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Welcome to the Skunkware '98 Audio / Video Tools section. Here you will find sound card drivers, MPEG players and encoders, midi players, audio CD players and mixers, and other tools used for developing and enjoying multimedia presentations.
| Name | Description | Version | OSR5 | UnixWare |
|---|---|---|---|---|
| mpg123 | MPEG audio player with HTTP support | 0.59k | Yes | Yes |
| maplay | MPEG audio player | 1.2 | No | Yes |
| 4front | SoundBlaster drivers | 3.7 | Yes | Yes |
| sox | Sound eXchange | 11.12 | Yes | No |
| timidity | Midi player | 0.2i | Yes | No |
| xmcd | Audio CD player | 2.1 | Yes | No |
| xmmix | Motif audio mixer | 1.2 | Yes | No |
| mpeg_bits | Bit rate monitor/modifier | 1.0b | Yes | No |
| mpeg_blocks | Analyze macroblocks | 1.0b | Yes | No |
| mpeg_encode | MPEG encoder | 1.5b | Yes | No |
| mpeg_play | MPEG video player | 2.3 | Yes | No |
| mpeg_stat | Analyze bitstreams | 2.2b | Yes | No |
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.
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.
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.
http://www.sco.com/skunkware/uw7/audio/mpg123/
maplay version 1.2 is the second release of my MPEG audio player/decoder. It decodes layer I and layer II MPEG audio streams and plays them using a CD-quality audio device. Currently supported devices are the dbri device of SPARC 10 computers and the audio ports of Silicon Graphics Indigo machines. Thanks to Louis P. Kruger (lpkruger@phoenix. Princeton.EDU), maplay 1.2 can also use the /dev/dsp device under Linux. Louis has tested it with the Pro Audio Spectrum 16 soundcard. Sound Blaster 16 and Gravis Ultrasound cards should also work, but a bug in the dsp driver prevents stereo playback on Gravis Ultrasound cards. An amd device of a SPARC 2/IPX/... machine can be used, too, but this device is only capable of producing audio output at 8 kHz in u-law format, which sounds like transmitted through a telephone. Other audio device are not supported directly, but can be used with the "decode to stdout" option and an audio format converter. Besides it shouldn't be a problem to adapt the program to other audio devices.
The player supports all modes, which are single channel, stereo, joint stereo and dual channel, and all bitrates except free mode. The missing free mode support should not be a problem for now, because I haven't seen such a stream yet.
maplay needs approximately 46% CPU time on SPARC 10/40 machines and 50% on Indigos for realtime stereo playback of a 44.1 kHz 128 kbit/s stream. Single channel playback needs about the half CPU time. On a SPARCstation IPX, maplay needs about 43% CPU time for realtime mono playback. Stereo playback is not possible via an amd device.
Besides realtime playing of audio streams, maplay can decode streams to stdout for further conversions. The output consists of 16 bit signed PCM values. For stereo streams, the values are interleaved, which means that a value for the left channel is followed by a value for the right channel and so on. If maplay has been compiled for u-law output, the output consists of 8 bit u-law samples at a rate of 8 kHz, no matter what frequency the stream uses.
Open Sound System for SCO OpenServer 5 provides device drivers for popular soundcards under SCO Open Server 5.0.2/5.0.4 and Free/SCO. OSS/SCO comes with a configuration tool and complies with the Open Sound System API.
Features include :
- OSS/SCO version 3.7.1s now available (April 24, 1997).
- Easy menu based installation and configuration program
- Support for Sound Blaster AWE32/AWE64 Emu8000 synth
- Supports PnP sound cards.
- Autodetection of Sound Blaster, ESS and GUS sound cards.
- Drivers for over 150 brand name soundcards and onboard audio devices.
- Support for a wide variety of audio applications
SCO Skunkware 7 includes a SoundBlaster compatible driver for SCO OpenServer. UnixWare 7 contains this audio driver in the standard distribution. Drivers for additional sound cards can be obtained from 4Front Technologies. In addition, 4Front maintains a pretty good set of links to free audio software at http://www.4front-tech.com/ossapps.html.
SoX is a sound file format converter for Unix and DOS PCs written by Lance Norskog and other invaluable contributors. It also does sample rate conversion and some sound effects. It's the swiss army knife of sound tools: the interface isn't great, but it does almost everything.
SoX uses file suffices to determine the nature of a sound sample file. If it finds the suffix in its list, it uses the appropriate read or write handler to deal with that file. SoX has an auto-detect feature that attempts to figure out the nature of an unmarked sound sample.
http://www.sco.com/skunkware/osr5/audio/sox/
TiMidity is a MIDI to WAVE converter using Gravis Ultrasound-compatible patch files to generate digital audio data from General MIDI files. The data can be stored in a file for processing, or played in real time through an audio device.
Xmcd is CD Player utility package including xmcd, a CD Player for the X window system using the Motif graphical user interface and cda, a command-line driven, text mode CD Player which also features a curses-based, screen-oriented mode. Both utilities transform your CD-ROM or CD-R drive into a stereo CD player, allowing you to play music CDs on your computer.
These CD player utilities are designed to be attractive, feature-rich yet intuitive to use, and takes advantage of many CD-ROM drive capabilities that are not accessible via other players. Moreover, a CD database feature is supported, maintaining the disc artist/title, track titles, and arbitrary text (such as band information and song lyrics).
Xmcd and cda have emerged as the most ported CD player package, supporting a substantial list of UNIX operating system variants (as well as a non-UNIX OS) and hardware platforms. Moreover, these utilities also support a vast spectrum of CD-ROM and CD-R drives, including many older SCSI-1 units.
Xmmix is an audio mixer utility for the X window system using the Motif graphical user interface. It operates the input and output mixer section on many PC sound cards.
mpeg_bits provides a GUI for the monitoring and modification of MPEG streams. As it displays an MPEG bitstream, it gives feedback on how bits are being allocated on a macroblock-by-macroblock level. It also enables the user to specify block-level q-scale changes, which are then compiled into a specifics file which can be used in later encodings.
mpeg_blocks provides an easy-to-use graphical interface to look at MPEG streams. It operates by playing a video stream in one window, while another window displays the block type and motion vectors for each block in the current frame.
mpeg_encode produces an MPEG-1 video stream. param_file is a parameter file which includes a list of input files and other parameters.
mpeg_play decodes and displays mpeg-1 encoded bitstreams on systems running X11. The player will create a new window, display the bitstream, and exit.
mpeg_stat decodes mpeg-1 encoded bitstreams collecting varying amounts of statistics. Errors are sent to stderr, basic statistics to stdout. The basic information is the pattern of frames used, number of bytes for each frame type, the specified parameters, and lengths of vectors. For each frame type, the average size, compression rate, Q-factor, and time to decode are given.
Last Updated: Tuesday Jul 28, 1998 at 09:47:22 PDT
© Copyright 1997 The Santa Cruz Operation, Inc. All rights reserved.
