Will I see a loss in quality if I re-render ?

FoskeyMedia wrote on 12/2/2015, 12:33 PM
I have a file...took about 4 hours to render. I need to make a minor audio change. If I make it to the rendered file will I see a drop in quality ? I'm guessing this would be quicker than doing the render all over again, but not worth it if there's be a change in quality.

(I'm presuming not with digital...but thought I'd ask the experts).

Comments

rs170a wrote on 12/2/2015, 1:53 PM
What's the file type? I've re-rendered MXF and XAVC files and the difference between the two was impossible to tell with my eyes.

Mike
Chienworks wrote on 12/2/2015, 1:57 PM
It's not that it's digital. It's that it is probably compressed. Using the rendered file then in order to do the fix Vegas will have to decompress and recompress the data. The recompression will lose quality. How much it loses depends on many factors, and may be an amount small enough to not worry about.
musicvid10 wrote on 12/2/2015, 2:10 PM
It's quite possible to remux the audio without recompressing the video.
File properties, please.
videoITguy wrote on 12/2/2015, 3:18 PM
The OP's quest is not specific enough to make a judgement of the process and the desired outcomes sought.

For the impact of the thread subject title, there are many render processes that are not discernible production of differences seen by the unaided eye of the viewer. All depends on the source file type, and the codec encoding.
For example if we use a DI type of codec like Cineform, you could render 5 generations away and still be lossless. Another codec that works even better than that is MagicYUV which is a lossless codec by design.
FoskeyMedia wrote on 12/2/2015, 7:11 PM
The original source matieral is a combination of .mov (avc). THe majority of the footage is .mts (avc) with a few .mp3, .jpg, and generated graphics (NewBlue).

It was rendered to MP4 Internet HD 1080p using the MainConcept AVC/AAC codec.
musicvid10 wrote on 12/2/2015, 7:30 PM
You can remux the audio without affecting the mp4 in Yamb.
May have to adjust the sync delay some.

Byron K wrote on 12/5/2015, 6:25 PM
Thanks Musicvid, I was curious about YAMB (Yet Another MP4 Box) that you mentioned and noticed that it can lossless covert .flv to mp4 also! You'll have to use another app to separate the .flv video from the audio and then use YAMB to rejoin them in an mp4 container.

I have been doing this with other apps but they always loose a little bit of quality in the conversion.

Thanks again! (:
Byron K wrote on 3/19/2016, 4:22 PM
Moved topic to new thread
http://www.sonycreativesoftware.com/forums/showmessage.asp?forumid=4&messageid=941428