOT have to reduce the resolution of the fcp source movie b4 using bitvice. bitvice will downscale it just fine -- and you can use a nice low bitrate because you are encoding one-half of the source movie's information.

All the more reason I said I was out of my league.
Glad others could post thier thoughts. Maybe someday I should toy around with FCP.

[donbarzini]

brett,

It worked! The guy's post on the innobits forum regarding the timecode track did the trick. As long as the timecode track is disabled, even from a FCP reference movie, the encoding at 352x480 works. Thanks for the info!