MP3ENC(1) MP3ENC(1)
NAME
mp3enc - create mp3 audio files
SYNOPSIS
games/mp3enc [ -hprv ] [ -b bitrate ] [ -B bitrate ] [ -m
mode ] [ -q q ] [ -s sfreq ] [ -V q ] [ long or silly
options ]
DESCRIPTION
Mp3enc compresses audio on standard input, normally PCM-
encoded, and produces MP3-encoded audio on standard output.
By default, the MP3 file will use `constant bit-rate' (CBR)
encoding, but that can be changed via --abr (average bitrate
desired, ABR) or -v (variable bitrate, VBR).
Options
-b set minimum allowed bitrate in Kb/s for VBR, default
32Kb/s. For CBR, set the exact bitrate in Kb/s, which
defaults to 128Kb/s.
-B set maximum allowed bitrate in Kb/s for VBR, default
256Kb/s.
-h same as `-q 2'.
-m mode may be (s)tereo, (j)oint, (f)orce or (m)ono
(default j). force forces mid/side stereo on all
frames.
-p add CRC error protection (adds an additional 16 bits
per frame to the stream). This seems to break play-
back.
-q sets output quality to q (see -V).
-r input is raw pcm
-s set sampling frequency of input file (in KHz) to sfreq,
default is 44.1.
-v use variable bitrate (VBR) encoding
-V set quality setting for VBR to q. Default q is 4; 0
produces highest-quality and largest files, and 9 pro-
duces lowest-quality and smallest files.
Long options
--abr bitrate sets average bitrate desired in Kb/s,
instead of setting quality, and generates
ABR encoding.
--resample sfreq set sampling frequency of output file (in
KHz) to sfreq, default is input sfreq.
--mp3input input is an MP3 file
Silly options
-f same as `-q 7'. Such a deal.
-o mark as non-original (i.e. do not set the original
bit)
-c mark as copyright
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MP3ENC(1) MP3ENC(1)
-k disable sfb=21 cutoff
-e emp de-emphasis n/5/c (default n)
-d allow channels to have different blocktypes
-t disable Xing VBR informational tag
-a autoconvert from stereo to mono file for mono
encoding
-x force byte-swapping of input (see dd(1) instead)
-S don't print progress report, VBR histograms
--athonly only use the ATH for masking
--nohist disable VBR histogram display
--voice experimental voice mode
EXAMPLES
Encode a `.wav' file as highest-quality MP3.
games/mp3enc -q 0 -b 320
Create a fixed 128Kb/s MP3 file from a `.wav' file.
games/mp3enc -h <foo.wav >foo.mp3
Streaming from stereo 44.1KHz raw PCM data, encoding mono at
16KHz (you may not need dd):
dd -conv swab | games/mp3enc -a -r -m m --resample 16 -b 24
SOURCE
/sys/src/games/mp3enc
SEE ALSO
dd(1), mp3dec(1), audio(3), cdfs(4), audio(7), juke(7),
playlistfs(7)
http://www.sulaco.org/mp3
BUGS
Quality is much better than encoders based on the ISO rou-
tines, but still not as good as the FhG encoder.
It's a GNU behemoth, lightly rehabilitated. There are zil-
lions of undocumented options.
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