RENDERING FOR DIGITAL INTERMEDIATE

K_T wrote on 5/25/2020, 9:47 PM

I am looking for the best rendering option to create a digital intermediate. I am working with archival footage, scanned in ProRes HD422 at 24p. This old footage involves considerable color correction, contrast, and sharpening. I would like to create an intermediate with little or no compression which will be used to add (a lot of) text and then used as a master to generate output formats as needed... as well as high bitrate MP4 and MOV, i hope to generate an uncompressed or lossless output which then will be used for the creation of a DCP.

working with MSP15 i can only see one option for uncompressed, Video for Windows AVI. I have run some tests, and the results are disappointing. when i A/B the original on the timeline with the AVI render, the render is soft (loss of resolution/definition), basically a loss of sharpness and contrast.

i tried adding an additional sharpening of .500 to create another render, but the improvement was minimal, still inferior to the original on the timeline.

your suggestions greatly appreciated (i have frame-grabs if useful).....

Comments

Musicvid wrote on 5/25/2020, 10:27 PM

1. Uncompressed AVI does not cause it to be "soft (loss of resolution/definition), basically a loss of sharpness and contrast," unless you have changed the resolution or frame rate from the original or added lossy effects. That is a promise.

2. Your question is an oxymoron. You want to add "considerable color correction, contrast, and sharpening," all of which are severely lossy editing procedures, then you want to save the result as lossless? 😳

Just adding a Sharpen filter in editing is more destructive than rendering to the worst possible intermediate codec you could think of.

3. If you want a lossless Archive, save the source as UT RGB (or 422 for even more compression). This gives the most manageable file sizes for editing

4. If you want to destructively edit your media in the way you suggest, it doesn't matter much how you save or store it. Common delivery codecs are good enough, and will retain plenty of quality and give you lightweight files for presentation.

5. If you eventually wish to do more judicious grading, use Unsharp Mask in place of sharpening, Levels and Gamma instead of contrast, and white balance instead of color correction; I simply can't agree with doing such destructive editing at the source level, and expecting a "lossless" result.

K_T wrote on 5/26/2020, 8:28 PM

Many thanks for your reply. Although I'm familiar with Premiere from a couple of years ago, there's much in your message that i don't understand.

Working with the ProRes HQ422 scan of the archival material, there's a fair bit of work to bring out an acceptable image. The MSP15 tools i use (Brightness/Contrast, Color Balance, HSL Adjust and Sharpen) seem to do the trick. However, as i mentionned, the render (AVI uncompressed, project setting "best") doesn't provide the WYSIWYG that i expected, particularly regarding sharpness and contrast.

Apparently, from your comments, these tools are severely lossy and "destructively edit your media". This seems strange to me. Why would Vegas tools be included that are destructive to the process? After achieving a good image on my edit (preview/best/auto), why do these tools not result in an accurate AVI render?

Using the Sharpen filter is seemingly a big mistake. I'm unfamiliar with the Unsharp Mask you suggest, however Sharpen does get the result i'm looking for quite easily. Is there a way to use it that isn't destructive?

Finally, i tried looking into your UT RGB file suggestion, but couldn't find it within MSP15. Where do i look?

Overall, perhaps i've been given the wrong advice. I was told that a project that builds on several renders (in this case, probably 3 with the last one our "master), it was best to use an uncompressed file type as an intermediate. Many codecs apparently compress, and compress again with each render/edit cycle. Perhaps MSP15 has such an "intermediate" that i should choose for the renders, a codec that is not recompressed each time?

i apologize for my confusion, and appreciate any suggestions...
KT

Former user wrote on 5/26/2020, 8:49 PM

AVI, like QT contains many codecs. Which AVI codec did you use for the render?

Musicvid wrote on 5/26/2020, 9:37 PM

@K_T

Welcome to the learning curve. All conventional video filters are destructive. The ones you name are among the worst at stealing something called bit depth. Once it's gone, it's gone, and can't be restored. Rendering "lossless" makes not a gnat's ass worth of difference at that point.

I suggest you learn to make a visually lossless intermediate first, and pack away the six-guns for now . There is absolutely nothing wrong with the ProRes codec; if you will upload an original example of your source to Drive or Dropbox, we may be able to help you make some more informed grading choices without resorting to such incendiary methods.

UT is a VFW AVI codec that you download and install separately. You can see that it is much smaller than uncompressed. You can also see that Uncompressed AVI is 100% mathematically lossless RGB 4:4:4, so your lingering remarks of less "sharpness and contrast" are caused by something else, not the codec. Maybe you could make that a topic of a separate thread, if it still seems that way to you, or if you are unsure how to match render-to-source properties, which may be the case here.

We encourage you to begin your learning curve here:

https://www.vegascreativesoftware.info/us/forum/speaking-good-video-a-beginner-s-guide--104463/

https://www.vegascreativesoftware.info/us/forum/new-users-consult-the-tutorials-first-please--118014/

K_T wrote on 5/26/2020, 11:58 PM

Render in the following format:

Video for Windows HD1920-1080 using Sony YUV codec, Open DML compatible

pixel aspect ratio: 1.00 format: uncompressed interleave 0.250 create Open DML

K_T wrote on 5/27/2020, 12:12 AM

thank you for your advice.
just to be clear, putting aside the destructive tools, is AVI uncompressed my best choice within MSP for an intermediate that can be survive several edits and renderings without undue visual degradation or artifacts? do i have that part right? use AVI uncompressed to get to a final "master", then generate what is needed from that, or would you recommend something else?