DivX Slowdowns and strange "line effects"

[Yas_Chan]

Thanks for very useful site.
I got few problems. I've installed DivX 3.11 Alpha version first like instructed, and after that I installed latest DivX 5.0 Codec.
However, there are few problems I've encountered.
One is occasional heavy slow-downs in the movies, and another is strange line effects in parts of the movies where is very fast moving objects. It's like half of the lines can't keep up with the pace.

At the moment I'm using BSPlayer and Windows Mediaplayer 6.4. The problem happens exactly the same way no matter which player I use. Should I change some settings of my divx codec? Obviously my codec has some problem.

What are filters by the way?
Should I install something else? Does anyone have experience of "XviD". I might give it a try, instead of DivX.

I would appreciate help of veterans. Thank you beforehand. (Therefore since I thank you, I don't leave you a choice but to answer this message.)

[Enchanter]

occasional heavy slow-downs in the movies

This happens during the fast-action scenes as well, I suppose? Your system is most probably struggling with the amount of CPU work required to decode that scene and hence the slow-down. Typically (for movies encoded with 2-pass mode, which are what you find most of the time), there is a high amount of bitrate assigned in fast-action movies. This amount of bitrate may be too high for older systems to comfortably handle. Your option would be to lower down the filter settings of the DivX codec. Play the movie in WMP 6.4 -> File -> Properties -> Advanced Tab -> [DivX Codec]. Double-click on it and set the slider to the left (all the way, if necessary). That should make playing the movie require less CPU power than before.

strange line effects in parts of the movies

That is interlacing artifacts. Whoever encoded the video was not doing a proper job at it. This is not a problem with your system nor the DivX codec. The only way you can remove it is to re-encode the file and apply a Deinterlacer on it.

[Yas_Chan]

thanks

Wow, cool. I will check these and report back later!

Regards,
Jason

[Yas_Chan]

Still slowdowns

I moved the "Quality Level" slider all way to the left. But still, I see slowdowns very often. Strange thing is that another movie played well without any slowdowns, could be this be also problem of the video file?

My computer is Duron 900 with Radeon DDR. I have 512mb memory in my machine.

[Enchanter]

And what is the resolution, length andfile size of the video?

[Yas_Chan]

This particular video file is 510mb, 608 x 368, 24 bit, 126149 , 23.976 frames/s, 99 kbps, DIVXMPG4 V3

I've tried to run it either from HD or from CD, but still the same slowdowns occur. The audio is played correctly though.

Another video file, which works just perfect is 580mb, 640 x 304, 24 bit, 142848, 23.976 frames/s, 97 kbps, DIVXMPG4 V3
Strange huh?

[Enchanter]

Probably the movie with the slow-down has a very high bitrate at the particular scenes, more than your system can handle. Try running your desktop at 16-bit colours, 800x600 (or even at 640x480), and see if it helps.

[Yas_Chan]

Well actually it didn't have any difference even if I try different resolutions in my desktop. Just like when I changed the quality of decoding. But the funny thing is that it's just this particular video file which flickers. Others are running just fine. I'm starting to doubt that what if there is a fault in this videofile?

By the way, I'd be really happy to know how to remove those interlacing artifacts from video files. Can VirtualDub do that?

Best thanks for your help! Now I'm lots of wiser!!

[Enchanter]

1. Open file in Virtualdub

2. Set Audio tab to Direct Stream Copy (I'm assuming you do not have a problem with the audio)

3. Set Video tab to Full Mode Processing

4. Under the Video tab, select Filters. Click Add... -> Choose Deinterlace (Or download the better Smart Deinterlacer). Read the manual for the filter and experiment around until you find the best setting for your particular video. Remember that the deinterlacing strength is increased the lower you set the thresold. You don't want to set it too low as it will blur out the video badly. Try to find the 'sweet spot' where the thresold is just low enough to remove your interlace artifacts.

5a. Go back to the video tab and choose Compression. Choose a DivX codec (3.11, 4.x or 5.x, depending on which you prefer) and configure its settings. Let's assume you are using 3.11. Choose DivX MPEG-4 Low-motion and then Configure. Set Smoothness to 75.

5b. For the bitrate, you need to use a calculator to determine how much you should use to end up with a file roughly the same size as the original file. Most calculators should work for you, so pick anyone of them. Enter into the calculator the file size and the play length of the original movie. The calculator will yield a bitrate value, which you will input into the codec configuration. Leave the other codec settings at their default.

6. Back to the main Virtualdub window, go to File -> Save as .AVI and give a name to the new file you're going to create. The process will take quite some time (hours), so relax and turn off unneeded programs so that Virtualdub can work at optimum speed.

That's basically the basic way of doing it, but that will get you started. Have fun.

[Yas_Chan]

Cool!

Thanks alot! I found this very interesting!

[Gammu]

Originally posted by Yas_Chan
This particular video file is 510mb, 608 x 368, 24 bit, 126149 , 23.976 frames/s, 99 kbps, DIVXMPG4 V3

I've tried to run it either from HD or from CD, but still the same slowdowns occur. The audio is played correctly though.

Another video file, which works just perfect is 580mb, 640 x 304, 24 bit, 142848, 23.976 frames/s, 97 kbps, DIVXMPG4 V3
Strange huh?

You know, if I use 640x480 or 320x240 I never get slowdowns. If I use other resolutions, sometimes I do. I'm not sure if this has to do with the aspect ratio, or whether you can divide by 8/16/32/64 or whateve, but I suspect you may be running into the same thing I have from time to time.

You could always crop and smart resize to 640x480 in VD and reencode your file to see if it plays smoother.

Good luck.

--Gammu

[Enchanter]

You know, if I use 640x480 or 320x240 I never get slowdowns. If I use other resolutions, sometimes I do. I'm not sure if this has to do with the aspect ratio, or whether you can divide by 8/16/32/64 or whateve, but I suspect you may be running into the same thing I have from time to time. You could always crop and smart resize to 640x480 in VD and reencode your file to see if it plays smoother.

That's something I've never experienced! Worth trying out though.

p.s. The video resolution is of acceptable factor, so that shouldn't be the problem.

[Batman]

To get the advantage of a lower resoultion consider gdivx, and drop the color to 16 bit, and quality to 0.