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Rendering to DVD

Posted: Sat Apr 04, 2009 4:06 pm
by Bytheseaside
I apologise if this topic has been covered elsewhere, but I couldn't find any reference.
I run a rather slow (Athlon XP2600+ running at 1.9GHz) 5 year old computer & use Ulead Video Studio 8 to edit stills & movies from my Canon camera. The camera produces 640x480 30fps movies. I have realised that there is some degradation of the picture when I transfer my completed movies to DVD. Past movies have been outdoor/wildlife subjects so the degradation has been less apparent.

When I convert the finished project from my Ulead Video Studio 8 to PAL DVD (I assume that is the best quality the software offers for my purposes, being based in the UK) the .mpg file has worse quality pictures than the source material. There seems to be sort of hoizontal tearing every few (10?) lines, most noticable with diagonals in the picture. Is this a feature when converting from 30fps source to 25fps mpeg, or is there something I can set in my Ulead software to improve the result? Would I get better results if I upgraded to Video Studio X2 or Pro X2?

I have some stills as examples of the source material & the DVD result, but I can't work out if I can them post them. There are 4, each about 7 or 8kB

Please can you help?

Thank you.

Athlon XP2600+ running at 1.9GHz, 1GB RAM, >500GB free disc, Windows XP + SP3, ATI All-in-wonder 9600

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Posted: Sat Apr 04, 2009 4:46 pm
by Ron P.
Welcome to the forums,

First video DVDs must meet international specifications, that include the frame sizes, and frame rates. For PAL DVD the frame size closest to what your camera produces would be 720 x 576. Since your video clips are 640 x 480, which is not part of the DVD specs, VS must enlarge your clips to meet that specification. So VS is in essence creating an additional 80 x 96 per frame. This would be the major cause of the degradation in quality.

Next your camera records at 30fps, and again the DVD specs for PAL state that the frame rate must be 25fps. So VS removes 5 frames for every second of video. This can cause the playback to not be very smooth. It may remove frames that are critical to the compression, called I frames. The I frames are full frames, just like a photograph. These are preceded and followed by P and B frames, that are partial frames that just contain changes to the I frame. So if VS removes an I frame, and leaves the B and P frames, they are not going to have all the necessary detail/data to make the video appear clear, and smooth.

There is such a resolution called Half D1, An MPEG-2 video encoding mode in which half the horizontal resolution is sampled (352x480 for NTSC, 352x576 for PAL). Full resolution DVDs are called D1.

In the burn module, click on the Gear looking icon (Project Settings), then press Change MPEG Settings. In the menu that appears, you will see one option for Half D1, 352 x 576, 24000kbps, 4hrs per DVD. This would better match to what your camera records. However the frame rate still will need to be 25fps and not 30.

So you could produce DVDs with the resolution is less than that of your source video clips, or use the Full (D1) resolution. Either way the quality will suffer. I might also add that your camera records non-interlaced or what's called Frame-Based. So you need to make sure that your project settings are for Frame-Based and not Upper or Lower Field first.

Posted: Sat Apr 04, 2009 10:19 pm
by sjj1805
Whilst this similar thread concentrates upon "going the other way"
Converting PAL to NTSC
it helps highlight the problems involved.

Posted: Mon Apr 13, 2009 8:18 am
by Bytheseaside
:) I think I've cracked it! To get from .MOV to .AVI files, I splashed out on bit of software from Aone Software. I now realise that one option it offers is to convert to 720x576 25fps at the same time as converting to .AVI. Converting in this way rather than leaving the conversion to Video Studio 8 has reduced the jagging hugely!! Anyone wishing to convert video file formats would be well advised to have a look at http://www.aone-video.com/mov.htm first. In terms of output quality, their converter was streets ahead of any of the others I looked at.

Now, if I render using "as project settings" I get a quite sharp, but slightly jaggy result. If I render using "PAL Mpeg2 720x576 25fps" I get no jaggies, but a slightly noisier & softer result.

I intend to experiment further, including seeing how things look on DVD played on the TV.

John.