In Praise of Large Disks
Oct. 19th, 2012 05:20 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
bjarvisI've been participating in a CALLERLAB project this month. Every year, CALLERLAB has been hosting a large conference of square dance callers, and most of the regular sessions (as opposed to committee meetings) have been recorded. In recent years, the recordings have been distributed on CD, but earlier years are on cassette tapes. We're now digitizing the cassettes into MP3 files for archiving and distribution.
I'm using an old cassette Walkman to play back each side of thirty-one 45 minute cassettes from the 1998 convention. The analog audio is piped into the sound card of a desktop workstation running WindowsXP and Audacity, sampling the data at 32,000 Hz. Last night, I finished digitizing the audio. The raw data on this first pass has chewed up 20GB of hard drive space.
Each side of each cassette was recorded into a single file. Today, I'm stitching the A & B data files into a single file, editing out the producer's comment "This is the end of side A. Please flip the tape over, rewind it and press play to hear the B side" and taking out any button click noise, then saving the resulting combo file, typically 600MB in size.
Once I have a single Audacity project file for each cassette, I convert the data into an MP3, typically about 70MB in size.
I'm keeping all of the intermediate files along the way so that if I find I've made a catastrophic mistake, I can pick up from part way through the pipeline instead of starting from scratch. And needless to say, I'm making a full backup of everything to an external drive every few hours, just in case I accidentally overwrite or corrupt any of my intermediate steps.
In all, I have 56GB of disk space tied up in this project right now. This isn't enormous, but it's enough that this work would have impractical if not impossible only a few years ago. A faster workstation with more RAM would have helped some of the editing and MP3 conversions but I was mostly constrained by the speed of the analog cassette playback anyway.
Now to package up the MP3 files and send them back to the home office...
I'm using an old cassette Walkman to play back each side of thirty-one 45 minute cassettes from the 1998 convention. The analog audio is piped into the sound card of a desktop workstation running WindowsXP and Audacity, sampling the data at 32,000 Hz. Last night, I finished digitizing the audio. The raw data on this first pass has chewed up 20GB of hard drive space.
Each side of each cassette was recorded into a single file. Today, I'm stitching the A & B data files into a single file, editing out the producer's comment "This is the end of side A. Please flip the tape over, rewind it and press play to hear the B side" and taking out any button click noise, then saving the resulting combo file, typically 600MB in size.
Once I have a single Audacity project file for each cassette, I convert the data into an MP3, typically about 70MB in size.
I'm keeping all of the intermediate files along the way so that if I find I've made a catastrophic mistake, I can pick up from part way through the pipeline instead of starting from scratch. And needless to say, I'm making a full backup of everything to an external drive every few hours, just in case I accidentally overwrite or corrupt any of my intermediate steps.
In all, I have 56GB of disk space tied up in this project right now. This isn't enormous, but it's enough that this work would have impractical if not impossible only a few years ago. A faster workstation with more RAM would have helped some of the editing and MP3 conversions but I was mostly constrained by the speed of the analog cassette playback anyway.
Now to package up the MP3 files and send them back to the home office...
