Weird video artifacts (Mobile at specific resolutions)

vbimport

#1

I’ve been ripping all my DVDs mostly in the Zune profile at 320x240 and Generic for 368x208 widescreen with fantastic results.

However the other day, I thought I would try 640x480 and also 480x360. However the results are disappointing. The video looks great at first, but then I notice in fast moving scenes there appears some horizontal line ‘smearing’. I not sure how else to describe it. It’s exactly what I have seen many times in the preview window.

Has any one else noticed this? This happens in both the the Zune and Generic profile. The last two shows I’ve ripped with this problem are ‘Everybody Love Raymond’ and ‘Family Guy’ (although I’m sure it would happen with all shows). I’ve ripped the same episodes with other DVD ripper programs and the problem isn’t there so it’s definately a DVDFab defect. I’m just surprised no one else has mentioned it.


#2

If you changed the screen size without increasing the video bitrate, you have fewer bits per pixel (there is a readout for this next to the screen sizes). After choosing the larger screen size, move the bitrate slider to the right until the bits/pixel equals what you had good pictures with on your earlier conversions. The files will be larger and it will take longer to convert, but the images will be much better.


#3

Thanks for your reply. I definately increased the bitrate, but perhaps not enough. I was at 640bps @ 320x240, and went to 1000bps for 640x480. The math tells me to go higher, but the compression artifacts weren’t too bad at all. Actually, compression artifacts were all I really expected and not this horizontal line smearing. But perhaps high compression of h264 could also produce these results. I’ll try again at the higher bitrates. If it works but the file sizes are to large however I’ll stick with 320x240. My goal was to also add the files to my home media player (not just have them for portable devices of which 320x240 is more than adequate). …but perhaps not worth the trouble.


#4

Could you see the “smear” in the original?


#5

[quote=dschematic;2066193]Thanks for your reply. I definately increased the bitrate, but perhaps not enough. I was at 640bps @ 320x240, and went to 1000bps for 640x480. The math tells me to go higher, but the compression artifacts weren’t too bad at all. Actually, compression artifacts were all I really expected and not this horizontal line smearing. But perhaps high compression of h264 could also produce these results. I’ll try again at the higher bitrates. If it works but the file sizes are to large however I’ll stick with 320x240. My goal was to also add the files to my home media player (not just have them for portable devices of which 320x240 is more than adequate). …but perhaps not worth the trouble.[/quote]The file requirements are very different for mobile and large screen devices. If your bits/pixel reading was 0.2-0.4 you should have had good video. What you are describing sounds more like a de-interlace problem. I do all my conversions with H264, 480x270, and around 700-1200kbps. These look great on my Archos and acceptable (but not great) full screen on my PC. It was the best compromise I could find that kept the files small enough that I could still keep a fairly large library on the Archos.


#6

“Could you see the “smear” in the original?”

The DVDs play fine one there own. And they are also fine at the lower resolution or when ripped with other programs. The ‘smear’ is like the horizontal scan lines are streaking slightly … but only for fast moving objects on the screen (esp when moving horizontaly). I see this often in the video preview window. This happens with current and older versions of DVDfab. Also when created on different computers. I’ll also try ripping to hardrive first to see if anything happens.


#7

“What you are describing sounds more like a de-interlace problem”

YES! Exactly it (the terminology escaped me at the time). One could suspect a video card problem but I don’t think it’s used when creating the files. Turns out the pixel reading was 0.14 so I’m now giving a try at 0.25.

Also, I’m only doing one-pass. What about you?

Thanks again.


#8

All one pass. I can’t see the difference with H264. Hope it works. :slight_smile: