Filter for eliminating DCT blocks

I don't see the point of adding noise prior to encoding as that just raises the bitrate. If you want to add noise to compensate for frailties in the video-encoding, do it on the decode (i.e. see: ffdshow).

I don't see the point of adding noise prior to encoding as that just raises the bitrate. Of course. That's what it's meant to do :). If you want to add noise to compensate for frailties in the video-encoding, do it on the decode (i.e. see: ffdshow). ffdshow is great, and if Panasonic would include it in my DVD player's firmware I'd stop adding noise during pre-processing ;).

Hmm...the next step here would be to create an inverted unsharp mask and use it to weight the noise so it's only added to areas with flat shading.

What if you use crappy cables? :D That's a good idea, but I think constantly switching back and forth depending on whether I'm watching a DVD or VCD would be bad for the connectors :D ;).

Hmm...the next step here would be to create an inverted unsharp mask and use it to weight the noise so it's only added to areas with flat shading. Funnily enough I was just reading up on spatial frequency, because it occurred to me that the problem is worst in areas of low spatial frequency (i.e. flat areas with little detail). I've not come across any comprehensible (to me anyway) explanation of it, so I was just about to ask in General Discussion :).

Hmm...I just had a thought... What if the noise were only added to the pixels on the edge of the macroblocks? Would this be enough for mpeg4 codecs to latch on to, while having the added benefits of (1) consuming less bandwidth than full-frame noise and (2) having the noise be smoothed away during deblocking?

What if the noise were only added to the pixels on the edge of the macroblocks? If someone (maybe me -- I'll think about it ;)) could come up with an effective algorithm for detecting just DCT blocks, then this would probably help with re-encoding MPEG sources. However bear in mind that almost all the DCT blocks you see in the grabs I posted above were generated by the second encode (that is, from MPEG-2 to MPEG-1). Since those DCT blocks don't exist yet it would be hard to blend them :).

New version of AddNoise 

SansGrip, Looking at your screenshot, it seems like the filter is definitely displaying the areas where noise would need to be added based on my experience. So to me this looks very promising and I'm anxious to do some testing in about 12hrs or so. I've been fighting the DCT blocks on stable backgrounds for sometime now and I'm glad to see your effort in the resolution. Thx!

it seems like the filter is definitely displaying the areas where noise would need to be added based on my experience It does seem that way, which is surprising since the algorithm is so simple. I wasn't expecting it to work so well. But it needs testing on a variety of sources before I'll get too excited ;). I'm anxious to do some testing in about 12hrs or so. I'll be very interested to hear your results. I've been fighting the DCT blocks on stable backgrounds for sometime now What version of MPEG do you encode to?