02-17-2016, 07:35 AM
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Join Date: Jun 2011
Posts: 40
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I have another question for you all. I am working on a project where I have to re-edit video that has been taken from a commercial Blu-ray disc, which naturally means I have to re-encode the video after the editing is completed. I understand that HD video taken from Blu-ray discs has already been compressed from the original, so having to re-encode a second time is not ideal but I have no choice in this situation. If I carefully choose the best settings in TotalCode Studio and choose a healthy bitrate, I can't really notice any quality decline compared to the original. Furthermore, I have done some color correction and restoration to the footage which makes a much bigger difference to my eyes regardless of whatever loss there is with compressing already compressed HD x264 video.
Anyway, I am not sure of the bitrates I should use for a project like this. I'm really picky about quality and I want to have the best quality I can. I'm using BD50 discs for authoring, but I've got almost three hours of video plus quite a few audio tracks so I am getting close to the maximum capacity.
My video encodes are currently between 20 and 22 Mb/s. Is this enough? Could I go even lower, to say 18 or 19 without any noticable difference?
I guess my thinking is that if you have to re-encode already compressed footage, you might need to have higher bitrates than you otherwise would to reduce a further noticeable quality reduction. If you started with a pristine uncompressed source, you might be able to get away with a lower bitrate without a noticeable difference.
I am just guessing however and I'd like some expert advice on the matter.
Thanks.
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Someday, 12:01 PM
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02-17-2016, 12:21 PM
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Join Date: Aug 2009
Location: N. Carolina and NY, USA
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Quote:
Originally Posted by jrodefeld
I have done some color correction and restoration to the footage which makes a much bigger difference to my eyes regardless of whatever loss there is with compressing already compressed HD x264 video.
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You can't color correct or make other image modifications to encoded video without re-encoding.
Just a minor correction here: "x264" is not a codec. It's an encoding engine, with many different implementations in different apps. The codec is "h.264", not x264.
Surprised to see that a BD video has image problems, but it does happen. For simple, frame-specific cuts without re-encoding I alays use one of two apps:
- VideoReDo TVSUite 5
- TMPGenc Smart Renderer (for MPEG, BluRay, AVCHD, mkv, mp4, other formats. Stop The Re-encoding Madness.
Color correction, denoising, etc., means re-encoding. Period. Cleanest way is to decode to lossless media, clean up, then encode properly. If you're using a laptop, a small hard drive, an "editor" that doesn't decode and re-encode cleanly, you're in trouble.
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02-18-2016, 04:12 PM
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Remembered
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Join Date: Aug 2013
Location: Switzerland
Posts: 453
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Quote:
For simple, frame-specific cuts without re-encoding I alays use one of two apps
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VideoReDo TV Suite 5
Xilisoft Video Cutter 2
previously I worked with Machete
http://www.machetesoft.com/
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04-26-2016, 04:46 AM
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Site Staff | Video
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Join Date: Dec 2002
Posts: 13,508
Thanked 2,449 Times in 2,081 Posts
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Quote:
Originally Posted by jrodefeld
I have another question for you all. I am working on a project where I have to re-edit video that has been taken from a commercial Blu-ray disc, which naturally means I have to re-encode the video after the editing is completed. I understand that HD video taken from Blu-ray discs has already been compressed from the original, so having to re-encode a second time is not ideal but I have no choice in this situation.
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Quality encodes, from quality content/footage, can withstand a few re-encodes with no perceived loss.
Quote:
If I carefully choose the best settings in TotalCode Studio and choose a healthy bitrate, I can't really notice any quality decline compared to the original. Furthermore, I have done some color correction and restoration to the footage which makes a much bigger difference to my eyes regardless of whatever loss there is with compressing already compressed HD x264 video.
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That's not uncommon, and how things should be!
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Anyway, I am not sure of the bitrates I should use for a project like this. I'm really picky about quality and I want to have the best quality I can. I'm using BD50 discs for authoring, but I've got almost three hours of video plus quite a few audio tracks so I am getting close to the maximum capacity.
My video encodes are currently between 20 and 22 Mb/s. Is this enough? Could I go even lower, to say 18 or 19 without any noticable difference?
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It really depends on what you're seeing. Some content is fine, while others will need max bitrates.
Quote:
I guess my thinking is that if you have to re-encode already compressed footage, you might need to have higher bitrates than you otherwise would to reduce a further noticeable quality reduction. I
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Not necessarily, especially when restoration is involved.
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f you started with a pristine uncompressed source, you might be able to get away with a lower bitrate without a noticeable difference.
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That's not necessarily true, either. Sometimes the uncompressed source has too much noise, and needs to be processed for disc encoding.
Quote:
Originally Posted by sanlyn
Surprised to see that a BD video has image problems
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Pffft, not me. As I recently wrote on VH, several labels quit sending me discs to review, because I'd ping them for visual quality. Too many BD have excessive noise, as the source wasn't properly cleaned for the format. So you get problems, including both broadcast master noise (rarely film) and encoding noise.
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