Hi there, I wanted to record a concert which was broadcasted on the radio and got burned by the 2G file size limitation.
Here's the command line I used:
rawrec -v -t 36600 | \
sox -t sw -r 44100 -c 2 - -t wav - | \
lame --alt-preset insane - `date +%T`.mp3
Packages: rawrec, sox, self-compiled lame.
I only used lame, because I thought my system wasn't LFS-ready (Large
File Support). The resulting file was 464 MB in size, which would be
exactly 2G if it were a wav file. The audio stops at 202:53 minutes,
exactly the length that fits in a 2G wav file.
Turns out, that my system is partially LFS-ready. Ie, the command
dd if=/dev/zero of=/tmp/large-file bs=1M count=2560
(as suggested in another thread, recently) creates a file that is 2.5 GB
big. (Both on a local harddrive and on a NFS-mounted file system.)
So the problem is either in the piping of the contents or one of the
programs isn't LFS-ready. Crap.
I'm using an partially up-to-date sid system. rawrec and sox are
up-to-date, lame is self-compiled, so I'm not sure, that this wasn't the
bottleneck. I'm pretty sure, that the piping wasn't either, because
cat /dev/zero > big-file
produced a file that is bigger than 2G.
Here's the output from the at job:
rawrec: warning: speed (-s) will be set to 44101 instead of requested
value of 44100
sox: Length in output .wav header will be wrong since can't seek to fix it
LAME: Can't get "TERM" environment string.
LAME version 3.91 (http://www.mp3dev.org/)
Using polyphase lowpass filter, transition band: 20094 Hz - 20627 Hz
Encoding <stdin> to /home/viktor/radio/fritz-7.9.2002-seeed-live.mp3
Encoding as 44.1 kHz 320 kbps j-stereo MPEG-1 Layer III (4.4x) qval=2
rawrec: write syscall to output failed: Broken pipe
rawrec: main buffer overflow, giving up
I'm guessing that sox is the problem here.
I've played along with the rec command from sox, but I get crappy audio
when recording from /dev/dsp.
What's a good way to record audio from /dev/dsp? I'm looking for a
solution that creates wav files that are bigger than 2G *and* works on
the command line. The command line is necessary, because I want to
schedule recordings with at.
Any hints are appreciated. I'm using an partially up-to-date
sid system. rawrec and sox are up-to-date, lame is self-compiled, so
I'm not sure, that this wasn't the bottleneck. I'm pretty sure, that
the piping wasn't either, because
cat /dev/zero > big-file
produced a file that is bigger than 2G.
Ciao,
Viktor
PS: The concert in question was Seeed, who played today in the Arena,
Berlin. Radio Fritz broadcasted it. I have the Gentleman set in
beautiful beautiful quality, if anybody is interested, but Seeed got cut
off after 15 minutes of their set. Fuck.
--
Viktor Rosenfeld
WWW: http://www.informatik.hu-berlin.de/~rosenfel/
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