How can I combine a video with Zoom H4n recorder audio?

[hariskar]

I want to take video of guitar playing with my camera but use the audio recorded the same time from my Zoom recorder. What programs (linux or windows) do I have to use to substitute the cameras audio with zooms and synchronize them?

Thank you!

[Baldrick]

You can start with Window live movie maker. Add the video and then the audio file. See for example https://www.youtube.com/watch?v=9xGarU_TArA how to get started.

If you are planning to edit several videos it might be worth getting a better video editor like moviestudio pro, vegas, etc.

[hariskar]

Thank you, but the video I will add will already have audio, is that not a problem?

[pippas]

You can do what you need using free software, but you will need to follow a procedure like the one below, to be able to 'sync' the Zoom track to the video track.

Use this free program https://www.videohelp.com/tools/MP4Cam2AVI to convert your video container to AVI. This program does not re-encode the video - it merely changes the header - so it's quite quick.

You might like to use that program to convert the video audio track to uncompressed PCM (.wav) though -- that will make it easier to 'sync' with the .wav output format of the Zoom audio track.

Open your new AVI in Virtualdub: https://www.videohelp.com/tools/Virtualdub , and save just the audio as a WAV file. (save as WAV, from the 'file' drop down menu)

Open this wav file in an audio editor of your choice: (this one is free: https://www.videohelp.com/tools/Audacity )

You will need to identify a 'sync'point. The easiest way of doing this is to use a 'clapperboard' reference (any sharp 'bang' will do!) at the start of your actual recording - once both the camera and Zoom recorder are already running of course!

Using your audio editor, line up the Zoom audio WAV track so that the clapper board reference is at exactly the same 'time' point as the 'clapper' point on the video audio. (You may need to introduce some silence at the start of your Zoom track to do this accurately). Also make sure that the Zoom audio track is exactly the same length in total as the original audio track.

Return to Virtualdub, and use the 'Audio from other file' to replace your audio track.

May sound a bit complex... but it's easy, once you've done it once!


You can do this more simply using 'Plural Eyes' (http://www.redgiant.com/products/all/pluraleyes/) software.... but that will set you back about $200 !

[bigass]

If all that's too complicated, and you have an off-the-shelf NLE like Vegas, you can do this:

1) Put the video with its attached audio on the timeline. You'll have one track of video, one track of audio.
2) Put the audio from the Zoom on another track.
3) Sync the Zoom audio to the camera audio. It's not that tricky to do. If you're a musician who's edited music, you'll be able to eyeball the transients easily and slide the Zoom audio to match the camera audio.
4) Mute the camera audio. Simple as that. Press the mute button on that track. You won't hear it any more.

[turk690]

I want to take video of guitar playing with my camera but use the audio recorded the same time from my Zoom recorder....

All tips above are valid, but how long is that video? Unlocked, non-related devices separately recording (the same live) audio and video source drift apart in sync after some time. I also use Zoom H2 to record FoH mixer output with 2 or 3 cameras for an event. With a Canon XA-10, after an hour, video it records will have drifted about 5 frames give or take compared with what H2 recorded when both laid down on the timelines, clapper syncing at the beginning notwithstanding. Obviously for video lengths of a few minutes it probably won't matter (we don't notice, or choose not to notice out-of-sync audio and video until it gets north of about 4 or 5 frames worth).

[pippas]

Simplest way to deal with the variations in device 'clock' speeds is to place a 'clapper' audio reference at the beginning and the end of your recording.
Then, use your audio editor to stretch (or squash!) your remotely recorded audio to match the camera audio. Remember, the camera audio is always the 'master' track. Even if it's the camera clock crystal frequency that's 'wrong', that's the audio that is in sync with the video!
As for frequency 'drifting' during a recording?... unlikely.
It's more likely to be that the clock crystal (or ceramic resonator on cheaper recorders) is oscillating at slightly the wrong frequency due to device tolerances.... not that it 'drifts' as you record.....

[turk690]

Simplest way to deal with the variations in device 'clock' speeds is to place a 'clapper' audio reference at the beginning and the end of your recording....

In situations without common or house sync such as that which I regularly deal with that has or 4 devices recording an event at the same time (3 prosumer camcorders, 1 audio recorder (Zoom R16 or H2)), after aligning the captured audio and video on the timeline with the clapper start, after an hour or so on the timeline they are no longer perfectly aligned. For example videos which were aligned perfectly at, say, 00;01;00;00 may be off with each other by anywhere from 3 to 10 frames by 00;55;00;00. It gets worse as timelines get longer that's why unless absolutely necessary I don't create sequences much longer than 1hr or so in PP5.0.3 if I can help it. If you periodically shot "claps" at, say, 15min intervals, they are not perfectly aligned on the timeline no matter how you apply it (a set of claps at all sources will be in sync at least once somewhere, but out of by a few frames elsewhere). I have accepted all that as a limitation of no common sync with consumer and prosumer equipment. That's why there is a distinction and a choice between consumer and professional hardware (where sync can be absolute with the latter). Correcting these minute out-of-syncs is an NLE art without stretching or compressing any of the captured audio or video placed on the timelines. In the face of all that, "clappers" as reference are a nicety that only minimally helps.

Remember, the camera audio is always the 'master' track...

May well be, but with several devices one has to decide of course which one will be the reference or 'master'; in my case I take the zoom audio. After laying it down on the timeline, I sync all the captured AV from the camcorders to it as much as I can.

Even if it's the camera clock crystal frequency that's 'wrong', that's the audio that is in sync with the video!...

...but it's not the audio OP wanted, remember? He wants the zoom audio.

[Cornucopia]

@turk690, I think you might be painting a darker picture than is common. I also have dealt with multiple (100s?), multi-cam/recorder situations (some professional, some prosumer/consumer), and rarely is the mis-sync as extreme as you claim. Instead of 100-300ms, I usually see <150ms, often ~40ms. And that is easily fixed with Time-compression/expansion of the audio.

Also, clappers at start and end as pippas mentioned makes it inconsequential whether there is drift. Combine TC/E (particularly one that can do sample-accurate fit-to-fill) with clappers and an audio editor that can slip/shift down to 1-sample increments (0.02ms) and you can get it right on the mark all the way through in no time. Yes, it is an art, but one that anyone can learn. And I DO NOT recommend you do audio adjustments on some NLEs - only those that allow sample-accurate adjustement of the audio (others can only go by the timescale of 1 video frame). If your NLE cannot do that, export your cam/video's audio track and sync with the Zoom's in a good DAW.

Regarding which audio to take:
The Zoom's audio will be the final copy, but not necessarily in its original form. You use TC/E on it as necessary to fix it to the sync of the picture (because even though video has less time placement resolution, it must be LOCKED and steady, so the Zoom must be adjusted to match. Frankly, if you attempt to modify the video's framerate, you will either be successful and have created a VFR file, which is known to cause playback problems, or your next stage in the edit/convert/distribute process will in a sense act like a TBC and UNDO your adjustment.

Scott

[pippas]

...but it's not the audio OP wanted, remember? He wants the zoom audio.

Which is why he needs to stretch or squash the length of the Zoom audio (if necessary!) -- to match the camera audio length.
Then it will fit easily, and in sync, when it is used to replace the camera audio. Two clapper points near the beginning and end of the track make that a bit simpler to do.

Much better to take the whole separately recorded soundtrack before any editing -correct the length if necessary - replace the camera audio, and then edit. That way you don't need to 'align' lots of small sections separately.

The OP here is asking about replacing one stereo audio track with another - not about multi source editing. For a 'pro' approach, you would probably considered Genlocked sources......or use Plural Eyes

[smrpix]

For a 'pro' approach, you would probably considered Genlocked sources......or use Plural Eyes

Plural Eyes has saved me dozens of hours in the past year, but it does not time compress/expand. It syncs to the middle of the clip.

OP's simplest and best bet (IMHO) is to follow bigass' 4 steps above. Vegas Movie Studio can handle any time expansion/compression if necessary by CTRL-dragging the audio and matching the waveforms.

[bigass]

If dude is just recording himself playing a song on the guitar, I think we're overcomplicating things. Even if he's playing the entirety of side one of Rush's 2112, the drift between audio and video is going to so minute that nobody's going to care.

OP: Roll camera. Roll audio. Clap your hands or give a quick single strum of the muted strings. Sync the transients. Mute the camera audio. If you want to trim the thing, just group the good audio and video together and make your cuts. You're golden. Easy peasy. NBD.

If you're shooting a whole concert, yeah, well, then you'll get into more convoluted solutions. Still, it's not doom and gloom. Cut your teeth on doing short things and re-syncing long stuff, even multi-camera stuff, will become nothing more than an occasional headache.

[pippas]

I think we're overcomplicating things

I think you're right! ... That wasn't my intention with my first post - that was just to suggest a way of doing this using freeware, rather than spending $600 on the Vegas NLE you linked to....

As I said in my first post, once you've done it once, it gets much easier....

Some of the suggestions in subsequent posts have rather taken it a bit further than he probably needs to go, at this stage?.......

[smrpix]

OP: Roll camera. Roll audio. Clap your hands or give a quick single strum of the muted strings. Sync the transients. Mute the camera audio. If you want to trim the thing, just group the good audio and video together and make your cuts. You're golden. Easy peasy. NBD.

And if you want to double-check sync, clap again at the end.