3 mp3dec, mp3enc, oggdec, oggenc, flacdec, sundec, wavdec, pcmconv, mixfs \- decode and encode audio files
56 .I "long or silly options"
83 These programs decode and encode various audio formats from and to
84 16-bit stereo PCM (little endian). The decoders read the compressed
85 audio data from standard input and produce PCM on standard output at
86 a sampling frequency of 44.1KHz.
89 decodes MPEG audio (layer 1, 2 and 3). The
91 option enables debug output to standard error.
99 but decode OGG Vorbis, FLAC lossless audio, Sun audio and RIFF wave.
101 .TF "\fB-s seconds \fP"
104 seek to a specific position in seconds before decoding.
107 The encoders read PCM on standard input and produce compressed audio
113 produce OGG Vorbis and MP3 audio. For
115 the MP3 file will use `constant bit-rate' (CBR) encoding by default,
116 but that can be changed via
118 (average bitrate desired, ABR)
121 (variable bitrate, VBR).
124 accepts raw PCM in the same byte order as
136 in Kb/s for VBR, default 32Kb/s.
138 set the exact bitrate in Kb/s, which defaults to 128Kb/s.
143 in Kb/s for VBR, default 256Kb/s.
159 forces mid/side stereo on all frames.
162 add CRC error protection (adds an additional 16 bits per frame to the stream).
163 This seems to break playback.
166 sets output quality to
175 set sampling frequency of input file (in KHz) to
180 use variable bitrate (VBR) encoding
183 set quality setting for VBR to
188 0 produces highest-quality and largest files, and
189 9 produces lowest-quality and smallest files.
191 .TF "\fB--resample sfreq \fP"
196 desired in Kb/s, instead of setting quality,
197 and generates ABR encoding.
199 .BI --resample " sfreq"
200 set sampling frequency of output file (in KHz) to
202 default is input sfreq.
204 .BI --mp3input " input"
216 mark as non-original (i.e. do not set the original bit)
222 disable sfb=21 cutoff
229 allow channels to have different blocktypes
232 disable Xing VBR informational tag
235 autoconvert from stereo to mono file for mono encoding
238 force byte-swapping of input (see
243 don't print progress report, VBR histograms
246 only use the ATH for masking
249 disable VBR histogram display
252 experimental voice mode
255 is a helper program used to convert various PCM sample formats. The
259 options specify the input and output format
263 is a concatenated string of the following parts:
266 sample format is little-endian signed integer where
268 specifies the number of bits
271 unsigned little-endian integer format
274 singed big-endian integer format
277 unsigned big-endian integer format
280 floating point format where
282 has to be 32 or 64 for single- or double-precision
291 specifies the number of channels
294 gives the samplerate in Hz
296 The program reads samples from standard
297 input converting the data and writes the result to standard output
298 until it reached end of file or, if
300 was given, a number of
302 bytes have been consumed from input.
305 is a fileserver serving a single
307 file which allows simultaneous playback of audio streams. When
310 and mixes the audio samples that are written to it.
313 can be given with the
315 option which gets posted to
325 A alternative mountpoint
327 can be specified with the
334 debug messages to be written to file-descriptor 2.
340 audio/mp3dec <foo.mp3 >/dev/audio
345 file as highest-quality MP3.
348 audio/mp3enc -q 0 -b 320 <foo.wav >foo.mp3
351 Create a fixed 128Kb/s MP3 file from a
356 audio/mp3enc -h <foo.wav >foo.mp3
359 Streaming from stereo 44.1KHz raw PCM data, encoding mono at 16KHz
364 dd -conv swab | audio/mp3enc -a -r -m m --resample 16 -b 24
367 .B /sys/src/cmd/audio
373 .B http://www.underbit.com/products/mad/
375 .B http://xiph.org/doc/
377 .B http://flac.sourceforge.net/documentation.html
380 first appeared in 9front (December, 2012).
382 first appeared in 9front (December, 2013).