Answers.Body: <p>I record conferences all the time, so I end up getting 10's of hours of footage at a time. I have a few tricks that help with syncing: </p>
  
  <ol>
  <li>Run all cams all the time. If a full day shoot gets only 3 files per cam, that's a lot less work to sync than 25 files from each cam. </li>
  <li>Stop and start all cams within the same few seconds. </li>
  <li>Learn to notice key waveforms. Things like applause, audience chatter, and music have unique shapes. You can also watch for "um" and long pauses. </li>
  <li>There's sync tools available, like <a href="http://www.redgiant.com/products/pluraleyes/" rel="nofollow noreferrer">PluralEyes</a>, that analyze the sound from each clip, then syncs them on the timeline. </li>
  <li>There's time code methods that many pros use, but I've never had any success with them. </li>
  </ol>
  
  <p>I depend on 1 through 3 almost exclusively. I've gotten very good at reading waveforms and I only stop cams for breaks longer than 10 minutes. All my clips are 30 seconds out of sync at most. It's pretty easy to sync a whole day in 15 minutes. I've used PluralEyes, but found it took too long to process the material, and it was off by about a half second most of the time, so I had to go though and move all the clips anyway. I only use it if I have tons of clips to sync (more than 15), instead of my typical four or five. PluralEyes will get you close, then you have to adjust manually. </p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-08-29T16:53:23.250Z
Answers.LastActivityDate: 2017-08-29T21:32:12.583Z
Answers.LastEditDate: 2017-08-29T21:32:12.583Z
Answers.UserDisplayName: user3643
Answers.Body: <p>Well, I feel a little dumb because the answer is that this camera actually does timestamp the video file with the starting time, NOT the ending time. So I can accomplish what I need by computing the time difference from the filenames and offsetting the start of a clip from the start of the first clip. Duh.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-04-30T01:52:34.960Z
Answers.LastActivityDate: 2017-04-30T01:52:34.960Z
Answers.UserDisplayName: Joshua Frank
Answers.Body: <p>From what I can see, your method requires two assumptions to be made (and I don't think either one can be safely made here).</p>
  
  <p><strong>The internal time of the cameras isn't synced.</strong>
  The two cameras you shot with probably used internal clocks that you set the first time you turned them on. They're not connected to the internet or getting updated with any sort of precision. You could manually change the time of one of them to 5:00 PM and the other to 2:30 AM and they'd operate normally. What may be 11:16:22 AM on one camera is probably more like 11:15:54 AM on the other.</p>
  
  <p><strong>Seconds aren't precise enough for syncing audio/video.</strong> If you are syncing with just using hours/min/seconds, you're not syncing as precise as if you were using frames, which in your case would be 1/24 of a second (in your sequence). Even if the internal clocks on both cameras were perfectly synced, it's not like you're starting and stopping recording at exactly 1 second, 0 frames each time. </p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-04-28T16:16:27.497Z
Answers.Text: These are both good points, but I think not what's causing my problem. I made an update to my question to address the first point. The second point is also well taken; I fully expect that I'll need to shift a clip by up to 24 frames to make it sync perfectly, but I'm finding that it's many *whole minutes* off.
Answers.UserDisplayName: Joshua Frank
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-04-28T15:42:17.780Z
Answers.LastActivityDate: 2017-04-28T15:42:17.780Z
Answers.UserDisplayName: John Barton
Answers.Body: <p>If the time (clock) settings for the two cameras are different, the 'end-time' relationship is meaningless. If you still have access to the cameras, start them both and record a clap. Ingest the two short clips and note any difference in time at the clap. This difference, plus or minus, should be added to the 6:56 to get a true offset. You can trim by frames from there.</p>
  
  <p>In any case it shouldn't be hard to find a matching audio event in the two clips. Any distinct sound can stand in for a clapper. Of course if your software has audio auto-alignment this becomes trivial.</p>
  
  <p>You may still have drift issues since the two cameras might not be clocked exactly the same, but once you have the gross offset, little trims are easier.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-04-28T16:12:53.503Z
Answers.Text: I wasn't clear. Both clips are from the same camera, which is camera 2. I have synced the first of these clips from camera 2 manually with camera 1, and now I need to sync the *remaining* clips from camera 2 with *each other*.
Answers.UserDisplayName: Joshua Frank
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-04-28T15:22:37.950Z
Answers.LastActivityDate: 2017-04-28T15:22:37.950Z
Answers.UserDisplayName: Jim Mack
Body: <p>I filmed an event with two cameras and I need to sync the second camera footage with the audio of the first. This was a live event and I couldn't record sync aids like a clapper.</p>
  <p>I name my video files after the timestamp from the camera, and I figured I could use this to do the sync. So for instance, I have one clip with name <code>VID-2017-04-22-11-09-26.mov</code> and another with name <code>VID-2017-04-22-11-16-22.mov</code>, so I can work out that the second clip ended 6 minutes and 56 seconds after the first. (The camera only knows when you finished filming and created the file, and the naming convention puts hh-mm-ss as the last three pairs of numbers.)</p>
  <p>So I figured that I could just note the spot on the timeline where clip 1 ends and place clip 2 so that it ends at that time plus 6:56.</p>
  <p>But when I did this, it was totally wrong, and I can't figure out why. The only variable I can think of it that the frame rate of this footage is 59.94 while the sequence is 23.976fps. But I'm not sure if that's relevant, and if so, I still can't figure out how to place these clips.</p>
  <p>Meanwhile, I'm stuck syncing the very hard way, by watching the clip and manually trying to find the matching footage from camera 1, and this is painfully tedious.</p>
  <h1>Update</h1>
  <p>From comments posted, I realize I wasn't clear. Both clips are from the same camera, which is camera 2. I have synced the first of these clips from camera 2 manually with camera 1, and now I need to sync the <em>remaining</em> clips from camera 2 with <em>each other</em>.</p>
  <h1>Update</h1>
  <p>The workflow was this: I set camera 1 on a tripod to film the speaker continuously (but rather boringly). I walked around with camera 2 for more dynamic angles, sometimes pausing between shots. So camera 2 has about 25 different clips, which I want to line up with camera 1, and then cut between them to make a more interesting video.</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-04-28T13:26:13.103Z
Comments.Text: Which editor are you using? Some, like Premiere Pro, have audio sync capabilities built in
Comments.UserDisplayName: John Barton
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-04-28T14:15:36.753Z
Comments.Text: I'm using Premiere CS5, but so far haven't been able to get this to work :-(
Comments.UserDisplayName: Joshua Frank
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-04-28T14:16:02.310Z
Comments.Text: Also, I'm just curious about what's going on here.
Comments.UserDisplayName: Joshua Frank
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-04-28T16:17:37.703Z
Comments.Text: Was Camera 1 rolling the entire time? What do you mean by sync clips from Camera 2 "with each other"?
Comments.UserDisplayName: John Barton
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-04-28T17:11:08.717Z
Comments.Text: @JohnBarton: See my second update. I wasn't so clear here either. What I mean by *each other* is really that I want to sync them with camera 1, but I don't have a good way to do that. I manually placed the first clip from camera 2 in the right place, and now I want to use the timestamps on the remaining camera 2 clips to offset them correctly relative to that first clip.
Comments.UserDisplayName: Joshua Frank
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-04-28T17:39:50.020Z
Comments.Text: Could be a couple different things happening, then. I don't think it's the difference in frame rates (though it couldn't hurt throwing everything into a 60 fps sequence just to check). The most likely option is that the timestamps on the files isn't accurate. I've seen that issue before, where it doesn't always mark the timestamp as the correct time.
Comments.UserDisplayName: John Barton
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-04-28T17:40:30.813Z
Comments.Text: Your best bet would be to use something like Pluraleyes or Premiere (CC) to auto-sync the two clips together
Comments.UserDisplayName: John Barton
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-07-29T04:00:05.693Z
Comments.Text: Though I am usually able to get the audio on top of my video clips this is exactly why I try to run straight through a whole day unless a break is longer than 20 minutes. This way if there is a problem with the audio and I have to manually sync I have a whole day of content but only four video clips. It's still tedious but I only have to do it 4 times.
Comments.UserDisplayName: user3643
Tags: <premiere><camera><timecode><multi-camera>
Title: Audio/video sync puzzle
UserDisplayName: Joshua Frank
ThreadText: # Audio/video sync puzzle
  
  (Asked by: username_0 on 2017-04-28)
  
  I filmed an event with two cameras and I need to sync the second camera footage with the audio of the first. This was a live event and I couldn't record sync aids like a clapper.
  
  I name my video files after the timestamp from the camera, and I figured I could use this to do the sync. So for instance, I have one clip with name `VID-2017-04-22-11-09-26.mov` and another with name `VID-2017-04-22-11-16-22.mov`, so I can work out that the second clip ended 6 minutes and 56 seconds after the first. (The camera only knows when you finished filming and created the file, and the naming convention puts hh-mm-ss as the last three pairs of numbers.)
  
  So I figured that I could just note the spot on the timeline where clip 1 ends and place clip 2 so that it ends at that time plus 6:56.
  
  But when I did this, it was totally wrong, and I can't figure out why. The only variable I can think of it that the frame rate of this footage is 59.94 while the sequence is 23.976fps. But I'm not sure if that's relevant, and if so, I still can't figure out how to place these clips.
  
  Meanwhile, I'm stuck syncing the very hard way, by watching the clip and manually trying to find the matching footage from camera 1, and this is painfully tedious.
  
  # Update
  
  From comments posted, I realize I wasn't clear. Both clips are from the same camera, which is camera 2. I have synced the first of these clips from camera 2 manually with camera 1, and now I need to sync the *remaining* clips from camera 2 with *each other*.
  
  # Update
  
  The workflow was this: I set camera 1 on a tripod to film the speaker continuously (but rather boringly). I walked around with camera 2 for more dynamic angles, sometimes pausing between shots. So camera 2 has about 25 different clips, which I want to line up with camera 1, and then cut between them to make a more interesting video.
  
  **Tags:** premiere, camera, timecode, multi-camera
  
  > **Comments:**
  > **username_1**: Which editor are you using? Some, like Premiere Pro, have audio sync capabilities built in  
  > **username_0**: I'm using Premiere CS5, but so far haven't been able to get this to work :-(  
  > **username_0**: Also, I'm just curious about what's going on here.  
  > **username_1**: Was Camera 1 rolling the entire time? What do you mean by sync clips from Camera 2 "with each other"?  
  > **username_0**: @username_1: See my second update. I wasn't so clear here either. What I mean by *each other* is really that I want to sync them with camera 1, but I don't have a good way to do that. I manually placed the first clip from camera 2 in the right place, and now I want to use the timestamps on the remaining camera 2 clips to offset them correctly relative to that first clip.  
  > **username_1**: Could be a couple different things happening, then. I don't think it's the difference in frame rates (though it couldn't hurt throwing everything into a 60 fps sequence just to check). The most likely option is that the timestamps on the files isn't accurate. I've seen that issue before, where it doesn't always mark the timestamp as the correct time.  
  > **username_1**: Your best bet would be to use something like Pluraleyes or Premiere (CC) to auto-sync the two clips together  
  > **username_2**: Though I am usually able to get the audio on top of my video clips this is exactly why I try to run straight through a whole day unless a break is longer than 20 minutes. This way if there is a problem with the audio and I have to manually sync I have a whole day of content but only four video clips. It's still tedious but I only have to do it 4 times.  
  
  ---
  
  ## 4 answers
  
  ### Answer by username_2 on 2017-08-29. Score: 1
  
  I record conferences all the time, so I end up getting 10's of hours of footage at a time. I have a few tricks that help with syncing:
  
  1. Run all cams all the time. If a full day shoot gets only 3 files per cam, that's a lot less work to sync than 25 files from each cam.
  2. Stop and start all cams within the same few seconds.
  3. Learn to notice key waveforms. Things like applause, audience chatter, and music have unique shapes. You can also watch for "um" and long pauses.
  4. There's sync tools available, like [PluralEyes](http://www.redgiant.com/products/pluraleyes/), that analyze the sound from each clip, then syncs them on the timeline.
  5. There's time code methods that many pros use, but I've never had any success with them.
  
  I depend on 1 through 3 almost exclusively. I've gotten very good at reading waveforms and I only stop cams for breaks longer than 10 minutes. All my clips are 30 seconds out of sync at most. It's pretty easy to sync a whole day in 15 minutes. I've used PluralEyes, but found it took too long to process the material, and it was off by about a half second most of the time, so I had to go though and move all the clips anyway. I only use it if I have tons of clips to sync (more than 15), instead of my typical four or five. PluralEyes will get you close, then you have to adjust manually.
  
  
  ---
  
  ### Answer by username_0 on 2017-04-30. Score: 0
  
  Well, I feel a little dumb because the answer is that this camera actually does timestamp the video file with the starting time, NOT the ending time. So I can accomplish what I need by computing the time difference from the filenames and offsetting the start of a clip from the start of the first clip. Duh.
  
  
  ---
  
  ### Answer by username_1 on 2017-04-28. Score: 0
  
  From what I can see, your method requires two assumptions to be made (and I don't think either one can be safely made here).
  
  **The internal time of the cameras isn't synced.**
  The two cameras you shot with probably used internal clocks that you set the first time you turned them on. They're not connected to the internet or getting updated with any sort of precision. You could manually change the time of one of them to 5:00 PM and the other to 2:30 AM and they'd operate normally. What may be 11:16:22 AM on one camera is probably more like 11:15:54 AM on the other.
  
  **Seconds aren't precise enough for syncing audio/video.** If you are syncing with just using hours/min/seconds, you're not syncing as precise as if you were using frames, which in your case would be 1/24 of a second (in your sequence). Even if the internal clocks on both cameras were perfectly synced, it's not like you're starting and stopping recording at exactly 1 second, 0 frames each time.
  
  > **Comments:**
  > **username_0**: These are both good points, but I think not what's causing my problem. I made an update to my question to address the first point. The second point is also well taken; I fully expect that I'll need to shift a clip by up to 24 frames to make it sync perfectly, but I'm finding that it's many *whole minutes* off.  
  
  ---
  
  ### Answer by username_3 on 2017-04-28. Score: 0
  
  If the time (clock) settings for the two cameras are different, the 'end-time' relationship is meaningless. If you still have access to the cameras, start them both and record a clap. Ingest the two short clips and note any difference in time at the clap. This difference, plus or minus, should be added to the 6:56 to get a true offset. You can trim by frames from there.
  
  In any case it shouldn't be hard to find a matching audio event in the two clips. Any distinct sound can stand in for a clapper. Of course if your software has audio auto-alignment this becomes trivial.
  
  You may still have drift issues since the two cameras might not be clocked exactly the same, but once you have the gross offset, little trims are easier.
  
  > **Comments:**
  > **username_0**: I wasn't clear. Both clips are from the same camera, which is camera 2. I have synced the first of these clips from camera 2 manually with camera 1, and now I need to sync the *remaining* clips from camera 2 with *each other*.  
  
  ---
  
  