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Slap Chop Remix Time Stretches
Of course, the Slap Chop remix is by no means the first video to use time stretching like it does, but it’s the example that caused me to post here.
How can video be slightly stretched the way that one is, to make the words fit the rhythm that the editor wanted? I know how to do this with audio software – usually just as simple as using a time-stretching cursor tool that can just grab and pull the ends of the clips.
Maybe this type of time-stretching with video is typically done with something besides FCP. I don’t see how someone could use FCP time remapping to do so many detailed edits.
I also wonder how people can stretch the video while the audio stays the same pitch – it gets synthetic sounding, but sometimes I’d like to have that option over changing the pitch of the audio. Again, I know how to do this in audio software.
Make sense?
Any help is very appreciated.
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2 Replies
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Hi Brad,
I don’t know of any other tool than time remapping that works only slightly like pitch and time for audio (like in pro-tools, which seems to be what you’re looking for), but I’m frequently faced with (lip-)sync problems as I often edit multitrack music videos and live performance relays. The one I’m finishing right now was shot 15 times with one camera, then another 2 live takes with audience, so I’m looking at 17 superimposed dailies video tracks and over 30 audio tracks to edit, plus the usual several effects tracks on top. I don’t use time remapping because I find it very inconvenient to have to use such long handles to make it work efficiently. In this case I’ll use the example of a progressive rock band whose drummer used a click to stay on time, but you can bet your fanny that despite the click, he was off by at least 1 or 2 16ths every 4 to eight measures, so over 3 minutes of hard rock, I had discrepancies of up to 10″ (short or long) on almost every track, and I needed to have them all in sync! Not to mention instrumental solos and vocals that are never identical from one take to the next. So here is how I do it if it’s of any help:
1) I select an audio/video track that’s going to be my (usually best performance) reference track and that I leave in sync on my timeline no matter what happens.
2) I sync up all my other tracks to the reference track by using audio phasing, listening to the reference on the left, and the track to sync up on the right, and sitting in the middle. When the reference audio and the audio of the track to sync up phase each other out, then they’re perfectly in sync. Headphones are best for that, but a good speaker set up is more comfortable and works too. Leave the audio of the tracks to sync up linked to the video, so when you make shifts later, you can compare and verify audio sync at any time, although your audio may sound off key (that’s where audio/video pitch & time would be convenient). There are 2 ways to do this: you can place cuts on the track to sync up every time it goes in and out of sync and shift that short section back and forth, which either leaves gaps to have to work around or shortened edits on that track. That’s ok if your tracks only go out of sync occasionally and if the synced sections are long enough for you not to be missing footage to edit with, but when you’re resyncing a track every 5 or 10″, you have too much loss to work around. That’s when “stretching” or “compressing” time comes in. Instead of shifting your track, you can use ins and outs to compare the length of your reference audio and the part you want to sync up. If you know that you’re reference section is 25 frames and your video is only 20, then you’ll want to use your speed tool (apple + ‘j’) to apply that length to the video, but don’t yet, or you’ll move all the following video out of sync!:
3) Keep your IN marker where it is (at the beginning of your reference IN), select the video section to modify, cut it (x), go to the end of your timeline (use a convenient shortcut key), copy (v) on the same track (always at the end of your timeline)!, command ‘j’ to open speed, change the length of the video (in frames, not in %age), don’t render yet, cut again, go back to IN, and copy again. Your video should now be in perfect sync with your audio and it should fit exactly in your reference track’s INs and OUTs. Now render that clip if needed and see for yourself. This may have sounded tedious, but when you get used to your shortcut keys, the whole procedure doesn’t last more than about 5″ or 10″.
4) Yes, there could be a gap to your next clip on the track section you just synced, but that’s normal. Either that next clip will be in sync again where it’s supposed to be, or it will need to be synced in turn. And so on and so forth.
5) There is an inconvenience to this that one can work around (very tedious!): depending on your system, your speed, and your FCP version, you may notice that you can no longer turn your tracks on and off without losing your render files (due to speed changes). You can either live with that by leaving all your tracks turned on and watching your dailies sections in the viewer, or you can export them to .dv for example and put them (rendered) back in to a new sequence, resync their staring points and you’re in business again. I did that for this last clip, but it was tedious and I’ll pass on that next time around and opt to make my selections using the browser.All this also works to lip-sync any other clip you want. I recently made a kind of just-for-fun home video clip in which I used on-screen dialogues to sync up to lyrics (competely different from the dialogue), by using markers to mark the consonants (lips closed on v’s, p’s, m’s and so on) and then stretching or compressing the time between those markers for the individual syllables. It’s tedious and very basic too, but it sure works and it’s loads of fun.
Hope this was of any help at all, all the best and good luck. Michael.
Michael Brown
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Sorry for the delay. Thanks for that description! That could come in handy someday.
However, it’s not quite what I’m looking for. I’m looking to create an effect more than to fix something. The Rap Chop video was probably a bad example because it’s more about “correcting” rhythm. It’s also a whole lot of small adjustments that would take a long time using speed/time remapping in FCP. In most DAW software like ProTools, you can set a bunch of markers and drag them around – stretching the time, but keeping the audio the same pitch.
Another example of what I’d like to do would be the BBC show, “Jam”. It has a lot of time stretching effects. This one isn’t extreme, but it might get the point across: https://www.youtube.com/watch?v=P0n4hclzCyE
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