VS 10 pixelation following transitions + text w/ SmartRender

humanoid · Post by **humanoid** » Sun May 06, 2007 5:12 am

I hope someone can help me here. I'm having a problem with pixelation occuring after transitions in VideoStudio 10 Plus when using SmartRender. I'd like to be able to not have to rerender my captured mpegs so the quality will not be lessened, so the SmartRender option is important to me.

When adding scenes to the timeline, I check yes on "do you want to change the project settings... perform SmartRender". Then in the project properties I only change the quality meter to 100% and deselect dvd-vr compatibility. I then add all the scenes, trim them, add transitions, and add text following some transitions. When I am done, I select "share", "create video file", and "same as project settings".

I've noticed that when Video Studio is using "smart render", only the places in the project having transitions and/or text will be displayed on the screen during the video file creation, whereas the percentage complete will speed up between these transitions. I am assuming the program correctly detects that these parts between transitions (or text) do not need to be rendered as they have not been altered in my project.

The video files end up with a second of pixelation (sometimes paired with a click sound) occuring at the exact place in the video where a transition completely ends. This pixelation will also happen right after text that I have added to the video. Apparently, these pixelation errors occur at the boundaries between the program rendering (the transitions and text) and then not rendering (video not being rendered in the next scene once the transition or text is done). The pixelation doesn't happen at every transition/text insertion, maybe about 60-70% of them, and within that percentage, the degree of pixelation (and how noticeable it is) also varies.

I've tried various things over the past month (can't remember them all) to see if I could fix the problem. I've noticed that the pixelation is not dependant on which transition is used. The several transitons I use, most multiple times, (mainly crossfade) do not always result in the pixelation. The pixelation seems to be dependent on the frame/scene immediately following the transition. A cut at the beginning of this scence may result in a less noticeable pixelation or maybe none at all. However I don't think this is a suitable fix because most of the time I don't want to cut anything more, not to mention the hundreds of times I might have to render the same video file just to get all 15 or so transitions in each video file looking good. I probably have about 10 or so video files I have spent much time editing that will just barely fit on 2 dvds.

I have also defragmented my hard drive and recently bought a 2nd hard drive to create the video file on to lessen the work load of my single hard drive to see if it was a problem with my computer being underpowered. However, there was absolutely no change in the results when rendering the same project file from one hard drive to the other.

In the past I have changed the project settings from Constant video data rate to Variable, thereby disabling the SmartRender, but I notice a quality improvement overall when left at Constant so no rendering takes place between transtions. I just wish I could use SmartRender without the pixelation errors.

-------

After writing all of the above I did another search on this board (have made several) and found someone else may be describing the same problem:

http://phpbb.ulead.com.tw/EN/viewtopic.php?t=15084

"...I made further investigations and found out that this problem defenitely comes from the smart-renderer.
If I view the generated mpeg2 file frame by frame using virtualdub then I can see that all portions that were reencoded by the smart-renderer have the sequence IBBPBBPBBPBBIBBPBBPBBPBBI...etc.
If the last frame of that sequence does not meet with an I-frame of the clip from the video track then VS generates this distortion.
In VS I did the following to fix the problem:
-switched to max. zoom on the timeline that the cursor will jump frame by frame
-enlarge the title by so many frames that the last frame of the title will meet an I-frame with the movie on the video track.
If I render the modified project but leave smart-renderer enabled then the distortions have disappeared and the resulting video is excellent.
Unfortunately VS can not tell you which frame of an mpeg2 file is I,B or P frame so an external program(like virtualdub) is required to see this.
This is defenitely a bug in VS10, I hope some project leaders at ulead will read this and apply a fix(a patch) in a future release.
Regards
Sektionschef"

I don't completely understand this persons post regarding which program he or she is doing the zooming in. As I understand it you can see frame boundaries in VideoStudio but not what kind of frame they are. Does this mean I need a separate program to cut up my mpegs on I-Frame boundaries using a separate program? I'm guessing there are typically about 2 I-frames per second so I might not lose too much, but that definitely takes away from VideoStudio's ease of use... I would hate to go through all of the project files I have already compiled to dvd folders on my pc.......

Any suggestions?

Is this a problem with VideoStudio 10? Might version 9 or 11 work better?

Will VideoStudio 10 project files work with other versions (older and newer)?

camera used:

Hitachi DZ-MV550 recorded onto dvd-ram discs and transfered/captured via usb cord within VideoStudio

Properties of raw video as seen in VideoStudio:

Video

MPEG-2 Video, Upper Field First
24 bits, 704 x 480, 4:3
29.970 frames/sec
5744 kbps constant data rate

Audio

MPEG Audio Layer 2 Files
48000 Hz, 16 Bit, Stereo
Layer: 2
Bit Rate: 256 kbps

my PC:

Windows XP Pro SP2
Athlon XP 2800+
Asus A78NX-LA (made for HP320n)
FSB 333MHZ
1024MB DDR SDRAM PC3200 (2x512) Samsung double-sided CL3, running 2700 speeds
in dual channel mode (matching pair)
Leadtek 6600gt 128MB AGP
master: Western Digital Caviar SE 250GB 7200 RPM 8MB Cache IDE Ultra ATA100 (UDMA 5)
slave: Seagate Barracuda (7200.

250GB 7200 RPM 16MB Cache IDE Ultra ATA100 (UDMA 5)
BENQ 1620 DVDRW
420 watt Thermaltake Purepower W0009r

Post by **Ken Berry** » Sun May 06, 2007 5:31 am

As you will have seen, that person making the post about I-frames etc, used another program called VirtualDub to see that information. As far as I am aware, you cannot see at that level of detail in VS, any version.

Now I have two suggestions, one easy, one more painstaking.

The easy one would be to try easing back on the quality/speed slider from 100% to see if that eradicates any or all of the pixelation. I personally always leave that slider alone in its default positions which from memory is 70%, and have no problems with the ultimate quality of my productions. But if you are really worried about maintaining a high quality in your video, then you could try easing back from 100%in increments of, say, 5% or 10% and see which one starts eradicating the pixelation.

Now for the more painstaking alternative. I had trouble in VS9 not so much with pixelation around transitions, but with a momentary flash of a scene unrelated to either scene at either end of the transition. And like you, it didn't matter which transition I used; nor was it consistent with every transition.

In the end, the only thing I could attribute it to was using the virtual clips that VS 'creates' when you make cuts in your original video, or multitrim, but do not use the 'Save Trimmed Video' command. Now the latter, as you may be aware, actually creates completely new files, while leaving the original video alone. And when I dragged these new files into the timeline, and expanded them to give a frame by frame view, I could see that particular cuts may have included a frame or two of the previous or following scene. And you can of course trim off those scenes.

Now if you on the other hand use the virtual clips, and do not go down to the frame by frame view, it is possible that the virtual cuts you make are not perfectly clean and in effect break up the Group of Pictures referred to by that other poster. When you move the virtual clips around extensively in the timeline, it is thus possible that you are dragging a frame or two of a scene (and GOP) some distance from where its main part is. And this could be enough to cause a mometary blip (pixellation in your case) when that spot is rendered.

Now I am not saying my situation is exactly the same as yours, only that it might be similar. And thus you might want to try using Save Trimmed Video and then replace the existing video with the newly saved clips, to see if you still have the problem.

But I suspect that changing the quality slider to something less than 100% may also help...

humanoid · Post by **humanoid** » Sun May 06, 2007 10:48 am

Thanks for your very quick response. You gave me some good ideas to work with. I did some experimenting with my shortest video file project which is about 3 minutes long and has about 5 transitions. I tried turning down the quality bar back to the default of 70 but results are exactly the same, with pixelation occuring at the same spots.

I then tried the "save trimmed video" idea you had on all of the videos in the project, put the saved trimmed videos into a new project with all the same transitions, etc. However this also ended with the same pixelation.

But then I noticed that all of the 5 videos I had used in this particular project didn't have any footage trimmed from their beginnings. I then remembered another version of this project file I did awhile ago in which I trimmed a little from the beginning of the first file to see if I could minimize a very noticable pixelation error. It also had resulted in an error, only it was in a different spot in the footage (about 2 seconds later in the video). I then wondered what might happen if I did the "save trimmed video" and not the "virtual clip" ,as you say, of this slightly shorter video I had trimmed the beginning from. So I created the video file from the saved trimmed video and it turns out there is no pixelation error in the same exact spot as there was before!

It seems that it's possible that forcing VideoStudio to make a cut somewhere at the beginning of each file through the "save trimmed video", before creating the video file, will get rid of these errors. Maybe the program is in someway cutting the video on a proper boundary or something. I still need to do some more experimenting to see if this is actually any real solution or just random (not to mention I may be trimming off footage I know I'd like to keep), but it's now 3 a.m on the opposite side of the planet in California and I need to get some sleep so I'll post back in a day or two.

Thanks again for your reply and I still welcome any others from you or anyone else.

Sektionschef · Post by **Sektionschef** » Sun May 06, 2007 12:57 pm

Hi
I am still surprised how few people have notified this terrible bug.
Especially in times where mpeg2 camcorders(miniDVD,HDD,etc) become more and more popular and smartrendering is required.
As you can read from my original thread this bug is still available in VS11 so you can save the money instead of updating.
Would be interesting whether you can find out a solution, I did a lot of investigations in the past but in the end I decided to move to Magix sw.
mfg
Sektionschef

humanoid · Post by **humanoid** » Mon May 07, 2007 12:51 am

Hi Sektionschef. I am also surprised that not many people have reported having this problem. Are we the only two? I didn't find your post in which you wrote that VS 11 does not fix this problem so thanks for letting me know. I did read in another post that you said Magix has the same problem but has it at the beginning of transitions and not the end. Are you still having this problem with your Magix program?

Unfortunately, I'm not getting any consistent good results from my experimenting. I'm really disappointed and the flashes of pixelation are even more annoying when viewing the actual dvd in a dvd player on tv. I think I'm about to give up on VS. Maybe time to learn a new program that can safely edit mpegs without completely rerendering them, using a similiar "smartrender" feature.

Anyone know of any good ones?

Sektionschef · Post by **Sektionschef** » Mon May 07, 2007 7:04 am

humanoid,
The camcorder I have is the Panasonic SDR-S100. It also records to mpeg2 in 704X576. I can choose 3 different quality settings: XP,SP and LP. In XP it uses a VBR of about 9Mbps,in SP a VBR of about 6Mbps. The max. Bitrate in all modes is always 9558kbps.
After I encountered the problem in VS10 I moved to Magix. The version I have is Magix Video deluxe 2007plus(european version). If I use my SDR-S100 in SP mode then I haven't seen any problems with Magix' smartrenderer. However, Magix has also problems if I use XP mode on my cam. I decided to stay with Magix because overall it is the better product than VS10(in my personal opinion). Either I use SP mode and have smartrenderer enabled or I use XP mode and disable the smart renderer. As XP mode has has higher quality the rerendering process does not decrease the final video quality alot.
Your camcorder seems to behave similar to mine in SP mode therefore it could be that you will not see any problems with magix. Try it out.
I have also heared that there is a smartrenderer pluging from mainconcept for adobe premiere elements and premiere pro. This could also be a good alternative but I haven't it tested yet.
Regards
Sektionschef