1mpg123(1)                   General Commands Manual                  mpg123(1)
2
3
4

NAME

6       mpg123 - play audio MPEG 1.0/2.0/2.5 stream (layers 1, 2 and 3)
7

SYNOPSIS

9       mpg123 [ options ] file-or-URL...
10

DESCRIPTION

12       mpg123  reads  one  or more files (or standard input if ``-'' is speci‐
13       fied) or URLs and plays them on the audio device (default)  or  outputs
14       them to stdout.  file/URL is assumed to be an MPEG audio bit stream.
15

OPERANDS

17       The following operands are supported:
18
19       file(s) The  path  name(s)  of  one  or more input files.  They must be
20               valid MPEG-1.0/2.0/2.5 audio layer 1, 2 or 3 bit streams.  If a
21               dash  ``-'' is specified, MPEG data will be read from the stan‐
22               dard input.  Furthermore, any name starting with ``http://'' is
23               recognized as URL (see next section).
24

OPTIONS

26       mpg123  options may be either the traditional POSIX one letter options,
27       or the GNU style long options.  POSIX style options start with a single
28       ``-'',  while GNU long options start with ``--''.  Option arguments (if
29       needed) follow separated by whitespace (not  ``='').   Note  that  some
30       options can be absent from your installation when disabled in the build
31       process.
32

INPUT OPTIONS

34       -k num, --skip num
35              Skip first num frames.  By default the decoding  starts  at  the
36              first frame.
37
38       -n num, --frames num
39              Decode  only  num  frames.   By  default  the complete stream is
40              decoded.
41
42       --fuzzy
43              Enable fuzzy seeks (guessing byte offsets or  using  approximate
44              seek  points  from  Xing TOC).  Without that, seeks need a first
45              scan through the file before they can jump  at  positions.   You
46              can decide here: sample-accurate operation with gapless features
47              or faster (fuzzy) seeking.
48
49       -y, --no-resync
50              Do NOT try to resync and continue decoding if an error occurs in
51              the  input  file.  Normally,  mpg123  tries to keep the playback
52              alive at all costs,  including  skipping  invalid  material  and
53              searching  new  header  when  something  goes  wrong.  With this
54              switch you can make it bail out  on  data  errors  (and  perhaps
55              spare  your  ears  a  bad  time). Note that this switch has been
56              renamed from --resync.  The old name still  works,  but  is  not
57              advertised or recommened to use (subject to removal in future).
58
59       -F, --no-frankenstein
60              Disable support for Frankenstein streams. Normally, mpg123 stays
61              true to the concept of MPEG audio being just a concatenation  of
62              MPEG  frames. It will continue decoding even if the type of MPEG
63              frames varies wildly. With this switch, it will only decode  the
64              input  as long as it does not change its character (from layer I
65              to layer III, changing sampling  rate,  from  mono  to  stereo),
66              silently  assuming  end  of  stream on such occasion. The switch
67              also stops decoding of compatible MPEG frames if  there  was  an
68              Info  frame  (Xing  header, Lame tag) that contained a length of
69              the track in MPEG frames.  This comes a bit closer to the notion
70              of a MP3 file as a defined collection of MPEG frames that belong
71              together, but gets rid of the flexibility that  can  be  fun  at
72              times  but  mostly  is hell for the programmer of the parser and
73              decoder ...
74
75       --resync-limit bytes
76              Set number of bytes to search for valid MPEG data once  lost  in
77              stream;  <0  means  search  whole stream.  If you know there are
78              huge chunks of invalid data in your files... here is  your  ham‐
79              mer.   Note:  Only  since  version  1.14 this also increases the
80              amount of junk skipped on beginning.
81
82       -p URL | none, --proxy URL | none
83              The specified proxy will be used for HTTP requests.   It  should
84              be specified as full URL (``http://host.domain:port/''), but the
85              ``http://'' prefix, the port number and the trailing  slash  are
86              optional (the default port is 80).  Specifying none means not to
87              use any proxy, and to retrieve files directly from  the  respec‐
88              tive servers.  See also the ``HTTP SUPPORT'' section.
89
90       -u auth, --auth auth
91              HTTP  authentication  to use when recieving files via HTTP.  The
92              format used is user:password.
93
94       --ignore-mime
95              Ignore MIME types given by HTTP server. If you know  better  and
96              want  mpg123 to decode something the server thinks is image/png,
97              then just do it.
98
99       --no-icy-meta
100              Do not accept ICY meta data.
101
102       --streamdump filename
103              Dump a copy of the input data (as  read  by  libmpg123)  to  the
104              given  file.   This  enables  you  to store a web stream to disk
105              while playing, or just create a concatenation of the local files
106              you play for ... why not?
107
108       --icy-interval bytes
109              This  setting  enables  you to play a stream dump containing ICY
110              metadata at the given interval in bytes (the value of  the  icy-
111              metaint  HTTP  response  header). Without it, such a stream will
112              play, but will cause regular decoding glitches with resync.
113
114       --no-seekbuffer
115              Disable the default micro-buffering of non-seekable streams that
116              gives the parser a safer footing.
117
118       -@ file, --list file
119              Read filenames and/or URLs of MPEG audio streams from the speci‐
120              fied file in addition to the ones specified on the command  line
121              (if any).  Note that file can be either an ordinary file, a dash
122              ``-'' to indicate that a list of filenames/URLs is  to  be  read
123              from  the standard input, or an URL pointing to a an appropriate
124              list file.  Note: only one -@ option can be used (if  more  than
125              one is specified, only the last one will be recognized).
126
127       -l n, --listentry n
128              Of  the playlist, play specified entry only.  n is the number of
129              entry starting at 1. A value of  0  is  the  default  and  means
130              playling  the whole list,  a negative value means showing of the
131              list of titles with their numbers...
132
133       --continue
134              Enable playlist continuation mode. This changes  frame  skipping
135              to apply only to the first track and also continues to play fol‐
136              lowing tracks in playlist after  the  selected  one.  Also,  the
137              option  to  play  a  number  of frames only applies to the whole
138              playlist. Basically, this tries to treat the playlist more  like
139              one  big stream (like, an audio book).  The current track number
140              in list (1-based) and frame number (0-based) are printed at exit
141              (useful if you interrupted playback and want to continue later).
142              Note that the continuation info is printed  to  standard  output
143              unless the switch for piping audio data to standard out is used.
144              Also, it really makes sense to work with actual  playlist  files
145              instead of lists of file names as arguments, to keep track posi‐
146              tions consistent.
147
148       --loop times
149              for looping track(s) a certain number of times, < 0 means  infi‐
150              nite loop (not with --random!).
151
152       --keep-open
153              For  remote  control  mode: Keep loaded file open after reaching
154              end.
155
156       --timeout seconds
157              Timeout in (integer) seconds before declaring a stream dead  (if
158              <= 0, wait forever).
159
160       -z, --shuffle
161              Shuffle play.  Randomly shuffles the order of files specified on
162              the command line, or in the list file.
163
164       -Z, --random
165              Continuous random play.  Keeps picking a random  file  from  the
166              command  line or the play list.  Unlike shuffle play above, ran‐
167              dom play never ends, and plays individual songs more than once.
168
169       -i, --index
170              Index / scan through the track before playback.  This fills  the
171              index  table  for seeking (if enabled in libmpg123) and may make
172              the operating system cache the file contents for smoother  oper‐
173              ating on playback.
174
175       --index-size size
176              Set the number of entries in the seek frame index table.
177
178       --preframes num
179              Set  the number of frames to be read as lead-in before a seeked-
180              to position.  This serves to fill the  layer  3  bit  reservoir,
181              which  is  needed  to faithfully reproduce a certain sample at a
182              certain position.  Note that for layer 3,  a  minimum  of  1  is
183              enforced (because of frame overlap), and for layer 1 and 2, this
184              is limited to 2 (no bit reservoir in that case, but engine spin-
185              up anyway).
186
187

OUTPUT and PROCESSING OPTIONS

189       -o module, --output module
190              Select  audio  output  module. You can provide a comma-separated
191              list to use the first one that works.  Also see -a.
192
193       --list-modules
194              List the available modules.
195
196       -a dev, --audiodevice dev
197              Specify the audio device to use.  The default  as  well  as  the
198              possible  values  depend on the active output. For the JACK out‐
199              put, a comma-separated list of ports to  connect  to  (for  each
200              channel) can be specified.
201
202       -s, --stdout
203              The  decoded  audio  samples  are  written  to  standard output,
204              instead of playing them through the audio device.   This  option
205              must  be used if your audio hardware is not supported by mpg123.
206              The output format per default is  raw  (headerless)  linear  PCM
207              audio  data, 16 bit, stereo, host byte order (you can force mono
208              or 8bit).
209
210       -O file, --outfile
211              Write raw output into a  file  (instead  of  simply  redirecting
212              standard output to a file with the shell).
213
214       -w file, --wav
215              Write  output as WAV file. This will cause the MPEG stream to be
216              decoded and saved as file file , or standard output if - is used
217              as  file  name.  You  can also use --au and --cdr for AU and CDR
218              format, respectively. Note that WAV/AU writing  to  non-seekable
219              files,  or  redirected stdout, needs some thought. Since 1.16.0,
220              the logic changed to writing the header with  the  first  actual
221              data.  This  avoids spurious WAV headers in a pipe, for example.
222              The result of decoding nothing to WAV/AU is  a  file  consisting
223              just  of  the header when it is seekable and really nothing when
224              not (not even a header). Correctly writing data  with  prophetic
225              headers to stdout is no easy business.
226
227       --au file
228              Does  not  play the MPEG file but writes it to file in SUN audio
229              format.  If - is used as the filename, the AU file is written to
230              stdout. See paragraph about WAV writing for header fun with non-
231              seekable streams.
232
233       --cdr file
234              Does not play the MPEG file but writes it to file as a CDR file.
235              If - is used as the filename, the CDR file is written to stdout.
236
237       --reopen
238              Forces reopen of the audiodevice after ever song
239
240       --cpu decoder-type
241              Selects  a  certain  decoder  (optimized  for specific CPU), for
242              example i586 or MMX.  The list of available decoders  can  vary;
243              depending on the build and what your CPU supports.  This options
244              is only availabe when the build actually includes several  opti‐
245              mized decoders.
246
247       --test-cpu
248              Tests your CPU and prints a list of possible choices for --cpu.
249
250       --list-cpu
251              Lists  all  available  decoder choices, regardless of support by
252              your CPU.
253
254       -g gain, --gain gain
255              [DEPRECATED] Set audio  hardware  output  gain  (default:  don't
256              change).  The unit of the gain value is hardware and output mod‐
257              ule dependent.  (This parameter is only provided  for  backwards
258              compatibility  and  may  be  removed in the future without prior
259              notice. Use the audio player for playing and  a  mixer  app  for
260              mixing, UNIX style!)
261
262       -f factor, --scale factor
263              Change scale factor (default: 32768).
264
265       --rva-mix, --rva-radio
266              Enable  RVA (relative volume adjustment) using the values stored
267              for ReplayGain radio mode / mix mode  with  all  tracks  roughly
268              equal loudness.  The first valid information found in ID3V2 Tags
269              (Comment named RVA or the RVA2 frame) or  ReplayGain  header  in
270              Lame/Info Tag is used.
271
272       --rva-album, --rva-audiophile
273              Enable  RVA (relative volume adjustment) using the values stored
274              for ReplayGain audiophile mode / album  mode  with  usually  the
275              effect of adjusting album loudness but keeping relative loudness
276              inside album.  The first valid information found in  ID3V2  Tags
277              (Comment named RVA_ALBUM or the RVA2 frame) or ReplayGain header
278              in Lame/Info Tag is used.
279
280       -0, --single0; -1, --single1
281              Decode only channel 0 (left) or channel 1 (right), respectively.
282              These options are available for stereo MPEG streams only.
283
284       -m, --mono, --mix, --singlemix
285              Mix  both  channels  /  decode mono. It takes less CPU time than
286              full stereo decoding.
287
288       --stereo
289              Force stereo output
290
291       -r rate, --rate rate
292              Set sample rate (default: automatic).  You may  want  to  change
293              this  if  you  need  a  constant bitrate independent of the mpeg
294              stream rate. mpg123 automagically converts the rate. You  should
295              then combine this with --stereo or --mono.
296
297       --resample method
298              Set  resampling  method  to  employ  if  forcing an output rate.
299              Choices (case-insensitive) are NtoM, dirty, and fine.  The  fine
300              resampler  is  the  default.  It employs libsyn123's low-latency
301              fairly  efficient  resampler  to  postprocess  the  output  from
302              libmpg123  instead of the fast but very crude NtoM decoder (drop
303              sample method) that mpg123 offers  since  decades.  If  you  are
304              really  low  on  CPU time, choose NtoM, as the resampler usually
305              needs more time than the MPEG decoder itself.  The  mpg123  pro‐
306              gram  is  smart  enough to combine the 2to1 or 4to1 downsampling
307              modes with the postprocessing for extreme downsampling.
308
309       -2, --2to1; -4, --4to1
310              Performs a downsampling of ratio 2:1 (22 kHz from 44.1  kHz)  or
311              4:1  (11 kHz) on the output stream, respectively. Saves some CPU
312              cycles, but of course throws away the high frequencies,  as  the
313              decoder does not bother producing them.
314
315       --pitch value
316              Set  a  pitch  change  (speedup/down,  0  is neutral; 0.05 is 5%
317              speedup).  When not enforcing an output rate, this  changes  the
318              output  sampling  rate, so it only works in the range your audio
319              system/hardware supports. When you combine  this  with  a  fixed
320              output rate, it modifies a software resampling ratio instead.
321
322       --8bit Forces 8bit output
323
324       --float
325              Forces f32 encoding
326
327       -e enc, --encoding enc
328              Choose  output  sample  encoding.  Possible values look like f32
329              (32-bit  floating  point),  s32  (32-bit  signed  integer),  u32
330              (32-bit  unsigned  integer) and the variants with different num‐
331              bers of bits (s24, u24, s16, u16, s8, u8) and also special vari‐
332              ants  like  ulaw  and  alaw  8-bit.   See the output of mpg123's
333              longhelp for actually available encodings.
334
335       -d n, --doublespeed n
336              Only play every n'th frame.  This will cause the MPEG stream  to
337              be played n times faster, which can be used for special effects.
338              Can also be combined with the --halfspeed option to play  3  out
339              of  4  frames  etc.  Don't expect great sound quality when using
340              this option.
341
342       -h n, --halfspeed n
343              Play each frame n times.  This will cause the MPEG stream to  be
344              played  at  1/n'th speed (n times slower), which can be used for
345              special effects. Can also be  combined  with  the  --doublespeed
346              option  to  double every third frame or things like that.  Don't
347              expect great sound quality when using this option.
348
349       -E file, --equalizer
350              Enables equalization, taken from file.  The file needs  to  con‐
351              tain  32 lines of data, additional comment lines may be prefixed
352              with #.  Each data line consists of two floating-point  entries,
353              separated  by whitespace.  They specify the multipliers for left
354              and right channel of a  certain  frequency  band,  respectively.
355              The  first line corresponds to the lowest, the 32nd to the high‐
356              est frequency band.  Note that you  can  control  the  equalizer
357              interactively with the generic control interface.
358
359       --gapless
360              Enable  code  that  cuts  (junk) samples at beginning and end of
361              tracks, enabling gapless transitions  between  MPEG  files  when
362              encoder  padding  and  codec  delays  would prevent it.  This is
363              enabled per default beginning with mpg123 version 1.0.0 .
364
365       --no-gapless
366              Disable the gapless code. That  gives  you  MP3  decodings  that
367              include encoder delay and padding plus mpg123's decoder delay.
368
369       --no-infoframe
370              Do  not  parse  the  Xing/Lame/VBR/Info frame, decode it instead
371              just like a stupid old MP3 hardware player.  This  implies  dis‐
372              abling  of  gapless  playback as the necessary information is in
373              said metadata frame.
374
375       -D n, --delay n
376              Insert a delay of n seconds before each track.
377
378       -o h, --headphones
379              Direct audio output to the headphone  connector  (some  hardware
380              only; AIX, HP, SUN).
381
382       -o s, --speaker
383              Direct  audio  output  to the speaker  (some hardware only; AIX,
384              HP, SUN).
385
386       -o l, --lineout
387              Direct audio output to the  line-out  connector  (some  hardware
388              only; AIX, HP, SUN).
389
390       -b size, --buffer size
391              Use  an  audio  output buffer of size Kbytes.  This is useful to
392              bypass short periods of heavy system activity, which would  nor‐
393              mally  cause  the  audio  output  to be interrupted.  You should
394              specify a buffer size of at least 1024 (i.e. 1 Mb, which  equals
395              about 6 seconds of audio data) or more; less than about 300 does
396              not make much sense.  The default is 0,  which  turns  buffering
397              off.
398
399       --preload fraction
400              Wait  for  the  buffer  to be filled to fraction before starting
401              playback (fraction between 0 and 1).  You  can  tune  this  pre‐
402              buffering to either get faster sound to your ears or safer unin‐
403              terrupted web radio.  Default is 0.2 (wait for 20 % of buffer to
404              be full, changed from 1 in version 1.23).
405
406       --devbuffer seconds
407              Set  device buffer in seconds; <= 0 means default value. This is
408              the small buffer between the application and the audio  backend,
409              possibly directly related to hardware buffers.
410
411       --smooth
412              Keep  buffer  over track boundaries -- meaning, do not empty the
413              buffer between tracks for possibly some added smoothness.
414
415

MISC OPTIONS

417       -t, --test
418              Test mode.  The audio stream is decoded, but no output occurs.
419
420       -c, --check
421              Check for filter range violations (clipping),  and  report  them
422              for each frame if any occur.
423
424       -v, --verbose
425              Increase  the  verbosity level.  For example, displays the frame
426              numbers during decoding.
427
428       -q, --quiet
429              Quiet.  Suppress diagnostic messages.
430
431       -C, --control
432              Enable terminal control keys. This is enabled automatically if a
433              terminal  is  detected.   By default use 's' or the space bar to
434              stop/restart (pause, unpause) playback, 'f' to jump  forward  to
435              the  next  song,  'b' to jump back to the beginning of the song,
436              ',' to rewind, '.' to fast forward, and 'q' to quit.   Type  'h'
437              for a full list of available controls.
438
439       --no-control
440              Disable terminal control even if terminal is detected.
441
442       --title
443              In  an xterm, rxvt, screen, iris-ansi (compatible, TERM environ‐
444              ment variable is examined), change the  window's  title  to  the
445              name of song currently playing.
446
447       --name name
448              Set  the name of this instance, possibly used in various places.
449              This sets the client name for JACK output.
450
451       --long-tag
452              Display ID3 tag info always in long format  with  one  line  per
453              item (artist, title, ...)
454
455       --utf8 Regardless  of  environment, print metadata in UTF-8 (otherwise,
456              when not using UTF-8 locale, you'll get ASCII stripdown).
457
458       -R, --remote
459              Activate generic control interface.  mpg123 will then  read  and
460              execute commands from stdin. Basic usage is ``load <filename> ''
461              to play some file and the obvious ``pause'', ``command.   ``jump
462              <frame>''  will  jump/seek to a given point (MPEG frame number).
463              Issue ``help'' to get a full list of commands and syntax.
464
465       --remote-err
466              Print responses for generic control mode to standard error,  not
467              standard out.  This is automatically triggered when using -s N.
468
469       --fifo path
470              Create  a  fifo  / named pipe on the given path and use that for
471              reading commands instead of standard input.
472
473       --aggressive
474              Tries to get higher priority
475
476       -T, --realtime
477              Tries to gain realtime priority.  This option  usually  requires
478              root privileges to have any effect.
479
480       -?, --help
481              Shows short usage instructions.
482
483       --longhelp
484              Shows long usage instructions.
485
486       --version
487              Print the version string.
488

HTTP SUPPORT

490       In  addition to reading MPEG audio streams from ordinary files and from
491       the standard input, mpg123 supports retrieval of MPEG  audio  files  or
492       playlists  via  the  HTTP protocol, which is used in the World Wide Web
493       (WWW).  Such files are specified using a so-called  URL,  which  starts
494       with  ``http://''.  When a file with that prefix is encountered, mpg123
495       attempts to open an HTTP connection to the server in order to  retrieve
496       that file to decode and play it.
497
498       It  is  often useful to retrieve files through a WWW cache or so-called
499       proxy.  To accomplish this, mpg123 examines the environment  for  vari‐
500       ables  named  MP3_HTTP_PROXY, http_proxy and HTTP_PROXY, in this order.
501       The value of the first one that is set will be used as proxy specifica‐
502       tion.   To  override  this, you can use the -p command line option (see
503       the ``OPTIONS'' section).  Specifying -p none will  enforce  contacting
504       the  server  directly without using any proxy, even if one of the above
505       environment variables is set.
506
507       Note that, in order to play MPEG audio files from a WWW server,  it  is
508       necessary that the connection to that server is fast enough.  For exam‐
509       ple, a 128 kbit/s MPEG file requires the network connection  to  be  at
510       least  128  kbit/s  (16 kbyte/s) plus protocol overhead.  If you suffer
511       from short network outages, you should try the -b  option  (buffer)  to
512       bypass  such outages.  If your network connection is generally not fast
513       enough to retrieve MPEG audio files in realtime, you can first download
514       the  files  to  your  local harddisk (e.g. using wget(1)) and then play
515       them from there.
516
517       If authentication is needed to access the file it can be specified with
518       the -u user:pass.
519

INTERRUPT

521       When  in  terminal  control  mode, you can quit via pressing the q key,
522       while any time you can abort mpg123 by pressing Ctrl-C. If not in  ter‐
523       minal  control  mode,  this will skip to the next file (if any). If you
524       want to abort playing immediately in that case, press Ctrl-C  twice  in
525       short succession (within about one second).
526
527       Note  that  the  result of quitting mpg123 pressing Ctrl-C might not be
528       audible immediately, due to audio data buffering in the  audio  device.
529       This  delay is system dependent, but it is usually not more than one or
530       two seconds.
531
532

PLAYBACK STATUS LINE

534       In verbose mode, mpg123 updates a line with various information center‐
535       ing  around  the current playback position. On any decent terminal, the
536       line also works as a progress bar in  the  current  file  by  reversing
537       video  for a fraction of the line according to the current position. An
538       example for a full line is this:
539
540            > 0291+0955  00:01.68+00:28.22 [00:05.30]  mix  100=085  192  kb/s
541       576 B acc   18 clip p+0.014
542
543       The information consists of, in order:
544
545       >      single-character  playback  state  (``>'' for playing, ``='' for
546              pausing/looping, ``_'' for stopped)
547
548       0291+0955
549              current frame offset and number of remaining  frames  after  the
550              plus sign
551
552       00:01.68+00:28.22
553              current  position from and remaining time in human terms (hours,
554              minutes, seconds)
555
556       [00:05.30]
557              fill of the output buffer in terms of playback time, if the buf‐
558              fer is enabled
559
560       mix    selected  RVA  mode  (possible values: mix, alb (album), and ---
561              (neutral, off))
562
563       100=085
564              set volume and the RVA-modified effective volume after the equal
565              sign
566
567       192 kb/s
568              current bitrate
569
570       576 B  size of current frame in bytes
571
572       acc    if positions are accurate, possible values are ``acc'' for accu‐
573              rate positions or ``fuz'' for fuzzy (with guessed  byte  offsets
574              using mean frame size)
575
576       18 clip
577              amount of clipped samples, non-zero only if decoder reports that
578              (generic does, some optimized ones not)
579
580       p+0.014
581              pitch change (increased/decreased playback sampling rate on user
582              request)
583
584

NOTES

586       MPEG audio decoding requires a good deal of CPU performance, especially
587       layer-3.  To decode it  in  realtime,  you  should  have  at  least  an
588       i486DX4,  Pentium,  Alpha, SuperSparc or equivalent processor.  You can
589       also use the -m option to decode mono only, which reduces the CPU  load
590       somewhat for layer-3 streams.  See also the -2 and -4 options.
591
592       If  everything else fails, have mpg123 decode to a file and then use an
593       appropriate utility to play that file with less CPU load.  Most  proba‐
594       bly  you  can  configure  mpg123  to produce a format suitable for your
595       audio device (see above about encodings and sampling rates).
596
597       If your system is generally fast enough  to  decode  in  realtime,  but
598       there  are  sometimes  periods  of heavy system load (such as cronjobs,
599       users logging in remotely, starting of ``big'' programs  etc.)  causing
600       the  audio  output to be interrupted, then you should use the -b option
601       to use a buffer of reasonable size (at least 1000 Kbytes).
602

EXIT CODE

604       Up to version 1.25.x, mpg123 always returned exit code 0 also for  com‐
605       plete  junk  on  the  input side. Fatal errors were only considered for
606       output. With version 1.26.0, this changed to  the  behaviour  described
607       below.
608
609       When not using the remote control interface (which returns input errors
610       as text messages), the process exit code is zero (success) only if  all
611       tracks  in a playlist had at least one frame parsed, even if it did not
612       decode cleanly, or are empty,  MPEG-wise  (perhaps  only  metadata,  or
613       really  an empty file).  When you decode nothing, nothing is the result
614       and that is fine. When a track later aborts because of parser errors or
615       breakdown  of  the  network  communication, this is treated as end of a
616       track, but does not make the process as such fail. One really  bad  (or
617       non-existing)  stream in the playlist results in a non-zero error code,
618       consistent with other UNIX tools.
619
620       An error in audio output results in the process ending with a  non-zero
621       exit  code  immediately,  regardless of how much data has been success‐
622       fully played before. The forgiveness is only on the input side.
623

BUGS

625       Mostly MPEG-1 layer 2 and 3 are tested in real life.  Please report any
626       issues and provide test files to help fixing them.
627
628       No CRC error checking is performed.
629
630       Some  platforms lack audio hardware support; you may be able to use the
631       -s switch to feed the decoded data to a program that  can  play  it  on
632       your audio device.
633

AUTHORS

635       Maintainer:
636              Thomas Orgis <maintainer@mpg123.org>, <thomas@orgis.org>
637
638       Original Creator:
639              Michael Hipp
640
641       Uses code or ideas from various people, see the AUTHORS file accompany‐
642       ing the source code.
643

LICENSE

645       mpg123 is licensed under the GNU Lesser/Library General Public License,
646       LGPL, version 2.1 .
647

WEBSITE

649       http://www.mpg123.org
650       http://sourceforge.net/projects/mpg123
651
652
653
654                                  26 Apr 2020                        mpg123(1)
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