weird banding after rendering project

[Bart Wierzbicki]

Hi guys,
I have an urgent question.
Tomorrow I have to deliver a video for a client.
I just finished the editing and I just exported the file to a H264 (mp4).

Now when I watch the clip, I see a lot of strange banding and stuff like that.
Very strange !
In my premiere project I don't see this.
Here is a link to a comparison between my premiere project and my output file.

www.motionpictures.be/after_render.jpg

Any idea why this is happening and is there a way to get rid of it and get exactly what I have in my premiere project file ?
Hope to hear from someone soon.

Thanks.

[Seth Bloombaum]

h264/mp4 is a compressed format. The usual cause of banding and other compression artifacts is insufficient bitrate (datarate) applied in the render controls.

Most of the renders that you'll do for client review and delivery should be very high bitrate, should not use "web" presets. For example, try 12Mbps (12000Kbps) for 1920x1080, 8Mbps for 720, 4Mbps for SD.

If these produce renders too large to email then you'll have to deliver them some other way, like using an online file sharing service such as dropbox or yousendit.

In looking at your screengrabs, it may be that your background is not pure white (it's hard to be sure from the grabs). Compressed codecs do not like subtle gradations. You might do well to use a color curves filter to select and bring up the background to a uniform 100% white. There are other methods, this is usually the most straightforward.

Hope this helps. If you continue to have problems with this, please post your exact render settings.

[Bart Wierzbicki]

Hi Seth, thanks for your help, but it keeps getting stranger.
I just called me client and told him I was working on that banding issue, but he told me that he doesn't see that issue.
So I just checked on another computer and there it's not visible, only on my computer screen.
I'm using a quite expensive Eizo screen.
Still I don't feel comfortable delivering it to my client eventough he doesn't see that problem.
I just installed X264pro trial version ... Anyone an experience with that ?

[Seth Bloombaum]

OMG! $299 for a free codec... but packaged as a Premiere plugin?

x264 is indeed the best h264 encoder, but you don't have to spend $299 to get it. How does "free" sound?

Of course the free version won't install as a plugin for Premiere. But, you would render a master out of Premiere, then create distributions with a (free) product like Handbrake. Highly recommended!

Perhaps your trial version will do the job for a while.

However, what is likely happening if you're seeing artifacts that your client isn't... is that your QT is picking the wrong codec for playback.

Have you installed a "codec pack" that promises every codec you'll ever need? Many of these packs are anybody's guess as to the actual codecs, and many people have mysterious playback problems with them, including "I can't use my XYZ footage anymore, but it worked perfectly last month..."

If your QT is not trustworthy... you can reinstall it to see if the problem clears up. And/or, you can install the excellent VLC Media Player, which plays many, many codecs and doesn't screw up your system.

Likely your encode out of Premiere is fine, this does sound like a playback problem.