I'm attempting to convert all of my old tapes to digital and have hit another road block. Currently capturing from a Sony Handycam 8mm camcorder (with internal TBC and DNR set to off) via composite source into a StarTech SVID2USB2, recorded as uncompressed YUY2 into VirtualDub.
The end goal will be to deinterlace with Avisynth and QTGMC, then compress in Handbrake to be streamed from a network storage device. I completed a couple videos and the quality seemed to be great, but then I noticed some artifacts in one particular scene I captured (see attached). There are some "screen door" type artifacts around the red golf ball during fast movement.
After searching around on the forums, I've concluded that this is dot crawl artifacts which are being introduced by the USB2 capture device. From what I understand, if I were to capture straight from S-Video, that artifact would not be present. Unfortunately, I cannot capture via S-Video as the Handycam model I'm using does not offer that type of output. I would also be out of luck when it comes to capturing VHS and Betamax tapes, as S-video output will not be an option.
Am I right by assuming the artifacts seen are dot crawl artifacts introduced by the capture device? Can someone help me with a recommendation to eliminate said artifacts while capturing from composite source? I do have an SC-512N1-L/DVI capture card on the way which I'll be using to capture Full HD content. The card will come with a breakout cable which allows capture from composite source. Could I expect better results from that setup, or will I still run into issues regardless with composite capture.
I'd appreciate any advice you can offer!
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Looks more like mosquito noise to me. How are you able to capture uncompressed? According to StarTech, the device encodes MPEG 1, 2 or 4.
Hmm. I must have misread a post suggesting that the device was capable of capturing uncompressed. VirutalDub is configured to grab uncompressed YUV 4:2:2 interleaved, but I guess that's uncompressed by VirtualDub after being encoded on-the-fly by the USB2. Could the MPEG encoding possibly be the cause of the noise you're seeing? If I were to capture uncompressed on the SC-512N1-L/DVI would you expect that noise to still be present?
I tried the BlackMagic Intensity Pro which captured well, but there were problems with black frames being introduced due to framerate sync issues. I bought an AVT-8710 TBC to try correcting that issue, but there was significant picture degradation that I didn't want to settle for. I know I'm being obsessive, but I figure if it's worth doing, might as well do it right and get the best quality transfer possible.
Looking at the clip again, I agree it's chroma crosstalk possibly exacerbated by compression. If you are truly obsessive , you will find another player with s-video output. I use the AVT-8710 and while the conversions do soften the picture a bit, I haven't found it to be troubling given the poor resolution of consumer videotape to begin with.
I've considered that, but then what would I do for the VHS and Betamax captures? I suppose I could find a VHS with S-Video output, but doubt I could find a Betamax player with one. I may hold off and wait until the SC-512N1-L/DVI arrives to see what kind of results I get via composite captures with it. I'll keep my fingers crossed that your first impression was correct and it was mostly compression noise.
Is dot crawl something that would be consistently visible on all media throughout the duration of the capture? Or would it tend to show itself more apparently during motion? The reason I ask is because my first two tapes captured were of outstanding quality and didn't have any noticeable artifacts. Could it have been the MPEG compression kicking in during a scene with fast motion that caused this?
I think it has more to do with the highly saturated color of the ball.
The avi sample is uncompressed (ever heard of huffyuv, Lagarith, etc., etc. etc.???). The avi has chroma upsampling error (usually shows up in highly saturated color as JVRaines noted, especially reds), and has obvious line timing errors. TBC turned off, was it? Bad idea. The side borders are wiggling and shifting position, and the golf club shaft has small notches in it. Internal line-level tbc's exist to prevent such problems.
If you can't find a decent VCR with s-video out (they haven't been made for years), can always use a Panasonic ES10 or ES15 for line tbc pass-thru and a decent y/c filter to help with dot crawl. A pass-thru device has the extra benefit of not tying you down to a single player or source.
Deinterlace? Don't. 59.94fps playback is OK, but you've eliminated DVD and standard definition BluRay/AVCHD, which are all interlaced. Looks like mp4 is where you'll be going.
If any of your VHS or Betamax tapes are movie-based recordings, you can't deinterlace those.
Last edited by LMotlow; 20th Mar 2015 at 02:15.- My sister Ann's brother
An easy way of reducing dot crawl is to blur it away. You can do this by downsizing to half width, then upscaling back to full width. This isn't acceptable with high quality video because the picture gets blurry. But VHS has such low resolution horizontally you can usually do this without harming the picture much. Try using VirtualDub's Resize filter in Lanczos3 mode to scale down to 360x480 then back to 720x480.
You can also use more sophisticated methods involving masks to limit the blur to edges, highly saturated areas, and moving areas. But I don't think it's necessary for this clip.
There are also dot craw filters for VirtualDub. But, as usual, they don't work really well on moving parts of the picture.
Last edited by jagabo; 20th Mar 2015 at 06:53.