26 Replies Latest reply on Feb 21, 2010 8:39 AM by Harm Millaard

    Syncing audio with video without a slate?

    Russell_MTL Level 1

      I'm considering using an external audio recorder (Zoom H4N) for videos shot with my dSLR and wonder if Premiere Pro offers an easy syncing feature for when I'll be syncing things up. I would still use the camera's own built-in mic to record the audio for reference, and perhaps even mix it with the H4N's recording if the camera's audio is of use.

       

      I've read about PluralEyes for Final Cut Pro, but would be using PPro as that's what I own. I also have Soundbooth CS4 as part of the same Suite in case that offers an even better solution for realigning the 2 audio tracks.

       

      I have not yet bought the Zoom H4N and wonder if the manual alignment task will be too difficult - it sounds pretty easy. But so does so many things when you've never tried ;-)

       

      Russell

        • 1. Re: Syncing audio with video without a slate?
          the_wine_snob Level 9

          Russell,

           

          I know of no syncing utility/plug-in for PrPro. I end up using the tips in this ARTICLE. Now, with a separate Audio source, you will likely have a dynamic OOS issue. One user here tested and found that Rate Stretch of 104% on the Audio from an external was the "magic number." He then always applies that to the external Clips, and all is perfect.

           

          In the "good old days" of cine, we'd choose the crystal clock in say the Nagra, and then set the camera as the slave, taking sync from that, or the other way around. Of course, we were tethered, so it was a different world back then.

           

          Good luck,

           

          Hunt

          • 2. Re: Syncing audio with video without a slate?
            Russell_MTL Level 1

            the_wine_snob wrote:

             

            I know of no syncing utility/plug-in for PrPro. I end up using the tips in this ARTICLE. Now, with a separate Audio source, you will likely have a dynamic OOS issue. One user here tested and found that Rate Stretch of 104% on the Audio from an external was the "magic number." He then always applies that to the external Clips, and all is perfect.

            Thanks for the article Bill. Why would there be a dynamic out of sync issue with 2 digital recorders? I would have expected that digital audio would be identical as there's no tape, stretching or mechanical parts and motors.

             

            Russell

            • 3. Re: Syncing audio with video without a slate?
              the_wine_snob Level 9

              Russell,

               

              Unfortunately, we tend to think of digital as being always on the same baseline. In reality, it never seems to be. In the old days, there was a crystal involved, and we accepted a bit of a variance, but it was usually well within "the norm." With digital, we've all been lulled into a false sense of security. Different mfgrs. choose different parameters. They are likely close, but NOT exact, regardless of how perfect we tend to think of them. Would be nice, if the exact speed was 100% constant over days, and not just minutes. Some day, in a land far away, we WILL have 100% accuracy in ALL devices. Until then, OOS is linger.

               

              Going back to the film days, I shot an open-heart surgery procedure. I was outside the OR, and my sound man was inside, doing wild sound. He changed tapes, and I changed mags. In the editing suite, we budgeted two days of the syncing. We found a bag being opened prior to the operation, and synced to that. In amazement, we watched all the footage, with the wild sound playing. Everything synced perfectly for all the footage that we shot! It was not until the procedure went bad, and the sound man was excused, that we lost things, but for our 2 min. "Clip," we had all that we needed - no crystal sync, and no tether between the Nagra and the camera. We got very lucky. Now, we had NO CU's of lips (behind masks, etc.) but all just fell into place. We finished in hours and not days, as budgeted.

               

              Good luck,

               

              Hunt

              • 4. Re: Syncing audio with video without a slate?
                shooternz Level 6

                What camera are you going to shoot with?

                • 5. Re: Syncing audio with video without a slate?
                  Russell_MTL Level 1

                  shooternz wrote:

                   

                  What camera are you going to shoot with?

                  A D3s.

                   

                  Found a thread on dvxuser.com on this exact issue (syncing a Zoom H4n with a D90) and the differing speeds was discussed as well as solutions described. This pointed to a video by the folks at Zacuto where they showed how the audio time was shrunk to 99.9% to compensate for the 30fps of the Canon cameras they were using in the demo. The D3S shoots at 24fps so Bill's 104% suggestion might be what's needed.

                   

                  Bottom line seemed to be that some time stretching /shrinking will probably be needed, which Soundbooth can do easily, so it seems like a decent sound solution that can be made to work without too much hassle.

                   

                  Do you have an experience with doing this with a Nikon?

                   

                  Russell

                  • 6. Re: Syncing audio with video without a slate?
                    shooternz Level 6

                    My experience when we multicam shoot and the Canon equvalent of your camera is in the mix,  ...we use my HVXs to capture the actual audio and the DSLR is only capturing reference audio.

                    • 7. Re: Syncing audio with video without a slate?
                      Matt Petersen Level 3

                      Since you're capturing audio on the DSLR as well, you only need to sync audio and don't need a slate as such (in other words, you don't need the visual part of the slate). As long as you have some way of organising your sound to your vision, you'll get away with an audio sync point. One of those kids "clickers" (often in the shape of a beetle!) will do the job nicely at the start and end of each take. if, after a while, you find that magic slip number for your recorder/each of your recorders, you can dispense with the "end click".

                       

                      You can help your edit experience if, in lieu of a slate, each take rolls on the readout screen of the audio recorder, showing the track number currently recording.

                       

                      cheers

                       

                      MP

                      • 8. Re: Syncing audio with video without a slate?
                        Level 4

                        Hi,

                         

                        If you don't have a clicker or slate you can maybe just shoot the fuzzy microphone whacking the talent you don't like the most in the noggin...which usually excites a nice sync....you see it , you hear it...youre in business !

                         

                        Rod

                        • 9. Re: Syncing audio with video without a slate?
                          Russell_MTL Level 1

                          robodog2 wrote:

                          shoot the fuzzy microphone whacking the talent you don't like the most in the noggin...which usually excites a nice sync....you see it , you hear it...youre in business !

                           

                          Thanks Rod. That's the best idea yet :-))

                           

                          LOL

                           

                          Russell

                          • 11. Re: Syncing audio with video without a slate?
                            the_wine_snob Level 9

                            Rod,

                             

                            That does work, and provides some comic relief, plus might make a point too. Now, when one considers that an old-fashioned slate still works, and cost so much less than those neat digital units, at 1/10th the price. Might not impress the clients, but then one could mention that Frank Capra used one just like that.

                             

                            Still, the mic to the forehead works too!

                             

                            Hunt

                            • 12. Re: Syncing audio with video without a slate?
                              Level 4

                              Hi,

                               

                              Bill, you said it all in your previous posts re: sync .. and a few other suggestions here were also great...

                               

                              I found it interesting to note the references to tweaking sound according to variant frame rates ( 29.97 vs 30 ----etc ) but mostly I work with film camera shoots and they are still using the quartz crystal stuff along with mixer using quartz also..with some infusion of digital based time code stuff....but we could and do still use regular slates.

                               

                              It might be worth noting to those not familiar with this , that the quartz crystal is in a way similar to quartz crystals in time pieces...the watches that keep very good time over a long period....  that is basically the usage of the quartz crystals in film....   they keep good time....or good " speed " .  Another simile might be the frequency use of quartz in 2 way radios ( each quartz crystal being a certain "channel" or specific frequency )

                               

                              There's no reason under the sun to have a digital slate showing time code unless you're jamming the thing with the mixer and camera, to sync them up to begin with....otherwise there's no point. A normal slate does same thing otherwise.

                               

                              That suggestion to shoot the digital readout of the recording device was a good suggestion  ...in lieu of having pro equipment to jam the stuff...but I guess you need to have those reference numbers in your timeline somewhere...I don't shoot digital ( have no video camera ) ...so I really don't know what is available for reference.....

                               

                              Usually my biggest concern about sound is whether or not the dolly wheels are squeeking, the track making noise, ...whether or not I can hold in the sneeze I feel coming until after the take is done...whether Im breathing too loud after a running shot...stuff like that...  and I have a feeling I'll be getting out of this stuff pretty soon and do something else...like maybe go to FLA keys and start thinking like a fish.... ?

                               

                              Rod

                              • 13. Re: Syncing audio with video without a slate?
                                the_wine_snob Level 9

                                Rod,

                                 

                                What happens with many digital setups is that each device uses its own "crystal." With film, we chose one crystal and everything took the signal from that. Now, everyone thinks that every device will be 100% locked to the FPS, say 29.97. That works in theory, but not in practice. Nothing is tethered, so there is no "master" signal/crystal. Everything is a "slave." They can be very close, but there is usually a few % of difference between the devices. Why? I do not know, but then I do not design cameras, or recorders.

                                 

                                The difference is usually slight, and short Clips might be very good. It is often when the Duration extends a bit, that the errors surface. One past contributor found that his difference was 104%, IIRC, and recently one user (maybe in this thread?) found that 99.8% was the "magic number."

                                 

                                I wish that we could just pick up cameras and recorders, and that things would be 100% - no correction, but that still seems to be in the future. Or, one can tether the gear and choose one crystal to use as the master - all others will be slaves, as it has been in film for many decades.

                                 

                                So much for our digital-age. It's good, but not perfect.

                                 

                                Hunt

                                • 14. Re: Syncing audio with video without a slate?
                                  Level 4

                                  Ya,  I have an interesting observation, but don't know how I can calibrate it...precisely determine what is happening...

                                   

                                  A friend here at the forums lent me some multi cam footage to use with CS3, for me to learn about using the program...in particular how to intercut between video etc... so , there's 3 cameras...front left and right....each recording sound on the video camera...multiplexed with the video clips.

                                   

                                  Also, there's a separate music track.

                                   

                                  Soooo, being not so smart when I started out, I unlinked the sound from the video and using the front camera soundtrack I made adjustments to the sound....volume levels at various points, some bass treble stuff, simple adjustments...

                                  Then put the front camera soundtrack back into Premiere and sync'd using slate .....

                                   

                                  But now...at that point I am now using the front camera sound for all cameras.....and I swear it was drifting off when I went to the left and right cameras toward the end of the clips ....about 4 minute clip or so ???   But it was such a minor shift that I couldn't be sure half the time.....and I certainly couldn't " correct " it without going into a huge rigamerole with editing back to 3 soundtracks instead of one  ( plus music ).  But this experience ( plus this other thing re: scale and position (pan) ) got me started understanding some of the reality with dealing with video and onboard sound vs separate soundtrack and so on...

                                   

                                  It also was an eye opener re: what someone once called "gymnastics" here .....   why bother ?   If a scene is not being shot with multiple takes (with clapper of course) for master and coverage....why bother thinking in terms of THAT way of making a storyline ?  In fact, WHY NOT just keep the stuff simple and use the source monitor and subclips and so on....and not even THINK in terms of cutting the thing up into pieces , resizing them according to a plan (script - storyboard ) and all that....when in fact you can just resize and scale and position on the fly ??

                                   

                                  I think I would have used a different term than 'gymnastics' to a newbie but the gist of the message was accurate as far as it went... and doing what I did with the sound for the front camera ended up being dumb in the long run, because of the drift ( I THINK....IT'S SO FINE A LINE ) from left and right cameras down the road....

                                   

                                  I am, luckily and thanks to this friend on the forum, now in possession of MORE of the same type video samples, which I will work on in a new workflow ....using what I've learned to get a little better at this....But I got sidetracked with the camera match move 3D stuff and have to deal with that first now.....as it applies to some work related seminar stuff ...but I'll get back to that project soon I hope.

                                   

                                  Rod

                                  • 15. Re: Syncing audio with video without a slate?
                                    the_wine_snob Level 9

                                    Rod,

                                     

                                    Were all cameras the exact same? Many will do multi-camera with different models and even makes of cameras and will get all sorts of sync issues. Were I shooting multi-cam, all would be matched 100%.

                                     

                                    Hunt

                                    • 16. Re: Syncing audio with video without a slate?
                                      Level 4

                                      Yes, I think they are all the same cameras....and like I said, the drift issue could be just my imagination...it's so slight...could be the camera on left on some shots , being five feet closer to subject talking on that side as opposed to right camera...maybe 25 feet total distance between left and right ??? ---that could have an effect I guess....it's such a fine distinction...

                                       

                                      haha....to tell you the truth if I have a beer and squint a little bit the thing final cut looks great to me, but I'm always partial to my own work !

                                       

                                      Even with all the black bars on left and right and top and bottom ....hehe

                                       

                                      Rod

                                      • 17. Re: Syncing audio with video without a slate?
                                        the_wine_snob Level 9
                                        Yes, I think they are all the same cameras...

                                         

                                        This is a great start indeed. Mostly, we see a crew using a pro-level Panny for the main, a Flip for the right-side and a cellphone for the left-side, and the OP wonders why things do not sync up perfectly. You are "ahead of the game." Just put that cellphone back in your pocket and only take it out to receive a call - it is NOT a viable video capture device, regardless of what the manual indicates....

                                         

                                        Hunt

                                        • 18. Re: Syncing audio with video without a slate?
                                          Level 4

                                          LOL

                                           


                                           

                                          Are you testing a new wine ?

                                           

                                          hehe...  it's not like you to break down and become the critic at large....  One of the things I love about your contributions to teaching is your infallible scrutiny coupled with a love for the medium , the people ( even youngsters with iphones as video cameras ), and vision  ....

                                           

                                          haha....thanks for the laugh !

                                           

                                          Rod

                                          • 19. Re: Syncing audio with video without a slate?
                                            Level 4

                                            I'm having a few beers myself here...sooo....this isn't the forum for this ...but I'm digressing into some art related personal feelings and just blurted out that stuff about your expertise about wine and food etc....   didn't mean anything negative about that...you know...

                                             

                                            I'm going to get another beer and go to another forum where I can hopefully find out who that blonde is in shooternz samples...

                                             

                                            Rod

                                            • 20. Re: Syncing audio with video without a slate?
                                              Russell_MTL Level 1

                                              Update....

                                               

                                              I got the H4n and it's very cool!

                                               

                                              As a test to see how they synchronized:

                                               

                                              I shot 5 minutes of video with the D3s (its MAX with 1280x720 HD) of a clock (w/ a second had running) while recording a radio newscast playing from some nearby speakers. The H4n recorded in 96kHz/24bit stereo mode at the same time a Sennheiser  MKE400 plugged straight into the camera recorded the audio with the video. I improvised a slate clapper at the beginning of the 5 minute sequence and repeated it again just before the end.

                                               

                                              Result:

                                               

                                              Once I aligned the clap at the beginning, both audio tracks stayed perfectly in sync until the clap at the end. If there is some variation it's certainly not showing any effect on a 5 minute recording. Since the camera cannot record any longer takes then it's moot.

                                               

                                              Conclusion:

                                               

                                              The D3s audio and video syncs perfectly with the H4n without any need for further adjusting. It would seem that Canon has a problem here that this Nikon does not.

                                               

                                              Hope this helps some others condsidering this combination. :-)

                                               

                                              Russell

                                              • 21. Re: Syncing audio with video without a slate?
                                                the_wine_snob Level 9

                                                Russell,

                                                 

                                                The user, who settled on the 104% was shooting weddings, and many shots were probably longer.

                                                 

                                                Glad that your test looked good. For shorter Clips, you should have great Audio and perfect sync.

                                                 

                                                Good luck,

                                                 

                                                Hunt

                                                • 22. Re: Syncing audio with video without a slate?
                                                  the_wine_snob Level 9

                                                  Rod,

                                                   

                                                  I could not find anything negative - maybe not enough beers for me?

                                                   

                                                  Hunt

                                                  • 23. Re: Syncing audio with video without a slate?
                                                    fuaho Level 1

                                                    Shooting 3D Hi-def Video with twinned Canon TX-1's and Fostex Fr-2LE.

                                                     

                                                    Frequently shoot 20-minute takes with perfect sync between all three units.

                                                     

                                                    And as far as the "good old days" of a crystal-sync Nagra and a crystal-controlled camera, Film loads were 11-minutes and there was never even a single frame of drift between them, if we even shot that long.

                                                     

                                                    Besides, even if there is drift, one never uses an 11-minute take, unless you're Hitchcock ("The Rope" comes to mind).

                                                     

                                                    As for sync points, a handclap, a finger snap, a mic tap, a cheek slap, anything that makes a distinct sharp noise and can be seen on camera is fine, but be sure to give a verbal tail slate description of the shot on the Audio Recorder so there are reference points for the editor to find what shot it matches. Time of Day metadata from BWF files is very helpful. Too bad Premiere doesn't read it! Something I requested in December of 2008 but to no avail.

                                                    • 24. Re: Syncing audio with video without a slate?
                                                      Level 4

                                                      Bill,

                                                      I had enough beers for both of us that day....

                                                       

                                                      "Rope"...  I guess if the mags didn't need to be changed there wouldn't have been ANY cuts in that film...

                                                       

                                                      Just finished 2 days of green screen match move thing...harder than I thought it would be...strange...it was easier to do the match move using footage shot outside...though that was static except for camera dolly / pan...this green thing has talent moving in it...and big pan...so you lose one wall and see a new one...trickier..

                                                       

                                                      Think I'll take a break and so something I know how to do for a change...tired of learning

                                                       

                                                      Rod

                                                      • 25. Re: Syncing audio with video without a slate?
                                                        Russell_MTL Level 1

                                                        fuaho wrote:

                                                         

                                                        As for sync points, a handclap, a finger snap, a mic tap, a cheek slap, anything that makes a distinct sharp noise and can be seen on camera is fine, but be sure to give a verbal tail slate description of the shot on the Audio Recorder so there are reference points for the editor to find what shot it matches.

                                                         

                                                        In my situation these are short 3 minute (max) monologues by guest speakers to company functions that I photograph. It's for folks who are not been able to attend so they can view a short piece on their Intranet. I've not been happy with with the audio I've done until now. On camera mics included too much room noise, and a lav I tried sounded too dull and 'bassy' (Sennheiser  G2 system). I'll do the next one with lav going into the H4n + record with the MKE 400 on camera, and then mix the two in post. The tests I've done so far sound good. And I'll also have the camera recorded audio to confirm that everything is synced.

                                                         

                                                        Russell

                                                        • 26. Re: Syncing audio with video without a slate?
                                                          Harm Millaard Level 7

                                                          For a Lav try Countryman on your G2.