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MP3ENC(1) General Commands Manual 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 bi‐ trate, 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 -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 playback. -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 produces lowest-quality and smallest files. Long options --abr bitrate sets average bitrate desired in Kb/s, instead of setting qual‐ ity, 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 Such a deal. -o mark as non-original (i.e. do not set the original bit) -c mark as copyright -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 file as highest-quality MP3. games/mp3enc -q 0 -b 320 Create a fixed 128Kb/s MP3 file from a 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 routines, but still not as good as the FhG encoder. It's a GNU behemoth, lightly rehabilitated. There are zillions of un‐ documented options. MP3ENC(1)