iMovie .dv -> DVD help needed

[zackthedog]

So far I'm doing a pretty good job of teaching myself to burn DVDs from my camcorder using ffmpegX and Dragonburn, but I'm still having some problems. I'm importing movies from my JVC camcorder to iMovie on an older G4 Powerbook, then editing and exporting (no fancy effects yet) to .dv using the "Expert" settings. Then I import the file into ffmpegX and use the "DVD mpg2enc" setting, and I get a good VOB that plays well. Using Dragonburn, I dropped the Video_TS and Audio_TS files into the burner, and burned a DVD that played fine on the Powerbook but got hung up on my DVD player, a Toshiba. The audio seemed out of sink then it froze five seconds into the video. Of course I'll keep fiddling, but I thought I'd ask for suggestions and maybe save myself some time .

ALSO, I'd like to find out why iMovie stretches the image. I'm pretty sure the camcorder records 640 x 480, but iMovie exports a 720 x 480 image that is not the correct aspect. There is a codec to fix this, but it takes a long time to process and I wondered if there's something I can do to correct the problem in iMovie. The camcorder only has normal and 16 x 9 settings.

[macevanscb]

I can't help you with your DVD authoring problem, but I can explain to you what iMovie is doing with your video.

DV spec is 720 x 480 and that's what iMovie is displaying. It looks stretched because a 720x480 picture is squished to be displayed on a TV at a 4:3 aspect ratio, while 720x480 is really a 4.5:3 aspect ratio. Any computer program that does not compensate for this will show a slightly stretched picture.

The main point here is not to trust what you see in the iMovie preview screen. On my Mac, iMovie's preview is too dark, too contrasty, and hue is off toward purple about 10deg, and, of course, the aspect ratio is always wrong. I recommend that you not use what you see in iMovie for any critical picture adjustments.

I get excellent results viewing exported clips in MPlayer OS X 2. Picture brightness, contrast, and hue are back to normal as compared to the iMovie screen. Also MPlayer resizes the picture for the correct aspect ratio instead of just throwing pixels at the screen.

[live4ever]

I get excellent results viewing exported clips in MPlayer OS X 2. Picture brightness, contrast, and hue are back to normal as compared to the iMovie screen. Also MPlayer resizes the picture for the correct aspect ratio instead of just throwing pixels at the screen.

I tried opening some DV clips in MPlayer by dragging them to the playlist and/or choosing File>Open but it won't open any. They are greyed out or they don't appear in the playlist.

[zackthedog]

Thanks for your reply, macevenascb. I think the authoring problem will get resolved with more practice and the right tools, but the iMovie export is bothering me. It definitely comes out stretched on the final DVD. Maybe I'll try some other export options within the program...?

[major]

I tried opening some DV clips in MPlayer by dragging them to the playlist and/or choosing File>Open but it won't open any. They are greyed out or they don't appear in the playlist.

The mplayer binary in the current Mplayer OS X 2 does not support raw .DV, but the mplayer binary used by ffmpegX supports raw .DV (click the "Play" button).

[macevanscb]

ZackTheDog & LiveForever .... sorry about the playback confusion. I use MPlayer to view MPG files encoded by ffmpegX. Due to the poor picture and slow performance in iMovie [even though full DV is keep behind the curtains], I am trying to get away from using it.

Zack: go to www.AVID.com and download AVID FREE DV and give it a try. Although it is a more complex program than iMovie, I think you might be impressed by the results from your digital camcorder.

By the way, what model JVC do you have? I can do some research and see what is supposed to come out of it. And, just to be clear, are you saying your DVD picture is stretched when viewing on TV or on your Mac???

[zackthedog]

Yes, that's right. I guess DVD should be 720 x 480, right? The camcorder is a JVC GR-D30US. It seems to record in 640 x 480, and there's no option to change the ratio that I can find. It's stretched to 720 x 480 on both my computer and the TV. I'll try Avid, thank you!

[macevanscb]

zack ... the thing to remember is that when displaying on a TV, it doesn't matter how many pixels there are in a horizontal line ... the TV just displays the signal between H pulses within the width of your TV screen. Resizing from 640 pixels to 720 pixels does not stretch the picture on a TV ... it should still show the same picture with the same apparent width, just with slightly more detail. The only way your picture would be stretched on a TV is if there were some horizontal cropping going on. If the picture was cropped to, say, 320 x 480, then resized back to 640/720 x 480, you would see a badly stretched picture. Is there any missing picture on the left and right sides of iMovie video as compared to the original video that might indicate a crop was done??

[zackthedog]

Thanks for your patience and persistence . Nothing is missing from the sides, but there is black space the top and bottom, and the image doesn't fill the TV screen vertically. Something is changing the aspect so that the image is stretched horizontally. The imported clips show up properly in the iMovie preview screen, but the .mov that iMovie creates and updates as you edit is distorted when viewed with QT, and the .dv I export to convert to m2v is also distorted, as is the final VOB file.

[macevanscb]

I guess its a matter of is the glass half full or half empty, but it sounds to me that if you're seeing black bars top and bottom that the video is being squished vertically, not stretched horizontally, and forced into a letterbox mode.

What you tell me has me really confused .... you say the video is totally normal in the iMovie preview window, while at the same time, the video in the project's MOV file has black bars?? .... and you're not applying any effects??

And I take it that in iMovie, to export you're using FILE > SHARE > QuickTime with Full Qualilty DV selected??

I don't have a camcorder, but I am importing rare and out-of-print VHS tapes into iMovie using a Canopus ADVC300 DV coverter box. As far as iMovie is concerned, it thinks its connected to a camcorder. I don't get any behavior like this at all.

[zackthedog]

I get the same thing with some footage grabbed from an old VHS cam. iMovie squeezes it vertically. What version are you using? This is 3.0.3 with Panther on a Powerbook G4 550. Maybe there are some bugs. I'm using FILE -> Export, Expert setting, DV--since ffmpegX seems to do better with the .dv than .mov's. It doesn't appear to be letterbox, from what I can tell. I think I'll tootle over to the iMovie Apple forum and see if they know what's going on. I might also try iMovie 2. IT"S SUPPOSED TO BE EASY!
I really appreciate your interest in the problem.

[macevanscb]

I'm running an up-to-day v4.0.1 iMovie on a G5 running Panther 10.3.5. I found a v4 iLife package on eBay for only $30. I saved $19 over Apple's regular price. So all my iApplications are up to date.

I'm out of suggestions other than updating to v4 to see what happens.

Have you tried downloading Avid Free DV and seeing if it works??

[Falcon500]

When using the mpeg2enc I assume you are ment to deselect the letterbox under the options tab so you don't end up with a squeezed image with black bars left and right. Should you also change the interlace option from Not interlaced to frame or field when doing a .dv to DVD conversion? Due to the source being interlaced because it is DV?

[major]

You should deinterlace in the Filters tab, and deselect letterbox.