make my pixels look good!

March 19, 2008 5:56 PM

I'm burning video to be played on a standalone LCD HDTV/DVD player. The video seems to be recorded at 720x480 pixel resolution at 24fps. what resolution should I set it to to look best on my 720p HDTV?

So yeah, I'm editing the movie in IMovie, possibly exporting to quicktime, doing a bit of home-brewed editing tricks to the individual frames of the movie then importing it as a quicktime movie to iDVD to burn it. I have been having all sorts of difficulty making the video look good on the TV, i.e. no too interpolated, distorted, jumpy, etc.

The Tv in question is a Polaroid 15.4" LCD HDTV, here:
http://www.circuitcity.com/ccd/productDetail.do?oid=175907&WT.mc_n=92&WT.mc_t=U&cm_ven=COMPARISON%20SHOPPING&cm_cat=NEXTAG&cm_pla=DATAFEED-%3EPRODUCTS&cm_ite=1%20PRODUCT&cm_keycode=92

previously I had some luck manually resizing the video to 640x400 resolution but that seems kinda low. Any help? Sorry if I'm not explaining this as well as I could. Fell free to ask me follow up questions.

also, I asked this before:
http://ask.metafilter.com/24130/What-resolution-and-framerate-to-use
but it was in reference to normal TVs not this new-fangled lat screen hdtv i got recently

posted by garethspor to computers & internet (9 comments total)

720x480 is standard DVD resolution; all else being equal, it should look just like any other non-HD DVD.

That's not to say there aren't a boatload of other reasons it might not look great, but resolution isn't the culprit here.
posted by Tomorrowful at 6:00 PM on March 19, 2008

and correct me if I'm wrong, but there's no way to get the full 720p resolution out of a normal DVD, yes?
posted by garethspor at 6:02 PM on March 19, 2008

If the resolution isn't there, it isn't there. Your best bet would be to buy an upconverting DVD player, but even that doesn't really add resolution.
posted by MythMaker at 6:06 PM on March 19, 2008

i wonder if my problem is that my video is running at 24fps and the dvd playes are doing a poor job of resampling that to 29.97 or 30fps? does that make any sense?
posted by garethspor at 6:13 PM on March 19, 2008

do you have anything else you can view the dvd on? i am skeptical of your lcd's resolution as it is not standard. 720p is 1280x720 where your tv is 1280x800. it is possible that this difference in aspect ratio is what is causing the image to look distorted. the folks over on the doom9 forums are a fantastic resource for these kind of questions.
posted by mailbox125 at 6:20 PM on March 19, 2008

The official video-industry term for converting progressive 24-fps video (e.g. a movie shot on film) to 30-fps interlaced video (e.g. DVD) is "3:2 pulldown". (DVDs and conventional TV are 60 fields per second, with 2 fields per frame, so you output 3 fields of one frame, 2 fields of the next frame, etc. and it all works out mathematically.)

The trick is to get the DVD player to recognize that the 30-fps interlaced video it's reading from the DVD was originally 24-fps progressive (since your TV is also progressive-scan, not interlaced). The DVD player will then reconstruct the original 24-fps progressive stream and output it to your TV. Usually, on commercial DVDs, this is accomplished by inserting special flags in the DVD video stream that tell your DVD player to reconstruct it this way. Some of the more clever DVD players can also detect this even if the flags are missing or erroneous.

This all assumes you're using a progressive-scan DVD player. You are using a progressive-scan player with component output, right? Because if you aren't, there's your problem. I wouldn't worry about the disparity between your TV and the video, since DVD video is 720x480 no matter what. If you want higher resolution, you'd have to use an HD format, which is a much trickier proposition.
posted by neckro23 at 7:25 PM on March 19, 2008

garethspor: "and correct me if I'm wrong, but there's no way to get the full 720p resolution out of a normal DVD, yes?"

You can encode HD video onto a DVD but you'd have to use a computer or other compatible device to play it back. A regular DVD player wouldn't be able to handle it.
posted by aerotive at 9:32 PM on March 19, 2008

aerotive: Couldn't you put HD video on a DVD & play that on a Bluray or HDDVD player? This is probably completely irrelevant to the question here though.
posted by Pronoiac at 1:41 AM on March 20, 2008

why didn't you ask me this question?
posted by Gankmore at 12:26 PM on April 17, 2008