3 mp3dec, mp3enc, oggdec, oggenc, flacdec \- decode and encode audio files
37 .I "long or silly options"
41 These programs decode and encode various audio formats from and to
42 16-bit stereo PCM (little endian). The decoders read the compressed
43 audio data from standard input and produce PCM on standard output at
44 a sampling frequency of 44.1KHz.
47 decodes MPEG audio (layer 1, 2 and 3). The
49 option enables debug output to standard error.
55 but decode OGG Vorbis and FLAC lossless audio.
57 The encoders read PCM on standard input and produce compressed audio
62 produce OGG Vorbis and MP3 audio. For
64 the MP3 file will use `constant bit-rate' (CBR) encoding by default,
65 but that can be changed via
67 (average bitrate desired, ABR)
70 (variable bitrate, VBR).
77 in Kb/s for VBR, default 32Kb/s.
79 set the exact bitrate in Kb/s, which defaults to 128Kb/s.
84 in Kb/s for VBR, default 256Kb/s.
100 forces mid/side stereo on all frames.
103 add CRC error protection (adds an additional 16 bits per frame to the stream).
104 This seems to break playback.
107 sets output quality to
116 set sampling frequency of input file (in KHz) to
121 use variable bitrate (VBR) encoding
124 set quality setting for VBR to
129 0 produces highest-quality and largest files, and
130 9 produces lowest-quality and smallest files.
132 .TF "\fB--resample sfreq \fP"
137 desired in Kb/s, instead of setting quality,
138 and generates ABR encoding.
140 .BI --resample " sfreq"
141 set sampling frequency of output file (in KHz) to
143 default is input sfreq.
158 mark as non-original (i.e. do not set the original bit)
164 disable sfb=21 cutoff
171 allow channels to have different blocktypes
174 disable Xing VBR informational tag
177 autoconvert from stereo to mono file for mono encoding
180 force byte-swapping of input (see
185 don't print progress report, VBR histograms
188 only use the ATH for masking
191 disable VBR histogram display
194 experimental voice mode
201 audio/mp3dec <foo.mp3 >/dev/audio
206 file as highest-quality MP3.
209 audio/mp3enc -q 0 -b 320
212 Create a fixed 128Kb/s MP3 file from a
217 audio/mp3enc -h <foo.wav >foo.mp3
220 Streaming from stereo 44.1KHz raw PCM data, encoding mono at 16KHz
225 dd -conv swab | audio/mp3enc -a -r -m m --resample 16 -b 24
228 .B /sys/src/cmd/audio
234 .B http://www.underbit.com/products/mad/
236 .B http://xiph.org/doc/
238 .B http://flac.sourceforge.net/documentation.html
240 It's another GNU behemoth, lightly tamed.