18 Replies Latest reply on Aug 10, 2008 12:51 PM by shooternz

    Need some help please - Several Questions

      Hi,

      I'm working with uncompressed 8-Bit UYVY and YUY2 4:2:2 video. So with that in mind, I have several questions.

      1st. In the Premiere export settings, under Microsoft AVI and in the compressor tab, it lists Uncompressed UYVY 422 8bit. So that takes care of UYVY. However, I don't see anything for YUY2. Should I just select "None"? Does that output uncompressed RGB? If not, how can I output YUY2?

      2nd. Under "Data Rate", what does the "Recompress" option do? With it on, you can select "maintain data rate" or "always". Should I leave that off? I'm already working with uncompressed video, do I need that? I'm looking to output uncompressed lossless video.

      3rd. Keyframe and Rendering -> Rendering Options -> Bit depth. Should I use 8-Bit or Maximum here? Does the 8-Bit stand for 8-Bit Video? The thing is I also have an custom designed image at the start and end of the video, would that lower the quality of the image? Should I set it to Maximum?

      4th. Is Optimize Stills a good thing to leave enabled? I only have one still image at the start and end, the rest is video. However, I do have a video overlay on the image. Should I Optimize Stills on or off?

      5th. Does Audio Interleave at a buffer before the audio starts? Like say for one second or one frame before the audio starts?

      6th. What does Title Safe Area and Action Safe area do? It is set to 20% for horizontal/vertical, but does that mean if I was to try and output a 1280x720 video it would add a black border of 20% on all sides of the video?

      Thank you.
        • 1. Re: Need some help please - Several Questions
          Jim_Simon Level 8
          1) Here's the thing. To the best of my knowledge, while Premiere can successfully ingest several kinds of color space videos, most of it's processing is done only in RGB mode. I found this out when some colors from DV source changed on me as soon as I added most any effect, whether or not I changed any of that effect's parameters. Simply adding the effect changed the color space Premiere was working in from the native YUV of DV to RGB. That change in color space caused the color shift, and nothing I did would bring it back.

          The point here is that if any affects are added to your video, Premiere has probably already shifted to the RGB color space, so you may as well keep it that way for export, rather than shifting it back to YUV causing further degradation.

          2) Leave it off.

          3) For your source, you can probably just leave it at 8.

          4) Turn off Optimize Stills. That setting can cause issues.

          5) No. Interleave is just combining the video and audio.

          6) Dude, this is Video 101 stuff. How does someone working with your source not know this already?
          • 2. Re: Need some help please - Several Questions
            Level 1
            Was asking to be sure.
            Since I was making a post, thought I ask everything.

            The main Premiere video effect I will be using is Luma Key and some opacity. Anyway, I take you mean to select "None" for the compressor, since there is no RGB output setting. How much degradation is being done when going from UYVY/YUY2 to RGB on export?

            When you say "probably just leave it at 8", that setting referred to video bit-depth?

            Thanks
            • 3. Re: Need some help please - Several Questions
              Jim_Simon Level 8
              "None" will give you Uncompressed RGB, I believe. I don't know how much degradation there will be going out to a YUV color space. Maybe none that you can notice at all. It's just something I thought you should be aware of.

              8 does refer to the bits/color channel. If your video starts at that, I see no benefit bumping it up to 10.
              • 4. Re: Need some help please - Several Questions
                Level 1
                The video input would be UYVY or YUY2. With "None", it would be going to RBG. That is what I meant for input/out and if there would be degradation in that case.

                I found a few topics on google where is says that DV Codec is supposed to be YUV, but not sure if that is true.

                Looking at the export settings, you can select Uncompressed Microsoft AVI and then it allows you to select "10-bit YUV (4:2:2 YUV)" or "8-bit YUV (4:2:2 YUV)" as the compressor.

                So I guess that would be a as close as you can get to YUY2. However, when I tried to feed the exported video into my encoder, it returned a can't read video error. So I'll have to try again.
                • 5. Re: Need some help please - Several Questions
                  Jim_Simon Level 8
                  >With "None", it would be going to RBG.

                  Sort of true. With the added Luma Key, it's converted to RGB. Exporting to RGB is simply keeping it that way. Going out to YUV will again change the color space. Whether or not you will notice any quality difference I leave to your eyes.

                  DV is a YUV format, 4:1:1 for NTSC, and 4:2:0 for PAL.

                  >you can select Uncompressed Microsoft AVI

                  That setting is only for use with the AJA Xena card. If you don't have that card, choose Microsoft AVI and select the compression on the Video tab.
                  • 6. Re: Need some help please - Several Questions
                    shooternz Level 6
                    @ OP

                    Not sure if you really supply enough info in regard to your questions

                    Base info missing for me is what exactly are your original media files and what are you exporting for?????

                    There can be many reasons to use different Color Spaces and I certainly export using different color spaces (and bits) to facilitate workflows with other facilities. Often Cross platform.

                    I doubt you or anyone can see the difference.

                    Note: AEFX is YUV Space and Premiere is a RGB space. Files play very nicely between them wouldnt you agree.

                    I also use Uncompressed Microsoft AVI for the same reason and I do not have an AJA Xena card.

                    Q.6 : No. Beware Safe areas for HD (16:9). I do not think they mean anything at all . (Redundant function)
                    • 7. Re: Need some help please - Several Questions
                      Jim_Simon Level 8
                      After Effects can work in several different color spaces as determined by the Project Settings.

                      >I also use Uncompressed Microsoft AVI for the same reason and I do not have an AJA Xena card.

                      You seem to be the only one. Seems like everyone else who tries it without the card has the expected issues.
                      • 8. Re: Need some help please - Several Questions
                        Dan Isaacs Level 2
                        > After Effects can work in several different color spaces as determined by the Project Settings

                        After Effects is RGBA from end-to-end. No YUV at all. Any YUV sources are converted to RGB on import: That conversion is controlled by the color profile / project settings. Not a single filter in AE supports YUV and all output is done as RGB(A).

                        Premiere supports both RGBA and AYUV internally, but most filters are RGB(A) only and force a conversion. All output via AME is converted to RGB first, then to YV12 or YUY2 as required by the output format. I am not certain about .AVI export, but I suspect it works the same way.
                        • 9. Re: Need some help please - Several Questions
                          Jim_Simon Level 8
                          I can't contradict you definitively, but your assertion does contradict my understanding of the Help file. So either you're incorrect, or my understanding of the Help file is incorrect. I'm inclined to believe the later, but I still have to ask for your source on this one.
                          • 10. Re: Need some help please - Several Questions
                            Dan Isaacs Level 2
                            > ...I still have to ask for your source on this one

                            Just observation, really. There are no YUV histograms, no YUV options on Output Module settings, all YUV sources I import get clipped to IRE 100, none of the filter reference YUV channels (other than "luminance", but that's calculated from the RGB values).

                            From AE CS3's Help file:

                            Adobe After Effects works in the RGB (red, green, blue) color space. Adobe Premiere Pro, however, works in the YUV color space. When you work with a dynamically linked composition, Adobe Premiere Pro either converts it to YUV or retains the RGB color space, depending on the output format.

                            Fairly unambiguous, I'd say :)
                            • 11. Re: Need some help please - Several Questions
                              Level 1
                              Thanks for the information.

                              The reason I was asking about the "Title Safe Area and Action Safe" areas is because I've been trying to output a video as 1276x716, but for some reason, based on export codec, I have either four pixels of black on the right side or distortions on the right size. Has anyone ever had this kind of problem with Premiere? What ever the case, I end up with 1276x716 video, but with 1272x716 of visible pixels.

                              In the case of Luma Key is for one of the two videos, so the other video would remain UYVY/YUY2, unless it converts on input. Below is my basic workspace setup.

                              Video Overlay (Luma Key)
                              PSD Image Overlay (Opacity)
                              Video (UYVY/YUY2)
                              Audio
                              • 12. Re: Need some help please - Several Questions
                                Harm Millaard Level 7
                                Odd frame size. Normal would be 1280x720.
                                • 13. Re: Need some help please - Several Questions
                                  Level 1
                                  Yes, not mod16. But in this case, the video's "visible" pixels works out to 1276x716, so I'm trying to export that. However, exported 1276x716 ends up with 1272x716 of visible pixels.

                                  Edit:
                                  Just to be clear, the video that I input, is 1276x716. But when I try to export 1276x716, I get problems. It plays fine before I import to Premiere.
                                  • 14. Re: Need some help please - Several Questions
                                    Jim_Simon Level 8
                                    Where did you get such a weird video frame?
                                    • 15. Re: Need some help please - Several Questions
                                      Level 1
                                      The video is 1280x720, but the "visible" pixels after crop works out to 1276x716.
                                      • 16. Re: Need some help please - Several Questions
                                        Jim_Simon Level 8
                                        Why crop? 1280 x 720 is the standard. Why not leave it that way?
                                        • 17. Re: Need some help please - Several Questions
                                          Level 1
                                          Because two pixels on each side are black/useless.

                                          Found a fix though, just not sure how much quilty loss there will be.
                                          It seems I'll have to do this:

                                          UYVY -> RGB24 -> YV12
                                          Raw | Premiere | Encoder
                                          • 18. Re: Need some help please - Several Questions
                                            shooternz Level 6
                                            >Note: AEFX is YUV Space and Premiere is a RGB space. Files play very nicely between them wouldnt you agree.

                                            Oops ...my bad...I got them around the wrong way. Sorry to mislead