miamicanes
23rd September 2007, 02:29
I have a DV-AVI captured from a bad VHS recording that's frankly a mess. Even with FFT3d de-noising and dePanStabilize, it's almost unwatchable. Every now and then, a frame just totally combs out as if there were major interlaced motion taking place, even though the scene is mostly stable & unmoving, and adjacent frames are crisp & fine.
I've decided to try something desperate: temporally smoothing it down from 720x480 interlaced to 360x240 @ 30fps progressive, then scaling it back up to 720 x 480 by showing each field twice in a row, with major horizontal smoothing, so I can make one final stab at encoding it to 7500kbit/sec 2-pass VBR with HCenc and see whether it's finally watch-able.
I was originally of the opinion that vertical smoothing was out of the question on the theory that VHS horizontal resolution was mangled, but vertical resolution was "real" and to be preserved at any cost. I've now concluded that with regard to this particular tape, it's all mangled, and the best thing I can try to do to save it at this point is to smooth out its jitters & lurches and try to make it lower-res, but watchable.
I'm open to suggestions as to how I might go about doing that. I'm fairly sure that the sequence would go something like:
* Motion-adaptive deinterlace to 480p30
* Massive denoising with something like FFT3d
* resize down to 360x240 in a way that takes into account the pixel's neighbors, both spatially AND temporally
* stretch it to 720x240 and smooth it horizontally (gaussian?)
* duplicate each frame twice to turn them into alternating fields
I'm definitely open to suggestions at this point.
I've decided to try something desperate: temporally smoothing it down from 720x480 interlaced to 360x240 @ 30fps progressive, then scaling it back up to 720 x 480 by showing each field twice in a row, with major horizontal smoothing, so I can make one final stab at encoding it to 7500kbit/sec 2-pass VBR with HCenc and see whether it's finally watch-able.
I was originally of the opinion that vertical smoothing was out of the question on the theory that VHS horizontal resolution was mangled, but vertical resolution was "real" and to be preserved at any cost. I've now concluded that with regard to this particular tape, it's all mangled, and the best thing I can try to do to save it at this point is to smooth out its jitters & lurches and try to make it lower-res, but watchable.
I'm open to suggestions as to how I might go about doing that. I'm fairly sure that the sequence would go something like:
* Motion-adaptive deinterlace to 480p30
* Massive denoising with something like FFT3d
* resize down to 360x240 in a way that takes into account the pixel's neighbors, both spatially AND temporally
* stretch it to 720x240 and smooth it horizontally (gaussian?)
* duplicate each frame twice to turn them into alternating fields
I'm definitely open to suggestions at this point.