1DC: is there any disadvantage to transcoding 1DC Mjpeg footage to 4K Pro Res LT???

N

Nicholas Natteau

Veteran
I was thinking of transcoding my 41DC K Mjpeg footage to 4K Pro Res LT to save hard drive space.
But would this cause any problems when it comes to color correction?
Would it degrade the image to transcode to Pro Res LT???

The appeal of doing this for me came when I discovered that Pro Res LT is only 300 Mbps as opposed to 500Mbps.
Is there a noticeable difference in quality between LT and regular Pro Res or Mjpeg???

Thank you in advance.
 
The best answer, by a large margin, is that you test it and decide for yourself.

This is from the ProRes white paper:

Apple ProRes 4444 XQ: The highest-quality version of Apple ProRes for 4:4:4:4 image sources (including alpha channels), with a very high data rate to preserve the detail in high-dynamic-range imagery generated by today’s highest-quality digital image sensors. Apple ProRes 4444 XQ preserves dynamic ranges several times greater than the dynamic range of Rec. 709 imagery—even against the rigors of extreme visual effects processing, in which tone-scale blacks or highlights are stretched significantly. Like standard Apple ProRes 4444, this codec supports up to 12 bits per image channel and up to 16 bits for the alpha channel. Apple ProRes 4444 XQ features a target data rate of approximately 500 Mbps for 4:4:4 sources at 1920 x 1080 and 29.97 fps.

Apple ProRes 4444: An extremely high-quality version of Apple ProRes for 4:4:4:4 image sources (including alpha channels). This codec features full-resolution, mastering-quality 4:4:4:4 RGBA color and visual fidelity that is perceptually indistinguishable from the original material. Apple ProRes 4444 is a high-quality solution for storing and exchanging motion graphics and composites, with excellent multi generation performance and a mathematically lossless alpha channel up to 16 bits. This codec features a remarkably low data rate compared to uncompressed 4:4:4 HD, with a target data rate of approximately 330 Mbps for 4:4:4 sources at 1920 x 1080 and 29.97 fps. It also offers direct encoding of, and decoding to, both RGB and Y’CBCR pixel formats.

Apple ProRes 422 HQ: A higher-data-rate version of Apple ProRes 422 that preserves visual quality at the same high level as Apple ProRes 4444, but for 4:2:2 image sources. With widespread adoption across the video post-production industry,Apple ProRes 422 HQ offers visually lossless preservation of the highest-qualityprofessional HD video that a single-link HD-SDI signal can carry. This codec supportsfull-width, 4:2:2 video sources at 10-bit pixel depths, while remaining visually lossless through many generations of decoding and reencoding. The target data rate ofApple ProRes 422 HQ is approximately 220 Mbps at 1920 x 1080 and 29.97 fps.

Apple ProRes 422: A high-quality compressed codec offering nearly all the benefits of Apple ProRes 422 HQ, but at 66 percent of the data rate for even better multi stream, real-time editing performance. The target data rate of Apple ProRes 422is approximately 147 Mbps at 1920 x 1080 and 29.97 fps.

Apple ProRes 422 LT: A more highly compressed codec than Apple ProRes 422, with roughly 70 percent of the data rate and 30 percent smaller file sizes. This codec is perfectfor environments where storage capacity and data rate are at a premium. The targetdata rate of Apple ProRes 422 LT is approximately 102 Mbps at 1920 x 1080 and 29.97 fps.

Apple ProRes 422 Proxy: An even more highly compressed codec than Apple ProRes 422 LT, intended for use in offline workflows that require low data rates but full-resolution video. The target data rate of Apple ProRes 422 Proxy is approximately 45 Mbps at 1920 x 1080 and 29.97 fps.


Note: Apple ProRes 4444 XQ and Apple ProRes 4444 are ideal for the exchangeof motion graphics media because they are virtually lossless, and are the onlyApple ProRes codecs that support alpha channels.
 
Last edited:
Hi Andreeonline. Thank you for that info. Via MPEG Streamclip, I just transcoded a bunch of old 1DC 4K files to 4K ProRes LT, and I couldn't tell the difference, though I'm no expert. Perhaps others might notice a difference in quality, but to me they look absolutely identical. I'm now transcoding to Proxy and they look just as good.
 
Last edited:
Are you a photoshop user? Grab the identical frame from a mjpeg clip and a converted clip. It has to be the exact frame. Put the two images on two different layers in photoshop and then set the top layer to the 'difference' mode.

An all black result would mean the two images are identical. Sometimes the result looks black, but isn't really. Apply the levels command and reduce the white input slider towards the shadows. This increases the contrast of artefacts and eventually you'll see the small differences.

But if you don't see anything at all before applying the levels commands, the visual differences are small. Still, they might show up in grading.

I convert all my 1Dc footage to ProRes 422. I replace my originals, so I don't want to skimp. ProRes LT might be fine for personal projects. I wouldn't go with Proxy to replace any footage. It's great for portability, but might show visual artefacts by just looking at the footage.
 
I see Andreeonline. Thank you very much for those tips. Yes I do use Photoshop frequently, and I'll be sure to test this. Thanks again.
 
Last edited:
Storage is becoming cheaper with each passing day. Why compromise?

How many TBs of 1DC footage do you have?
 
AndyHood said:
You do that in FCPX or you use an other software?
Click to expand...

CF card into card reader, FCPX-->import ('optimize media' is already checked since I did it last time too), start working with 4k source while still at CF-card being imported (organizational tasks, light skimming). When I see the import/background render is complete, I replace my 'original media' with the 'optimized media (high quality)'.

At least that's how I used to do it. Can't beat FCPX for ProRes conversion in my eyes.

Now I'm trying a different workflow where I keep my originals outside my FCPX library. In this scenario I only create proxy media (FCPX generates 2k proxy files), not 4k ProRes files. The advantage is a very light library (despite 4k sources) that I can put on any laptop and still work at full speed. When I'm happy with my sequence I just reconnect to 4k sources and export xml to resolve.
 
AndreeOnline said:
CF card into card reader, FCPX-->import ('optimize media' is already checked since I did it last time too), start working with 4k source while still at CF-card being imported (organizational tasks, light skimming). When I see the import/background render is complete, I replace my 'original media' with the 'optimized media (high quality)'.

At least that's how I used to do it. Can't beat FCPX for ProRes conversion in my eyes.

Now I'm trying a different workflow where I keep my originals outside my FCPX library. In this scenario I only create proxy media (FCPX generates 2k proxy files), not 4k ProRes files. The advantage is a very light library (despite 4k sources) that I can put on any laptop and still work at full speed. When I'm happy with my sequence I just reconnect to 4k sources and export xml to resolve.
Click to expand...

Two questions on this (im new to fcpx :))

So when you mean " I replace my 'original media' with the 'optimized media (high quality)'." Do you manually delete your "original media" and keep working with the optimized? or does fcpx have an option that once the "optimized media" is created to dump out the original media? if so where is that option located?

on your new workflow, when you create the 2k proxy files and work on your "project" and create your timeline and so on.. and Let say for some reason you want to export that but want the 4k files not the 2k proxies; once you reconnect the 4k files does the media downscales to 2k seamlessly at export? or I need change the project settings to accommodate the 4k files/different media size?

I hope what i asked makes sense.

Thanks in advance.
 
Hi Edry,

I should say, normally you wouldn't replace the original media of course. I only do this so that I don't maintain two full size 4k files for each clip when working, and because the 4k ProRes is a more flexible master format going forward. I haven't felt the need to keep the original .mjpeg.

My procedure is right click and 'show contents' of the FCPX library, then navigate to the high quality ProRes render files. I then drag those into the 'original media' folder, replacing the original clips that have the same file names. After that, FCPX treats those clips as original media. And since they are ProRes already, FCPX won't generate new optimized files after that. There is no option in the software to do this.

Your project setting will determine your output file size. If you have 4k source material and edit in a 2k or HD project, FCPX will always reference the high quality 4k files on export, but the exported file will of course be 2k or HD depending on your setting.

Proxy workflow is fully supported and the necessary files are generated by FCPX on import or after the fact. They can be deleted when no longer needed.

If I edit from a library in proxy mode, I can still export from it, but it will reference the proxy material. This is good for drafts, maybe dailies and stuff like that. It's a very portable way to carry files around and nice to work off of on a lesser computer or notebook.
When you want to export based on the 4k sources you just flip a switch in FCPX (top right of the program monitor) and select 'original/optimized' instead of 'proxy'. Now FCPX uses that material instead, both for editing and export.

Regardless of proxy/original setting, you don't have to change your actual project setup or sequence settings.
 
Nice, thanks for sharing the info! despite what people say I think fcpx is bit underrated, i'm coming from premiere and i'm actually quite liking fcpx way more seems more "modern" way to deal with things its awesome!
 
You must log in or register to reply here.
Back
Top