MPEG2 render looks bad

Spot|DSE wrote on 3/15/2004, 7:14 AM

Lotsa things can make this happen.
Smoke, Fire, Water, fine detail with lots of motion are hard for the encoder to handle.
Also, the bitrate may be fixed rather than variable. (I've blown away the defaults so can't tell you)

Reducing saturation on a given section, cropping to be sure that the fringes from DV noise are gone both will help a little. Making sure you have no illegal colors will help. Upping the bitrate will do the same. A mix of all might accomplish what you need.

craftech wrote on 3/15/2004, 7:16 AM

Which default settings have you changed in Vegas? Also, "Reduce Interlace Flicker" doesn't work well for me in terms of artifacts and blurring that it can create.

John

Randy Brown wrote on 3/15/2004, 7:22 AM

That was fast, thanks guys!

>>"Which default settings have you changed in Vegas?"<<

None, the only thing I can think of is that I changed the project properties to "best" ( I usually use good) but I wouldn't think that could make it worse.

>>"Also, "Reduce Interlace Flicker" doesn't work well for me in terms of artifacts and blurring that it can create."<<

I didn't use it this time.

Thanks again guys,
Randy

Randy Brown wrote on 3/15/2004, 7:43 AM

>>"Smoke, Fire, Water, fine detail with lots of motion are hard for the encoder to handle.Also, the bitrate may be fixed rather than variable. "<<
This is Basketball highlights and the variable bitrate is checked in the default mpeg2..
>>"A mix of all might accomplish what you need"<<.
I've rendered over 100 mpeg2s and never had any problems, it's gotta be something simple...no?
Randy

johnmeyer wrote on 3/15/2004, 8:09 AM

How long is the DVD? I just did different five basketball DVDs. I was forced to put over two hours on two of them, and the pixelization was getting noticeable. (I improved that by getting the Mainconcept standalone encoder and tweaking the settings). In general, I recommend encoding less than 90 minutes on DVDs.

Randy Brown wrote on 3/15/2004, 8:18 AM

>>"How long is the DVD?"<<

26 minutes....the pixelation is also there when played on Windows Media Player. I'm trying different settings now with just a few seconds but no luck so far.

Thanks John,
Randy

Laser wrote on 3/15/2004, 10:17 AM

Have you tried just rendering the portion of the video that pixelates badly when in motion to its own mpeg2 and then pull it back into the video. Also, I had a wedding video that had alot of artifacts show when the groom was dancing and spinning with the bride. I placed reduce interlace flicker on that event alone and it seem to work fine.

Randy Brown wrote on 3/15/2004, 11:27 AM

Thanks Laser, I tried your suggestion but it actually looked worse when viewing the rendered MPEG2 on the timeline...reduce interlace flicker didn't seem to help either; never the less, thank you for trying!
If anyone would like to take a look at it you can find it here . It's only 7 seconds but it's 4MB. It should stream or download. Anyone's suggestions would be very much appreciated!!!
Randy

johnmeyer wrote on 3/15/2004, 12:42 PM

Other things to try:

Try rendering using one of the default templates, and don't modify anything. Perhaps you have "tweaked" a setting.

Try using a different medium. I suppose that you might be using a DVD-RW that is barely readable and therefore not many bits are getting through (although I think this would cause hesitations, rather than pixelization).

Check your project settings to make sure that everything (such as frame rates, resolutions, etc.) are correct. Do the same for a few of the events on the timeline (i.e., check their properties).

Randy Brown wrote on 3/15/2004, 1:05 PM

Thanks John,
<<"Try rendering using one of the default templates, and don't modify anything. Perhaps you have "tweaked" a setting.">>

I'm almost positive that I have never modified anything for MPEG2 but if I had it would have required me to name it to have been able to save those settings, right?

<<"Try using a different medium. I suppose that you might be using a DVD-RW that is barely readable and therefore not many bits are getting through (although I think this would cause hesitations, rather than pixelization).">>

Don't forget John, it's doing the same thing when playing the MPEG2 directly in WMP 9 so I'm guessing it has nothing to do with the media.

<<"Check your project settings to make sure that everything (such as frame rates, resolutions, etc.) are correct. Do the same for a few of the events on the timeline (i.e., check their properties).">>

I haven't changed anything (intentionally) in that respect but I'll go see if I can just default everything.
Hey thanks again for your efforts John, I'd hate to turn this 50 hours plus project in on a VHS tape!
Randy

winrockpost wrote on 3/15/2004, 1:31 PM

That camera is really whippin fast, you mentioned you have done numerous mpeg renders that were fine, had you done one with the cam panning at that speed ?
Sorry , thats all i got.

Randy Brown wrote on 3/15/2004, 1:37 PM

<<" ...had you done one with the cam panning at that speed ?">>

Yes sir and they rendered fine. This one looks fine too when played from the timeline (the background is of course blurred but it's not pixelated).

<<"Sorry , thats all i got.">>
Thanks for keeping the thread alive if nothing else : )
Randy

johnmeyer wrote on 3/15/2004, 2:27 PM

Are you SURE you are using the DVD template? What you describe sounds like what you would get with the SVCD template or something similar. If you have any MPEG tools, you might want to use an MPEG analysis tool to see what the maximum and average bitrates of the file might be.

Randy Brown wrote on 3/15/2004, 3:07 PM

<<"Are you SURE you are using the DVD template? What you describe sounds like what you would get with the SVCD template or something similar.">>
At this point John I ain't sure about nothin'...however here is the procedure I'm following: Render as/mpeg2/default and the description = Audio: 224 Kbps, 44,100 Hz, Layer 2 Video: 29.97 fps.
Does that sound right?
If I select custom it has VBR selected with the max =6 mil, avg=4 mil, and min.= 192 K....I hope that tells you something because I don't even know what the heck MPEG analysis tools are : )
Thanks again John,
Randy

johnmeyer wrote on 3/15/2004, 3:23 PM

Yes, that all sound right. I assume you checked File -> Properties and made sure that you are using the standard NTSC template.

Ah, another thing just occurred to me. You say that your project is quite short -- I think you said twenty minutes. How long did it take to render? A long time??

You might check this: Open the project in Vegas, put the cursor on the timeline, and then press Ctrl-End. Is the cursor at the end of the video you want to encode, or is it way the heck beyond that point? I am just wondering if you might have some media asset "lost" somewhere, and you have accidentally encoded a really long video.

You might want to contact Sony directly about this one, using the Support button at the top of this page.

Randy Brown wrote on 3/15/2004, 3:37 PM

<<Yes, that all sound right. I assume you checked File -> Properties and made sure that you are using the standard NTSC template.>>

yep

<<Ah, another thing just occurred to me. You say that your project is quite short -- I think you said twenty minutes. How long did it take to render? A long time??>>

Yes only 26 minutes but I don't recall taking a longer than usual time to render...maybe a half hour? I can do it again and time it if you'd like. It had a substantial amount of color corrections and cross fades.

<<You might check this: Open the project in Vegas, put the cursor on the timeline, and then press Ctrl-End. Is the cursor at the end of the video you want to encode, or is it way the heck beyond that point? I am just wondering if you might have some media asset "lost" somewhere, and you have accidentally encoded a really long video.>>

2 things come to mind that might eliminate that theory : WMP shows it as being 26 min. and when I was doing all of my testing I was only rendering out a few seconds of it (unless of course the theory just went right over my head : ).

<<You might want to contact Sony directly about this one, using the Support button at the top of this page.>>

I'm trying to meet a deadline but I'll certainly take your advice there...I was hoping that Sony EPM might jump in here but it seems they don't do that any more : ( perhaps too busy working on V5 : )
Worst case scenario I suppose I could always put it on VHS but....ARRRRRRGH!
Thanks again John,
Randy

JL wrote on 3/15/2004, 4:18 PM

Ok, I know it's kind of a long shot but as it sounds like you've tried pretty much everything else... you could try encoding at a fixed bit rate of say 8.5 and see if it helps; 26 minutes at this rate should easily fit on the DVD. Did you say what the source was, DV captured in Vegas?

JL

Randy Brown wrote on 3/15/2004, 4:33 PM

<<Ok, I know it's kind of a long shot but as it sounds like you've tried pretty much everything else... you could try encoding at a fixed bit rate of say 8.5 and see if it helps>>

I have e-mailed support but I will certainly try it tomorrow,

<<Did you say what the source was, DV captured in Vegas?>>

Yes sir, shot on a Canon XL1s and capture with V4's Vidcap.
Thanks JL,
Randy

wobblyboy wrote on 3/15/2004, 6:19 PM

Sometimes best is not as good as "good".

Randy Brown wrote on 3/16/2004, 5:57 AM

Thanks wobbly but I tried "good" also : (
Randy

winrockpost wrote on 3/16/2004, 6:34 AM

Why dont you try to render a portion of an avi file that you know has produced a good mpeg in the past. See what kind of results you get. Narrow down the suspects.

craftech wrote on 3/16/2004, 6:58 AM

Two things come to mind:
1. You have used one or more filters incorrectly such as color correction way out of spec which after compression shows the problem.
2. Unnecessary compression is going on due to a less than optimum setting.

Try rendering the timeline project to an uncompressed avi file, then put it back on the timeline and render to Mpeg 2 video only using the DVDA NTSC video stream template. The DVD NTSC template produces an elementary video stream which can cause some problems with some 3rd part applications. Use an average bitrate of somewhere around 6,000,000 , a minimum of 2,000,000 and a maximum of 8,000,000, quality slider at 31, and change the DC Coefficient to 10 bit when you do. You may also try checking:
Write Sequence Display Exension.

John

Randy Brown wrote on 3/16/2004, 12:35 PM

Sorry it took so long to get back...

<<Why dont you try to render a portion of an avi file that you know has produced a good mpeg in the past. See what kind of results you get. Narrow down the suspects.>>

That's a good idea, I'm actually capturing footage right now as I write this that was shot at a TV studio this morning. I'll render it out to the default MPEG2 setting and see what happens.,,,thanks risce1!

<<1. You have used one or more filters incorrectly such as color correction way out of spec which after compression shows the problem.
2. Unnecessary compression is going on due to a less than optimum setting.>>

I did use a slight bit of color correction on a few clips but not in the first clip at the front (the one I have posted) and it seems the most noticeable. Does that make any difference?

<<Try rendering the timeline project to an uncompressed avi file, then put it back...>>

Thanks John I'll try that.
I e-mailed support yesterday asking them to check out this thread, hopefully they'll throw in their suggestions too before long.

Thanks again guys,
Randy

winrockpost wrote on 3/19/2004, 4:09 AM

bump

is the problem solved ?