How do I make an mpg2 file encoded in 368x480 DVD-compliant?

[WaverBoy]

Do I have to convert it to 720x480, which takes about an hour for a 16-minute clip? Or is there a simpler, faster way to do it?

[adam]

You have to encode to a DVD compliant resolution, there's no way of getting around it and yes it does take a while. You would not want to convert to 720x480 though since scaling something up this much ruins quality. It would be better to resize or crop down to 352x480. This is also a dvd compliant resolution and very close to your source's resolution.

[WaverBoy]

Thanks for the reply! So, is there a good freeware program with which to do this? And is there a way to convert to 352x480 without cropping, i.e. windowboxing perhaps? Someone told me that, to get around converting, I could just patch the header of the file; here's exactly what he said:

"All you need to do to author these "non-standard" resolutions with a program like TMPG DVD Author is patch the headers of the files with a program like DVD Patcher (search Google). It takes about 0.1 seconds to patch the header of any MPEG file to the DVD standard (720x480). No re-encoding of the files is necessary. Patch the header of the MPEG to DVD standard. Import it into TMPG DVD author. Burn DVD and playback on TV.

The DVD player only cares that the files have a 4:3 aspect ratio, the resolution is irrelevent."

I tried that using DVD Patcher, but when I imported the files into DVD Author, in the little preview window of the program that shows the beginning still from the video file, the still appeared squeezed, all the way to the left, and a blank space on the right. I'm presuming it's going to look the same as this after I burn it, so I didn't bother. Will DVD Patcher in fact work? I'm guessing not, and that, as you say, converting is the only option...

[adam]

You want to decrease the resolution. In order to do this, you've got to re-encode. You can simply set the encoder to resize your video to 352x480, or you can manually crop the video to reach this resolution. Either method will work just as well. I suggest you use TMPGenc to do the encoding. Its trial version works completely during the trial period, in other words it doesn't add a logo to your output or anything.

Whoever you got that advice from doesn't really understand the point of standards. If you repatch your file all you are doing is tricking your authoring software into authoring it anyway. The resulting disk is still non-compliant and thus no DVD player is guaranteed to play it. I can say with certainly that the majority of DVD players on the market will not properly play back a DVD with a resolution of 368x480, no matter how its authored.

[wulf109]

Try IFOEDIT to author it. IFOEDIT makes no compliance checks. I've used IFOEDIT to author SVCD 480x480 to DVD and the results played on all of my DVD players. Try it on an RW disk first of course.

[FOO]

You can patch headers all day , but the mpeg2 stream still knows what
its resolution is.

and... no big deal to fool a player that can play SVCDs
into playing DVDs with 480 x 480... 368 is another matter

[WaverBoy]

I tried IFOEdit, burned the VIDEO_TS file to DVD-R, and it wouldn't play in my player, which is a Zenith DVB-318 that plays anything you throw in it. Well, except for that. Can you do me a big, big favor? Download the mpeg-2 clip of the old Lucky Strike cigarette commercial here:

http://www.archive.org/movies/movies-details-db.php?collection=prelinger&collectionid=...rom=mostViewed

It's encoded at the offending ratio of 368x480. Try authoring it with IFOEdit and burning it, and see if it plays in your player. If so, tell me EXACTLY what you did, because I suppose I could have screwed something up somewhere. There are a TON of amazing films for download in mpeg-2 at that site; unfortunately, many of them are encoded in the non-DVD-compliant ratio. I'm beginning to think I'll have to bite the bullet and convert to 352x480. Another question: if I do convert 368x480 to 352x480 by resizing (not cropping), will it still be a little squeezed, or will it play normally? Also, if I decide to crop instead of resizing, can I do that with TMPGEnc, or will TMPGEnc just resize it?

[adam]

If you resize to 352x480 then it won't have any effect on the aspect ratio it is played in, assuming you did the conversion correctly. The aspect ratio is set in a flag in the stream and the DVD player resizes the image accordingly to make the image appear in correct proportion. The problem though is that the DVD player is only required to have the capabilities to do this with DVD compliant resolutions, which is why your source won't play on many dvd players.

Regarding your test, I'd be more inclined to blame your poor results on IFOEdit itself. It does not author compliant DVDs at all. Nevertheless, the question isn't even whether authoring a non-compliant DVD, at 368x480 for example, will play on your dvd player...the real question is whether it will play on the next dvd player you purchase, and the next and so on. By making non-compliant disks you run the risk of one day having a collection that isn't playable on any hardware player.

My recommendation is to bite that bullet.

As for cropping versus resizing, TMPGenc can do either and you should get similar results. If you are unsure, you can run a 5 min little test encode and test the results.

[WaverBoy]

Adam, thanks so much. I really appreciate your help. One final question: will it take less time to convert it to 352x480 than it would to convert it to 720x480? If so, that would be smashing.

[adam]

Yes, all things being equal it should take about half as long since you have half as many pixels. It will vary depending on the encoder used, but yes it will definitely take less time.

[Craig Tucker]

Would'nt it take the same amount of time if the bitrates were the same, regarless of the resolution.

[FOO]

MPEG encoding:
The picture is divided into 8 x8 blocks.
then a discreet cosine transform is done on each
then all the results are quantized.

that's a lengthy process and doing half as many would be faster.

even the motion search has half as much to do

Half the picture - half the time