Corrupted DV?

[wfn2004]

Hi,

I have some amateur sporting footage (Australian Rules Football) that I consider to be reasonably historic (South Africa's first ever win in an international, over Japan).

It was recorded using Mini-DV and transferred from tape to a friend's Mac. He burnt a DVD of the footage, along with several other bits of footage, producing several chapters. Some of the chapters look fine, but the first few have a very ugly artefact. Whenever there is movement there's an uneven horizontal line effect on edges. Anyone have any ideas? The problem is that the original footage was lost, so this hacky DVD is all that is left.

You can see a small 8 MB sample here: http://www.worldfootynews.com/images/bad_sample.mpg

I'm wondering whether it was interlaced PAL and somehow in doing the DVD or importing it from the mini DV the software thought it wasn't interlaced, or NTSC.

I don't know, I just wish there was some way to repair the damage. I realise it's a ridiculously difficult problem, but figured I'd ask anyway.

Thanks for reading.

[atifsh]

does ur standalone dvd player also shows these lines?
get ur video to harddisk and use tmpgenc use filter deinterlace, it will solve ur problem.
iv managed to fix similar problem with my one recording iv done [for testing] i had the dv so i encoded it again later.
if it helps i got it when i used realtime encoding while i was asleep. dont remember the progrm i used.

[wfn2004]

Sorry for taking so long to reply - I hate that when people ask something then never respond! I won't bore you with excuses.

Yes, just playing on TV with DVD player shows the jagged line edge / motion effect too.

I downloaded TMPGEnc and for Video Source selected Browse and my bad_sample.mpg file but the program came up with "File <the file> can not open, or unsupported".

I've now got some other countries who played in these games asking about my footage, and I'm having to say sorry, it's corrupt. If only some of them were professional not amateur they might be able to shell out to get someone to look at it.

The bad_sample.mpg file is still there. Any other suggestions? (It's about 9 MB - I can put a smaller bite there if that helps anyone).

[paglamon]

Well, I could open your uploaded file in both TMPGEnc Plus and TMPGEnc Express.Applying the Deinterlace filter didn't help much.In fact it is advised to keep Interlaced material as Interlaced if they are meant to be viewed on TV.For viewing on PC just use the deinterlacing filter of FFDSHOW and play in Media Player Classic.
But, as you say,the lines are present even while viewing on TV.Probably they are artifacts resulting from a bad encoding.

P.S. I am trying to make a better video out of your sample. If I succeed I will upload it for you to have a look at.

[wfn2004]

That's strange regarding loading into TMPGEnc. I can import an AVI but not an mpg - maybe some restriction of the freeware. But sounds like it won't really help. Thanks for your efforts, maybe you'll be able to come up with something, but suspect they're now permanent artifacts.

[paglamon]

That's strange regarding loading into TMPGEnc. I can import an AVI but not an mpg

Try this.In TMPGEnc go to OPTIONS/Environmenmtal Setting/VFAPI plug-in.Once there make sure that DirectShow Multimedia File Reader is on top(i.e it has the highest priority,usually +2).Then try to reopen the file.

[wfn2004]

Hmm, I just did what you suggested, +2 compared with zeros and a -2, but got the same error. I tried downloading the same sample as I uploaded, just to make sure it was the same. Other programs like Ulead have no problem with it.

When I put my cursor over the DirectShow option, it says it supports what Windows Media can support, then says supported file extension *.avi, *.asf.

i.e. not mpg.

The only one that claims to is Microsoft MPEG-1 Decoder, so I put that top, but same error.

Ah, now I tried opening another version of the mpg, that I'd saved as mpeg-1, and it did load it okay.

I tried the de-interlace option and both field orders, but no good. No surprise since you've obviously had a go yourself. Thanks for your patience.

[wfn2004]

I'm back after being away for a week or so. I'm pretty sure the situation is unfixable though. I also asked on another forum (is that sacrilegious?!) and some also thought it should be fixable, but working exhaustively through various methods, nothing helped, and the answer I thought probably closest to reality was:

In the MPEG-2 encoding process the movie has been deinterlaced with both fields merged together, to make it progressive.
Also there is a 5 + 1 frame step effect, as if 25fps PAL has been converted to 30fps NTSC by adding an extra frame every five.
There may also be field-blending effect from adjacent frames arising out of this 'conversion'.
And what appears to be vertical scaling artifacts, possibly as if 576 lines has been scaled to 480....
As the two fields are intermingled the damage is irrevocable, practically speaking.

To which my response was:

Without being completely across the technical details, that has been my basic impression - what should be interlaced fields merged into single frames, so the jagged motion effects are permanent. Throw in PAL to NTSC conversion and it's a mess.

I guess the bottom line at this stage is to accept that it's unrecoverable and move on to deciding whether there's any filters worth running to smooth it out to make the best of the unfortunate situation.