Converting DivX and Xvid to DVD, but question regarding picture...

[primus_fan2001]

Hey, I've recently obtained some wrestling events from Japan in Xvid and DivX formats. Now, these were all taped live, but thanks(?) to the compression, the video scale has been changed, thus making the video appear to be slower (I've had this problem before, but never knew exactly how to describe it). Is there any way to change/tinker with the video so that it appears to be its original appearance, despite being changed to either DivX or Xvid?

[jagabo]

You can change the frame rate (make it play faster or slower) of an AVI file simply by changing a few bytes in the AVI header. Use a program like AVIFrate. This will cause the audio to get out of sync though.

For DVD the frame rate will have to be either 25 fps (PAL) or 23.976 or 29.97 fps (NTSC). Most MPEG encoders will do the conversion for you but won't necessarily do it the best way. Most either duplicate frames or remove frames to make the frame rate match.

[dadrab]

So what is the better way to change the frame rate. I'm having a similar issue on some Xvid files as well.

[jagabo]

What's the frame rate of your source? Are you making and NTSC DVD? I assume so since you're in the USA.

It's odd that your Divx/Xvid videos from Japan would be at something other than 29.97 fps. Japanese TV uses NTSC too, so the frame rate should be the same.

[jman98]

jagabo - Of course you are correct, but a lot of people who use Divx/Xvid don't know what the heck they are doing and through ignorance convert to Divx/Xvid with strange frame rates because they think it "helps". I've seen some really strange frame rates used, like 20 fps and less.

[dadrab]

Whereas the quality of some of the Xvids I have are really good, and the configuration seems to be NTSC, the framerate corresponds with those that should be PAL, or 23.XX.

My NTSC DVD player will play the re-encoded file, but the motion freezes momentarily every 10 seconds or so.

Very annoying.

I've encoded this particular piece several times using several methods and the outcome is still the same.

Thanks.

[jagabo]

23.976 fps would be NTSC film. You should convert that to 23.976 fps MPEG2 marked with 3:2 pulldown flags. That should play smoothly on your DVD player -- it's what most commercial DVD use.

Does the AVI file play back at a normal speed when you watch it on the computer? Or does it look like it's running 20 percent slow? Does it play smoothly or is it jerky too?

[dadrab]

jagabo,

Does the AVI file play back at a normal speed when you watch it on the computer? Or does it look like it's running 20 percent slow? Does it play smoothly or is it jerky too?

The file plays just fine on the computer. That's why it's baffling me.

In fact, the encoded MPEG2 file plays fine on the computer as well, but the burned disc displays the jerky behavior.

[jagabo]

In fact, the encoded MPEG2 file plays fine on the computer as well, but the burned disc displays the jerky behavior.

Your computer is much more flexible than a DVD player at playing MPEG files. I suspect your MPEG file isn't encoded properly for DVD. What tools did you use to convert? Use GSpot to examine the file. Post a screenshot if you can.

[dadrab]

Unfortunately, by "play" computer system's at home. I can post a screenshot, but it'll be a pain since I've worked really hard to keep that system at least 6 feet away from the nearest internet outlet. I'll make it happen, though.

Funny thing about GSpot, which I use religiously... my version shows the group of blocks that lists whether a file is in NTSC, PAL...etc., but I've run several files through lately where none of the blocks show as highlighted when the processing's finished.

This particular file is like that.

Could it be the encoding is so mucked up that GSpot can't recognize any pattern there?

[jagabo]

Old versions of GSpot didn't work well with MPEG files. Maybe that's your problem?

[dadrab]

I believe I have the latest version, but, in any case, these are MPEG4 and Xvid files I'm trying to look at.

I'm not getting a reading, though.

I appreciate the help.

[jagabo]

I don't think GSpot can tell you much of anything about the internals (interlace, AR, etc.) of Xvid/Divx/MPEG4 files.

[dadrab]

Thanks again. Apparently, I was expecting to get information from a tool that cannot give it.

Cheers.