3 mp3dec, mp3enc, oggdec, oggenc, flacdec, wavdec \- decode and encode audio files
39 .I "long or silly options"
43 These programs decode and encode various audio formats from and to
44 16-bit stereo PCM (little endian). The decoders read the compressed
45 audio data from standard input and produce PCM on standard output at
46 a sampling frequency of 44.1KHz.
49 decodes MPEG audio (layer 1, 2 and 3). The
51 option enables debug output to standard error.
58 but decode OGG Vorbis, FLAC lossless audio and PCM Wave.
60 The encoders read PCM on standard input and produce compressed audio
65 produce OGG Vorbis and MP3 audio. For
67 the MP3 file will use `constant bit-rate' (CBR) encoding by default,
68 but that can be changed via
70 (average bitrate desired, ABR)
73 (variable bitrate, VBR).
80 in Kb/s for VBR, default 32Kb/s.
82 set the exact bitrate in Kb/s, which defaults to 128Kb/s.
87 in Kb/s for VBR, default 256Kb/s.
103 forces mid/side stereo on all frames.
106 add CRC error protection (adds an additional 16 bits per frame to the stream).
107 This seems to break playback.
110 sets output quality to
119 set sampling frequency of input file (in KHz) to
124 use variable bitrate (VBR) encoding
127 set quality setting for VBR to
132 0 produces highest-quality and largest files, and
133 9 produces lowest-quality and smallest files.
135 .TF "\fB--resample sfreq \fP"
140 desired in Kb/s, instead of setting quality,
141 and generates ABR encoding.
143 .BI --resample " sfreq"
144 set sampling frequency of output file (in KHz) to
146 default is input sfreq.
161 mark as non-original (i.e. do not set the original bit)
167 disable sfb=21 cutoff
174 allow channels to have different blocktypes
177 disable Xing VBR informational tag
180 autoconvert from stereo to mono file for mono encoding
183 force byte-swapping of input (see
188 don't print progress report, VBR histograms
191 only use the ATH for masking
194 disable VBR histogram display
197 experimental voice mode
204 audio/mp3dec <foo.mp3 >/dev/audio
209 file as highest-quality MP3.
212 audio/mp3enc -q 0 -b 320
215 Create a fixed 128Kb/s MP3 file from a
220 audio/mp3enc -h <foo.wav >foo.mp3
223 Streaming from stereo 44.1KHz raw PCM data, encoding mono at 16KHz
228 dd -conv swab | audio/mp3enc -a -r -m m --resample 16 -b 24
231 .B /sys/src/cmd/audio
237 .B http://www.underbit.com/products/mad/
239 .B http://xiph.org/doc/
241 .B http://flac.sourceforge.net/documentation.html
243 It's another GNU behemoth, lightly tamed.