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Rhys

Alexa Timecode Question

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Hi, I have a very strange question about the Alexa and was just wondering if anyone knew if this was possible.

 

If I have a receiver on the Alexa, can I remotely send timecode to it that changes while the Alexa is recording?

 

E.G. My ext TC generator is sending the Alexa free running time code at 25fps starting at 14:02:23:12, everything is running normally and then my TC Generator will send time code (Still at 25fps) starting at 00:00:12:20

 

I know for Audio files on the SD 552 / 664, the timecode is more like a stamp and it is based on what ever the 1st timecode frame was when the recorder starts recording but does the Arri Alexa keep a continuous record of what the timecode is at that specific time?

 

And if so, is it even possible for the Alexa to automatically receive timecode jumping back and fourth as its recording (And update in real time). 

 

I hope this makes sense, thanks for your help.

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What I've found with transmitting time code wirelessly in the past, is that some devices accept it fine, and others are picky about it.

Time code is basically a square wave signal and some devices want to see a clean signal with little rounding of the wave form. Some transmitter/receiver links don't do so well with that.  Also, the level of the signal can matter.

 

It's kind of a try it, and if it works, it works. I'm guessing that it'll probably work okay with an Alexa.

 

The "proper" (note the quotes) way to send time code is to have the receiving device "reshape" the signal prior to sending it into the device it's feeding. 

 

For instance, I've had good success with sending time code to a Denecke slate via a Comtek PR72 receiver, but have run into difficulties with a Sony broadcast camera.  In that instance, it took a lot of tweaking to get the Sony to like the code.  YMMV.

 

 

 

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If I have a receiver on the Alexa, can I remotely send timecode to it that changes while the Alexa is recording? E.G. My ext TC generator is sending the Alexa free running time code at 25fps starting at 14:02:23:12, everything is running normally and then my TC Generator will send time code (Still at 25fps) starting at 00:00:12:20.

 

My advice is not to do this. With tape-based devices, if you change the timecode source on the fly to a different number, the videotape machine will generally glitch and fracture the video, corrupting the signal. With file-based material (like the Alexa), in some cases, the machine will simply start a brand-new file, but in others, it'll again corrupt the signal; with other cameras, they'll note that the new timecode is bad while recording and just ignore it and continue to jam based on the last good timecode signal.

 

I don't think it's a good idea to jump back and forth. You should just record time-of-day and let the timecode continue to move forwards, never jump backwards to a previous number. 

 

What specifically are you trying to do?

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I just got booked to do a music flim clip and am just setting up (in my head) the work flow. I am a sound recordist but will also be doing doing play back on this shoot.
 
- I have asked the production company to send me a copy of the music track so that I can record it straight into my 664 and in the process, give the music track a timecode starting at 00:00:00:00
 
- I want to have time code outputting wirelessly from my 664, it will be going to two Arri Alexas and my Ambient RF 301 Timecode slate.
 
- Timecode will be free running Time of day out of my 664 so when cameras roll up and shoot the slate clap, my 664 will be outputting TOD to all the camera's and slate so the slate will show something like 14:34:32:12
 
-When I press play on my 664, this will all change, Timecode will be altered and will no longer be free running TOD from the 664 generator but instead will be generated from the track i recorded into my mixer days earlier starting at 00:00:00:00
 
Ideally, once I have set everything up, I can just push play on the 664, and all the cameras will change timecode to the what's coming off the recoding and then when they pull it into the edit, everything will line up perfectly with the audio track.
 
This will save heaps of time in post because they will be able to line up all the different shots in post directly to the specific part of the song that it was shot for, it will all be in sync and the editor will be able to choose which angle / shot he likes best.
 
I havent ever done a film clip before, and I only just started thinking about this about 5 mins after I got booked for this job today but in my mind: this is the most efficient way of doing it.

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Thanks John but this is why I was apprehensive about posting exactly what this was about.

 

I knew people would get confused as to what exactly I was asking about, in this case, the fact that i'm making a music video is irrelevant, as is the way other people do them.

 

This thread is really about The Arri Alexa and wether or not it can change timecode streams in real time / mid record, Thanks for your help though.

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I knew people would get confused as to what exactly I was asking about, in this case, the fact that i'm making a music video is irrelevant, as is the way other people do them.

Wow, that's pretty dismissive of a ) the knowledge of the people that have replied to you (undoubtably far greater than your own), and b ) the invaluable information stored in these here pages,

Your proposed setup won't work, but not because of the Alexa - the 664 does not output timecode unless you are in record, regardless of timecode mode.

Recording a file into a the 664 will stamp it to the file header, not cause it or any other device to output a stream of LTC upon playback.

People (including myself) have done MV with timecode plenty of times in the past. It works, but not with the workflow you've come up with. Take a slice of humble pie and do the search.

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Also, I believe that the image files functions the same way that the sound files do, meaning that they are stamped with a TC value at the beginning of the recording but no more.

But I might be wrong.

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the 664 does not output timecode unless you are in record, regardless of timecode mode.

Recording a file into a the 664 will stamp it to the file header, not cause it or any other device to output a stream of LTC upon playback.

People (including myself) have done MV with timecode plenty of times in the past. It works, but not with the workflow you've come up with. Take a slice of humble pie and do the search.

 

 

Wow, I'm very honoured at the opportunity to get some of your feedback Justin but before you go on about how much experience you have with timecode and music videos, you should make sure you are correct when giving advice. Humble Pie? LOL!

 

Here is a video I just shot on my iPhone of my slate in "Reader" mode accepting free run timecode from the 664 and then switching to the timecode of the audio file i'm playing

 

Personally; I have no idea why ANYONE would believe that the 664 can only output timecode whilst in record, Do you actually put your mixer in record while you go and jam all the cameras on set?

 

 

 

Pvanstry: Yeah, thats one of the things i'm worried about. I will have to wait till I get my hands on a camera to test it.

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Hi Rhys,

it seems like you are not going to RECORD any sound before or inbetween the playback, are you?

In that case why bother with TOD timecode at all?

 

I would feed music timecode to camera & slate, you will just need to have enough preroll and start playback before camera rolls.

Depending on your setup you could send audio to the alexas as well, as a bonus.

 

Anyway, ask what editorial department wants!

 

Best,

Claus

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Hi Rhys,

it seems like you are not going to RECORD any sound before or inbetween the playback, are you?

In that case why bother with TOD timecode at all?

 

I would feed music timecode to camera & slate, you will just need to have enough preroll and start playback before camera rolls.

Depending on your setup you could send audio to the alexas as well, as a bonus.

 

Anyway, ask what editorial department wants!

 

Best,

Claus

 

Thanks Claus, I had a chat with another Sound Recordist tonight and he suggested the same thing, Thats now the new plan and I think its going to work beautifully.

 

I love it when a good idea evolves into a great one.

 

I cant wait to see how it all goes, Thanks for the input.

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Wow, I'm very honoured at the opportunity to get some of your feedback Justin but before you go on about how much experience you have with timecode and music videos, you should make sure you are correct when giving advice. Humble Pie? LOL!

Here is a video I just shot on my iPhone of my slate in "Reader" mode accepting free run timecode from the 664 and then switching to the timecode of the audio file i'm playing

Personally; I have no idea why ANYONE would believe that the 664 can only output timecode whilst in record, Do you actually put your mixer in record while you go and jam all the cameras on set?

Admission: missed a line in the manual re: playback TC output. Yum, pie. I admit fault, and I don't have to make a smart-ass remark about it. I don't 'go on about my years of experience', I openly admit when I don't know. Your attitude is pretty foul, frankly.

Obviously the 664 outputs timecode whilst not in record IF the the unit is if free-run or 24-hr run, which allows you to jam devices.

However, you're still faced with the timecode flipping around, which the Alexa probably isn't going to like / if it does, actually takes a few seconds to update to (which HAS to happen before it rolls).

So, you have two options:

1. Give yourself 20 seconds of pre-roll on each take (to get the timecode flowing, jammed into the Alexa, THEN roll the cameras

2. Forget feeding the cameras and use the slate that obviously auto-updates much faster (as proven in your video). This is the method that's been tried and tested for years (and works for non-TC cameras like Film or DSLR). Obviously, it does not have the advantage of stamping the file with TC, so there are caveats with both methods.

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Hi Rhys,

To my knowledge - Alexa 'looks' at the TC generator (within the camera) at the moment when you push the record button, and 'stamps' that TC value onto the file. I believe that 664 does a similar thing. That said, it is possible that either or both devices may look at the TC value when you push the 'stop' button, and back calculates the 'IN' TC value for the file and records that.

Your original masterplan may fall over on account of even if it would work (which I believe the camera will not allow you to do) you would end up with loads of takes with the same TC value in them (say the TC at the 1st verse or chorus) and so would get confuced - which particular 'take' of picture do you wish to associate with this particular set of frames of video.

I would suggest that in this case, you take the TC (or the audio) from your PB machine, and feed either or both to the Alexa's AUDIO tracks when you do the takes. This might be more like what the editors are used to and can cope with.

The other age old method is to use a Denecke GR1, which can do a trick where it generates TOD tc for your recorder, but burns the PLAYBACK TC into the userbits of the TOD codr. SOME video edit machines can make sense of this!!!!

Good luck,

Simon B

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I think this whole idea is just massively confusing in an editorial way.

The only thing that should be done is jam those Alexas together so they are running on the same time of day code. This gives the editors the idea of when the shots were done and allows seamless cuts together in a sequence.

Feed wirelessly each camera a mono track of the output from playback machine. This gives another sync reference to the music and each other in terms of performance.

Send a wireless Rx to the input of slate for t/c playback and hit both cameras when they roll, w numbers (few seconds)

Done. More than enough info.

Don't over complicate time code. Most editors are happy w audio sync and slates run pretty good if they are fed wirelessly. That would be the key test in my opinion.

Give a few seconds lead time on the recorded playback. 20 seconds is wayyyyyy too long for playback on music video. Also have a few beeps at the head.

Personally I think a laptop running protools or what have you is the best tool for the job. Cueing is gonna be a pain in the ass if its further into the song w the 664. Boom Recorder might be a good piece of software for this sort of thing. They do have a thirtybday free trial.

http://www.vosgames.nl/products/BoomRecorder/

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Much good advice above. Some music video playback discussions are at these links:

 

 

 

 

 

The bottom line: don't try to use the music timecode as timecode for the cameras, and don't worry about the timecode restarting over and over again from the music playback. If possible, feed a scratch track to at least one of the cameras so when the editor syncs up all the cameras together, he or she will have an audible reference to use for sound. 

 

It's a bad idea to have identical conflicting timecode on camera files, particularly in non-linear editing on the first day. For example, if camera roll #3A has six different takes that all start with 00:01:30:00, this will wreak havoc on the conform (depending on how it's done). Using time-of-day timecode is much more flexible. 

 

It does help to use a timecode slate feed wirelessly from the playback source. And I'm a fan of starting the music with four count-off beats around 00:59:58:00 and then have the music start right at 1 hour straight up... but not everybody agrees, and lots of different systems can work, provided it's what the post department wants.

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It does help to use a timecode slate feed wirelessly from the playback source. And I'm a fan of starting the music with four count-off beats around 00:59:58:00 and then have the music start right at 1 hour straight up... but not everybody agrees, and lots of different systems can work, provided it's what the post department wants.

This is what I do too. I have a pre-made timecode stream and pips that line up with the song in ProTools (or any DAW/music playback software, really), one channel goes to the loudspeaker, the other channel is timecode sent to a slate. Nothing goes into camera, but they are synced TOD if that's possible.

 

I think it's the Denecke TS-2 that can handle off-speed timecode. I tried 'sped up' timecode (for 35 and 50fps) with my TS-3EL and it didn't like it much...

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This is what I do too. I have a pre-made timecode stream and pips that line up with the song in ProTools (or any DAW/music playback software, really), one channel goes to the loudspeaker, the other channel is timecode sent to a slate. Nothing goes into camera, but they are synced TOD if that's possible.

I think it's the Denecke TS-2 that can handle off-speed timecode. I tried 'sped up' timecode (for 35 and 50fps) with my TS-3EL and it didn't like it much...

Earlier TS-3 slates couldn't handle time code that was sped up more than a little. Newer ones can handle high speed. The earlier TS-3 slates can be updated to handle it.

For high speed music videos I prefer using my TS-1 over the TS-3. I just throw a Comtek receiver on the TS-1 and it'll handle anything I throw at it, speed-wise. The broader base of the 1 means that it'll also sit upright nicely if need be.

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I mean if you want to get really fancy you could feed track one of the Alexa w a mono PB track and the other side the playback TC audio. But in my opinion it's somewhat overkill with the slate involved.

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Since you've got the Ambient RF Slate, you could use the READER/GEN Mode:

 

When slate is opened it displays ext TC (= Playback timecode, via RF) and when the slate is closed it displays generator TC (which you can sync to your 664 TOD and Alexa timecode)

 

So you would have both time codes displayed, I just tried it out myself and it works beautifully  8)

 

Best,

Claus

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" I knew people would get confused as to what exactly I was asking about, in this case, the fact that i'm making a music video is irrelevant, as is the way other people do them. "

wrong,  wrong, and wrong.

 

this is and was standard music video workflow.

 

you could theoretically put the music playback TC in the userbits. (this takes care of having the same timecode for multiple takes...)

typically, you use a TC slate being fed the TC from the music  roll the playback before camera, and shoot the slate.

or you could theoretically  feed  TC w/ music TC in UB, and feed the PB as TC to the visual slate.

 

in any and every case, a workflow test is required.

Edited by studiomprd

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" I knew people would get confused as to what exactly I was asking about, in this case, the fact that i'm making a music video is irrelevant, as is the way other people do them. "

wrong,  wrong, and wrong.

 

this is and was standard music video workflow.  you put the music playback TC in the userbits. (this takes care of having the same timecode for multiple takes...) you use a TC slate being fed the TC including music TC in the UB... roll the playback before camera, and shoot the slate.

 

We actually tried this at Complete Post quite a few times, and were never able to get the User Bits code out of the signal for reliably logging onto Evertz or Aaton timecode systems. For Dreamgirls -- which was a long-term, huge feature project -- they cobbled together a custom-made, jury-rigged system that could do it to some degree, but we still had to have a human come in after every dailies reel was completed and manually read the User Bits code off the screen and painstakingly type it in. Suffice it to say, it was laborious and expensive to do. (And I'm not sure what any editor could do with User Bits in Avid or Final Cut today, in terms of syncing stuff up beyond just using the scratch track as reference.)

 

I think people make out music video production to be a lot more complicated than it needs to be. Just regular playback with a timecode slate showing the music timecode works great. Dreamgirls was a special case since there was live production dialogue during the music, so there was no other way to get around it there. But for regular music, it ain't no thang.

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