How much space is audio gonna take

[Blayne Gorum]

Now that we have roadmap indicating that audio recording is to be implemented sometime in October, do we know what the data rate and the storage space requirements will be?

I know that current CF (8Gb) cards hold roughly 4 minutes and 20 seconds. What happens when 2 channels of audio are added to that? 4 channels?

[Jim Hoffman]

48k 16bit audio is about 6megs per minute of mono audio provided there in no data compression. The question is are all 4 channels recording all the time or can you limit use to select tracks???

[Blayne Gorum]

I thought the spec was 48K/24bit. I know I saw that in a couple threads.

I was assuming no compression, but I haven't seen that answered either.

[jbeale]

Red One FAQ: http://www.reduser.net/forum/showthread.php?t=1487

Mini-XLR Audio Inputs – These ports provide phantom power for either line or mic input for four channels of balanced audio input. They are capable of recording uncompressed 16/24-bit audio at 48KHz. Pin-outs consist of ground, audio in [H], audio in [C].

[Conrad Kucharski]

I can see the practical uses for implemented audio in documentary or ENG type work.. but for feature use, I would just stick with a nagra and keep the extra space for my picture.

[Blayne Gorum]

I can see the practical uses for implemented audio in documentary or ENG type work.. but for feature use, I would just stick with a nagra and keep the extra space for my picture.

I couldn't agree more. But I don't do feature work right now.

And Nagras? I think those went out about the same time as leaded gas. ;)

[Craig Schober]

I couldn't agree more. But I don't do feature work right now.

And Nagras? I think those went out about the same time as leaded gas. ;)

nagras and dats are great but i'm looking to do feature production with a smaller crew and not have re-sync everything in post. to me that means, let the sound guy boom the shoots and work levels on a little preamp. so long as he can monitor and knows my baseline settings in cam, it should be fine. that cuts out one crew member. now if only i can get good enough to pull my own focus too.

[ChrisLyon]

DATS are great for backup. We use one in conjunction with our HDD based system just in case of a failure. They are inexpensive and we already had one before going digital... so why not?

[Billy Summers]

IMHO...DATS SUCK!!!

Nagra's work, but are things of the past...
Since about 04-05 I've seen everybody (audio dudes) switch over to the Fostex (and "other brands") Hard disk recorders and haven't seen anyone look back since. "higher quality, easier workflow etc."



my 25 cents...

[ChrisLyon]

Looks nice :ph34r:

[Conrad Kucharski]

I couldn't agree more. But I don't do feature work right now.

And Nagras? I think those went out about the same time as leaded gas. ;)

I guess I just aged myself...

[Damien Molineaux]

IMHO...DATS SUCK!!!

Nagra's work, but are things of the past...
Since about 04-05 I've seen everybody (audio dudes) switch over to the Fostex (and "other brands") Hard disk recorders and haven't seen anyone look back since. "higher quality, easier workflow etc."



my 25 cents...

DAT is definitely on its way out. Manufacturers have stopped making them and some can't even be serviced anymore, and for those that can be serviced, it'll cost ya an arm and a leg.

If I'm not mistaken however, Nagras make HD recorders now, and they're top of the line.

As to other brands, there are many out there. For the doc. I'm producing right now : "Unwanted witness", being shot in Colombia as we speak, the sound engineer just purchased a Sonosax miniR82 ( http://www.sonosax.ch/index2.html ), what a beauty. It is tiny, has an internal HD and CF module. Two powered XLR inputs and other inputs including midi allowing for a total of up to eight channels. Also has TC input of course. I'll just add it is swiss made.

Cheers,
Damien

[David Battistella]

There is little data about how the audio recording will work.

Aside from putting it on the disk along side the picture in sync, there are a few other things to consider.

1. Is it 48K 24 bit or 16 bit?
2. With four tracks of audio will you still be able to record to CF?
3. how does one adjust incoming audio levels? (as there are no audio potentiometers on the camera body)

Practical questions that I have not been able to find an answer to.


David

[John Cordell]

The RED.com site claims 4 channel 24bit 48khz uncompressed once audio is fully enabled.

That's about .6MB per second. So full sound will only add about 2% to the total storage and bandwidth needed for the image. Another way to think of it is an 8GB card will hold 4 minutes 30 seconds of footage, or 4 minutes 25 seconds of footage plus sound.

[Mark L. Pederson]

METACORDER -

http://www.gallery.co.uk/metacorder/intro.html

[Jarred Land]

John is pretty close.. its definitely not something you will really need to be too worried about.

[David Battistella]

John is pretty close.. its definitely not something you will really need to be too worried about.

Jarred,

Thanks for the clarification.

David

[Blayne Gorum]

METACORDER -

http://www.gallery.co.uk/metacorder/intro.html


Boom Recorder-- It's like getting Metacorder, but the MacBook is free!:bleh:

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

[Rob Lohman]

24-bit 48 KHz. If I remember correctly you can choose between storing 0, 2 or 4 channels of audio (I could be wrong on that though, Stuart knows all).

For 2 channels you're looking at an additional 0.37 MB/s of data. For 4 channels it's 0.73 MB/s of extra data. There is a little bit of extra overhead, but that's small.

So I think we're good for compact flash, but it will of course have to verified that this is indeed the case.

[The Subsidiary]

IMHO...DATS SUCK!!!

Nagra's work, but are things of the past...
Since about 04-05 I've seen everybody (audio dudes) switch over to the Fostex (and "other brands") Hard disk recorders and haven't seen anyone look back since. "higher quality, easier workflow etc."



my 25 cents...
I love my Aaton Cantar HD Recorder, I have a trusty old Nagra too, I pull it out if we're doing a lot of gunshots or other really loud things, when it gets blown out, on analog it can sound good, on Digital, when it blows out it's all over. NG...I wish I could use the Nagra it more, but reloading every 10 minutes doesn't work for most productions. I still use my DAT as a backup, they're all just tools. Just like the mics.

[The Subsidiary]

METACORDER -

http://www.gallery.co.uk/metacorder/intro.html

I have this too, If I need 20 tracks at once and you don't have to move around much it's a good way to go. All you need is this software, a MBP some kind of a Fire wire interface, (I like Metric Halo) a lot of people use MOTU Traveler. Mackie Onyx is apparently a good way to go too if you want to be able to process the tracks more directly.

I used this system last for a Pilot reality show kind of like "The Real World." Nineteen tracks at once...Just remember to set your computer to not Sleep...That's where I had little snafu...

[David Battistella]

24-bit 48 KHz. If I remember correctly you can choose between storing 0, 2 or 4 channels of audio (I could be wrong on that though, Stuart knows all).


OK 48K 24bit. Excellent. Up to four tracks excellent.

Anything on level adjustment? Is it a menu option?

Is there any word on whether RED can be record "audio only" clips as well?

David

[Kevin Halverson]

24-bit 48 KHz. If I remember correctly you can choose between storing 0, 2 or 4 channels of audio (I could be wrong on that though, Stuart knows all).

For 2 channels you're looking at an additional 0.37 MB/s of data. For 4 channels it's 0.73 MB/s of extra data. There is a little bit of extra overhead, but that's small.

So I think we're good for compact flash, but it will of course have to verified that this is indeed the case.

These numbers would indicate more than a 'bit' of overhead (pun intended).

Consider the following: 16 bit is 2 bytes per channel per sample

2 x 2 x 48,000 = 192,000 b/s for 2 channel 16 bit @ 48 kS/s (minimum configuration)

24 bit is 3 bytes per channel per sample

4 x 3 x 48,000 = 576,000 b/s for 4 channel 24 bit @ 48 kS/s (maximum configuration)

The headers used in PCM audio formats (Wave or AIFF) have very small overhead (the minimum for a valid AIFF header is only 54 bytes).

There is either additional overhead or something is wrong with the indicated numbers.