Choppy playback with DivX 5.0.1 pro

[freezer]

I was really happy when 5.0.1 arrived as I thought it will be a nice fix for the buggy start of 5.0. But now I have to face a very nasty bug: Playback of Divx4.12 and DivX5 encoded movies is very choppy.
I use keyframes every 25 frames, the movie has 512x304 pixel and no sound atm. The choppy playback occurs with WMP6.4 and DivXPlayer2.0, but not in VDub (regardless if with or without direct draw enabled).
I suspect the keyframes to be the source of the problem, but I can't figure it out.
I have an Athlon 1200, W2kSP2, 768MB, GeforceMX2, and never had problems with the playback before (since the upgrade of the codec).

Does somebody have encountered similar problems?

[DJ Bobo]

25 keyframe intervall is crazy!
Use a normal value like 250 or 300, DivX5 detects the scene changes anyway and introduces keyframes automatically when they are needed!

[freezer]

25 keyframe intervall is crazy!

Why should it be crazy? I made more than 200 2 CD rips with this setting. It has the big advantage, that you can fastforward through the movie with no delay, and you can cut frames relatively exact.
When I do 1 CD rips I use Nandub with SBC and a max keyframe intervall of 300, of course.

Correction of my posting: Just discovered, that only DivX4.12 encoded movies have this choppy playback, DivX 5.0.1 seems to be ok.

[DJ Bobo]

you can encode as many movies as you can with that setting, but it still crazy! this is a too small intervall!

If you wanna cut, cut before you encode! even then, it's no problem, since people cut usually on scene changes, and there is keyframe on every scene change, so it's not problem, even if you wanna cut later!
And fastforwarding is not thaat important, since you're not jumping into the movie 100 times an hour aren't you!?

Leaving the setting on 250 will give you 2 to 7 seconds keyframe intervall most of the time, so it isn't a problem! it's comfortable enough!

You should also consider that introducing keyframes where they are not needed, introduces some bizarre effect, it's like the picture is refreshing every second, that means it jumps somehow every second!
AND it delivers worse quality than with a higher setting like 250, since Keyframes consume more bitrate than others and you'll have too many of them

[freezer]

I don't see why this intervall setting should be any more crazy than yours. It serves my needs well, it doesn't increase the size a lot, so far it has no negative side effects. I want to cut exactly, and that is not possible with the 300 keyframes intervall setting. And yes I am jumping through the movie very often, if I check the quality, if I search a special scene, and if I continue watching the movie were I broke up the day before.

I couldn't see neither any bizzare effect in any of my 200+ movies, nor could I see any better visible quality.
I did some tests with different settings, and a keyframe intervall of 50 gave me 2.5% larger file size than a keyframe intervall of 300. The visual quality was the same. The only codec which had the problem with too much keyframes is the old divx 3.11, were the refreshing problem occured.

But my question is: Have you tried to playback 4.12 encoded videos with 5.0.1? And did you see choppy playback yes or no?

[kermit70]

I've noticed this 'choppiness' too since I installed 5.01. The problem seems to be the post-processing filter and somehow keyframe related. Just converted back to 5.0 - plays smoothly again. So, until they fix this, I stay with 5.0.

kermit70

[DJ Bobo]

@ freezer
Do what you will, someday you'll change your mind, I'm sure of that ;)

I got also choppy playback of DivX4 content, but only if I set a higher post processing setting.
I mean, the video stops sometimes for a moment, until the next keyframe comes.
The DivX5 decoder is quite crappy...

[freezer]

Do what you will, someday you'll change your mind, I'm sure of that

:-) Don't be too sure ;-)
Maybe you will try my variant some day...

Thanks for the replies anyway, now I know that the choppy playback is not my fault. I have to reverse to 5.0 too, but I hope this silly bug will be fixed soon.

[DJ Bobo]

I used your variant earlier, that's why I told you that ;)

BTW, I got the same playback problems with 5.0 AND 5.01, no change for me.

[dragoman]

Hi,

Just a quick question......@freezer and @bobotns, are you two married? :D

dragoman

[oddball]

Keyframes lack the compression of non-keyframes (I think) thus are somewhat sharper and closer to what the original frame is. The problem is with setting a low keyframe interval is that you begin to see those keyframes quite clearly because you are immediately seeing a a keyframe and then right away a non-keyframe every second or so. This creates what can be called a pulsing effect on screen. I know because I had this problem when I tried making my keyframes low. It also as has been said increases the size of the total video file (well it doesn't but what happens is that you end up wasting valuable bits that could be used to make better quality non-keyframes on just the keyframes. So more keyframes in the video = shittier quality 'overall').

If you are not seeing any of these effects then maybe you need a better monitor/TV or need to adjust the TV sharpness a touch. But then you may also be short sighted or something ;)

Then again it may be something else causing you not to notice any probs. Send us a sample of one of your encodes and I will see if it looks OK to me eyes :)

[llemor]

am i watching a movie?

i love this forum. it teaches me a lot and entertains me!!!:D

[oddball]

I told you. If you spank that monkey anymore he will bite your ass! :P

[freezer]

thanks for your explainations, but I know that all. If you've read my replies, you might have seen that I use the 25 keyframes intervall only for 2 CD rips with DivX4.12 where size doesn't really matter (well most of the time).

So those look really great.

I had this discussion last year with another guy on this forum, but unfortunately the old postings seem to be deleted.

And I have attached a screenshot of a keyframe from one of the latest rips I made. It's from the movie 'Dogma'. So have a look if you can see more than I. :D

[oddball]

Hehe. Looks like the gif is corrupted :)

[freezer]

OK, here is it again:

[Acaila]

That one was even more corrupted than your previous one :D
So I didn't validate it.

Anyways, why are you trying to show us that your keyframes look good? Ofcourse they look good, they're keyframes, they're supposed to be near-perfect! It's the rest of the movie that will decrease in quality with the keyframe interval you're using.
But if that method works great for you, by all means stick to it. It's just that theoretically it's better not to use a small interval.

[ppera2]

After getting freezes and choppy sound on my new encoding with res 704x448 I made some research.
Finally I saw that CPU load while playback with DivX 5.01 is very high. On my Athlon@1270 MHz on DDR board it gone sometimes over 100 % when CPU quality was on the max (7-th stage).
I needed to lower it to third stage to get good playback, but CPU load was still very high - ~80 % in XP and couple % less in 98 SE.

Now we have 7 grades instead 4 in older codecs. Are stages 5-7 for some stronger postprocessing, for very fast CPU-s, over 1.5 GHz ?

[dragoman]

Hi,

Not sure what other programs you have running, but I usually play my DivX 5.01 encodes with Post-processing set to highest level.

With a 640x272 encode, playing at full screen, I get only a CPU load of 60%.

If I reduce the post-processing level to 5, I get around 45-50% CPU load.

I am running an Athlon 800 Thunderbird w/ 448 MB Ram (SDRAM).

The player I use is bsplayer....

Oh yeah, almost forgot....the above numbers are with an encode using ac3 sound....vbr mp3 at highest level I get 50% max cpu load.

dragoman

[freezer]

AFAIK it is the same post-processing as with DivX 4.12 Codec. Somewhere it was said that the QPel, GMC whatever features from 5.x eat extra CPU power during playback. I don't know if this is right.
Anyway, a quick test shows me a 50% CPU load during playback with level 6 of post-processing filters (they range from 0 to 6). I have an Athlon 1200 with 133 MHz SDRAM and GF2MX running W2k SP2.

So maybe there is a problem with your gfx hardware acceleration?

[ppera2]

I talk about player's load alone.
Maybe it has something with video card ? I have Voodoo 3.

With DivX 3.11 I have also big CPU load, 50-85 % depending on resolution.

It is very funny, it looks that playback is more demanding than encoding. I say it, because I can get over 35 fps with DVD2AVI and DivX 5 codec.

[freezer]

I also meant player's load alone.

You say you have Vodoo 3, so I think that is the problem. Having an Athlon 1200 something, DDR Ram you have not spent any money on a faster gfx board? If money is the issue, you should be an Geforce MX2 which are very cheap nowadays.

Meanwhile it could help to reduce screen resolution during playback, give 800x600 a try.

[ppera2]

I tried today GF4 MX card, and CPU load was much lower, about 50-70 %. So V3 is outdated...
But... TV out of GF 4 MX is still not enough good, V3 has better picture and more settings. Because of bad TV out I didn't buy GF2 MX card, although I tried 3 diverse ones.
Perhaps I should try some ATI card ?

[dragoman]

Hi,

I have a Radeon All In Wonder, and my results using it for both Comp and TV-out are outstanding.

dragoman

[Scorpius]

May I ask why u ppl use post processing level at max? I never use post processing level. IMHO it makes picture much worse. Afterall, its a filter, am I right? When I compare picture with post processing off and post processing on I notice that picture comes "unnatural" and unpleasant to the eye.

Your opinions, please :)

[ppera2]

Until now I used to set postprocessing level to max. It makes some kind of bilinear filtering and masks blocks with it. It was important with some 1 CD rips.
However now I don't see any diff. in my encodigs with DivX 5 when set to level 2-6 . But it surprised me how big CPU load I have...

[freezer]

May I ask why u ppl use post processing level at max? I never use post processing level. IMHO it makes picture much worse. Afterall, its a filter, am I right? When I compare picture with post processing off and post processing on I notice that picture comes "unnatural" and unpleasant to the eye.

I know what you mean. For me it depends on the movie I watch, if it has low quality with a lot of blocky scenes I prefer a high postprocessing setting, but for good quality rips I leave it at level 2 or off. But especially cartoons and animes can benefit a lot from the filter system.
The problem with the filter is that they tend to smooth the grainy look away, so the picture looks more unnatural. The idea of the ffplayback filter creating some noise during playback is brilliant, because it fools the eye to belief that there are more details. It is the same trick Photoshop pros use to create the illusion of details in extremly interpolated images.

[grug2k]

I just use TVTool (http://www.tvtool.de) to get my TV Out looking better. 768x576 looks good.

--

My postprocessing settings is in the middle, or the one after it I think. The last two consume the most CPU power but also offer the least gain, I think.

[hippoth]

I found out, that a movie encoded with quarter pixel results in choppy playback...without quartel pixel everythink seems to be fine
with divx 5.0.1 pro

Is there somebody with the same impression?

my system:
win xp pro
1.1 ghz athlon
256 mb ram
matrox 450 max

:o)

[dragoman]

Hi,

Yeah, qpel seems to take more resources to decode, and also slows down encoding process....

Don't use it.

dragoman