home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Skunkware 98
/
Skunkware 98.iso
/
html
/
src
/
mpg123.src
< prev
next >
Wrap
Text File
|
1998-03-23
|
3KB
|
65 lines
@@@STARTPACK(mpg123;mpg123 - MPEG audio player)
<P>
mpg123 reads one or more files (or standard input if ``-''
is specified) or URLs and plays them on the audio device
(default) or outputs them to stdout. File/URL is assumed to
be an MPEG-1/2 audio bit stream.
<P>
In addition to reading MPEG audio streams from ordinary
files and from the standard input, mpg123 supports retrieval
of MPEG audio files via the HTTP protocol, which is used in
the World Wide Web (WWW). Such files are specified using a
so-called URL (universal resource location), which starts
with ``http://''. When a file with that prefix is encountered.
mpg123 attempts to open an HTTP connection to the
server in order to retrieve that file to decode and play it.
It is often useful to retrieve files through a WWW cache or
so-called proxy. To accomplish this, mpg123 examines the
environment for variables named MP3_HTTP_PROXY, http_proxy
and HTTP_PROXY, in this order. The value of the first one
that is set will be used as proxy specification. To override
this, you can use the -p command line option (see the
``OPTIONS'' section). Specifying -p none will enforce
contacting the server directly without using any proxy, even if
one of the above environment variables is set. Note that,
in order to play MPEG audio files from a WWW server, it is
necessary that the connection to that server is fast enough.
For example, a 128 kbit/s MPEG file requires the network
connection to be at least 128 kbit/s (16 kbyte/s) plus protocol
overhead. If you suffer from short network outages,
you should try the -b option (buffer) to bypass such
outages. If your network connection is generally not fast
enough to retrieve MPEG audio files in realtime, you can
first download the files to your local harddisk (e.g. using
lynx(1)) and then play them from there.
<P>
MPEG audio decoding requires a good deal of CPU performance,
especially layer-3. To decode it in realtime, you should
have at least a Pentium, Alpha, SuperSparc or equivalent
processor. You can also use the -singlemix option to decode
mono only, which reduces the CPU load somewhat for layer-3
streams. See also the -2 and -4 options. If everything
else fails, use the -s option to decode to standard output,
direct it into a file and then use an appropriate utility to
play that file. You might have to use a tool such as sox(1)
to convert the output to an audio format suitable for your
audio player. Also note that mpg123 always generates 16 bit
stereo data (if one of the -single* options is used, two
identical stereo channels are generated). If your hardware
requires some other format, for example 8 bit mono, you also
have to use a converter such as sox(1). If your system is
generally fast enough to decode in realtime, but there are
sometimes periods of heavy system load (such as cronjobs,
users logging in remotely, starting of ``big'' programs
etc.) causing the audio output to be interrupted, then you
should use the -b option to use a buffer of at least 1000
Kbytes.
</P>
@@@UW2DIST(http://www.sco.com/skunkware/uw7/audio/mpg123/)
@@@OSR5DIST(http://www.sco.com/skunkware/osr5/audio/mpg123/)
@@@HOMEPAGE(http://mpg.123.org/)
@@@ENDPACK