maximum audio filesize?

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maximum audio filesize?

Postby kelldammit » Wed Jul 12, 2006 3:43 pm

hmmm, well so much for the new macbook being "non-mission critical"...
just curious if there's a maximum record length or filesize limitation i need to be aware of as regards metro (latest prerelease ub), as i will be recording a couple seminars over the next few days...i'm looking at minimum 1 1/2 hour record times uninterrupted, most likely as long as 3 hours at a pop. each 1 1/2-3 hour segment will be a separate file.
i'll most likely record at 44.1/24 to an external usb2 drive (firewire will be used by my traveler).
any known boogaboos?
kelldammit
 

Postby Jerm » Wed Jul 12, 2006 8:39 pm

Metro can only position within a file to 2^32 bytes or 4 gigs. It can write bundle files bigger than 4 gigs but not audio files (off the top of my head).
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Postby kelldammit » Wed Jul 12, 2006 9:18 pm

oh, cool. i'm pretty sure the last of these i did, the average filesize was quite a bit smaller...perhaps only up to 1g a piece. i'll probably break them up as best i can, as doing a bunch of edits on one or two humongous files is less than ideal :)

thanks so much for the info...i'll rest much better tonight :)
kelldammit
 

Postby Scoot » Thu Jul 13, 2006 1:43 am

Are you planting the macbook in front of the speaker (person) beforehand, running a microphone or just using the mac screen's mic?
The screen mic may be a little weak if far away.

Make sure they don't grab the mac for keynote presentations or start playing with front row while you're not looking :lol:


Have happily recorded 2 hours and 25 minutes in Metro non-stop - wanting a DVD audio commentary to go onto my ipod.......and it was around a gig......then cut right back as a mp3 in itunes.


If you use 16bit you cut down the size of the file by a third ( 8+8 instead of 8+8+8 )......and would you notice the 24 bit quality?
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Postby kelldammit » Thu Jul 13, 2006 2:23 pm

scoot:
i've done similar (much longer) events with my old powerbook/dp4.61/lacie external usb2 drive/traveler. they were fairly simple, just took an aux send off of the board, and hit go as necessary. started new files at breaks. each recording ran 2-3 hours a pop, for a total of 10-12 hours per day, for 3 days. i did not particularly enjoy the editing/burning of such a long event (editing speeches you've already sat through is a whole new definition of tedious!), but it went without a hitch.
for this event though, they didn't have a nicer mixer budgeted, so...
i ran the two wireless mics (a handheld and a headworn) directly into the traveler. i then used cuemix and created 3 separate mix busses.
one bus went to a marantz tape deck (backup recording), the second went to the house pa (overhead speakers), the third went to headphones for monitoring.
each mic got its own track in metro. oh, and the recording rig was at the back of the room, away from prying eyes/curious fingers, and the front row remote was safely locked up in the office! :D
i usually record 44.1/24 rather than 16 because i typically end up using some eq and compression after the fact to "even out" the overall sound across different mics and presenters. also, since i track at pretty low levels (to try and avoid clipping as best i can), i use the compressors to kick up the end levels. so since i'm using effects, etc, i just keep at 24 bit to preserve as much as i can. it's more a matter of me being anal than any kind of real necessity dictated by the program material. after the editing, compression, and eq, i bounce/dither, then take the final aiff, and slice it up into the various tracks for burning.

i'm pleased to report that the recording went well this morning...i really need to read the manual...i found it disconcerting that the graphic editor/channels window waveform displays did not update as things were recording, but only after i hit stop...
the only real serious glitches i've run into thus far, were unrelated to metro itself:
the first anomoly was during a test run prior to the event, i got a couple of "device has been disconnected without being ejected...some data may have been lost" warnings. the scary part was that the lacie had NOT been disconnected. all connections were snug, etc. needless to say, i ended up tracking to the macbook's internal drive.
the second anomoly was a couple of clips as the second speaker got settled in, but i'm not sure what they're from (perhaps they bumped the mic, adjusting it?). here's the waveform of one of them:
Image
fortunately, neither such clip was during a necessary part of the presentation, so they can be edited out without issue.
otherwise, it went smooth as glass.
now, to editing...and another identical session tomorrow!
:D
kelldammit
 

Postby Jerm » Thu Jul 13, 2006 4:17 pm

The click definitely looks like the audio level was too hot like a microphone bump.
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Postby Scoot » Fri Jul 14, 2006 3:18 am

I suppose the place to adjust levels is the mixer meters.
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Postby kelldammit » Fri Jul 14, 2006 4:50 pm

on record, the traveler WAS the mixer, or isn't that what you mean? the levels were good, nominally not even pushing 1/2 the travel on any meter i used (cuemix, traveler front panel, metro).
recording today went without incident.
now i'm just finishing up the edits, then i put an eq on each mic track, balance levels, put a compressor on the master, and i'm home for the night :)
kelldammit
 


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