Page 1 of 1

Weird Blocking/Distotion when encoding VC1 from BBC Blu-Ray

Posted: Fri Sep 12, 2014 2:43 am
by fatpizza
Hi,
I was trying to rip my copy of the Life documentary series from BBC which uses the VC1 codec. It seems to use a weird mix of progressive for the main feature then interlaced for the credits. Anyway I tried converting this with 0.9.9 last night and it was a complete disaster. It would go extremely slowly and the resulting video was completely stutter and full of noise etc. So I'm using the new 0.10 beta 3 on Windows 7 Ultimate 64bit.
So I thought I'd try the new beta and it seems work wonderfully. Except for some weird blocking/distorted noise which appears on the right side of the screen at certain points. I've tried different quality settings, I've tried encoding to both MPEG2 and h265 but no matter what I do the same thing happens at the exact same time. IT happens during both the progressive and interlaced parts.
I've tried some other encoding software(XMedia Recode) and they work fine however they lack the decombing filter which is handy for this source which contains both progressive and interlaced material.
I've uploaded a screenshot here:
Image
Not sure if this makes a difference but when I ran mediainfo against each file the writing library used by xmedia recodeseems to be a higher version(lavf56.1.100 vs lavf55.12.0 used by handbrake) ?

Any ideas?

Edit: Pastebin of the encode: http://pastebin.com/RHXRz1Mi

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 4:22 am
by mduell
The container writing library isn't likely the problem, the decoding library is.

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 4:46 am
by fatpizza
mduell wrote:The container writing library isn't likely the problem, the decoding library is.
I guess that makes sense, since it does it regardless of what format I encode it to.

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 5:05 am
by fatpizza
Incidentally I did also try enabling DXVA decoding but with no luck.

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 11:26 am
by fatpizza
I guess I'll try the latest nightly to see if that makes a difference...

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 1:40 pm
by Rodeo
Won't, if you already tried Beta 3. We support interlaced VC-1 decoding now, but unfortunately it's not bug-free :(

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 1:54 pm
by fatpizza
Rodeo wrote:Won't, if you already tried Beta 3. We support interlaced VC-1 decoding now, but unfortunately it's not bug-free :(
Thanks for saving me a little time then. :)
Is Interlaced-VC1 still a work in progress? Or is this as good as it's going to get for the next release?

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 2:02 pm
by Rodeo
I don't expect any bugfixes for the next release, no. I do hope libav devs will fix it eventually though. I might look into it myself at some point, but I'm no VC-1 expert by any means.

While we do have some samples, one more isn't going to hurt. Could you maybe split a 20-second clip that includes the frame in your above screenshot and upload it somewhere? You can use mkvmerge GUI (part of Mkvtoolnix) to split by timestamp.

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 3:07 pm
by fatpizza
Rodeo wrote:I don't expect any bugfixes for the next release, no. I do hope libav devs will fix it eventually though. I might look into it myself at some point, but I'm no VC-1 expert by any means.

While we do have some samples, one more isn't going to hurt. Could you maybe split a 20-second clip that includes the frame in your above screenshot and upload it somewhere? You can use mkvmerge GUI (part of Mkvtoolnix) to split by timestamp.
As requested: http://s000.tinyupload.com/index.php?fi ... 8428584648
:)

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 3:25 pm
by Rodeo
We need a sample of the *source* please :P

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 3:50 pm
by fatpizza
Rodeo wrote:We need a sample of the *source* please :P
Whoops... :P
Well, my source is my own bd. I'll rip it directly to mkv without encoding using makemkv and then do what you said to upload a sample shortly.

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 4:40 pm
by Rodeo
Yes, that's what we need. Thanks.

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-

Posted: Fri Sep 12, 2014 5:18 pm
by fatpizza
Ok, here is a 10 second clip. Came out at 45MB so I couldn't go much higher. Sorry this file is on a different upload page as the last one wouldn't work again for some reason...
http://speedy.sh/BtJX5/Life-Disc-1-t02-1.mkv

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-Ray

Posted: Sat Feb 21, 2015 3:40 am
by fatpizza
I've just started encoding some more BBC Blu-Rays I've purchased and this issue Is popping up again. Is this sort of thing being looked into for future releases? Thanks.

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-Ray

Posted: Sat Feb 21, 2015 1:08 pm
by Rodeo
Yes, but there hasn't been much progress yet.

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-Ray

Posted: Mon Feb 23, 2015 2:12 am
by stryfewalker
If you think that little bit of distortion is bad, you should have tried it before January 2014 or so. It was pretty nasty with unwatchable digital tiling and corruption. Since that update most of the corruption I have noticed with interlaced vc1 has been like the example screenshot you provided, mostly black bits of tiling around the edges of the picture and not constant, just in certain scenes.

It would be great if it was fixed completely, but after seeing what it was like before, it's hard for me to complain, especially when the amount of interlaced vc1 content I have is not substantial.

Re: Weird Blocking/Distotion when encoding VC1 from BBC Blu-Ray

Posted: Thu Jun 04, 2015 4:42 am
by fatpizza
OK, sorry to bump my own thread but I've worked out a sort of workaround which I think works great. Basically I use XMedia Recode to encode the video from VC1 to AVC/H264 whilst setting the video to stay interlaced tff, I also set the CRF at 0 to ensure there isn't any quality loss.
The resultant video shows up as MBAFF tff interlaced in mediainfo.
I then simply pass this AVC video through handbrake using the bob decomb filter, and the previously interlaced parts now run at 50fps, whilst the progressive frames stay as is. The main bonus of course is that since I'm not encoding from VC1 there is no weird distortion.
Only real small roadblocks is that the initial encode with XMedia takes about 5-6 hours per 1 hour episode, and the resultant XMedia file is around 60-70GB. But that is of course reduced when I re-encode with handbrake.