Removing jagged interlacing artifacts from a progressive file?

[tfolder]

I have a problem which seems a bit unusual because I can't find any solutions on the web. I downloaded (legally) an .avi file, and when I watch it I see the typical jagged artifacts of interlaced video. According to MediaInfo the file has the following properties:

Video
ID : 0
Format : MPEG-4 Visual
Format profile : Advanced Simple@L5
Format settings, BVOP : Yes
Format settings, QPel : No
Format settings, GMC : No warppoints
Format settings, Matrix : Default (H.263)
Muxing mode : Packed bitstream
Codec ID : XVID
Codec ID/Hint : XviD
Duration : 1h 22mn
Bit rate : 1 590 Kbps
Width : 704 pixels
Height : 576 pixels
Display aspect ratio : 1.222
Frame rate : 29.970 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.131
Stream size : 934 MiB (89%)
Writing library : XviD 1.0.1 (UTC 2004-06-05)

I'm pretty new to video editing so correct me if I'm wrong - but I'm assuming "Scan type: Progressive" means those artifacts must be stuck in there, maybe left over from a previous conversion from an interlaced format? And if that is the case, how can I get rid of them? Is there a program (preferably freeware) with some kind of filter that will do it? Nothing happens when I use the standard "Deinterlace" filters found in VirtualDub etc.

[poisondeathray]

I'm assuming "Scan type: Progressive" means those artifacts must be stuck in there, maybe left over from a previous conversion from an interlaced format?

Usually that's the case, but if it's already been (poorly) deinterlaced, you might be able to improve slightly it by using various avisynth antialiasing filters , or QTGMC's progressive mode

Deinterlacing it now won't help because there are no fields left

If you post a video sample, you might get better suggestions

[manono]

It's possible it can be fixed if it hasn't been resized. A small sample - 10 seconds or so with steady movement - would be helpful. It'll require reencoding the entire thing, of course.

It's very peculiar, though, as it's 29.97fps but at a PAL resolution. Maybe it has been resized already and can't be fixed.

[PuzZLeR]

I'd love to see what can be done about this. I get this too from TV captures - visually progressive pictures that are the result of a bad deinterlacing procedure from their end. I get jaggies and, what I call, "Atari 2600-type" of blocks. What sucks is that I know it's a film source (repeats 1 frame every 5) so it could have been done so much better or simply left hard telecined.

I have a hunch my case is similar to this. The following script has helped somewhat on a re-encode:

unblend()
tdecimate(cycler=3)

But I'm curious if there are better methods.

I too would love to see a sample. I can also provide one from my end too if it helps.

It's very peculiar, though, as it's 29.97fps but at a PAL resolution. Maybe it has been resized already and can't be fixed.

Sounds awfully familiar... Another Drunk Chimp Production uploaded on the Internet, this time we get bad de-interlacing as a bonus!

[tfolder]

Thanks all for the replies... sorry about the delay in getting back, I've been insanely busy this past week.

Short video sample attached. The interlacing is quite fine-grained, but still obvious. Underlying image quality isn't great anyway (slightly better in the real thing than in the sample) and the whole video is quite dark too, so I'm not expecting fantastic results, I'd just like to blur those jagged edges away somehow.

I've never used avisynth and I've heard that the learning curve is steep... but if it's still my best chance of success here, I'm willing to give it a try if somebody can guide me through the process.

[jagabo]

The two fields are co-mingled (it was resized vertically before being encoded). There's no way to fix it. About the only thing you could do is a vertical blur.

The video is also way over compressed and full of macroblocks.

[tfolder]

The video is also way over compressed and full of macroblocks.

I'm not surprised, if that's the technical term for general lousiness
Like I said, I have low expectations. As far as I'm aware, this is basically the best version of this particular video out there - I can deal with the quality, it's just the lines that bug me.

So, apologies for my inexperience... what is the easiest recommended way for me to do a blur like you suggest?

[davexnet]

You can deblock it and soften a little, also the audio is terrible.
I declipped it and reduced the level slightly. Here's my effort:

http://www.mediafire.com/download.php?2n6w0ukanot63ez

[jagabo]

You can deblock it by turning on Xvid's Deblocking option. What you'll get is a fuzzy video instead of a blocky video.

Not deblocked:


Deblocked, deringed, film effect:


That won't fix the comb artifacts. You can use Blur(0, 1.0) in AviSynth for that. Or the Deinterlace (blend) filter in VirtualDub.

[tfolder]

Wow, thanks guys! davexnet: what you've done looks fine for my purposes. Could you please tell me exactly how you did it?

[davexnet]

Of course. First of all, the file doesn't really have much detail; the bitrate is too low Vs. the resolution of the file,
resulting in those ugly macro blocks. It seems to have some burned in artifacts from the interlaced file,
it usually occurs when an interlaced file is resized incorrectly.

I processed the file in Virtualdub, I didn't bother with Avisynth in this case. Open the file and look at File/Information.
If it's FFDshow add the MSU smart deblocker 0.8 as the first filter. If it's divx or xvid you may want to use their deblocker
instead. Check the xvid/divx decoder config to see if it's turned in.

Use the "cropping" button to crop as necessary. (I cropped 58 from the top, 70 from the bottom) .

To improve the interlacing artifacts, I used Donald Graft's smart deinterlace filter version 2.8 beta 1

Third, I then resized it down slightly to 608/384

http://neuron2.net/smart/smart.html

http://compression.ru/video/deblocking/smartdeblocking_en.html

[lordsmurf]

Deinterlace Area-Based, not blend.

[redwudz]

This thread would be better in our Restoration Forum. Moving.

[tfolder]

Thanks redwudz

I've had a go with Donald Graft's smart deinterlace filter. After playing around with the settings, this seemed to work best:

"Field-based differencing"
"Blend"
"Motion map denoising" ticked
"Compare color channels" unticked
"Motion threshold" didn't seem to make much difference, so I set it to 5

Using anything other than "Blend" for that option created a lot of horizontal smearing which was definitely worse than the interlacing. The final result is obviously far from perfect, but it's a lot better than what I started with and I doubt it can be improved -- I've basically found the solution I came here for, and it works for me

So, unless someone has any suggestions for how I could improve on the settings I've used... I guess I'm happy. Many thanks to all who contributed!