recordaifc(1)recordaifc(1)NAME
sfrecord, recordaifc, recordaiff - record an audio file
SYNOPSISsfrecord [sfoptions] [options] filename
recordaifc [options] filename
recordaiff [options] filename
sfoptions: [-w samplewidth]
options: [-help] [-verbose]
[-n nchannels]
[-s samplefmt]
[-r rate]
[-t time secs]
[-f filefmt]
[-d device]
[-c compression]
DESCRIPTIONsfrecord creates an output file containing audio sample data recorded
through the audio hardware. sfrecord records audio input for a time
equal to a given -t argument, or until the user sends it an interrupt.
The file's sampling rate will be equal to the rate of the default audio
input device. This can be set via the -r argument. The format,
compression, and channel count can be set via the appropriate arguments.
Silicon Graphics has adopted AIFF-C (".aifc" suffix) as its standard
interchange file format for digital audio sample data. AIFF-C is an
extension of the AIFF standard which includes support for compressed
audio data. The recordaifc and recordaiff programs provide a restricted
interface to sfrecord as follows:
recordaifc creates output files exclusively in AIFF-C (or AIFF) file
format, and supports a smaller number of compression types. recordaiff
creates output files in AIFF file format with no compression options.
The -c option allows you to compress audio data in real-time while
writing it to an formats which support compression. There are several
compression algorithms available: G.711 2:1 mu-law or A-law recommended
for 8 KHz, 16-bit mono or multichannel data, G.722 4:1 compression
recommended for 16 KHz, 16-bit mono or stereo data, G726, G728, GSM,
MPEG1 Audio, and DVI ADPCM (for WAVE files only).
When any of these programs receives a user interrupt, it writes all
sample data in the audio buffer out to disk and updates the header before
it exits.
recordaiff and recordaifc are installed as links to sfrecord for backward
compatibility. The only difference between the first two is that
recordaifc creates AIFF-C files by default, while recordaiff creates AIFF
files by default. sfrecord's functionality is a superset of the others.
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recordaifc(1)recordaifc(1)OPTIONS-h help: print out a list of command line options and their
descriptions
-v verbose: output to stdout
-f file format: aifc or aiff [for recordaifc], aifc, aiff, next, wave,
or raw [for sfrecord].
-n number of channels: 1 = mono, 2 = stereo, 4 = 4-channel,
-s sample format: 8, 16 [for recordaifc]
-d audio device from which to get audio
-r sample rate: 48000, 44100, 32000, etc
-c compression type (mono or stereo AIFF-C only): ulaw , alaw, or g722
-t length of recording session in seconds: floating point value
FILES
Source code for recordaifc is installed here:
/usr/share/src/dmedia/soundcommands
BUGS
To record files containing sample data which is compressed with G.722 or
Aware you will need to run recordaifc with nondegrading high priority
(this is especially true for stereo compressed data).
If being run as root, the priority is set to NDPNORMMAX which is the
highest normal process priority. If run as a user, the process is set to
the highest non-degrading priority allowed by the system. This parameter
is unfortunately by default lower than any normal process, but can be
changed using systune(1M). Alternately, see the man page npri(1) for
information about how to set custom priorities and time slices.
SEE ALSOplayaifc(1), apanel(1), aiff2aifc(1), aifcresample(1), aifccompress(1)
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