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Tiling, Macroblocking, & Pixelation after 9 min H.264 Mp4 Encoding
I am stumped with some home video quality (it’s pretty bad) footage I was handed to do a simple edit on.
I have finished the edit in FCP7 and created a ProRes timeline and exported it in ProRes to try to get it to behave. I then take the footage into Episode Pro for an H.264 Mp4 and it comes out with macroblocking and pixelation at around 9 minutes every time, no matter how large I change the Kbps.
I have tried Noise filtration but the image looses definition, goes soft. I thought of trying to get rid of the noisiness of the original by using Neat Video, but haven’t done that.
I have other footage that is doing the same thing but came from a Panasonic HDX-900. This footage came from some consumer camcorder. It’s footage of a talking head being interviewed. I had to take up the exposure, it was on the dark side. In doing so it has a washed look, but hey, I didn’t shoot it.
I should also mention this happens when I transcode to QuickTime as well, at the same place for the rest of the program. I do not see this in the FCP timeline.
Can anyone tell me what I can do to keep from getting pixelation that starts at 9 minutes into the encode? How does one obviate this kind of pixelation behavior in the first place? What causes this? Here’s what I am using:
Mac OS 10.6.8
Quad-Core Intel Xeon
3.2 Ghz
2 GB Memory
Final Cut Pro 7
Episode Pro 5.3.2
H.264 Mp4
VBR using Peak Rate, Average 2000, Peak 2400
5 reference frames
3 B-frames
High CABAC 2-pass using deblocking filter
Black and White Restore 15 for Black
640×360Greg Ondera
http://www.Plexus.tv
http://www.SurgeonToday.org -
4 Replies
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Perhaps whatever is happening at that point is bit starved. While the data rate is reasonably high, your peak isn’t much higher than your average making it very nearly a CBR encode. Try setting the peak at 4000kbps.
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Well, that didn’t seem to work. It is still pixelating at the same location for the rest of the shot. Here is what I used:
Episode Pro 5.3.2
H.264 MOV this time
1280×720
VBR using Peak Rate
Average 5000 – Peak 10,000I am wondering about another thing that is going on too, which is that I cannot scroll through these encoded files either. I have to play them from the start to observe them. I have gotten this same report from some clients too.
Any help is greatly appreciated.
Greg Ondera
http://www.Plexus.tv
http://www.SurgeonToday.org -
Sounds like you need to put in a proper key frame rate. Include both natural and forced key frames with forced being no more than 5 seconds apart (150 frames).
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Thanks tremendously. That worked. Also it seems to allow easy scrolling of the Mp4 version of the program, which it didn’t before.
Is there any good material to read that could tell me how this works under the hood? I want to know how to think about it.
Greg Ondera
http://www.Plexus.tv
http://www.SurgeonToday.org
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