Analog audio into multi-channel mix

[Piotr Wozniacki]

As a fresh NanoFlash owner, I'd just like to ask this question:

What I had been suggesting to our fiends Mike and Dan of CD before I got sick for a long time, and stopped following the NanoFlash development, was this:

- would we be able to combine the HD-SDI embedded audio tracks (2 in the case of XDcam) with 1 or 2 additional (analog) audio channels from a device plugged directly to the Nano?

My question is (sorry if I've been left behind due to my period of illness inactivity):

- Can we do this with the current hardware/firmware?
- If not, is it coming as a firmware update, or will it require hardware upgrade?

Thanks,

Piotr

[Dan Keaton]

Dear Piotr,

We are working on 8-Channel Audio.

And we are working on +2 Channel Audio. This is x number of Embedded Channels plus two channels of analog audio.

These two features are major developments that require lots of work.

We were trying to get these ready, for a beta release, for December.

It now appears that these new features will not be in our December Beta release.

[Mark Job]

Hi Dan:
This could be really cool. This could open the door for on set location recording of 7.1 Surround Audio, plus 2 tracks extra for dialogue. Imagine a job where you have to shoot a live concert for television or Blu-ray DVD release ? Imagine Andrea Bochelli on Analogue 1 and 2, plus accompanying piano on 3(embedded), then bass violins on 4 and 5(embedded), then horns on 6 and 7(embedded), and finally piccolo flute on channel 8. Wow !

[Billy Steinberg]

Mark,

I shot the last four of five Bochelli concerts (including a couple in Italy; alas I was unavailable for the last Bochelli Christmas show recently shot in Las Vegas). I've also shot many, many, many live concerts, including the 22 camera Rock and Roll Hall of Fame 25th Anniversary concert from Madison Square Garden that's been playing all month on HBO, and I hate to be the one to tell you that no one uses the audio tracks from the video tape recorders for the final product...

The HBO show, for example, recorded the audio on two 96 track recorders. It's remixed and sweetened as part of the editing process. The audio tracks on the video recorders are only used for reference.

That said, I too am looking forward to 8 channels of SDI on the nano (as well as hot swapping; sorry I had to put my monthly hot swapping request :).

Billy

[Piotr Wozniacki]

As someone who also does live classical performance recording, I second what Billy said about how professional audio is acquired.

Nevertheless, I'm looking forward to the mere possibility of recording stereo ambient sound AND the main voice track without a need of any extra equipment, and using just the EX1 2-track camera! Not for the final music masters perhaps but for general use, it's going to be awesome.

[Dan Keaton]

Dear Friends,

We are planning on 8-Channel Audio.

Also we are developing +2 Channel Audio.

The maximum number of channels will be 8

If you have 2 channels of embedded audio, either from HD-SDI, SD-SDI or HDMI, then with +2 you get four channels.

If your camera or other source has 4 embedded channels, then you can have 6.


Another very important aspect of 8-Channel audio is for program delivery.

We expect that you will be able to setup a timeline with 8 channels of audio, then render it, then use our File Converter to load it to a CompactFlash card.

Then, you can use this for delivery purposes.

[Mark Job]

Originally Posted by Billy Steinberg

Mark,

I shot the last four of five Bochelli concerts (including a couple in Italy; alas I was unavailable for the last Bochelli Christmas show recently shot in Las Vegas). I've also shot many, many, many live concerts, including the 22 camera Rock and Roll Hall of Fame 25th Anniversary concert from Madison Square Garden that's been playing all month on HBO, and I hate to be the one to tell you that no one uses the audio tracks from the video tape recorders for the final product...

The HBO show, for example, recorded the audio on two 96 track recorders. It's remixed and sweetened as part of the editing process. The audio tracks on the video recorders are only used for reference.

That said, I too am looking forward to 8 channels of SDI on the nano (as well as hot swapping; sorry I had to put my monthly hot swapping request :).

Billy

.....Hi Billy:
Wow ! 2 x 96 track recorders ! Of course, I would indeed try and use the tracks available on the XDR via HD-SDI 8 Channel embedded + 2 Analogue balanced inputs on the XDR ? Right Dan ? What did I miss ? Or is it 2 channels of balanced Analogue in + remaining 6 channels available via the HD-SDI common embedded standard ? I understood you can have a maximum of 16 channels of embedded 24 bit 48 Khz audio in the SDI- spec. (??) I also think this is why there should be the *Option* in the audio setup menu to have at least *two channels of 96Khz 24 bit audio.*

So Billy, they use a master TC clock and Jam Sync the cameras to that and lay down a TC control track on one or both of the 96 track audio recorders from the master TC clock as well ? Why not use an SDI audio embedder and do a live mix down to 8 channels from there going to an XDR or a Nano along with master TC.

[Mark Job]

Originally Posted by Dan Keaton

Dear Friends,

We are planning on 8-Channel Audio.

Also we are developing +2 Channel Audio.

The maximum number of channels will be 8

If you have 2 channels of embedded audio, either from HD-SDI, SD-SDI or HDMI, then with +2 you get four channels.

....Hi Dan: Perhaps my math may well be faulty here, but if you are developing 8 Channel recording which is embedded in the SDI stream, and you already have 2 channels embedded, then shouldn't you have an additional *6* channels available via embedding into the HD-SDI stream ?? Did I miss something ?

Respectfully,

[Dan Keaton]

Dear Mark,

I believe that, at this time, we are planning on a maximum of 8 channels.

Mark, if you have the equipment to record isolated channels, it is always better to do so.

We will be discussing 96K audio, but I am making no promises. I doubt we could do some 96K and some 48K.

[Mark Job]

Hi Dan:
OK. I was suggesting this option in order to be able to secure a hi-fi Stereo Master Mix which could be taken from the location audio mixer at the concert. This special Hi-Fi feature would be like an extra safety backup in case something went wrong. Is the 96 Khz 24 bit option a technical limitation for the Nano and XDR ? EDIT: Or are you saying it has to be one or the other setting ? In other words, It can't be two channels of 96 KHz and the rest be 48 KHz. It must all be 48 or all be 96 Khz.

[Dan Keaton]

Dear Mark,

We are not currently working on 96K audio.

Without researching it, I expect that all of the channels will have to be the same bit-rate, either 48K or 96K.

[Mark Job]

Hi Dan:
Understood. I do recognize that 96 Khz 24 bit audio is outside the current SDI Standard for embedded audio channels.

Respectfully

[Lance Librandi]

Hi Dan,
This will be a great feature I am currently looking for ways to embed 8 -16 audio channels into the SDI stream. The quality of the mixed down audio signal I get from some of the venues is very poor. I would be better off recording everything flat and mixing down in post, I will wait and see what you guys come up with.

[Billy Steinberg]

Originally Posted by Mark Job

.....So Billy, they use a master TC clock and Jam Sync the cameras to that and lay down a TC control track on one or both of the 96 track audio recorders from the master TC clock as well ? Why not use an SDI audio embedder and do a live mix down to 8 channels from there going to an XDR or a Nano along with master TC.

Not exactly. The cameras are not jam synced to anything. In fact there is no way to jam sync a camera since there is no time code being generated in the camera. The cameras are all genlocked to a master sync generator (again, having nothing to do with time code). So all the cameras are in perfect sync with each other. The cameras you're used to using have a recorder in them, and with it, a timecode generator. When you jam sync one of them, what you're doing is jam syncing the timecode generator. That feeds the built in recorder. The nano has a timecode generator built in too (as do most recording devices these days), and that's what's being jam synced. Our cameras aren't camcorders, they're "just" cameras.

Our master time code generator is synced to the same sync generator everything else is (including the cameras). So the timecode coming out of the timecode generator is in sync with everything (not the other way around). The master sync generator is god; the timecode generator is a slave to god, like everything else. (note the lower case g). You can set whatever time you want on the generator, and whether it's drop frame or not, but the timecode generator is still synced to the master sync generator that's syncing everything else. The master sync generator does not put out timecode, it puts out tri-level sync and blackburst.


We recorded each the cameras (22 in the HBO concert we were talking about) on their own tape machine, as well as a "line cut" (to two other tape machines, a main and a backup). The individual recordings are called iso recordings. The line cut is a scratch cut of what the director thinks he will want for the final product, but he has all the individual camera recordings available in post, and he fixes up any mistakes in the line cut, as well as cuts in different camera shots that he feels are better than the ones he used in the live line cut. Since this show was not aired live, he got to make it much better than the one he cut on the fly.

The same thing (essentially) is done with the audio. There is a truck just for the audio, and every sound source (microphones, instruments, etc) is individually recorded. The audio engineer (called the A1) makes sure the levels for each channel are as desired (not that they remain constant) and the equalization is close to what he wants for each channel being recorded. Then he also (simultaneously) makes a live mixdown (can be two channel or 5.1 or whatever) that is used as a rough mix that all of us listen to while the live show is going on. This live mix goes to all the tape machines. And yes, we do feed timecode to the audio guys to record on one track on each machine they use. We also feel them our locked sync. The sync is necessary to make sure the audio from the audio tapes stays in sync with the picture from our video tapes when everything is posted. The timecode allows the machines to be locked to the same place in time (not just synced in speed, but synced in position as well).

Much like the director fixes up the (video) line cut in post, he also fixes up the audio mix as well.

Billy

[Mark Job]

Originally Posted by Billy Steinberg

Then he also (simultaneously) makes a live mixdown (can be two channel or 5.1 or whatever) that is used as a rough mix that all of us listen to while the live show is going on. This live mix goes to all the tape machines. And yes, we do feed timecode to the audio guys to record on one track on each machine they use.....The timecode allows the machines to be locked to the same place in time (not just synced in speed, but synced in position as well).

Much like the director fixes up the (video) line cut in post, he also fixes up the audio mix as well.

Billy

....Hi Billy:
Yes indeed. This is precisely why I suggested this live line audio mix could be sent to an XDR or a Nano along with the video of the live cut (Switched Live ?) and the audio TC as a backup, but @ the 96 KHz 24 bit audio level. Both Avid Media Composer and Final Cut Pro 7 are ready for audio this high up, while FCP can even do 128 KHz @ 32 bit samples ! The amount of time which could be saved in post production by going this route would be significant in a high end Tv production like Andrea Bochelli in Concert on PBS or CBC in Canada.

Billy, what is the video format you folks are shooting these kind of productions in ?