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Sudden HUGE pixels appearing for no apparent reason...

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Mathias Mestermann
Sudden HUGE pixels appearing for no apparent reason...
on Dec 13, 2015 at 2:27:02 pm

Hi guys,

After looking for a while I find no real solution to my problem...

I rendered a video in adobe premiere CS6 to upload in youtube and facebook with the following setting:

Width: 1,920
Height: 1,080
Frame Rate: 23.976
Field Order:Progressive
Format: H264
Level: 5.1
Bitrate Encoding: VBR, 2 Pass
Mbps: 120-140 (Just so there can be no excuse)
Selected "Render at Maximum Depth"
selected "Use Maximum Render Quality"

Now both youtube and facebook show some crazy fat pixels when shown in HD specially from 0:42 in the video.

What I find very strange is that those pixels are not seen when you watch the video in lower quality.

I know the background is complex with lots of trees and that is not ideal but as you can see on another video I made it is not near as bad as the new one...

Here is the last video showing extreme pixels on some transitions from 0:42 to end:

Here is a previous video without those huge pixels and the background is still pretty much as "complex":

Any help is extremely appreciated!!

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Tero Ahlfors
Re: Sudden HUGE pixels appearing for no apparent reason...
on Dec 13, 2015 at 4:52:51 pm

That's a really bad situation for an encoder. I guess the original was shot with a gopro or similar? Recompressing compressed footage doesn't help either.

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Mathias Mestermann
Re: Sudden HUGE pixels appearing for no apparent reason...
on Dec 13, 2015 at 6:05:31 pm

Hi Tero,

Thanks for your input. Yes it was shot with a Gopro hero4 black and a gimbal.

On the last video some shots were with the auto protune and the rest in the woods set to native (with my newbie effort to make it look ok on adobe...)

Is there a better way to help the encoder for example increase contrast or anything else?

I know it's the worst situation as I read on some other threads but I really don't have any choice... The most interesting shots are always in the woods and I really need to try my best with it...

What's even crazier is that by recharging the youtube video, sometimes the pixels are less dominant!
So sometimes it play better for some reason....!

Does that make any sense...???

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Ivan Myles
Re: Sudden HUGE pixels appearing
on Dec 14, 2015 at 8:21:52 pm
Last Edited By Ivan Myles on Dec 14, 2015 at 8:28:28 pm

Welcome to the forum, Mathias.

The pixelation or blocking appears directly after a cut from a city street to the woods, which is then followed by high motion footage through the woods. Most likely the blocking is caused by bitrate starving; the required bitrate peaks because of the scene change following by relatively large frame-to-frame differences in the video. By comparison, the reference footage you provided in the second clip is a longer continuous shot.

First, download the re-encoded YouTube file from the Video Manager page within your YouTube account. Play the video from a local disk and scrub through it within Premiere Pro to confirm that this is a YouTube encoding issue and not a bandwidth streaming issue.

As a resolution try using slow motion or a speed ramp when you cut to the woods. It might give the encoder enough headroom to fit a higher quality reference frame at the scene change. If that doesn't work, intentionally adding noise or blur for a short interval *might* reduce the blocking.

Otherwise, you either need to rethink the edit or upload the file to websites that support higher bitrates. Vimeo produces slightly better results than YouTube; the Internet Archive ( allows you to upload larger files.

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