6 Replies Latest reply: Jan 25, 2014 9:18 AM by JSS1138 RSS

    Playback Video Device?

    ArtifaktAstrix Community Member

      Dear PrP CC Users,

       

      I wanted to ask a few questions regarding setting up playback for best accuracy performace when dealing with video and sound.

       

      In Preferences > Playback. I have 4 Dell monitors (connected to GPU via HDMI, DVI-D x2 and a DisplayPort) and a Samsung TV (connected to a DeckLink Blackmagic Mini Monitor Video I/O). The 4 monitors for me to work off from and the TV for the Director/Client.

       

      My query is regarding the Audio Device selection. I have it selected as Adobe Desktop Audio, there is the option of Blackmagic playback (my amplifier is also connected to the TV).

       

      My regular desktop audio is connected to my Mac Pro output jack at the rear to my amplifier.

       

      When dealing with editing projects such as music videos, syncing is an important factor and I want to make sure where I'm getting the most accurate synced representation. What is the best Audio Device to use and should I Offset my Video Blackmagic Playback, is there some way to properly calibrate for this? Also, depending on that, where should I focus my attention when making sure audio is synced to video. - I'm not talking about how to merge audio with video clips and syncing using the clapper-board. I'm talking about playback accuracy once sound is synced. As often the client/director will say its out of sync on the TV when its not out of sync with me on my monitors.

       

      Perhaps if someone can explain on here or recommend me a link to how best set up and calibrate for video/audio sync whilst editing, it would be greatly appreciated.

       

      Thank you.

        • 1. Re: Playback Video Device?
          JSS1138 CommunityMVP

          As you're looking at the Program Monitor when making the edits, that's the most important place to make sure sync is in.  If you have it there, you're good.  How you get it is less important, I think.

          • 2. Re: Playback Video Device?
            Andrew_S Community Member

            On my system, the audio and video from CS6 go through a BM intensity card to a TV monitor via HDMI. The audio and video are therefore in sync. The audio from the TV (it has an optical audio output) then goes into the audio amp / speakers/ monitoring. ( I don't use the TV speakers.) The TV has a variable delay for the audio output, so you can adjust the timing to get audio and video in sync. Probably best done using a clapperboard or two pieces of wood.

             

            If you are monitoring the audio out of the computers audio output, the audio and video will not be in sync due to delays in the BM card and the TV.

            • 3. Re: Playback Video Device?
              Richard M Knight Community Member

              I have a similar setup as the OP, 4 computer screens for the work space and a Plasma connected via a Blackmagic HDMI output for the program monitoring. I use the BM card AES outputs for the audio monitoring going via a Dolby decoder. I measured the video delay to the Plasma and it was 38ms compared to the audio. I have set a delay in the Dolby box to 32ms, this plus the acoustic delay form my speakers gives me good lipsync. (There is a delay of aprox 1ms for each foot you are from the speakers). I used to have a crt as my grading monitor fed from the SD SDI op of the BM card, this had a delay of 50ms, caused by the hardware convertor in the BM card.

               

              As the brain expects to see something before it hears it, if something looks slightly out of sync it is likely that the audio is early.

              • 4. Re: Playback Video Device?
                ArtifaktAstrix Community Member

                Thank you very much. Very helpful. I normally have relied on Adobe Audio Built-In Line Output from my Mac and never had issues which is good. I plan to get a Blackmagic Ultra 4K soon so will experiement with that. Other than using clapperboard clips to see and hear if it in sync, is there some other more accurate way to detect sync using software or hardware which I can purchase? If so what kind?

                 

                Thank you.

                • 5. Re: Playback Video Device?
                  Richard M Knight Community Member

                  I built my own sync tester. I put one frame of bars and tone in a sequence. I use the audio output of my mixer to start a timer and I have a photo transister in front of the screen that I use to stop the timer. This gives me the amount that the video is behind the audio, I then dial the delay into my audio monitoring. I have also made a bluray of the same tone and bars 'blip' so I can check the output sync of my BD player.

                  In the UK the BBC used to transmit a sync check testcard on BBC HD but I'm not sure they do any more. Other broadcasters may do the same.

                  • 6. Re: Playback Video Device?
                    JSS1138 CommunityMVP

                    The countdown leader is a good way to check sync.