URN Logo
UNIX Resources » Linux » China Linux Forum » 翻译作坊 » 4 » mpg123.1
announcement 声明: 本页内容为中国Linux论坛的内容镜像,文章的版权以及其他所有的相关权利属于中国Linux论坛和相应文章的作者,如果转载,请注明文章来源及相关版权信息。
Resources
China Linux Forum(finished)
Linux Forum(finished)
FreeBSD China(finished)
linuxforum.net
  业界新闻与评论
  自由软件杂谈
  IT 人生
  Linux软件快递
  翻译作坊
  Linux图书与评论
  GNU Emacs/XEmacs
  Linux 中文环境和中文化
  Linux桌面与办公软件
  Linux 多媒体与娱乐版
  自由之窗Mozilla
  笔记本电脑上的Linux
  Gentoo
  Debian 一族
  网络管理技术
  Linux 安装与入门
  WEB服务器和FTP服务器
  域名服务器和邮件服务器
  Linux防火墙和代理服务器应用
  文件及打印服务器
  技术培训与认证
  Linux内核技术
  Linux 嵌入技术
  Linux设备驱动程序
  Linux 集群技术
  LINUX平台数据库
  系统和网络安全
  CPU 与 编译器
  系统计算研究所专栏
  Linux下的GUI软件开发
  C/C++编程版
  PHP 技 术
  Java&jsp技术
  Shell编程技术
  Perl 编 程
  Python 编 程
  XML/Web Service 技术
  永远的Unix
  FreeBSD世界
   
mpg123.1
mpg123.1 - groove [2004-02-29 15:43 | 13,564 byte(s)]
 
 
Re: mpg123.1 - bbbush [2004-03-01 20:28 | 303 byte(s)]
 
Re: mpg123.1 - xuming [2004-03-01 14:18 | 14 byte(s)]
 
Re: mpg123.1 - bbbush [2004-03-01 13:27 | 21 byte(s)]
 
Re: mpg123.1[English Version] - groove [2004-02-29 15:54 | 15,732 byte(s)]
 
Subject: mpg123.1
Author: groove    Posted: 2004-02-29 15:43    Length: 13,564 byte(s)
[Original] [Print] [Top]


." @(#)mpg123.1 0.01 21-Apr-1997 OF; from mpg123 archive
." Chinese version copyright (c)linuxipy <groove@ustc.edu> , href=http://www.linuxforum.net>www.linuxforum.net 2003.
." Chinese version last update on 29-Dec-2003
."
."
." This file may be copied under the conditions described
." in the LDP GENERAL PUBLIC LICENSE, Version 1, September 1998
." that should have been distributed together with this file.
."
.TH mpg123 1 "21 Apr 1997"
.SH 命令名
mpg123 - 播放 MPEG 1.0/2.0 Layer-1, -2, -3 音频文件
.SH 语法
.B mpg123
[
.B -tscvqy01m24
]
[
.BI -b " size"
]
[
.BI -k " num"
]
[
.BI -n " num"
]
[
.BI -f " factor"
]
[
.BI -r " rate"
]
[
.BI -g " gain"
]
[
.BI -a " dev"
]
[
.BR "-o s" " | " "-o h" " | " "-o l"
]
[
.BI -d " n"
]
[
.BI -h " n"
]
[
.BI -p " proxy"
]
[
.BI -@ " file"
]
.IR file " ... | " URL " ... | "
.B -
.SH 描述
.B mpg123
从一个或多个
.I 文件
或者
.I URL
读取MPEG-1/2音频比特流 (如果指定 `-' 选项, 则从标准输入读取),
然后使用音频设备进行播放(默认), 或将解码结果送 到标准输出上.
.SH 选项
.B mpg123
接收传统的POSIX风格的单字母选项, 也接收GNU风格的长单词选项. 这两 种选项分别以 `-' 和
"-^-" 开头.
.TP
.BR -t ", " --test
测试模式. 对音频流进行解码, 但不输出.
.TP
.BR -s ", " -^-stdout
将解码结果送到标准输出上, 而不使用音频设备进行播放. 如果
.B mpg123
不支持你的音频硬件, 你就可以试试这一选项, 这时,
.B mpg123
以本机 字节顺序(host byte order)输出16比特的立体声线性PCM(脉冲编码调制)
音频裸数据(没有数据头).
.TP
.BR -c ", " -^-check
对每一帧进行滤波器越界检查, 如发生则报告之.
.TP
.BR -v ", " -^-verbose
播放时显示更多信息, 比如显示当前正在解码的帧号.
.TP
.BR -q ", " -^-quiet
安静模式. 不显示诊断信息.
.TP
.BR -y ", " -^-resync
如果输入文件发生错误, 则重新进行同步并继续解码. 另外, 对那些文件 头损坏的MPEG文件,
通常
.B mpg123
会拒绝播放并显示 ' Illegal header', 但如果指定本选项,
.B mpg123
会试图从损坏的文件头中恢复并进行播放. 小心:
损坏的MPEG文件在播放到损坏处时可能出现尖利刺耳的噪声, 如果 音量过大, 可能损坏扬声器.
.TP
.BR -0 ", " -^-single0 "; " -1 ", " -^-single1
只对0(左) 声道或者1(右) 声道进行解码. 这两个选项只对立体声的MPEG 音频流有效.
.TP
.BR -m ", " -^-singlemix
将两个声道混音. 此选项只对MPEG Layer-3的立体声音频流有效, 并可比
完全立体声解码节省一些
CPU时间.
.TP
.BR -2 ", " -^-2to1 "; " -4 ", " -^-4to1
将输出流的采样率将低至标准的1/2 (22kHz) 或者1/4 (11kHz). 使用这
两个选项可以减少一些CPU的负荷, 但是声音质量会下降(至少使用11kHz 采样率时会很难听).
.TP
fB-b fIsizefR, fB-^-buffer fIsize

.I size
指定输出缓冲区的大小, 单位为千字节. 使用此选项通常可以避 免由频繁的系统操作造成的
声音输出时断时续的现象.
.I size
的值小于 300时就没什么意义了, 建议至少取1024(即使用1Mb的缓冲区, 可以缓冲
相当于6秒钟的音频数据).
.I size
的默认值为0, 即不进行输出缓冲.
.TP
fB-k fInumfR, fB-^-skip fInum
跳过前
.I num
帧. 不指定此选项时, 默认从第1帧开始解码.
.TP
fB-n fInumfR, fB-^-frames fInum
只对前
.I num
帧进行解码. 不指定此选项时, 默认对整个音频流进行解码.
.TP
fB-f fIfactorfR, fB-^-scale fIfactor
改变缩放因子
.I factor
的值(默认值为32768).
.TP
fB-r fIratefR, fB-^-rate fIrate
设置采样率
.I rate
(默认为自动设置). 使用这一选项后,
.B mpg123
会自动 将速率转换成不依赖于MPEG流速率的一个恒定比特率.
此选项应该和 --stereo 或 --mono 联合起来使用.
.TP
fB-g fIgainfR, fB-^-gain fIgain
设置音频硬件输出增益
.I gain
(默认为保持不变).
.TP
fB-a fIdevfR, fB-^-audiodevice fIdev
指定音频设备. 默认的音频设备与系统配置有关(通常是 /dev/audio 或 /dev/dsp ),
如果系统中有多个音频设备而默认的又不是你想用的那个, 就可使用本选项.
.TP
.BR "-o s" ", " -^-speaker
将声音导出到主板上的扬声器上.
.TP
.BR "-o h" ", " -^-headphones
将声音导出到耳机连接器上.
.TP
.BR "-o l" ", " -^-lineout
将声音导出到Line-Out连接器上.
.TP
fB-d fInfR, fB-^-doublespeed fIn

.IR n
帧播放一帧. 这会使MPEG流的播放速度提高为正常速度的
.I n
倍, 从而可以产生特殊的声音效果. 此选项可以和
.B -^-halfspeed
选项组合使 用, 实现类似每4帧播放3帧(译者注: 指定-d 4 -h 3)的效果.
如果使用 此选项, 不要指望声音质量会很好.
.TP
fB-h fInfR, fB-^-halfspeed fIn
将每帧都播放
.I n
遍. 这会使MPEG流的播放速度降低为正常速度的
.IR 1 / n ,
从而可以产生特殊的声音效果. 此选项可以和
.B -^-doublespeed
选项组合 使用, 实现类似每3帧播放2帧(译者注: 指定-h 2 -d 3)的效果.
如果使 用此选项, 不要指望声音质量会很好.
.TP
fB-p fIURL fR| fBnonefR, fB-^-proxy fIURL fR| fBnone
指定
.I proxy
作为HTTP请求的代理. 指定的格式应是一个完整的URL (如"http://host.domain:port/"),
但是可以省略前缀"http://", 端口 号port(默认的端口为80)和末尾的'/'.
如果指定为
.B none
,则不使用代 理, 直接向服务器请求文件. 更多细节请看 "HTTP 支持" 小节.
.TP
fB-u fIauthfR, fB-^-auth fIauth
如果通过HTTP下载文件时服务器要求提供认证信息, 则由
.I auth
指定, 其 格式为 "用户名:密码" (不包括引号).
.TP
fB-@ fIfilefR, fB-^-list fIfile

.I file
指定的文件中读取将要播放的MPEG音频流所在的文件和(或)URL, 如果
命令行中还指定了其它的文件和(或)URL, 也将其包含进播放清单.
如果指定
.I file
为 `-'而非一个普通的文件名,
.B mpg123
将从标准输入读 取文件名和(或)URL, 或者读取一个指向播放清单文件的URL.
注意:
.B -@
选项只能使用一次(如果多处指定, 则只有最后一个有效).
.TP
.BR -z ", " -^-shuffle
随机播放. 按随机的顺序播放命令行和清单文件中指定的音频文件.
.TP
.BR --stereo
强制立体声输出.
.TP
.BR --reopen
强制在播放完一个文件后重新打开音频设备.
.TP
.BR --8bit
强制8比特输出.
.TP
.BR -Z ", " --random
完全随机播放. (译者注: 与 --shuffle 选项的区别是, 指定本选项有可
能重复多次播放同一文件)
.SH 操作数
.B mpg123
支持下面的操作数:
.TP
.IR file
指定输入文件的路径. 这些文件必须包含合法的MPEG-1/2音频 Layer-1,
Layer-2或Layer-3的比特流.
如果指定为'-', 将从标准输入读取MPEG数 据. 进一步, 如果以"http://"开头, 则认为指定
了一个
.I URL
(请看下一 节).
.SH HTTP 支持
除了能从普通文件和标准输入读取MPEG音频流,
.B mpg123
还支持通过HTTP协 议从万 维网(WWW)上获取由URL(统一资源定位符)指定的文件.
一个URL是一个以 "http://" 为前缀的字符串, 当
.B mpg123
识别到这个前缀, 它会尝试开启一个 到相应服务器的连接,
接着获取相应的文件并进行解码播放.
.P
很多时候, 从WWW缓存, 或所谓的网络代理比直接从服务器更容易获取文件. 为利 用这种便利,
.B mpg123
会依次检查
.BR MP3_HTTP_PROXY ", "http_proxy "和" HTTP_PROXY,
这三个环境变量是否被设置, 并将第一个被设置的变量的值作为指定的代理.
如 果你需要自己指定另外的代理, 可以使用
.B -p
命令行选项 (请看"选项"小节). 使用
.B "-p none"
选项将不使用任何代理而直接连接服务器, 即使前面所述的三个 变量被设置.
.P
值得注意的是, 为了能从一个WWW服务器获取并流畅地播放MPEG音频文件,
必须有 足够快的网络连接. 例如, 为了能播放速率为128kbit/s的MPEG文件, 所需的
网络带宽至少应该是128kbit/s加上网络协 议本身的传输开销.
如果网络常发生 短时中断, 可以试试用
.B -b
选项指定一个缓冲区. 如果你所在的网络根本无 法达到实时传输MPEG音频文件所需的带宽,
就只好使用
.BR lynx (1)
之类的软件先将 文件下载到本地硬盘上再进行播放了.
.P
如果服务器要求认证, 可以使用
.BR "-u auth"
选项(请看"选项"小节)指定用户名和密 码.
.SH 中断
任何时候按Ctrl-C键都能中断
.B mpg123
的运行. 如果有多个文件在播放, Ctrl-C 会终止当前文件的播放并
开始播放下一个文件, 这种情况下, 如果你想终止整 个程序的运行, 必须连按两次Ctrl-C
(在约一秒钟之内).
.P
注意, 按了Ctrl-C之后声音也许不会马上消失, 这是因为系统的音频设备缓冲了
一部分数据. 这种延迟随系统不同而不同, 但通常都不超过1到2秒.
.SH 相关说明
.BR lynx (1),
.BR sox (1),
.BR intro (1)
.SH 注意
MPEG音频解码, 特别是Layer-3的解码, 需要CPU进行大量的运算. 为能达到实时
解码, 你的计算机至少应该配备Pentium, Alpha, SuperSparc或性能相当的处 理器.
同时你可以使用
.B -singlemix
选项进行单声道解码, 对Layer-3, 这多少 能减少一点CPU负荷. 此外你也可以考虑使用
.BR -2 " 和 " -4
选项.
.P
如果这些方法都不奏效, 试试用
.B -s
选项将解码结果送到标准输出上并将其定向 到一个文件中, 然后再用适当的工具播放这个文件.
你也许会用到
.BR sox (1)
这个 工具, 它能将文件转换成你的音频播放器所用的格式.
.P
还有一点就是
.B mpg123
总是输出16比特的立体声数据(如果指定
.BR -0 "或" -1
选项中 的一个, 立体声两个声道的数据是相同的). 如果系统硬件要求其它格式, 比如8
比特的单声道的数据, 同样可以使用
.BR sox (1)
进行转化.
.P
如果你的系统本身足够快, 能够进行实时解码, 只是在系统负荷较重时(如定时任
务, 用户远程登录或启动`大'程序等)出现停顿, 你应该用
.B -b
选项指定一个不小 于1000K字节的缓冲区.
.SH BUGS
.TP
已知的BUG和局限性:
.br
MPEG-2, Layer-1和-2未经 测试. 可能不能工作.(Layer-3应该能工作.)
.br
不提供对自由格式的音频流的支持.
.br
对Layer-1的支持未经 严格测试.
.br
未进行CRC错误校验.
.br
没有对DEC Digital Unix, Ultrix 和 IBM AIX平台上的音频硬件提供支 持,
因此在这些平台上必须使用
.B -s
选项.
.SH 作者
.TP
主要作者:
.br
Michael Hipp <hippm@informatik.uni-tuebingen.de>
.TP
使用了下面的代码或借鉴了其中的思想:
.br
MPEG Software Simulation Group (Base package)
.br
Philipp Knirsch <phil@mpik-tueb.mpg.de> (DCT36/manual unroll)
.br
Tobias Bading <bading@cs.tu-berlin.de> (subband synthesis)
.br
Jeff Tsay <ctsay@pasteur.eecs.berkeley.edu> (DCT36)
.br
Thomas Woerner (SGI Audio)
.br
Damien Clermonte <clermond@esiee.fr> (HP-UX audio fixes)
.br
Oliver Fromme <oliver.fromme@heim3.tu-clausthal.de>
.P
网络参考资料:
.br
href=http://www.sfs.nphil.uni-tuebingen.de/~hipp/mpg123.html>http://www.sfs.nphil.uni-
tuebingen.de/~hipp/mpg123.html

.br
href=http://www.heim3.tu-clausthal.de/~olli/mpg123/>http://www.heim3.tu-clausthal.de/~
olli/mpg123/

.br
(包含关于mpg123邮件组的信息)
.P
在此获取最新版本:
.br
ftp.tu-clausthal.de:/pub/unix/audio/mpg123
.br
href=http://ftp.tu-clausthal.de/pub/unix/audio/mpg123>http://ftp.tu-clausthal.de/pub/u
nix/audio/mpg123

.SH 中文版维护人
linuxipy <groove@ustc.edu>
.SH 中文版最新更新
2004/2/29

----
hey god, tell me what the hell is going on.
[Original] [Print] [Top]
Subject: Re: mpg123.1[English Version]
Author: groove    Posted: 2004-02-29 15:54    Length: 15,732 byte(s)
[Original] [Print] [Top]

." @(#)mpg123.1 0.01 21-Apr-1997 OF; from mpg123 archive
.TH mpg123 1 "21 Apr 1997"
.SH NAME
mpg123 - play audio MPEG 1.0/2.0 file (layers 1, 2 and 3)
.SH SYNOPSIS
.B mpg123
[
.B -tscvqy01m24
]
[
.BI -b " size"
]
[
.BI -k " num"
]
[
.BI -n " num"
]
[
.BI -f " factor"
]
[
.BI -r " rate"
]
[
.BI -g " gain"
]
[
.BI -a " dev"
]
[
.BR "-o s" " | " "-o h" " | " "-o l"
]
[
.BI -d " n"
]
[
.BI -h " n"
]
[
.BI -p " proxy"
]
[
.BI -@ " file"
]
.IR file " ... | " URL " ... | "
.B -
.SH DESCRIPTION
.B mpg123
reads one or more
.IR file^ s
(or standard input if ``-'' is specified) or
.IR URL^ s
and plays them on the audio device (default) or
outputs them to stdout.
.IR file^ / URL
is assumed to be an MPEG-1/2 audio bit stream.
.SH OPTIONS
.B mpg123
options may be either the traditional POSIX one letter options,
or the GNU style long options. POSIX style options start with a
single ``-'', while GNU long options start with ``-^-''.
.TP
.BR -t ", " -^-test
Test mode. The audio stream is decoded, but no output occurs.
.TP
.BR -s ", " -^-stdout
The decoded audio samples are written to standard output,
instead of playing them through the audio device. This
option must be used if your audio hardware is not supported
by
.BR mpg123 .
The output format is raw (headerless) linear PCM audio data,
16 bit, stereo, host byte order.
.TP
.BR -c ", " -^-check
Check for filter range violations, and report them for each frame
if any occur.
.TP
.BR -v ", " -^-verbose
Increase the verbosity level. For example, displays the frame
numbers during decoding.
.TP
.BR -q ", " -^-quiet
Quiet. Suppress diagnostic messages.
.TP
.BR -y ", " -^-resync
Try to resync and continue decoding if an error occurs in
the input file. Also try to recover from certain broken
headers. Useful if you have a broken MPEG file, on which
.B mpg123
normally gives up saying `Illegal header'. Be careful:
Broken locations in MPEG files might cause sharp, loud pops or
clicks, which might damage your speakers if played too loud.
.TP
.BR -0 ", " -^-single0 "; " -1 ", " -^-single1
Decode only channel 0 (left) or channel 1 (right),
respectively. These options are available for
stereo MPEG streams only.
.TP
.BR -m ", " -^-singlemix
Mix both channels. This option is available for
stereo MPEG layer-3 streams only. It takes less
CPU time than full stereo decoding.
.TP
.BR -2 ", " -^-2to1 "; " -4 ", " -^-4to1
Performs a downsampling of ratio 2:1 (22 kHz) or 4:1 (11 kHz)
on the output stream, respectively. Saves some CPU cycles, but
at least the 4:1 ratio sounds ugly.
.TP
fB-b fIsizefR, fB-^-buffer fIsize
Use an audio output buffer of
.I size
Kbytes. This is useful to bypass short periods of heavy
system activity, which would normally cause the audio output
to be interrupted.
You should specify a buffer size of at least 1024
(i.e. 1 Mb, which equals about 6 seconds of audio data) or more;
less than about 300 does not make much sense. The default is 0,
which turns buffering off.
.TP
fB-k fInumfR, fB-^-skip fInum
Skip first
.I num
frames. By default the decoding starts at the first frame.
.TP
fB-n fInumfR, fB-^-frames fInum
Decode only
.I num
frames. By default the complete stream is decoded.
.TP
fB-f fIfactorfR, fB-^-scale fIfactor
Change scale factor (default: 32768).
.TP
fB-r fIratefR, fB-^-rate fIrate
Set sample rate (default: automatic). You may want to
change this if you need a constant bitrate independed of
the mpeg stream rate. mpg123 automagically converts the
rate. You should then combine this with --stereo or --mono.

.TP
fB-g fIgainfR, fB-^-gain fIgain
Set audio hardware output gain (default: don't change).
.TP
fB-a fIdevfR, fB-^-audiodevice fIdev
Specify the audio device to use. The default is
system-dependent (usually /dev/audio or /dev/dsp).
Use this option if you have multiple audio devices and
the default is not what you want.
.TP
.BR "-o s" ", " -^-speaker
Direct audio output to the speaker.
.TP
.BR "-o h" ", " -^-headphones
Direct audio output to the headphone connector.
.TP
.BR "-o l" ", " -^-lineout
Direct audio output to the line-out connector.
.TP
fB-d fInfR, fB-^-doublespeed fIn
Only play every
.IR n 'th
frame. This will cause the MPEG stream
to be played
.I n
times faster, which can be used for special
effects. Can also be combined with the
.B -^-halfspeed
option to play 3 out of 4 frames etc. Don't expect great
sound quality when using this option.
.TP
fB-h fInfR, fB-^-halfspeed fIn
Play each frame
.I n
times. This will cause the MPEG stream
to be played at
.IR 1 / n 'th
speed (n times slower), which can be
used for special effects. Can also be combined with the
.B -^-doublespeed
option to double every third frame or things like that.
Don't expect great sound quality when using this option.
.TP
fB-p fIURL fR| fBnonefR, fB-^-proxy fIURL fR| fBnone
The specified
.I proxy
will be used for HTTP requests. It
should be specified as full URL (``http://host.domain:port/''),
but the ``http://'' prefix, the port number and the trailing
slash are optional (the default port is 80). Specifying
.B none
means not to use any proxy, and to retrieve files directly
from the respective servers. See also the
``HTTP SUPPORT'' section.
.TP
fB-u fIauthfR, fB-^-auth fIauth
HTTP authentication to use when recieving files via HTTP.
The format used is user:password.
.TP
fB-@ fIfilefR, fB-^-list fIfile
Read filenames and/or URLs of MPEG audio streams from the specified
.I file
in addition to the ones specified on the command line (if any).
Note that
.I file
can be either an ordinary file, a dash ``-'' to indicate that
a list of filenames/URLs is to be read from the standard input,
or an URL pointing to a an appropriate list file. Note: only
one
.B -@
option can be used (if more than one is specified, only the
last one will be recognized).
.TP
.BR -z ", " -^-shuffle
Shuffle play. Randomly shuffles the files specified on the command line
and in the list file.
.TP
.BR --stereo
Force stereo output
.TP
.BR --reopen
Forces reopen of the audiodevice after ever song
.TP
.BR --8bit
Forces 8bit output
.TP
.BR -Z ", " --random
Full random play
.SH OPERANDS
The following operands are supported:
.TP 8
.IR file (s)
The path name(s) of one or more input files. They must be
valid MPEG-1/2 audio layer-1, -2 or -3 bit streams.
If a dash ``-'' is specified, MPEG data will
be read from the standard input. Furthermore, any name
starting with ``http://'' is recognized as
.I URL
(see next section).
.SH HTTP SUPPORT
In addition to reading MPEG audio streams from ordinary
files and from the standard input,
.B 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,
.B mpg123
attempts to open an HTTP connection to the server in order to
retrieve that file to decode and play it.
.P
It is often useful to retrieve files through a WWW cache or
so-called proxy. To accomplish this,
.B mpg123
examines the environment for variables named
.BR 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
.B -p
command line option (see the ``OPTIONS'' section). Specifying
.B "-p none"
will enforce contacting the server directly without using
any proxy, even if one of the above environment variables
is set.
.P
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 -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
.BR lynx (1))
and then play them from there.
.P
If authentication is needed to access the file it can be
specified with the
.BR "-u user:pass".
.SH INTERRUPT
You can abort
.B mpg123
at any time by pressing Ctrl-C. If you are playing multiple
files, this will stop the current file and begin playing the
next one. If you want to abort playing immediately instead
of skipping to the next file, press Ctrl-C twice in short
succession (within about one second).
.P
Note that the result of pressing Ctrl-C might not be audible
immediately, due to audio data buffering in the audio device.
This delay is system dependent, but it is usually not more
than one or two seconds.
.SH "SEE ALSO"
.BR lynx (1),
.BR sox (1),
.BR intro (1)
.SH NOTES
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
.B -singlemix
option to decode mono only, which reduces the CPU load
somewhat for layer-3 streams. See also the
.BR -2 " and " -4
options.
.P
If everything else fails, use the
.B -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
.BR sox (1)
to convert the output to an audio format suitable for
your audio player.
.P
Also note that
.B mpg123
always generates 16 bit stereo data (if one of the
.BR -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
.BR sox (1).
.P
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 -b
option to use a buffer of at least 1000 Kbytes.
.SH BUGS
.TP
Known bugs and limitations:
.br
MPEG-2, Layer 1 and 2 not tested. May not work. (Layer 3 should work.)
.br
Free format streams are not supported.
.br
Layer-1 support is not heavily tested.
.br
No CRC error checking is performed.
.br
There is currently no support for audio hardware on
DEC Digital Unix, Ultrix and IBM AIX, therefore the
.B -s
option has to be used on those platforms.
.SH AUTHORS
.TP
Main author:
.br
Michael Hipp <hippm@informatik.uni-tuebingen.de>
.TP
Uses code (or at least ideas) from:
.br
MPEG Software Simulation Group (Base package)
.br
Philipp Knirsch <phil@mpik-tueb.mpg.de> (DCT36/manual unroll)
.br
Tobias Bading <bading@cs.tu-berlin.de> (subband synthesis)
.br
Jeff Tsay <ctsay@pasteur.eecs.berkeley.edu> (DCT36)
.br
Thomas Woerner (SGI Audio)
.br
Damien Clermonte <clermond@esiee.fr> (HP-UX audio fixes)
.br
Oliver Fromme <oliver.fromme@heim3.tu-clausthal.de>
.P
Internet references:
.br
target="_blank">http://www.sfs.nphil.uni-tuebingen.de/~hipp/mpg123.html
.br
target="_blank">http://www.heim3.tu-clausthal.de/~olli/mpg123/
.br
(includes information about the mpg123 mailing list)
.P
The latest version is also available from here:
.br
ftp.tu-clausthal.de:/pub/unix/audio/mpg123
.br
target="_blank">http://ftp.tu-clausthal.de/pub/unix/audio/mpg123



----
hey god, tell me what the hell is going on.
[Original] [Print] [Top]
Subject: Re: mpg123.1
Author: bbbush    Posted: 2004-03-01 13:27    Length: 21 byte(s)
[Original] [Print] [Top]
多谢多谢!马上加入cvs
[Original] [Print] [Top]
Subject: Re: mpg123.1
Author: xuming    Posted: 2004-03-01 14:18    Length: 14 byte(s)
[Original] [Print] [Top]
谢谢你的贡献。
----
@ 拜托!大家都是神仙,留下点回忆好不好?
[Original] [Print] [Top]
Subject: Re: mpg123.1
Author: bbbush    Posted: 2004-03-01 20:28    Length: 303 byte(s)
[Original] [Print] [Top]
以后能不能在提交以前用 :%s/^$ //g 处理一下?把空行全部删掉。空行会当作另起一段来处理的。
我也觉得附件或者邮件方式比较好了。这样贴上来虽然容易查错,但是很多地方会出问题,比如网站的链接会变掉
至于校对,可以用webcvs 来做,只要把最新的版本和最旧的版本一对比就可以了。试了一下还是挺好用的。
[Original] [Print] [Top]
Subject: groove,能不能把译件用附件发到我的邮箱
Author: xuming    Posted: 2004-03-04 13:56    Length: 141 byte(s)
[Original] [Print] [Top]
从WEB上抽取的PAGE效果不太好,请把译件直接发给我吧,谢谢。
xuming@shdv.com
----
@ 拜托!大家都是神仙,留下点回忆好不好?
[Original] [Print] [Top]
« Previous thread
这个计划还在进行否?
翻译作坊
4
Next thread »
wc 的man 文件觉得应更新一下。
     

Copyright © 2007 UNIX Resources Network, All Rights Reserved.      About URN | Privacy & Legal | Help | Contact us
备案序号: 京ICP备05006143    webmaster: webmaster@unixresources.net
This page created on 2008-07-17 01:58:42, cost 0.10200786590576 ms.