I wanted to record a talk this week so I took my MacBook Pro laptop with me to the auditorium where the talk was being held. I normally use the QuickTime Player to record audio in such cases. But this time when I attempted to use the QuickTime Player, it wouldn't actually start recording. The presenters had started talking when I attempted to begin recording their presentation, so I opted to install Sound eXchange (SoX), which provides a command-line interface (CLI) for recording and editing audio on a variety of operating systems, including Microsoft Windows, Linux, and OS X. Since I had previously installed Homebrew on OS X on the system, I opened a Terminal window and used it to install SoX.
$ brew install sox Updating Homebrew... ==> Auto-updated Homebrew! Updated 1 tap (homebrew/core). ==> New Formulae brew-php-switcher fortio libbitcoin-protocol eccodes goreleaser nifi-registry fork-cleaner kakoune wireguard-go ==> Updated Formulae poppler ✔ gst-plugins-bad pdftoedn ace gst-plugins-base pdftoipe activemq gst-plugins-good pdnsrec agedu gst-plugins-ugly pdsh ammonite-repl gst-python pegtl amqp-cpp gst-rtsp-server percona-toolkit angular-cli gst-validate perkeep annie gstreamer petsc ansible gtksourceview@4 pgloader apibuilder-cli gx pgroonga aptly gx-go pidgin arangodb heroku pilosa archey hesiod pipenv aria2 hopenpgp-tools plantuml armadillo icarus-verilog plowshare artifactory imagemagick postgresql aws-sdk-cpp imagemagick@6 postgresql@9.4 awscli inetutils postgresql@9.5 azure-cli infer postgresql@9.6 babeld ipfs postgrest babl ipython pound bcal ipython@5 pre-commit bettercap iso-codes presto binaryen ispc proguard bind jenkins proxytunnel bitrise jfrog-cli-go psqlodbc bmake jhiccup pumba byacc jhipster purescript caddy joplin qcachegrind cake jsonpp qjackctl calicoctl keepassc qpm cargo-completion kitchen-sync qt carrot2 knot raine cask kompose raylib cfitsio kubeless redshift cfssl kubernetes-cli reminiscence cglm kubernetes-helm restic cimg lastpass-cli restview citus launch4j rhino clang-format libbi rocksdb clojure libbitcoin-client root cmake libbitcoin-explorer rsyslog cockroach libbitcoin-server s-nail coffeescript libgphoto2 sagittarius-scheme consul libidn schismtracker convox libidn2 shfmt coreos-ct libphonenumber siril cppcms libpq skaffold cromwell libpqxx skafos curl libqalculate skipfish dartsim librealsense snakemake dash libswiften snownews dbxml libu2f-host solr dcd libxlsxwriter sonar-scanner debianutils libxo sops dependency-check links source-to-image dhall-json logtalk spades diamond loudmouth spdlog diff-pdf lua spigot diffoscope lxc spring-roo dlib mariadb srtp dnscrypt-proxy maxwell stella docfx mcabber stubby doitlive mercurial stunnel dscanner meson sundials dspdfviewer metabase swiftformat dxpy micropython synfig e2fsprogs mikutter telegraf elektra mill tepl emscripten mitmproxy texmath ethereum mlt thefuck faas-cli monero tile38 fabio mongo-c-driver tippecanoe fabric mongodb todoman fdroidserver mongodb@3.2 tor feh mpc traefik firebase-cli mpd twarc fluent-bit msgpack txr fmt mupdf uhd fn mupdf-tools uncrustify folly mutt unrar fq n vala freediameter nano vegeta fribidi neofetch vim fstrm neomutt vte3 gandi.cli node-build vtk gauge node@8 watch gdal nsd webpack gegl nss whois geoserver open-mpi winetricks get_iplayer opensc wireguard-tools getdns osm2pgrouting wireshark git-ftp osquery wtf git-lfs osrm-backend x265 gitlab-runner pam-u2f xonsh glib-networking pandoc xqilla gnome-builder paps xsv goenv parallel you-get googler pari youtube-dl grafana passenger z3 grpc pcb zabbix gst-editing-services pdal zopfli gst-libav pdfgrep zsh-autosuggestions ==> Renamed Formulae latexila -> gnome-latex ==> Installing dependencies for sox: flac, lame, libogg, libvorbis, mad ==> Installing sox dependency: flac ==> Downloading https://homebrew.bintray.com/bottles/flac-1.3.2.el_capitan.bottl ######################################################################## 100.0% ==> Pouring flac-1.3.2.el_capitan.bottle.tar.gz 🍺 /usr/local/Cellar/flac/1.3.2: 53 files, 1.8MB ==> Installing sox dependency: lame ==> Downloading https://homebrew.bintray.com/bottles/lame-3.100.el_capitan.bottl ######################################################################## 100.0% ==> Pouring lame-3.100.el_capitan.bottle.tar.gz 🍺 /usr/local/Cellar/lame/3.100: 27 files, 2.1MB ==> Installing sox dependency: libogg ==> Downloading https://homebrew.bintray.com/bottles/libogg-1.3.3.el_capitan.bot ######################################################################## 100.0% ==> /Pouring libogg-1.3.3.el_capitan.bottle.tar.gz 🍺 /usr/local/Cellar/libogg/1.3.3: 97 files, 460.7KB ==> /Installing sox dependency: libvorbis ==> /Downloading https://homebrew.bintray.com/bottles/libvorbis-1.3.6.el_capitan. ######################################################################## 100.0% ==> /Pouring libvorbis-1.3.6.el_capitan.bottle.tar.gz 🍺 /usr/local/Cellar/libvorbis/1.3.6: 157 files, 2.3MB ==> /Installing sox dependency: mad ==> /Downloading https://homebrew.bintray.com/bottles/mad-0.15.1b.el_capitan.bott ######################################################################## 100.0% ==> /Pouring mad-0.15.1b.el_capitan.bottle.1.tar.gz 🍺 /usr/local/Cellar/mad/0.15.1b: 12 files, 325.2KB ==> /Installing sox ==> /Downloading https://homebrew.bintray.com/bottles/sox-14.4.2_1.el_capitan.bot ######################################################################## 100.0% ==> /Pouring sox-14.4.2_1.el_capitan.bottle.tar.gz 🍺 /usr/local/Cellar/sox/14.4.2_1: 23 files, 1.8MB $
I was then able to record the talk to a
WAV file using
sox -d film.wav. I hit the control-c keys to terminate
the recording. The -d option tells SoX to use the default audio
device. The filename that follows it is the output file name. SoX can also
record to an MP3
file.
$ sox -d film.wav Input File : 'default' (coreaudio) Channels : 2 Sample Rate : 44100 Precision : 32-bit Sample Encoding: 32-bit Signed Integer PCM In:0.00% 01:08:41.38 [00:00:00.00] Out:182M [ -==|==- ] Clip:1.24k^C sox WARN sox: `coreaudio' input clipped 1238 samples Aborted. $ ls -lh film.wav -rw-r--r-- 1 jasmith1 1286109195 1.4G May 23 12:12 film.wav $
I was then able to listen to the WAV output file with
iTunes or using
the sox play command, i.e., play film.wav. On OS X
systems, you can also use the afplay command to listen to audio files. The volume was much louder when I used
the play command to listen to the file than it was when I used iTunes.
$ play film.wav film.wav: File Size: 1.45G Bit Rate: 2.82M Encoding: Signed PCM Channels: 2 @ 32-bit Samplerate: 44100Hz Replaygain: off Duration: 01:08:41.36 In:0.38% 00:00:15.60 [01:08:25.75] Out:688k [ | ] Clip:16
You can see the options for the sox command using sox --help.
$ sox --help
sox: SoX v
Usage summary: [gopts] [[fopts] infile]... [fopts] outfile [effect [effopt]]...
SPECIAL FILENAMES (infile, outfile):
- Pipe/redirect input/output (stdin/stdout); may need -t
-d, --default-device Use the default audio device (where available)
-n, --null Use the `null' file handler; e.g. with synth effect
-p, --sox-pipe Alias for `-t sox -'
SPECIAL FILENAMES (infile only):
"|program [options] ..." Pipe input from external program (where supported)
http://server/file Use the given URL as input file (where supported)
GLOBAL OPTIONS (gopts) (can be specified at any point before the first effect):
--buffer BYTES Set the size of all processing buffers (default 8192)
--clobber Don't prompt to overwrite output file (default)
--combine concatenate Concatenate all input files (default for sox, rec)
--combine sequence Sequence all input files (default for play)
-D, --no-dither Don't dither automatically
--dft-min NUM Minimum size (log2) for DFT processing (default 10)
--effects-file FILENAME File containing effects and options
-G, --guard Use temporary files to guard against clipping
-h, --help Display version number and usage information
--help-effect NAME Show usage of effect NAME, or NAME=all for all
--help-format NAME Show info on format NAME, or NAME=all for all
--i, --info Behave as soxi(1)
--input-buffer BYTES Override the input buffer size (default: as --buffer)
--no-clobber Prompt to overwrite output file
-m, --combine mix Mix multiple input files (instead of concatenating)
--combine mix-power Mix to equal power (instead of concatenating)
-M, --combine merge Merge multiple input files (instead of concatenating)
--norm Guard (see --guard) & normalise
--play-rate-arg ARG Default `rate' argument for auto-resample with `play'
--plot gnuplot|octave Generate script to plot response of filter effect
-q, --no-show-progress Run in quiet mode; opposite of -S
--replay-gain track|album|off Default: off (sox, rec), track (play)
-R Use default random numbers (same on each run of SoX)
-S, --show-progress Display progress while processing audio data
--single-threaded Disable parallel effects channels processing
--temp DIRECTORY Specify the directory to use for temporary files
-T, --combine multiply Multiply samples of corresponding channels from all
input files (instead of concatenating)
--version Display version number of SoX and exit
-V[LEVEL] Increment or set verbosity level (default 2); levels:
1: failure messages
2: warnings
3: details of processing
4-6: increasing levels of debug messages
FORMAT OPTIONS (fopts):
Input file format options need only be supplied for files that are headerless.
Output files will have the same format as the input file where possible and not
overridden by any of various means including providing output format options.
-v|--volume FACTOR Input file volume adjustment factor (real number)
--ignore-length Ignore input file length given in header; read to EOF
-t|--type FILETYPE File type of audio
-e|--encoding ENCODING Set encoding (ENCODING may be one of signed-integer,
unsigned-integer, floating-point, mu-law, a-law,
ima-adpcm, ms-adpcm, gsm-full-rate)
-b|--bits BITS Encoded sample size in bits
-N|--reverse-nibbles Encoded nibble-order
-X|--reverse-bits Encoded bit-order
--endian little|big|swap Encoded byte-order; swap means opposite to default
-L/-B/-x Short options for the above
-c|--channels CHANNELS Number of channels of audio data; e.g. 2 = stereo
-r|--rate RATE Sample rate of audio
-C|--compression FACTOR Compression factor for output format
--add-comment TEXT Append output file comment
--comment TEXT Specify comment text for the output file
--comment-file FILENAME File containing comment text for the output file
--no-glob Don't `glob' wildcard match the following filename
AUDIO FILE FORMATS: 8svx aif aifc aiff aiffc al amb au avr cdda cdr cvs cvsd cvu da
t dvms f32 f4 f64 f8 flac fssd gsm gsrt hcom htk ima ircam la lpc lpc10 lu maud mp2
mp3 nist ogg prc raw s1 s16 s2 s24 s3 s32 s4 s8 sb sf sl sln smp snd sndr sndt sou
sox sph sw txw u1 u16 u2 u24 u3 u32 u4 u8 ub ul uw vms voc vorbis vox wav wavpcm w
ve xa
PLAYLIST FORMATS: m3u pls
AUDIO DEVICE DRIVERS: coreaudio
EFFECTS: allpass band bandpass bandreject bass bend biquad chorus channels compand
contrast dcshift deemph delay dither divide+ downsample earwax echo echos equalizer
fade fir firfit+ flanger gain highpass hilbert input# loudness lowpass mcompand no
iseprof noisered norm oops output# overdrive pad phaser pitch rate remix repeat rev
erb reverse riaa silence sinc spectrogram speed splice stat stats stretch swap synt
h tempo treble tremolo trim upsample vad vol
* Deprecated effect + Experimental effect # LibSoX-only effect
EFFECT OPTIONS (effopts): effect dependent; see --help-effect
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