SansGrip
15th October 2002, 15:42
(Note: I asked about this in the General Discussion forum but figured this is probably a more appropriate venue.)
I recently picked up an AIW Radeon 7500 and am experiencing some weirdness with the capturing side of things. This problem occurs with both the coax input (from satellite receiver) and the composite input (from VCR). I'm capturing with VirtualDub at 640x480 29.97fps YUV2 Huffy, so we know the codec is not introducing any artifacts. I did a clean removal and reinstall of the latest ATI drivers.
I've included a framegrab that illustrates what I'm talking about. In it the leftmost grab is the output of Avisynth's FieldDeinterlace() function, the middle of SeparateFields().SelectEven(), and the rightmost of SeparateFields().SelectOdd(). No other processing was done in Avisynth except to convert to RGB. I then imported the grabs into Photoshop, cut out a section, and blew it up 300% nearest neighbour (in the case of the separate fields I also doubled the height).
As you can see there seem to be strange intermittent differences between the fields, causing "horizontal streaks" to appear when the fields are interlaced. While these aren't too noticible when viewing the clip, they cause a slight shimmer in static areas and totally mess up MPEG encoding.
If anyone can shed any light on this, or suggest things I could try, or even point out that I'm an idiot because I misunderstood something, I'd be very grateful. Luckily when I bought the card I paid a little extra for their "bring it back within the next 3 years if you're not happy for any reason" deal... ;)
(You can see the image at http://www.jungleweb.net/~sansgrip/tvcap.png until the attachment is moderated)
[Edit: removed attachment so I could post it to the other thread, so that this one can be deleted ;)]
I recently picked up an AIW Radeon 7500 and am experiencing some weirdness with the capturing side of things. This problem occurs with both the coax input (from satellite receiver) and the composite input (from VCR). I'm capturing with VirtualDub at 640x480 29.97fps YUV2 Huffy, so we know the codec is not introducing any artifacts. I did a clean removal and reinstall of the latest ATI drivers.
I've included a framegrab that illustrates what I'm talking about. In it the leftmost grab is the output of Avisynth's FieldDeinterlace() function, the middle of SeparateFields().SelectEven(), and the rightmost of SeparateFields().SelectOdd(). No other processing was done in Avisynth except to convert to RGB. I then imported the grabs into Photoshop, cut out a section, and blew it up 300% nearest neighbour (in the case of the separate fields I also doubled the height).
As you can see there seem to be strange intermittent differences between the fields, causing "horizontal streaks" to appear when the fields are interlaced. While these aren't too noticible when viewing the clip, they cause a slight shimmer in static areas and totally mess up MPEG encoding.
If anyone can shed any light on this, or suggest things I could try, or even point out that I'm an idiot because I misunderstood something, I'd be very grateful. Luckily when I bought the card I paid a little extra for their "bring it back within the next 3 years if you're not happy for any reason" deal... ;)
(You can see the image at http://www.jungleweb.net/~sansgrip/tvcap.png until the attachment is moderated)
[Edit: removed attachment so I could post it to the other thread, so that this one can be deleted ;)]