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Editing in Higher Bit depths or maximizing 8bit H.264 quality
Hi
In a previous post I was told ‘If you want to edit 8 bit footage in 10-bit, you can override the default sequence settings, ‘ok, but how? In the sequence settings there is only a ‘Preview’ section with checkboxes for maximum render quality and bit depth.
Do I first need to transcode my footage to a higher bit depth BEFORE importing and applying effects?
The moment I increase saturation in my H.264 footage, which uses a flat picture profile, I see VERY visible blocky artifacts. I want to remove (or at least suppress) these.
I’ve also seen demos where people suggest to transcode all your footage to a higher bit depth Cineform or ProRes format and apply some dithering to .
Can anyone share their tips for maximizing the quality of 8bit footage?
Local is the new global
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4 Replies
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Using the Saturation slider in the ColorBalance HLS effect seems to give VERY poor results.
If instead I boost the saturation the same amount using Magic Bullet Looks I see none of these artifacts. Why??Local is the new global
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Ok, answering my own thread, but obviously its because it is an 8bit effect. Should ONLY use those effects marked 32.
So does this mean PPro automatically works in a 32 bit color space the moment you apply a 32bit effect?
And wouldn’t some slight dithering noise be a good first step to reduce banding?Local is the new global
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You are correct – Premiere works in this higher-than-8 bit color space called 32bpc, but only if the footage and effects are compatible with it. An h.264 sequence won’t default to showing you a true 10-bit colorspace in the timeline, however. To override this, go to the sequence menu, and select sequence settings. At the very bottom, check the Maximum Bit Depth checkbox. You can also choose the preview codec here as well (for true 10-bit, pick a V210-compliant codec (I have an AJA Kona, so I can pick one of theirs, for instance. To save HD space, this is where Cineform comes in handy). You can increase preview render quality as well (bear in mind, this is always on if Mercury Engine is being hardware-accelerated). Regardless of what you do in the timeline, you can change any of these settings when you’re ready to output.
Increasing bit-depth significantly increases RAM usage. You’ll be hurting if you have less than 12GB.
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I’d add to Chris’s very good explanation that for the best experience with high bit depth editing, a custom sequence setting is helpful as you’ll have better access to options for preview render formats, etc.
In CS5, a 32 bit float sequence will be truncated to 8 bits with the use of any 8 bit effect on any one clip…in CS5.5, Adobe improved the intelligence of that process so that it will use 8 bit where forced to and will use 32 bit float where it can if the sequence supports it.
(Keep in mind that 8 bit effects also convert their calculations to RGB if there is no “YUV” symbol beside the effect in the list.)
TimK,
Director, Consultant
Kolb Productions,Adobe Certified Instructor
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