Demux/Remux DNxHD and ProRes 422 HQ?

[Wayne Waag]

Since DNxHD is in an mov container (I think), you could try FFmpeg. I remux MP4 files with a new audio track all the time. If you’re on a Windows machine, I’d stay away from ProRes that was encoded on a Mac, if at all possible.

wwaag

[John Rofrano]

I believe you can replace the audio track using QuickTime 7 Pro. I also found this utility for Mac called QT Edit that can do this. I’ve never use this tool but the blog post in the link explains how.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Michael Gibrall]

Thank you both for the tips. I’ll look into this later.

John, will I be able to use Quicktime Pro 7 to do the remux on a PC? Or would I be restricted to doing it on a Mac, since ProRes is Mac specific?

Thanks in advance.

[John Rofrano]

I haven’t tried it but you should be able to use a PC even for ProRes because you are not encoding. You are just copying the video stream from one file to another adding a different audio stream. Muxing doesn’t involve encoding so it should work. If not, then I guess you would need to do the ProRes remux on a Mac.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Michael Gibrall]

Thanks, John.

I am assuming I can use my aiff stereo file, 48khz 24 bit file just fine?

[John Rofrano]

[Michael Gibrall] “I am assuming I can use my aiff stereo file, 48khz 24 bit file just fine?”

AIFF is the native audio format on the Mac so yes, it’s perfectly fine for use in QuickTime.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Michael Gibrall]

Wayne, thank you. I successfully encoded using ffmpeg and made a new dnxhd file with the added audio file. It took me a little while to understand the command line commands, but it worked great!

[Wayne Waag]

[michael]
Glad it worked for you. It does take awhile at first, but it’s a very powerful and useful bit of software to keep in your toolbox.

wwaag

[Michael Gibrall]

John,

I actually gave FFMPEG a try on my PC with the ProRes 422 HQ file, since I was able to demux and remux a DNxHD file successfully. (And free is hard to beat.)

I got it to work.

I have played the file back with a Quicktime Player on both a PC and a Mac without issue, had it imported into Sony Vegas Pro 12 on my PC without a hitch, had it accepted into Adobe CS4 on a MAC (it initially was shown with digital breakup for a split second as the file was first called up, then it went away. It played back normally in Adobe CS4 and I had no trouble jumping back and forth on the file, randomly playing it back on the timeline.)

When using FCP, here’s what it did…

When I selected the file in Finder and said OPEN WITH FCP, it did just that, without a problem, and played back normally.

When I was in FCP and ‘imported’ the file, I got the following notice from FCP:

“The following media files are not optimized for Final Cut Pro.

It is highly recommended that you either recapture the media or use the Media Manager to create new copies of the files to improve their performance for multi-stream playback.”

“The ProRes 422 directory and filename”

That being said, the file played back normally, and I was able to go anywhere I wanted to on the timeline without issue.

Should I worry, or is this just one of those “Hey, he didn’t use FCP to compile this file” things?

Thanks in advance.

[John Rofrano]

[Michael Gibrall] “Should I worry, or is this just one of those “Hey, he didn’t use FCP to compile this file” things?”

FFMpeg does not contain a “licensed” encoder for ProRes. It’s a “hack” that was “illegally” created by reverse engineering the real encoder but the country that the developer lives in doesn’t honor international patents so the author will never be prosecuted for it. It’s up you as to whether you want to give your clients files that were created by an unlicensed encoder. The fact that Apple software flagged this file as not being ProRes compliant tells the whole story, i.e., it’s not a “real” ProRes file and it has caused performance problems when working with them in a project.

Whether you worry about it or not is up to you. If you are giving this file to a post production house and they are going to charge you real money to re-encode it before they work with it… then I would worry. If you don’t care that it’s “fake” ProRes and no one you give it to cares either… then don’t worry.

Personally, I would be embarrassed to give my clients files that were not encoded by a licensed encoder. Your mileage may vary. 😉

~jr

http://www.johnrofrano.com
http://www.vasst.com