MPEG2 (DVD) question: Can re-encoding eliminate macroblocking?

[AnitaPeterson]

Hi folks,

I have a question, and wasn't able to find any real answers through Google (by the way, am I the only one thinking that Google search results are getting less and less relevant?)...

Anyway... I have an MPEG2 file which was taken from a rather bad DVD rip. Whoever did the ripping was an idiot - the DVD file structure is borked. I was able to extract the raw MPEG-2 file with ancient version of TMPGEnc DVD Author (which somehow works as a portable program on Win7), only to discover that there's occasional (yet noticeable) macroblocking in the image. I suspect that the original was recorded on a DVD-9, and the ripper used a cheap, crappy encoder to do a rush job on a DVD-5 conversion.

I am really bothered by the macroblocking, and I'm wondering if it can be "smoothed out", perhaps by reencoding the file with another piece of software - and I'd like to keep the file as MPEG-2, which would allow me to recreate a DVD which could be shared with others.

Is this feasible, or just wishful thinking?

 

[mmntech]

There are deblocking filters incorporated into playback software on PCs and higher end DVD/BD players. The problem is that once you make a copy, you can't add data. You can only make an exact duplicate or take data away. So no, it won't work. Not without making the video look even worse.

 

[Saint Nick]

You need to decompress the Vob and re-encode the audio with a xpassFilter2 plugin, then encode the MPEG-2 into a more formidable format such as QuickTime. Then, use Windows Movie Maker to sync up the time and film. Afterwards, export as WMV and finally burn to disc.

 

[artvscommerce]

the problem with trying to "smooth it out" is that I don't know of an easy way to apply an effect like that to ONLY the moments or spots on the video where the blocking occurs. If you applied the filter or effect to the entire video the parts without macroblocking would be severely degraded.

 

[Crono]

Yes, it's possible to smooth out the video or use deblocking filters, but the question becomes how much detail are you willing to lose?

Deblocking only works really well for animated content (which tends to resist oversmoothing/smearing because of simplicity and strong lines versus live action), otherwise if your source isn't low quality to begin with, you tend to oversmooth and lose sharpness as well as overall video quality.

It's been a while since I did any encoding, but I used to use MeGUI/avisyth or VDubMod with filters for this.

 

[bbhaag]

I'm pretty sure Handbrake has a deblocking filter built into it. It's free so it might be worth trying. The only downside if you can call it that is it will output your file to either and MP4 or MKV file using the x.264 video codec.

Like others have mentioned though, the output quality may suffer a bit especially if the original source file is crappy to begin with. Oh, and it takes forever to reencode with the filter enabled.

 

[tommo123]

the whole video will be smoothed out. IMO you can either try to grab the original video again without the screw up or go to doom9 and ask there. some uber video geeks there. just tread lightly and don't mention any internet downloads otherwise you'll be struck for rule violations.

they're a touchy but handy bunch