Dave Clark.com

In these couple of posts I’m going to go over how we do HD video at NCC. I’ll try and keep it technical enough to satisfy you techno-geeks out there and non-technical enough so the rest of us can understand it. I’ll also use lots of links to product pages and wikipedia, a great resource for learning some of the technical stuff. Feel free to post any questions or suggestions in the comments

It all starts with the camera. We use a Canon XLH1 mounted on the ceiling at Ebenezer’s. The mounting does involve a level of adjustment so we can re-aim the camera for different speakers. Unfortunately, we currently can’t do any camera movements during service and only have the one camera that we use for the video message. The camera has a HD-SDI output that sends out uncompressed HD signal that we run up into Pastor Dave’s office. We’ll probably never use the tape heads in the camera as we get such a high quality signal from the SDI out.

In his office he has a beast of a machine. PD uses a quad 2.5 GHz processors Mac G5 with 8Gig of memory. (It’s where all our HD editing and rendering is done.) His main monitor is a 30in cinema display and he has a Toshiba 27in LCD TV that is connected as a secondary display on which we can preview the shot. We are able to evaluate the camera shot from PD’s office before service so we can adjust the camera shot, light levels, white balance and get a pretty good idea of what the shot looks like.

We use a Blackmagic HD PCIe card, the DeckLink HD Pro PCIe, that has an SDI in and allows us to capture full uncompressed 10bit, 1080i with 4:2:2 chroma sampling. Using Final Cut Pro HD we capture the sermon as it is preached. For audio there is also a mix out from the soundboard that goes up to PD’s office. He has a mini board there that he can use to adjust levels before the sound going into the line-in input on the Mac.

After capture of the video post-production begins. We’ll cut what we’ve captured to include just the sermon (trimming things from the beginning and end), add some fades, and splice in any video clips that happen during the message. (This way when the video is played on Sunday it can run straight through without having to worry about the clips.) We’ll also do any color correction we might think is necessary, although we try and avoid this by getting a good white balance as it takes a bit of time to render 40 minutes of HD video, not something we want to do on a Saturday night. And then we add the audio track. Now, the audio is a little tricky as we’ve discovered that there’s a small delay in the playback of video compared to audio during service. So we have to move the audio about 5-7 frames back in the timeline so that when played on Sunday morning it all matches up. After we’re all done with this we export to a quicktime movie format.

National Community Church, High Definition, HD, Cannon XL-H1, DVCPRO HD, Decklink Pro HD, Apple, G5 Quad

Technorati Tags: National Community Church, High Definition, HD, Cannon XL-H1, DVCPRO HD, Decklink Pro HD, Apple, G5 Quad