interlace result is not good

[george_zhu]

I have some 480x480 interlaced footage captured from a Hi8 camcorder. The original footage is compressed by PicMJPG at 19 and looks pretty good. I than compressed it by Xvid at 2000kbps with interlaced on, other configuration is Adaptive Quantization, GMC, QPel, 2 consecutive B -frame, packed stream, closed GVP, Treill Quantization, chroma motion are on. The result looks pretty bad. Quite a lot of big blurred areas. And jerky somehow. Is 2000kbps too low? During the compressing, in the display window, I found quantizator of I-fram is between 4 and 6, p:5-8, b: 6-10. These numbers are not accurate. What should I do? Is there anything special for interlaced mode?

I am testing DivX and see whether it is any good.

[sysKin]

What decoder is being used? Only XviD and ffdshow decode interlaced video correctly (as far as I know).

[george_zhu]

I had uninstalled divx and xvid. Then I dragged the file into edia Player Classic 6.4.7.6, it told me there were no decoder for this file. I installed Xvid1.0RC1 afterward. Right now it report errror when I am trying to play them. When I check the detail, it said it is xvidcore.dll. So my guess is the problem in xvid's decoder or encoder.

Originally posted by sysKin
What decoder is being used? Only XviD and ffdshow decode interlaced video correctly (as far as I know).

[george_zhu]

I made another test by disabling the GMC and packed stream. It seems working. It can play it although the quality is still low. I find "xvid filter" in the filter menu of the pop-up menu in media player classic. So the xvid is definetely working. But after a while it keeps error for xvidcore.dll. I will try after restart.

[george_zhu]

Well. Finally I find it seems some problem of GMC. I test quite lots of options with/without GMC. All of the clips without GMC play correctly while all of the clips with GMC on make the player (both WMP9 and Media Player classic 6.4) crash.

However, I turned GMC on previously for clips at 320x240 non-interlaced. They can play correctly.

Is there any known issue about interlace and GMC?

I remember somewhere in this forum said GMC doesn't work well with VHQ>=1. Is that still true for 1.0RC1? I did put VHQ=1.

[sysKin]

No, GMC works with VHQ (actualy requires it to be any good) and is supposed to work with interlacing. I'll take a look what's wrong...

Radek

PS. Any good way to create interlaced videos if I don't have them? IVTC on progressive source maybe? I just want xvid to use field-dct so it has to see the lines.

[Koepi]

Try something like

SeparatFields()
Trim(1,0)
Weave()

That should be quite interlaced ;) (A simple Swapfields() produces such artefacts as well, but maybe not "visible" enough)

Regards
Koepi

[george_zhu]

I have put a short clip on web. The original one (test.avi) is the one I got from capture card with Pic MJPG 18. ( I recompressed the 19 one to make it smaller). The testxvid.avi is the one with no GMC on. While the testxvidgmc.avi is the one with GMC on. The xvid file is the one I am using to encode and decode.


I failed to play any of the encoded file until I uninstalled xvid1.0RC1 and reinstalled it again. The testxvidgmc.avi always crash my player, while the testxvid.avi can play but crash my explorer. :confused:

Maybe you can try to encode it yourself and see the difference.

Thank you for your help.

Originally posted by sysKin
No, GMC works with VHQ (actualy requires it to be any good) and is supposed to work with interlacing. I'll take a look what's wrong...

Radek

PS. Any good way to create interlaced videos if I don't have them? IVTC on progressive source maybe? I just want xvid to use field-dct so it has to see the lines.

[sysKin]

Great, thanks for the clips.

Since ffdshow decodes correctly it's a decoding problem. Will fix it an a moment :)

Radek

[george_zhu]

So ffdshow will work? Do you reencode with my configuration or do you mean ffdshow works with my encoded clips (testxvid.avi and testxvidgmc)?

[sysKin]

..and fixed ^__^

Thanks a lot george_zhu, it's the first bigger bug in the core found since beta1 I think :)

Yes, ffdshow, as well as new xvidcore (Gamer is your frind), will decode testxvidgmc.avi perfectly. No need to reencode anything :)

Radek

[george_zhu]

Do I need to download some new encoder? Koepi's website still has the same RC1-25012004.exe I used. Where can I get the new xvid decoder?

BTW: What is the meaning of "Gamer is your frind"?

Originally posted by sysKin
..and fixed ^__^

Thanks a lot george_zhu, it's the first bigger bug in the core found since beta1 I think :)

Yes, ffdshow, as well as new xvidcore (Gamer is your frind), will decode testxvidgmc.avi perfectly. No need to reencode anything :)

Radek

[sysKin]

Gamer's instabuilds at http://xvid.gamrdev.com/ . Newest at the bottom of the page. Have fun~~~~

[george_zhu]

new xvid from gamedev rocks! :D

I tested ffdshow-20021213, it does work with interlaced GMC ones. But it makes all the the interlaced file blink like mad. (It shows non-interlaced ones correctly). Do you use the other version. Have they updated this project or just stopped. On their homepage, it just stoped at 2002-6. :confused:

I am have 2-b frame and packed stream. Is that the reason for the problem in your signature?

BTW: Could you guys put this site xvid.gamedev.com to newbie or faq? I would certainly like to test these newest build and I believe that lots of others would like to.

[george_zhu]

I have pulled out the video clip on web since the issue has been solved. Thank you so much, syskin.

[Koepi]

No, putting that site in the newbie faq is like microwaving your own head.

Here we only support the "releases", not current CVS. So if you use latest CVS you're on your own with your problems (only if we tell you to use it as your bug is fixed in there I can recommand and support that).

Koepi

[george_zhu]

Well. Maybe you can put the link to somewhere on faq or somewhere easier to find. I do not have money or knowledge for VC to compile the source myself. (It is even harder than those in Linux:mad:) But I would like to test it and help a little bit if possible. However, it is not eaiser to find these binary package except your builds and Nic's. You may put some caution around the link and I think it will be fine.

[Koepi]

george:

I get your point, but my experience around this place is different - people get really mad if tey download "bleeding edge" bugs and await workarounds later on. Which won't happen as it wasn't some "officially" announced milestone...

The time before 1.0 betas was different - there weren't as many people using xvid and they knew which responsibility they had with that (i.e. properly reporting bugs, reading up a lot of documentation,...), but now XviD is getting closer to 1.0final more and more unexperienced users use the codec. Without knowning those things. Not knowing (n)etiquette. Just complaining about some problems they experience with those builds (they think - most of the times it's a problem with other software or hardware on the computers of those users).

Just a small insight from my point of view.

I don't have too much time(work, real life, GF), and I'd like to use the little time I have to support the official milestones properly.

Regards
Koepi

[george_zhu]

Well. I see. Thanks anyway. Your guys did a great job and xvid is a great. I start to capture video a year before with DivX 5.0. Now I almost convinced by the quality of Xvid both by the review and my own experience. (It has much more details.) And I will completely switch to Xvid until DivX get new version to consider.

[sysKin]

Originally posted by Koepi
Here we only support the "releases", not current CVS. So if you use latest CVS you're on your own with your problems (only if we tell you to use it as your bug is fixed in there I can recommand and support that).
Actually most "release" bug reports are useless. I definitely prefer people using CVS/Gamer's builds - if not, we wouldn't (for example) discover U/V flip until RC2 and then it would be quite late.

I'd say I can live with many CVS-related posts, they are the only way to fix remaining bugs now.

Regards,
Radek

[Koepi]

My point is that newbies should use the "release" builds - experienced users of course should use CVS builds if they want to help development.

I think that was a misunderstanding :)

Regards
Koepi

[symonjfox]

You're right. Experienced users know where to find new CVS builds (or build their own) and know what IS a bug.

After 1.0 beta1 I read so many threads about "B Frame lag" and "Packed Bitstream" as Xvid internal bug ... :confused: