6 Replies Latest reply on Oct 11, 2012 3:59 PM by Bernie at Clarity

    Video noise in exported blu-ray

    Bernie at Clarity Level 1

      Hi - I don't know where to start with this one. I exported a project from PPro to Encore for menus, etc, and built a blu-ray ISO image. So far, so good. I burn a BD-R from that image using imgburn, then I took the disc upstairs to watch it on the big screen, and YUCK!

       

      Before I go on, here's the details:

       

      Win 7 Pro SP1

      Core i5

      8GB memory

      200 PATA for OS, programs,

      500GB SATA for media

      500GB for scratch disc, etc

      1TB e-sata for backups

       

      Production Premium CS5.5

      PPro 5.5.2

       

      i have CS6 waiting, but I want to finish this project before installing CS6.

       

      ~2 hour film of a stage musical production, plus a bit of behind-the-scenes/backstage stuff

      Footage from 2 x Sony Z1P cams (1440x1080 1.33 HDV), and 1 x Canon XF300 (1920x1080 1.0 - I think it uses XDCAM)

       

      Due to the nature of the stage lighting, i.e. lots of deep colours, this footage needed a great deal of colour correction and frequently needed big boosts to brightness. I mainly used the RGB colour corrector, as it was easy to boost or reduce the red, blue and/or green gain to get a reasonable result. I was mostly trying to return skin tones to something resembling human, and leave the rest of the colours alone. Sometimes I needed to use "Change to colour" because the lighting crew used a different colour backdrop from one night to the next

       

      I used brightness and contrast adjustments to start, and played around with gamma and overall gain to fine tune the brightness. Also had the reference monitor on display - mostly RGB but also YC waveform.

       

      Anyway, playback in PPro looked OK, I thought it was as good as it was going to get, so I added chapter markers, exported to Encore, built the menus, FINALLY got a clean bill of health from "Check project", built a blu-ray ISO image on the hard drive, then burnt a BD-R for testing.

       

      Took it upstairs to the lounge room (where the blu-ray player, big screen and audio systems live), loaded and started to play. The menus look and work OK (buttons, scene selections, etc). Here's the strange parts:

       

      1. the footage from the Canon and ONLY the Canon, appears to have had a lot of noise ADDED (video noise, not audio). This was the first time I used this camera, and I noted that when light levels got really low, the auto gain control kicked in, but it also got very noisy, so I had to decide to limit the AGC, take underexposed footage and "fix it in post". Now it looks OK on my monitor (ASUS 24" 1920x1080), only a little bit of noise that I can put up with but when played back on the blu-ray player and big screen, it looks ridiculous.

       

      2. some footage from one of the Sony cams is way over-bright - that's something that I can easily correct.

       

      I matched brightnes and colour from the 3 cameras as best I could, and it looks OK in PPro on the program monitor, but looks awful when exported and played via the blu-ray player to the big screen. I put the same disc in the blu-ray drive on my computer and watched the film on my monitor, and it looks OK. I mounted the ISO as a disc, and watched that with VLC, and it looks OK.

       

      I took one section of "noisy" video, approx 60 seconds, and exported it 3 times, playing around with bit rates and noise reduction settings. The uncorrected export was very noisy, and each of the 2 "corrected" versions are improvements, but all of them are very noisy compared to the same footage previewed in PPro.

       

      The export setting "use previews" was unchecked, so presumably it re-rendered everything for the build.

       

      Where should I look to identify the place where the video noise is being added or exacerbated? It's ONLY on the Canon footage, so could it be a codec issue? I started to play with the footage in After Effects, but I haven't had a lot of experience with AE yet.

       

      cheers

      Bernie Dwyer