Main Concept mpeg2 render w/non-std bitrate crashes

RichMacDonald wrote on 12/18/2001, 11:33 PM

While building a CD with "SVCD" format but pushing the bitrate, I found what appears to be a memory leak that eventually crashes VV3.

Try the following: Start with a Main Concept mpeg2 render at NTSC SVCD settings. I used Highest quality. Change the Video Type from SVCD to mpeg-2. Increase the max and average bitrates above the standard to, say max=3.5Mbps, avg=3Mbps. Then do a render.

If the clip is short, it might work. However, watch the memory usage in Windows (Win2K). It will climb until either the clip finishes or VV3 shuts down completely.

Guess not too many have used this option yet :-)

Comments

RonC wrote on 12/19/2001, 12:50 AM

yes! I have had a simular thing happen in 98SE. If I use CBR at 2600kbs with a SVCD setting, it hangs every time. If I lower it to 2520, it competes just fine. (2600 should be a valid bitrate!!!) I was real fustrated with it since I was working on a Christmas project. Fortunately 2520 was adequate for the project.

Ron

wvg wrote on 12/19/2001, 8:37 AM

Pushing the bitrate to the levels you tried trying to make a SVCD CD seems an exercise in futility.

a. anything less than a very short video wouldn't fit on a CD at those bitrates.

b. I know of no DVD player that would play a SVCD at such a ridiculous bitrate.

You are talking about a CD and not a DV disk, right?

RonC wrote on 12/19/2001, 9:18 AM

wvg,

You are right as far as the 3Mbps, HOWEVER, my bitrates are completely valid and in the pulldown menu to boot.(2600). I found that it VV3 would just hang/halt at the same time every render until I lowered the bitrate (in my case I tried 2520).

Ron

bcbarnes wrote on 12/19/2001, 10:08 AM

This may be exactly the problem that I've been experiencing. I've tried to make MPEG-2 w/VBR and alter some of the settings, and it hangs at frame 111 every time. I'll need to check my memory usage and see if it's the same problem. Thanks for the insight.

RichMacDonald wrote on 12/19/2001, 6:05 PM

>a. anything less than a very short video wouldn't fit >on a CD at those bitrates.

Sure. However, let's say I have one project that fills up 50% of a single CD. I'm not going to put a 2nd project on that CD, so the space is wasted. If my DVD player supports a higher bitrate (better resolution), why not?

Do a search on miniDVD. Non-standard format writing DVD quality to a CD. Gives 10-20 min per CD. How many projects are 10-20 min? Enough to be interesting, given the nightmare of DVD compatibility. The players are perhaps $130, which is low enough to buy something temporary.

(And frankly, I dislike SVCD format because I still cannot find the settings to get rid of the blockiness
during a hard pan/fast action. The DVD "format" is perhaps a yr out from being able to remove the quotes. And I just hate to waste the quality of my expensive camera with a weak final output.)

>b. I know of no DVD player that would play a SVCD at >such a ridiculous bitrate.

They are out there. Apex, raite, afrey, tokai to name some I have read about. Non-standard and probably short-term. But I want a non-standard CD so I can test them in the store.

>You are talking about a CD and not a DV disk, right?

Yup.

smeredith wrote on 12/21/2001, 10:47 PM

I experience the same bug: rendering CBR at 2600kbs with a SVCD setting hangs on some projects. If it does hang on a particular project, it hangs at the same frame every time. If I lower it to 2520, it competes just fine.

RichMacDonald wrote on 1/15/2002, 11:37 PM

I'll know for sure after an overnight run, however, MainConcept seems to have fixed the problem in the latest VideoFactory 2.0b release. (Running VV3 using the MainConcept mpeg2 encoder from the latest VF2 release.) The encoder still requires a lot of memory and memory requirements seem to build as the render continues, however, it does a better job asking the OS for additional memory before it runs into problems.

I'm now running in DVD-level bitrates (2MB/s - 7MB/s) and am not crashing. However, this was only a short test. I'll run overnight and see how it goes. Note: If I don't followup to this post, it means things went ok.

liquid324 wrote on 2/26/2002, 12:24 PM

i realize that this thread is long over, but i thought i would throw my two cents in. i have had a similar problem with mpeg2 crashing because of obnormal bitrates that i was using, but i found the solution. First, update the mainconcept with the demo of videofactory 2c. then when you begin rendering your video, save it as separate streams (video and audio). once it finishes, simply remux it with tmpgenc and its finished. just my two cents.

liquid324 wrote on 2/26/2002, 12:47 PM

btw, im using the opposite end, really low bitrates with mpeg2 (1000000 or so)

RichMacDonald wrote on 2/26/2002, 3:46 PM

And i'm using really high bitrates, using the same technique as you, and also having no problems. I noted this in another thread, but forgot to come back here and close up the issue.