Jesse Parker Posted August 29, 2012 Report Share Posted August 29, 2012 I tried manually adjusting the audio speed for those takes in the timeline. When I slowed them down to 91.85% it roughly looks in sync - but that's just by eye, based on trial and error. Interestingly enough, 44.1k is 91.875% of 48k. I believe converting the sample rate of the files in question to 48k will fix the problem. Quote Link to comment Share on other sites More sharing options...
studiomprd Posted August 29, 2012 Report Share Posted August 29, 2012 " 44.1k is 91.875% of 48k. " problem solving 101. we seem to have a winner. Quote Link to comment Share on other sites More sharing options...
Mike Wally Posted August 29, 2012 Author Report Share Posted August 29, 2012 ...can it change randomly just for those takes? The takes are all normal...and wave agent says the files are 48k. I never had a reason to change them, nor do i think you can even accidently change it... Quote Link to comment Share on other sites More sharing options...
Jesse Parker Posted August 29, 2012 Report Share Posted August 29, 2012 ...can it change randomly just for those takes? The takes are all normal...and wave agent says the files are 48k. I never had a reason to change them, nor do i think you can even accidently change it... So says the metadata. You may have accidentally changed this when you did a batch frame rate conversion. Does it sound like playback is fast in WaveAgent? If so, change it to 44100 and click save. Outside of WaveAgent, navigate to where that file is on your hard drive and play it back just using the finder window. Does it playback normally now? Quote Link to comment Share on other sites More sharing options...
Mike Wally Posted August 29, 2012 Author Report Share Posted August 29, 2012 ...you guys rock. That was exactly what it was. Changed it to 44100 in wave agent, opened it up, and it was fine. I'm still a bit concerned as to why it did that. Silly Nomad -.- Quote Link to comment Share on other sites More sharing options...
Jesse Parker Posted August 29, 2012 Report Share Posted August 29, 2012 ...you guys rock. That was exactly what it was. Changed it to 44100 in wave agent, opened it up, and it was fine. Glad to help! Because this was just an issue with an improper sample rate stamp, SRC will most likely be avoided. Guess you'll have to wait to hear back from post but now we know.. Quote Link to comment Share on other sites More sharing options...
Mike Wally Posted August 29, 2012 Author Report Share Posted August 29, 2012 Haha, win. Quote Link to comment Share on other sites More sharing options...
Marc Wielage Posted September 4, 2012 Report Share Posted September 4, 2012 Very true. I suppose I am just trying to provide a reasonable example as to why one would choose to use true 24fps when using digital video. I think many times the decision to use true 24 fps is made with no real reason behind it, aside from, "we want that film look." Uh... 23.98 is the film look. The "Film Look" is a vague concept that has just as much to do with lighting and lens choices, contrast range, and motion artifacts as it does with frame rates. There is no visual difference between 24.00fps and 23.98fps. To me, anybody who chooses the former generally does so out of ignorance. 23.98 will be infinitely easy and is more standardized to deal with in post. We really have to fight this kind of ignorance when we can. But I agree, at some point, all you can say is, "hey, it's your film -- I'm on the record as giving you a specific recommendation, we're going in a different direction -- no problem, let's move on." Awhile back I did a project where they insisted on shooting 29.97 (for a dramatic shoot). I tried reasoning with the director and editor that this will look a lot more "electronic" than they may anticipate, but they pooh-poohed me and said, "we've had trouble with converting from 23.98 to the web in the past." I sighed and said, "this was solved 10 years ago -- just find somebody who knows how to use Apple Compressor," but they stood firm. I gave them what they asked for, and the sound was fine. Quote Link to comment Share on other sites More sharing options...
canaantriplett Posted September 4, 2012 Report Share Posted September 4, 2012 I don't understand why people would recommend a pull up or pull down. Audio (usually) does not have continuous time code, just a stamp of where the beginning of said file will be. If your clock drifted you will have to do manual sync with the sticks. Audio goes by sampling rate not frame rate. There are 48,000 samples per second (or whatever your sample rate is) regardless of what your time code settings are. As long as it starts in the right place your audio should not drift out of sync with the picture unless the footage was sped up or slowed down. Obviously the time stamps for the start of the audio files will be more out of sync later in the day if the time code settings were not compatible. Anyone care to set me straight? p.s. - Don't trust the Assistant Editor. Quote Link to comment Share on other sites More sharing options...
greg sextro Posted September 4, 2012 Report Share Posted September 4, 2012 I don't understand why people would recommend a pull up or pull down. Ever worked with film? p.s. - Don't trust the Assistant Editor. Very very true. Quote Link to comment Share on other sites More sharing options...
canaantriplett Posted September 4, 2012 Report Share Posted September 4, 2012 Yes, but I don't think anybody was talking about film. Quote Link to comment Share on other sites More sharing options...
Philip Perkins Posted September 4, 2012 Report Share Posted September 4, 2012 I don't understand why people would recommend a pull up or pull down. Audio (usually) does not have continuous time code, just a stamp of where the beginning of said file will be. If your clock drifted you will have to do manual sync with the sticks. Audio goes by sampling rate not frame rate. There are 48,000 samples per second (or whatever your sample rate is) regardless of what your time code settings are. As long as it starts in the right place your audio should not drift out of sync with the picture unless the footage was sped up or slowed down. Obviously the time stamps for the start of the audio files will be more out of sync later in the day if the time code settings were not compatible. Anyone care to set me straight? p.s. - Don't trust the Assistant Editor. The sound will drift out of sync with the picture if the camera's internal clock (or whatever is clocking it) is either at a different rate than that used to clock the audio, or is inaccurate. The latter describes the clocks in most video cameras, computers, digital mixers and audio interfaces. phil p Quote Link to comment Share on other sites More sharing options...
canaantriplett Posted September 4, 2012 Report Share Posted September 4, 2012 The sound will drift out of sync with the picture if the camera's internal clock (or whatever is clocking it) is either at a different rate than that used to clock the audio, or is inaccurate. The latter describes the clocks in most video cameras, computers, digital mixers and audio interfaces. phil p In that case, would a standard pull up/down percentage even fix the problem? Quote Link to comment Share on other sites More sharing options...
Marc Wielage Posted September 5, 2012 Report Share Posted September 5, 2012 p.s. - Don't trust the Assistant Editor. Lordamighty, no. (Though I have occasionally met some really good ones.) In that case, would a standard pull up/down percentage even fix the problem? I would try a varispeed in ProTools at several different rates, find out what that magic percentage is, and figure out then if this is a sampling rate issue or a pull-down issue. We did that all the time with problematic dailies sessions, and even had a magic black box that would force-feed "wrong" reference signals to get the sound to play back at different speeds in order to sync it with film... in the old days. Quote Link to comment Share on other sites More sharing options...
canaantriplett Posted September 5, 2012 Report Share Posted September 5, 2012 I guess I assumed that most modern pro gear has accurate enough clocking to not drift noticeably over the length of an average take. Are internal clock differences between recorder/camera still causing problems for people? Even with newer high end gear? Quote Link to comment Share on other sites More sharing options...
Marc Wielage Posted September 6, 2012 Report Share Posted September 6, 2012 Are internal clock differences between recorder/camera still causing problems for people? Even with newer high end gear? It depends! I did a Sony PMW-F3 project not long ago and that went all over the place, because the camera timecode sucked. The editor told me, "don't worry -- your slates were perfect," and we pressed on. And the F3 costs well over $15,000, not a crap camera by any means. I have never had a problem with an F900, F950, F23, F35, an Alexa, or a Genesis. The Canons are dicey. The Reds are unreliable unless you run them from a jammed timecode box, and I've had great luck with that. Quote Link to comment Share on other sites More sharing options...
studiomprd Posted September 12, 2012 Report Share Posted September 12, 2012 " assumed that most modern pro gear has accurate enough clocking " assuming = not a good idea! and as Marc noted most real, pro gear has accurate SMPTE TC, though there are also often quirks (like changing batteries, or turning off!) Quote Link to comment Share on other sites More sharing options...
Marc Wielage Posted September 13, 2012 Report Share Posted September 13, 2012 I have admitted this story before: I had a yelling match with a production crew who shot 24fps film and gave us 24fps TC audio. We pulled both down during dailies telecine and it all went to hell. Very frustrating. Eventually, we determined that our reference was wrong in the building (!!!), but was correct in two out of 11 telecine rooms. I humbly apologized to the client, assured them their mixer was absolutely right, and we got along fine. There was much grumbling amongst the engineering department that day, I can tell you... but by the end of the week, all 11 rooms were wired correctly. Quote Link to comment Share on other sites More sharing options...
Jack Norflus Posted September 14, 2012 Report Share Posted September 14, 2012 Eventually, we determined that our reference was wrong in the building (!!!), Sorry to sound like an idiot but how does this affect the sync? Quote Link to comment Share on other sites More sharing options...
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