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<TITLE>Python OSS Module</TITLE>
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<BODY>
<H1>Python OSS Module</H1>
<H2>A Python interface to the Open Sound System API</H2>
<H2>July 1997</H2>
<ADDRESS>Timothy Butler</ADDRESS>
<P>
<P><HR><P>
<H1>Table of Contents</H1>
<UL>
<LI><A NAME="TOC1" HREF="ossmodule.html#SEC1">Introduction</A>
<UL>
<LI><A NAME="TOC2" HREF="ossmodule.html#SEC2">Essential References</A>
<LI><A NAME="TOC3" HREF="ossmodule.html#SEC3">Obtaining the oss Module</A>
<LI><A NAME="TOC4" HREF="ossmodule.html#SEC4">Installation</A>
<UL>
<LI><A NAME="TOC5" HREF="ossmodule.html#SEC5">Linking into the Interpreter</A>
<LI><A NAME="TOC6" HREF="ossmodule.html#SEC6">Building a Shared Library</A>
</UL>
<LI><A NAME="TOC7" HREF="ossmodule.html#SEC7">Feedback</A>
<LI><A NAME="TOC8" HREF="ossmodule.html#SEC8">Design and Implementation</A>
<LI><A NAME="TOC9" HREF="ossmodule.html#SEC9">Future Development</A>
</UL>
<LI><A NAME="TOC10" HREF="ossmodule.html#SEC10">Mixer Programming</A>
<UL>
<LI><A NAME="TOC11" HREF="ossmodule.html#SEC11">Channel Identifiers</A>
<UL>
<LI><A NAME="TOC12" HREF="ossmodule.html#SEC12">Channel Numbers</A>
<LI><A NAME="TOC13" HREF="ossmodule.html#SEC13">Channel Labels</A>
</UL>
<LI><A NAME="TOC14" HREF="ossmodule.html#SEC14">mixer Objects</A>
<UL>
<LI><A NAME="TOC15" HREF="ossmodule.html#SEC15">mixer Instantiation</A>
<LI><A NAME="TOC16" HREF="ossmodule.html#SEC16">mixer Methods</A>
</UL>
</UL>
<LI><A NAME="TOC17" HREF="ossmodule.html#SEC17">Sequencer Programming</A>
<UL>
<LI><A NAME="TOC18" HREF="ossmodule.html#SEC18">sequencer Objects</A>
<UL>
<LI><A NAME="TOC19" HREF="ossmodule.html#SEC19">sequencer Instantiation</A>
<LI><A NAME="TOC20" HREF="ossmodule.html#SEC20">sequencer Methods</A>
</UL>
<LI><A NAME="TOC21" HREF="ossmodule.html#SEC21">synth_info Objects</A>
<UL>
<LI><A NAME="TOC22" HREF="ossmodule.html#SEC22">synth_info Instantiation</A>
<LI><A NAME="TOC23" HREF="ossmodule.html#SEC23">synth_info Members</A>
</UL>
<LI><A NAME="TOC24" HREF="ossmodule.html#SEC24">midi_info Objects</A>
<UL>
<LI><A NAME="TOC25" HREF="ossmodule.html#SEC25">midi_info Instantiation</A>
<LI><A NAME="TOC26" HREF="ossmodule.html#SEC26">midi_info Members</A>
</UL>
</UL>
<LI><A NAME="TOC27" HREF="ossmodule.html#SEC27">Audio Programming</A>
<UL>
<LI><A NAME="TOC28" HREF="ossmodule.html#SEC28">Audio Formats</A>
<LI><A NAME="TOC29" HREF="ossmodule.html#SEC29">audio Objects</A>
<UL>
<LI><A NAME="TOC30" HREF="ossmodule.html#SEC30">audio Instantiation</A>
<LI><A NAME="TOC31" HREF="ossmodule.html#SEC31">audio Methods</A>
</UL>
</UL>
<LI><A NAME="TOC32" HREF="ossmodule.html#SEC32">Miscellaneous</A>
<UL>
<LI><A NAME="TOC33" HREF="ossmodule.html#SEC33">Sound Card ID Numbers</A>
</UL>
<LI><A NAME="TOC34" HREF="ossmodule.html#SEC34">Variable Index</A>
<LI><A NAME="TOC35" HREF="ossmodule.html#SEC35">Function Index</A>
</UL>
<P><HR><P>


<H1><A NAME="SEC1" HREF="ossmodule.html#TOC1">Introduction</A></H1>

<P>
The <B>oss</B> module provides access to the Open Sound System from the
Python programming language.  The Open Sound System is a UNIX device
driver that allows you to record and play digitized audio, control input
and output volume levels, select recording sources, and generate
synthesizer commands and midi bytes controlled by a low-level sequencer.
It runs on FreeBSD, Linux, BSD/OS, Solaris, and other operating systems.

</P>
<P>
Python is an interpreted, interactive, object-oriented, extensible,
and way-cool programming language.  An interactive programming environment
extended with objects to control your sound card can be a powerful and
fun combination.

</P>



<H2><A NAME="SEC2" HREF="ossmodule.html#TOC2">Essential References</A></H2>

<P>
This manual does not cover all of the details you need to program 
the Open Sound System. You should consult the following resources 
to learn about the Open Sound System.

</P>
<DL COMPACT>

<DT>Open Sound System
<DD>
http://www.4front-tech.com/oss.html

<DT>Open Sound System (OSS) Free
<DD>
http://www.4front-tech.com/usslite/

<DT>OSS Programmer's Guide
<DD>
http://www.4front-tech.com/pguide/index.html

<DT>OSS documentation (contains link to valuable "Hackers Guide to VoxWare")
<DD>
http://www.4front-tech.com/usslite/docs.html

</DL>

<P>
You can find more information about Python at 

</P>
<DL COMPACT>

<DT>Python Home Page
<DD>
http://www.python.org
</DL>



<H2><A NAME="SEC3" HREF="ossmodule.html#TOC3">Obtaining the oss Module</A></H2>

<P>
You can download the oss Module from

<PRE>
    http://www.indra.com/~tim/ossmodule
</PRE>



<H2><A NAME="SEC4" HREF="ossmodule.html#TOC4">Installation</A></H2>

<P>
The <B>oss</B> module consists entirely of a single C language source file,
<TT>`ossmodule.c'</TT>.  You must either 

</P>

<OL>

<LI>

compile and link the module into the Python interpreter or

<LI>

create and install a shared library in a directory named by your
<CODE>PYTHONPATH</CODE>.

</OL>



<H3><A NAME="SEC5" HREF="ossmodule.html#TOC5">Linking into the Interpreter</A></H3>


<OL>

<LI>Copy <TT>`ossmodule.c'</TT> into Python's <TT>`Modules'</TT> directory.


<PRE>
    &#62; cp ossmodule.c Python-1.4/Modules
</PRE>

<LI>Edit <TT>`Modules/Setup'</TT> and add an entry for the <B>oss</B> module.


<PRE>
    oss ossmodule.c -I/usr/include/machine -I/usr/include/sys
</PRE>

You may need to add or change the C preprocessor's search directories so
it can find <TT>`soundcard.h'</TT> on your system.

You can also create a shared library this way if you place the module
line in the <CODE>*shared*</CODE> section of the <TT>`Setup'</TT> file.  Read the
comments in the <TT>`Setup'</TT> file for details.

<LI>Recompile, test, and install the Python interpreter


<PRE>
    &#62; cd Python-1.4
    &#62; make

    &#62; ./python
    &#62;&#62; import oss

    &#62;make bininstall
</PRE>

        
</OL>



<H3><A NAME="SEC6" HREF="ossmodule.html#TOC6">Building a Shared Library</A></H3>

<P>
You can use the <TT>`Makefile'</TT> provided with the <B>oss</B> module
distribution to compile a shared library.  You will have to edit the
<TT>`Makefile'</TT> to match your system.  Copy the resulting shared library
to a directory named by your <CODE>PYTHONPATH</CODE>.

</P>

<OL>

</OL>



<H2><A NAME="SEC7" HREF="ossmodule.html#TOC7">Feedback</A></H2>

<P>
Please email bug reports and comments concerning the <B>oss</B> module to
<CODE>tim@netbox.com</CODE>.

</P>
<P>
I am not qualified to answer questions about the OSS itself.  Part of
the reason I wrote the <B>oss</B> module was to create an environment where
I could experiment with and learn about the OSS.

</P>
<P>
If you can't get your sound card to work in the first place
I can't help;  but you might check out the resources listed above.
See section <A HREF="ossmodule.html#SEC2">Essential References</A>.

</P>


<H2><A NAME="SEC8" HREF="ossmodule.html#TOC8">Design and Implementation</A></H2>

<P>
The C language header file, <TT>`sys/soundcard.h'</TT>, defines the OSS API.
Most of the API consists of macros which define operations and arguments
for the <CODE>ioctl()</CODE> system call. 

</P>
<P>
The <B>oss</B> module implements only the bare minimum to use the API
including:

</P>
<DL COMPACT>

<DT><B>Sound device objects.</B>
<DD>
Represent devices such as a mixer, sequencer, and digital audio
devices. The sound device objects in the <B>oss</B>
module store a file descriptor and their methods typically involve
little more than a call to <CODE>ioctl()</CODE> with the proper arguments.

<DT><B>Functions that open and return sound device objects.</B>
<DD>
<DT><B>Module-level variables holding macro "constants".</B>
<DD>
Bitmasks or device numbers that are ultimately provided as arguments to
the <CODE>ioctl()</CODE> calls. Many module-level variables exist in the
<B>oss</B> module which correspond to the exact same names of macro
constants in <TT>`soundcard.h'</TT>.  For example the value of
<CODE>oss.SOUND_MIXER_NRDEVICES</CODE> is the same as
<CODE>SOUND_MIXER_NRDEVICES</CODE> in <TT>`soundcard.h'</TT>.

<DT><B>"Structure" objects.</B>
<DD>
Hold read-only information about system capabilities.

</DL>

<P>
The API operations, such as <CODE>SOUND_MIXER_READ_RECMASK</CODE>, typically
translate into methods of sound device objects, such as
<CODE>mixer.read_recmask()</CODE>.  The correspondence should be clear from the
documentation if not from the names.

</P>
<P>
None of the objects provided by the <B>oss</B> module can serve as base classes.

</P>
<P>
Not every name and data structure provided by <TT>`soundcard.h'</TT> is
available through the <B>oss</B> module. The <B>oss</B> module provides only
the interface that is described in the official OSS API documentation.
Many parts of <TT>`soundcard.h'</TT> are either unsupported, obsolete, not
portable, or undocumented.

</P>
<P>
The MIDI interface and the /dev/sndstat objects are not provided because
these interfaces are simply read and write operations.
 
The <B>oss</B> module was developed using the OSSFree implementation under
FreeBSD. Your mileage may vary.

</P>


<H2><A NAME="SEC9" HREF="ossmodule.html#TOC9">Future Development</A></H2>

<P>
I would like to stick as close as possible to the OSS API as opposed to
implementing old or undocumented features.  So far, I have provided
that part of the API provided implemented by OSSFree.  I may add
features of the commercial version as an option.

</P>
<P>
As a separate project I'd like to add a layer on top of the <B>oss</B>
module (called "possum") that provides graphical interfaces to the sound
devices.  MIDI protocol support would be handy also.

</P>



<H1><A NAME="SEC10" HREF="ossmodule.html#TOC10">Mixer Programming</A></H1>



<H2><A NAME="SEC11" HREF="ossmodule.html#TOC11">Channel Identifiers</A></H2>



<H3><A NAME="SEC12" HREF="ossmodule.html#TOC12">Channel Numbers</A></H3>

<P>
Mixer channels are identified by channel numbers stored in these
module-level variables. Each channel number variable has a corresponding
"MASK" variable has a single bit set shifted left by the channel number.

</P>
<DL COMPACT>

<DT><CODE>SOUND_MIXER_NRDEVICES</CODE>
<DD>
<A NAME="IDX1"></A>
number of channels known to OSS [0,30] 

<DT><CODE>SOUND_MIXER_VOLUME</CODE>
<DD>
<A NAME="IDX2"></A>
<DT><CODE>SOUND_MASK_VOLUME</CODE>
<DD>
<A NAME="IDX3"></A>
 master output level     
	
<DT><CODE>SOUND_MIXER_BASS</CODE>
<DD>
<A NAME="IDX4"></A>
<DT><CODE>SOUND_MASK_BASS</CODE>
<DD>
<A NAME="IDX5"></A>
bass level of all output channels  

<DT><CODE>SOUND_MIXER_TREBLE</CODE>
<DD>
<A NAME="IDX6"></A>
<DT><CODE>SOUND_MASK_TREBLE</CODE>
<DD>
<A NAME="IDX7"></A>
treble level of all output channels

<DT><CODE>SOUND_MIXER_SYNTH</CODE>
<DD>
<A NAME="IDX8"></A>
<DT><CODE>SOUND_MASK_SYNTH</CODE>
<DD>
<A NAME="IDX9"></A>
level of synthesizer (e.g. FM, wave-table)

<DT><CODE>SOUND_MIXER_PCM</CODE>
<DD>
<A NAME="IDX10"></A>
<DT><CODE>SOUND_MASK_PCM</CODE>
<DD>
<A NAME="IDX11"></A>
output level for audio device (/dev/dsp, /dev/audio) 

<DT><CODE>SOUND_MIXER_SPEAKER</CODE>
<DD>
<A NAME="IDX12"></A>
<DT><CODE>SOUND_MASK_SPEAKER</CODE>
<DD>
<A NAME="IDX13"></A>
volume of PC speaker signal routed through card 

<DT><CODE>SOUND_MIXER_LINE</CODE>
<DD>
<A NAME="IDX14"></A>
<DT><CODE>SOUND_MASK_LINE</CODE>
<DD>
<A NAME="IDX15"></A>
level for line-in jack

<DT><CODE>SOUND_MIXER_MIC</CODE>
<DD>
<A NAME="IDX16"></A>
<DT><CODE>SOUND_MASK_MIC</CODE>
<DD>
<A NAME="IDX17"></A>
input level from microphone jack

<DT><CODE>SOUND_MIXER_CD</CODE>
<DD>
<A NAME="IDX18"></A>
<DT><CODE>SOUND_MASK_CD</CODE>
<DD>
<A NAME="IDX19"></A>
input level from CD

<DT><CODE>SOUND_MIXER_IMIX</CODE>
<DD>
<A NAME="IDX20"></A>
<DT><CODE>SOUND_MASK_IMIX</CODE>
<DD>
<A NAME="IDX21"></A>
output (headphone jack) vol for rec monitor (rec only)

<DT><CODE>SOUND_MIXER_ALTPCM</CODE>
<DD>
<A NAME="IDX22"></A>
<DT><CODE>SOUND_MASK_ALTPCM</CODE>
<DD>
<A NAME="IDX23"></A>
volume of alternative CODEC device

<DT><CODE>SOUND_MIXER_RECLEV</CODE>
<DD>
<A NAME="IDX24"></A>
<DT><CODE>SOUND_MASK_RECLEV</CODE>
<DD>
<A NAME="IDX25"></A>
global recording level (rec only)

<DT><CODE>SOUND_MIXER_IGAIN</CODE>
<DD>
<A NAME="IDX26"></A>
<DT><CODE>SOUND_MASK_IGAIN</CODE>
<DD>
<A NAME="IDX27"></A>
??

<DT><CODE>SOUND_MIXER_OGAIN</CODE>
<DD>
<A NAME="IDX28"></A>
<DT><CODE>SOUND_MASK_OGAIN</CODE>
<DD>
<A NAME="IDX29"></A>
??

<DT><CODE>SOUND_MIXER_LINE1</CODE>
<DD>
<A NAME="IDX30"></A>
<DT><CODE>SOUND_MASK_LINE1</CODE>
<DD>
<A NAME="IDX31"></A>
vendor specific

<DT><CODE>SOUND_MIXER_LINE2</CODE>
<DD>
<A NAME="IDX32"></A>
<DT><CODE>SOUND_MASK_LINE2</CODE>
<DD>
<A NAME="IDX33"></A>
vendor specific

<DT><CODE>SOUND_MIXER_LINE3</CODE>
<DD>
<A NAME="IDX34"></A>
<DT><CODE>SOUND_MASK_LINE3</CODE>
<DD>
<A NAME="IDX35"></A>
vendor specific

</DL>



<H3><A NAME="SEC13" HREF="ossmodule.html#TOC13">Channel Labels</A></H3>

<P>
Two module-level lists, <CODE>SOUND_DEVICE_LABELS</CODE> and
<CODE>SOUND_DEVICE_NAMES</CODE>, store strings that can be used to name
channels. These lists can be indexed by channel number
(e.g. <CODE>SOUND_DEVICE_LABELS[SOUND_MIXER_VOLUME]</CODE>).

</P>
<DL COMPACT>

<DT><CODE>SOUND_DEVICE_LABELS</CODE>
<DD>
<A NAME="IDX36"></A>
channel names that are suitable for user presentation.
<DT><CODE>SOUND_DEVICE_NAMES</CODE>
<DD>
<A NAME="IDX37"></A>
lowercase fixed-size names without spaces.

</DL>



<H2><A NAME="SEC14" HREF="ossmodule.html#TOC14">mixer Objects</A></H2>

<P>
A mixer object controls the volume levels of input and output channels.
A mixer object also selects input sources from the microphone, line, and
CD inputs.

</P>
<P>
Read and write operations on a mixer's file descriptor are undefined and
there are no <CODE>read()</CODE> or <CODE>write()</CODE> methods on a mixer.
    

</P>


<H3><A NAME="SEC15" HREF="ossmodule.html#TOC15">mixer Instantiation</A></H3>

<P>
Create an mixer object using the module function <CODE>open_mixer()</CODE>.
The same mixer device may be opened more than once.
An open mixer object will be closed before it is deleted.

</P>
<P>
<DL>
<DT><U>Function:</U> <B>open_mixer</B> <I>(filename, flags)</I>
<DD><A NAME="IDX38"></A>
        
Create, open, and return a new mixer object.
<DL COMPACT>

<DT><VAR>filename</VAR>
<DD>
 defaults to <CODE>"/dev/mixer"</CODE>.
<DT><VAR>flags</VAR>
<DD>
defaults to <CODE>FCNTL.O_RDWR</CODE>.
</DL>

</DL>



<H3><A NAME="SEC16" HREF="ossmodule.html#TOC16">mixer Methods</A></H3>

<P>
<DL>
<DT><U>Method:</U> mixer <B>fileno</B> <I>()</I>
<DD><A NAME="IDX39"></A>
Return the file number associated with this mixer.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> mixer <B>close</B> <I>()</I>
<DD><A NAME="IDX40"></A>
Free the resources associated with this mixer.

</P>
<P>
Called on deletion if not called explicitly.  Do not call any
methods of a closed mixer.
</DL>
    
<DL>
<DT><U>Method:</U> mixer <B>devmask</B> <I>()</I>
<DD><A NAME="IDX41"></A>
Return a bitmask of available mixer channels.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> mixer <B>recmask</B> <I>()</I>
<DD><A NAME="IDX42"></A>
Return a bitmask of channels that may be used as recording sources.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> mixer <B>stereodevs</B> <I>()</I>
<DD><A NAME="IDX43"></A>
Return a bitmask of stereo channels.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> mixer <B>caps</B> <I>()</I>
<DD><A NAME="IDX44"></A>
Return a bitmask describing the general capabilities of a mixer.

</P>
<P>
Currently, the module-level constant mask <CODE>SOUND_CAP_EXCL_INPUT</CODE> is
the only mixer capability defined. 

</P>
<DL COMPACT>

<DT><CODE>SOUND_CAP_EXCL_INPUT</CODE>
<DD>
<A NAME="IDX45"></A>
If this bit is set to 1, then only one mixer channel can be selected at
the same time.
</DL>

</DL>

<P>
<DL>
<DT><U>Method:</U> mixer <B>read_recsrc</B> <I>()</I>
<DD><A NAME="IDX46"></A>
Return a bitmask of active recording sources.
</DL>

</P>

<P>
<DL>
<DT><U>Method:</U> mixer <B>write_recsrc</B> <I>(mask)</I>
<DD><A NAME="IDX47"></A>
Select recording source channels with a bitmask.
	
If <VAR>mask</VAR> is zero, then the mic input will be used.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> mixer <B>read_channel</B> <I>(channel_num)</I>
<DD><A NAME="IDX48"></A>
Return the level (volume) of a channel.

</P>
<P>
The volume is returned as a tuple, ( <VAR>left</VAR>, <VAR>right</VAR> ),
representing the level of both stereo channels.  For mono devices, only
<VAR>left</VAR> is valid, (the right channel value is set to the left).
	
Levels are between 0 (off) and 100 (maximum), inclusive.

</P>
</DL>

<P>
<DL>
<DT><U>Method:</U> mixer <B>write_channel</B> <I>(channel_num, level)</I>
<DD><A NAME="IDX49"></A>
Set the level (volume) of a channel.

</P>
<P>
<VAR>level</VAR> may be either a single integer or a tuple
(<VAR>left</VAR>, <VAR>right</VAR>) with values from 0 (off) to 100
(maximum), inclusive.
	
If <VAR>level</VAR> is a single integer, it is applied to just a mono
channel or both sides of a stereo channel.
	
If <VAR>level</VAR> is a tuple, then each side of a stereo channel will
be assigned its own level. Mono-devices use the left value
of a tuple.
	
<CODE>write_channel()</CODE> returns a tuple that represents the new
level(s) of a channel.  Because some mixers will quantize
levels with only 3 to 8 bits, the new levels may <EM>not</EM> be
exactly the same as what was requested. See the OSS
developer's guide for details.
</DL>

</P>


<H1><A NAME="SEC17" HREF="ossmodule.html#TOC17">Sequencer Programming</A></H1>



<H2><A NAME="SEC18" HREF="ossmodule.html#TOC18">sequencer Objects</A></H2>

<P>
The sequencer object controls the on-board synthesizer using MIDI-like
commands and allows I/O through MIDI ports.

</P>

<P>
Synthesizers accept commands that resemble MIDI commands but otherwise
have nothing to do with the MIDI capabilities of a soundcard. For
example, some synthesizer methods are called <CODE>note_on()</CODE> and
<CODE>chn_pressure()</CODE> but these do not send bytes out the MIDI
port. Instead, they only mimic similar effects with the synthesizers.

</P>
<P>
MIDI I/O support consists entirely of simple commands to read and
write individual bytes through specific MIDI ports. MIDI input is not
implemented in this version.
    
Read and write operations on a mixer's file descriptor are undefined and
there are no <CODE>read()</CODE> or <CODE>write()</CODE> methods on a mixer.

</P>
<P>
Many methods of a sequencer generate an <STRONG>event</STRONG> (synthesizer command
or a MIDI byte) that is written immediately to a buffer in the <B>oss</B>
module.  As the buffer fills, events will eventually be passed to the
driver's queue. The sequencer <CODE>dump_buf()</CODE> method flushes the
module's buffer to the driver's event queue.
 
The sequencer driver processes most events in its queue immediately.
The sequencer method <CODE>wait_time()</CODE> intersperses timing events
between other events. When the driver processes a timing event in the
queue, it waits until that absolute time before continuing. Note that in
order for the sequencer to see the timing event it must be flushed to
the event queue using <CODE>dump_buf()</CODE>.
    

</P>


<H3><A NAME="SEC19" HREF="ossmodule.html#TOC19">sequencer Instantiation</A></H3>

<P>
Create an sequencer object using the module function <CODE>open_sequencer()</CODE>.
Only one sequencer may be open at a time; even within the same 
application.

</P>
<P>
An open sequencer object will be closed before it is deleted.
    
<DL>
<DT><U>Function:</U> <B>open_sequencer</B> <I>(filename, flags):</I>
<DD><A NAME="IDX50"></A>
Create, open, and return a new sequencer object.

</P>
<DL COMPACT>

<DT><VAR>filename</VAR>
<DD>
 defaults to <CODE>"/dev/sequencer"</CODE>.
<DT><VAR>flags</VAR>
<DD>
defaults to <CODE>FCNTL.O_RDWR</CODE>.

Use <CODE>FCNTL.O_WRONLY</CODE> for an output-only program so unnecessary
functions like MIDI input aren't initialized.  Likewise, use
<CODE>FCNTL.O_RDONLY</CODE> for input-only programs.
</DL>

</DL>



<H3><A NAME="SEC20" HREF="ossmodule.html#TOC20">sequencer Methods</A></H3>

<P>
<DL>
<DT><U>Method:</U> sequencer <B>fileno</B> <I>()</I>
<DD><A NAME="IDX51"></A>
Return the file number associated with this sequencer.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>close</B> <I>()</I>
<DD><A NAME="IDX52"></A>
Free the resources associated with this sequencer.

</P>
<P>
Called on deletion if not called explicitly.  Do not call any
methods of a closed sequencer.
	
<CODE>close()</CODE> shuts off all synthesizer sounds immediately, so you might
want to add an extra delay before closing this device.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>nrsynths</B> <I>()</I>
<DD><A NAME="IDX53"></A>
Return the number of internal synthesizer devices.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>synth_info</B> <I>(obj)</I>
<DD><A NAME="IDX54"></A>
Describe a specific synthesizer.

</P>
<P>
<VAR>obj</VAR> may be either an integer device number or a 
synth_info object with its <CODE>device</CODE> member initialized.

</P>
<P>
If <VAR>obj</VAR> is an integer then return a new synth_info object
describing the device.  If <VAR>obj</VAR> is an existing synth_info then it
is filled in with the description and returned.

</P>
<P>
You must provide a device number that is less than the value
returned by the method <CODE>nrsynths()</CODE>.

</P>
<P>
See section <A HREF="ossmodule.html#SEC21">synth_info Objects</A>
</DL>
	
<DL>
<DT><U>Method:</U> sequencer <B>nrmidis</B> <I>()</I>
<DD><A NAME="IDX55"></A>
Return the number of MIDI ports available.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>midi_info</B> <I>(obj)</I>
<DD><A NAME="IDX56"></A>
Describe a specific MIDI port.

</P>
<P>
<VAR>obj</VAR> may be either an integer port number or a midi_info object
with its <CODE>device</CODE> member initialized to the desired MIDI port.

</P>
<P>
If <VAR>obj</VAR> is an integer then return a new midi_info object describing
the port.  If <VAR>obj</VAR> is an existing midi_info then it is filled in
with the description and returned.

</P>
<P>
You must provide a port number that is less than the value
returned by the <CODE>nrmidis()</CODE> method.

</P>
<P>
See section <A HREF="ossmodule.html#SEC24">midi_info Objects</A>.

</P>
</DL>

<P>
<DL>
<DT><U>Method:</U> sequencer <B>start_timer</B> <I>()</I>
<DD><A NAME="IDX57"></A>
EVENT Reset the sequencer's timer.

</P>
<P>
Note that this method generates an <EM>event</EM> that will 
be processed only when it makes it to the head of the queue.

</P>
<P>
The timer may not be restarted immediately.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>wait_time</B> <I>(time)</I>
<DD><A NAME="IDX58"></A>
EVENT Pause the sequencer until <VAR>time</VAR>.

</P>
<P>
<VAR>time</VAR> is the absolute time when the driver should continue reading
the event queue.  Absolute time is measured in units of the kernel timer
(typically 100 Hz, 10 ms/tick) from the time the device was opened.

</P>
<P>
Use the <CODE>ctrlrate()</CODE> method to determine the actual timer
resolution.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>ctrlrate</B> <I>()</I>
<DD><A NAME="IDX59"></A>
Return the timer resolution in ticks per second.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>midiout</B> <I>(midi_dev, byte)</I>
<DD><A NAME="IDX60"></A>
EVENT Write a byte to a MIDI port.

</P>
<DL COMPACT>

<DT><VAR>midi_dev</VAR>
<DD>
the MIDI port number.
<DT><VAR>byte</VAR>
<DD>
either an integer or a single character that is the byte to output.
</DL>
</DL>

<P>
<DL>
<DT><U>Method:</U> sequencer <B>set_patch</B> <I>(dev, voice, patch)</I>
<DD><A NAME="IDX61"></A>
EVENT Assign synthesizer instrument number (patch) to a voice.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>start_note</B> <I>(dev, voice, note, vel=64)</I>
<DD><A NAME="IDX62"></A>
EVENT Start a voice on a synthesizer device.

</P>
<DL COMPACT>

<DT><VAR>note</VAR>
<DD>
<DT><VAR>vel</VAR>
<DD>
valid MIDI note number and velocity values, [0,127].
</DL>

<P>
Some synthesizers support adjusting the volume of a note (rather than
starting a new note) with a <VAR>note</VAR> value of 255.  A <VAR>vel</VAR> of 255
may specify a volume stored in some synthesizers' internal tables. The
use of these values is not portable.

</P>
</DL>

<P>
<DL>
<DT><U>Method:</U> sequencer <B>stop_note</B> <I>(dev, voice, note, vel=64)</I>
<DD><A NAME="IDX63"></A>
EVENT Stop the synthesizer note being played.

</P>
<DL COMPACT>

<DT><VAR>note</VAR>
<DD>
the MIDI note number
<DT><VAR>vel</VAR>
<DD>
the speed of the key release.
</DL>

<P>
For portability, use the same note number that started the voice.

</P>
<P>
The voice may have already stopped or decayed.  The release time is an
instrument-specific parameter so the sound may not stop immediately.
Consider adding a delay between the final note and the <CODE>close()</CODE>
method, so the last notes have time to decay before being cut off.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>chn_pressure</B> <I>(dev, voice, pressure)</I>
<DD><A NAME="IDX64"></A>
EVENT Change the channel pressure.
	
<CODE>chn_pressure()</CODE> mimics the pressure used on some MIDI keyboards.
The driver translates pressure into the amount of vibrato in 
OPL-3 voices.  <VAR>pressure</VAR> may be in the range [0,127].
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>panning</B> <I>(dev, voice, pos)</I>
<DD><A NAME="IDX65"></A>
EVENT  Pan the voice between the left and right voice channels.

</P>
<P>
<VAR>pos</VAR> is an integer [-128, 127] where -128 is far left, 0 is
center, and 127 is far right.
	
The pan position is determined by adding <VAR>pos</VAR> to the pan
value stored in the instrument parameters and lasts until
until the note is stopped. The OPL-3 pan value is
simply its volume level.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>control</B> <I>(voice, controller, value)</I>
<DD><A NAME="IDX66"></A>
EVENT Mimic standard MIDI controllers with the synthesizer.

</P>
<P>
The change may be made before starting a note and lasts until the note
is stopped. Once a note is stopped the controller value reverts to its
default.
	
Midi controllers that may be supported are:
<DL COMPACT>

<DT><CODE>CTRL_EXPRESSION</CODE>
<DD>
<A NAME="IDX67"></A>
expression controller of MIDI with values in the range [0,127].

<DT><CODE>CTRL_MAIN_VOLUME</CODE>
<DD>
<A NAME="IDX68"></A>
main volume controller with values in the range [0,100].
</DL>

<P>
Note that these values may have different ranges than their
standard MIDI counterparts.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>bender_range</B> <I>(voice, value)</I>
<DD><A NAME="IDX69"></A>
Define the magnitude of the lowest and highest pitch-bends.
	
<VAR>value</VAR> is in units of cents (1/100 of a semitone).  Although
<VAR>value</VAR> may be set larger, the maximum bend is two octaves (1200
cents or 12 semitones).

</P>
<P>
See <CODE>pitch_bend()</CODE>.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>pitch_bend</B> <I>(voice, value)</I>
<DD><A NAME="IDX70"></A>
EVENT Alter the pitch of a sequencer voice.

</P>
<P>
<VAR>value</VAR> is in the range [-8192, 8191] representing the pitches of
the most extreme low and high bends.

</P>
<P>
The magnitude of the pitch bend is determined by the method
<CODE>bender_range()</CODE>.  If you want *value* to be in units of cents
(1/100 semitone) then call <CODE>bender_range()</CODE> with a value of 8192.

</P>
<P>
The value can be assigned before or after starting the note
and the effect lasts until the note stops.

</P>
<P>
See <CODE>bender_range()</CODE>.

</P>
</DL>

<P>
<DL>
<DT><U>Method:</U> sequencer <B>expression</B> <I>(voice, value)</I>
<DD><A NAME="IDX71"></A>
EVENT Apply an "expression" MIDI controller to a synthesizer voice.
	
???
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> sequencer <B>main_volume</B> <I>(voice, value)</I>
<DD><A NAME="IDX72"></A>
EVENT Apply a "main volume" MIDI controller to a synthesizer voice.

</P>
<P>
???
</DL>

</P>



<H2><A NAME="SEC21" HREF="ossmodule.html#TOC21">synth_info Objects</A></H2>

<P>
A synth_info object is a description of a synthesizer device.

</P>



<H3><A NAME="SEC22" HREF="ossmodule.html#TOC22">synth_info Instantiation</A></H3>

<P>
Typically a sequencer's <CODE>synth_info()</CODE> method creates and returns a
synth_info object.  You can also create a synth_info (for a sequencer to 
fill in) with the module-level function <CODE>synth_info()</CODE>.

</P>
<P>
<DL>
<DT><U>Function:</U> <B>synth_info</B> <I>()</I>
<DD><A NAME="IDX73"></A>
Return a new, uninitialized synth_info object. 
</DL>

</P>


<H3><A NAME="SEC23" HREF="ossmodule.html#TOC23">synth_info Members</A></H3>

<P>
All of these members are read-only except for <CODE>device</CODE>.

</P>
<P>
When a synth_info object is printed, it decodes and displays all of its
members.  This behavior may change in a future release.

</P>
<DL COMPACT>

<DT><CODE>name</CODE>
<DD>
a string containing the name of the device

<DT><CODE>device</CODE>
<DD>
the device number of the synthesizer 
This is used only when this synth_info object is 
passed to a sequencer's <CODE>synth_info()</CODE> method. 

<DT><CODE>synth_type</CODE>
<DD>
integer describing the type of synthesizer.

<DL COMPACT>

<DT><CODE>SYNTH_TYPE_FM</CODE>
<DD>
<A NAME="IDX74"></A>
<DT><CODE>SYNTH_TYPE_SAMPLE</CODE>
<DD>
<A NAME="IDX75"></A>
<DT><CODE>SYNTH_TYPE_MIDI</CODE>
<DD>
<A NAME="IDX76"></A>
</DL>

<DT><CODE>synth_subtype</CODE>
<DD>
integer which may be used to detect the hardware type.

<DT><CODE>nr_voices</CODE>
<DD>
maximum number of voices the device supports in its current mode. If you
change the mode, the value will change also.

</DL>



<H2><A NAME="SEC24" HREF="ossmodule.html#TOC24">midi_info Objects</A></H2>

<P>
A midi_info object describes a MIDI port.

</P>



<H3><A NAME="SEC25" HREF="ossmodule.html#TOC25">midi_info Instantiation</A></H3>

<P>
Typically a sequencer's <CODE>midi_info()</CODE> method creates and returns a
midi_info object.  You can also create a midi_info (for a sequencer to 
fill in) with the module-level function <CODE>midi_info()</CODE>.

</P>
<P>
<DL>
<DT><U>Function:</U> <B>midi_info</B> <I>()</I>
<DD><A NAME="IDX77"></A>
Return a new, uninitialized midi_info object. 
</DL>

</P>


<H3><A NAME="SEC26" HREF="ossmodule.html#TOC26">midi_info Members</A></H3>

<P>
All of these members are read-only except for <CODE>device</CODE>.

</P>
<P>
When a midi_info object is printed, it decodes and displays all of its
members.  This behavior may change in a future release.

</P>
<DL COMPACT>

<DT><CODE>name</CODE>
<DD>
a string containing the name of the device

<DT><CODE>device</CODE>
<DD>
the midi port number, less than sequencer.nrmidis().
This is used only when this midi_info object is 
passed to a sequencer's <CODE>midi_info()</CODE> method. 

<DT><CODE>dev_type</CODE>
<DD>
integer describing the type of sound card where
the MIDI port resides.

See section <A HREF="ossmodule.html#SEC33">Sound Card ID Numbers</A>.

<DT><CODE>capabilities</CODE>
<DD>
bit mask describing some MIDI capabilities?? One mask is defined:

<DL COMPACT>

<DT><CODE>MIDI_CAP_MPU401</CODE>
<DD>
<A NAME="IDX78"></A>
mask
</DL>

</DL>



<H1><A NAME="SEC27" HREF="ossmodule.html#TOC27">Audio Programming</A></H1>



<H2><A NAME="SEC28" HREF="ossmodule.html#TOC28">Audio Formats</A></H2>

<P>
Audio formats are represented by the following module-level bit-flag
values.

</P>
<DL COMPACT>

<DT><CODE>AFMT_MU_LAW</CODE>
<DD>
<A NAME="IDX79"></A>
logarithmic mu-Law (8-bit)
<DT><CODE>AFMT_A_LAW</CODE>
<DD>
<A NAME="IDX80"></A>
logarithmic A-Law  (8-bit)
<DT><CODE>AFMT_IMA_ADPCM</CODE>
<DD>
<A NAME="IDX81"></A>
ADPCM as defined by the Interactive Multimedia Association (IMA).  This
is <EM>not</EM> the Creative ADPCM format. Requires an average of 4 bits
per sample.
<DT><CODE>AFMT_U8</CODE>
<DD>
<A NAME="IDX82"></A>
unsigned 8-bit 
<DT><CODE>AFMT_S16_LE</CODE>
<DD>
<A NAME="IDX83"></A>
signed 16-bit little-endian (Intel)
<DT><CODE>AFMT_S16_BE</CODE>
<DD>
<A NAME="IDX84"></A>
signed 16-bit big-endian (Motorola)
<DT><CODE>AFMT_S8</CODE>
<DD>
<A NAME="IDX85"></A>
unsigned 8-bit
<DT><CODE>AFMT_U16_LE</CODE>
<DD>
<A NAME="IDX86"></A>
unsigned 16-bit little-endian
<DT><CODE>AFMT_U16_BE</CODE>
<DD>
<A NAME="IDX87"></A>
unsigned 16-bit big-endian
<DT><CODE>AFMT_MPEG</CODE>
<DD>
<A NAME="IDX88"></A>
MPEG audio format
</DL>



<H2><A NAME="SEC29" HREF="ossmodule.html#TOC29">audio Objects</A></H2>

<P>
An audio object allows you to play and record digitized audio.

</P>
<P>
You do so by writing and reading samples to the audio device.

</P>
<P>
Please be aware that because Python is not as fast as languages that
are compiled to machine code, you may have difficulty producing
some sounds without output buffer underruns and input overflows.
These may manifest themselves as pauses, clicking, humming, or other
distortions in the sound. 

</P>
<P>
You may have some luck, however, if you use some of the built-in modules
and modules compiled from C. Consider using operations in the
<CODE>array</CODE> and <CODE>audioop</CODE> modules.

</P>
<P>
Before an audio object can be read or written, you must perform 
at least three operations on it:

<OL>
<LI>

Set its sample format with the <CODE>format()</CODE> method.
<LI>

Set the number of channels (mono or stereo) with the <CODE>stereo()</CODE> method.
<LI>

Set the sample rate with the <CODE>speed()</CODE> method.
</OL>

<P>
These operations must be performed in the order presented above.  Please
consult the OSS Programmer's Guide for more information.
 

</P>


<H3><A NAME="SEC30" HREF="ossmodule.html#TOC30">audio Instantiation</A></H3>

<P>
Create an audio object using the module function <CODE>open_audio()</CODE>.

</P>
<P>
An open audio object will be closed before it is deleted.
    
<DL>
<DT><U>Function:</U> <B>open_audio</B> <I>(filename, flags):</I>
<DD><A NAME="IDX89"></A>
Create, open, and return a new audio object.

</P>
<DL COMPACT>

<DT><VAR>filename</VAR>
<DD>
 defaults to <CODE>"/dev/audio"</CODE>.
<DT><VAR>flags</VAR>
<DD>
defaults to <CODE>FCNTL.O_RDWR</CODE>.

Use <CODE>FCNTL.O_WRONLY</CODE> if you intend to only play audio.
Likewise, use <CODE>FCNTL.O_RDONLY</CODE> to only record audio.
</DL>

</DL>



<H3><A NAME="SEC31" HREF="ossmodule.html#TOC31">audio Methods</A></H3>

<P>
<DL>
<DT><U>Method:</U> audio <B>fileno</B> <I>()</I>
<DD><A NAME="IDX90"></A>
Return the file number associated with this audio object.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> audio <B>close</B> <I>()</I>
<DD><A NAME="IDX91"></A>
Free the resources associated with this audio object.

</P>
<P>
Called on deletion if not called explicitly.  Do not call any
methods of a closed audio object.
	
<CODE>close()</CODE> performs a <CODE>sync()</CODE> operation.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> audio <B>reset</B> <I>()</I>
<DD><A NAME="IDX92"></A>
Stop the audio device.

</P>
<P>
Once an audio device is reset you may set new format, stereo, and speed
parameters.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> audio <B>sync</B> <I>()</I>
<DD><A NAME="IDX93"></A>
Wait until the last byte has been played.

</P>
<P>
Once all of the bytes that were written have been played, <CODE>sync()</CODE>
performs a <CODE>reset()</CODE> on the audio device.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> audio <B>post</B> <I>()</I>
<DD><A NAME="IDX94"></A>
Warn the audio device of a pause in the output.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> audio <B>format</B> <I>(format_flag)</I>
<DD><A NAME="IDX95"></A>
Select and return the audio format.

</P>
<P>
See section <A HREF="ossmodule.html#SEC28">Audio Formats</A> for valid values of <VAR>format_flag</VAR>.

</P>
<P>
You should check the return value to ensure that the format you
requested is supported.  

</P>
<P>
To check the current audio format, pass <CODE>AFMT_QUERY</CODE> as
<VAR>format</VAR> or use the <CODE>query_format()</CODE> method.

</P>
</DL>

<P>
<DL>
<DT><U>Method:</U> audio <B>get_formats</B> <I>()</I>
<DD><A NAME="IDX96"></A>
Return a mask of all the audio formats supported by this device.

</P>
<P>
See section <A HREF="ossmodule.html#SEC28">Audio Formats</A>.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> audio <B>query_format</B> <I>()</I>
<DD><A NAME="IDX97"></A>
Return the current audio format.

</P>
<P>
This is a shortcut for <CODE>format(AFMT_QUERY)</CODE>.
See section <A HREF="ossmodule.html#SEC28">Audio Formats</A>.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> audio <B>stereo</B> <I>(is_stereo)</I>
<DD><A NAME="IDX98"></A>
Set the number of channels. 

</P>
<P>
<VAR>is_stereo</VAR>: 0=mono, 1=stereo
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> audio <B>channels</B> <I>(num_channels)</I>
<DD><A NAME="IDX99"></A>
Set the number of channels. 

</P>
<P>
<EM>This operation is documented in the OSS manuals, but not implemented
in my version. -twb</EM>

</P>
<P>
<VAR>num_channels</VAR>: 1=mono, 2=stereo
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> audio <B>speed</B> <I>(sampling_rate)</I>
<DD><A NAME="IDX100"></A>
Set the sampling rate. 

</P>
<P>
Sets and returns the sampling rate that was as close as the device could
get to the requested <VAR>sampling_rate</VAR>.
</DL>

</P>
<P>
<DL>
<DT><U>Method:</U> audio <B>read</B> <I>(bytes_requested)</I>
<DD><A NAME="IDX101"></A>
Record bytes from the audio device. 

</P>
<P>
Returns a string holding the bytes that were read.  This may 
not be the same length as the number of bytes requested.

</P>
<P>
Note that the request is in units of <EM>bytes</EM>, not samples.
For example, if the device is configured for 16-bit stereo, you
should request multiples of four bytes.

</P>
</DL>

<P>
<DL>
<DT><U>Method:</U> audio <B>write</B> <I>(samples)</I>
<DD><A NAME="IDX102"></A>
Play a string of samples.

</P>
<P>
<VAR>samples</VAR> is a string holding the bytes that should be written
to the audio device.

</P>
<P>
Returns the actual number of bytes that were written. This could
be less than the length of <VAR>samples</VAR>.

</P>
<P>
<VAR>samples</VAR> should be a length that is a multiple of the the sample
size (#channels * format size).

</P>
</DL>



<H1><A NAME="SEC32" HREF="ossmodule.html#TOC32">Miscellaneous</A></H1>



<H2><A NAME="SEC33" HREF="ossmodule.html#TOC33">Sound Card ID Numbers</A></H2>

<P>
These module-level variables hold numbers that identify sound cards. 

</P>
<DL COMPACT>

<DT><CODE>SNDCARD_ADLIB</CODE>
<DD>
<A NAME="IDX103"></A>
<DT><CODE>SNDCARD_SB</CODE>
<DD>
<A NAME="IDX104"></A>
<DT><CODE>SNDCARD_PAS</CODE>
<DD>
<A NAME="IDX105"></A>
<DT><CODE>SNDCARD_GUS</CODE>
<DD>
<A NAME="IDX106"></A>
<DT><CODE>SNDCARD_MPU401</CODE>
<DD>
<A NAME="IDX107"></A>
<DT><CODE>SNDCARD_SB16</CODE>
<DD>
<A NAME="IDX108"></A>
<DT><CODE>SNDCARD_SB16MIDI</CODE>
<DD>
<A NAME="IDX109"></A>
<DT><CODE>SNDCARD_UART6850</CODE>
<DD>
<A NAME="IDX110"></A>
<DT><CODE>SNDCARD_GUS16</CODE>
<DD>
<A NAME="IDX111"></A>
<DT><CODE>SNDCARD_MSS</CODE>
<DD>
<A NAME="IDX112"></A>
<DT><CODE>SNDCARD_PSS</CODE>
<DD>
<A NAME="IDX113"></A>
<DT><CODE>SNDCARD_SSCAPE</CODE>
<DD>
<A NAME="IDX114"></A>
<DT><CODE>SNDCARD_PSS_MPU</CODE>
<DD>
<A NAME="IDX115"></A>
<DT><CODE>SNDCARD_PSS_MSS</CODE>
<DD>
<A NAME="IDX116"></A>
<DT><CODE>SNDCARD_SSCAPE_MSS</CODE>
<DD>
<A NAME="IDX117"></A>
<DT><CODE>SNDCARD_TRXPRO</CODE>
<DD>
<A NAME="IDX118"></A>
<DT><CODE>SNDCARD_TRXPRO_SB</CODE>
<DD>
<A NAME="IDX119"></A>
<DT><CODE>SNDCARD_TRXPRO_MPU</CODE>
<DD>
<A NAME="IDX120"></A>
<DT><CODE>SNDCARD_AWE32</CODE>
<DD>
<A NAME="IDX121"></A>
</DL>



<H1><A NAME="SEC34" HREF="ossmodule.html#TOC34">Variable Index</A></H1>
<P>
<H2>a</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX80">AFMT_A_LAW</A>
<LI><A HREF="ossmodule.html#IDX81">AFMT_IMA_ADPCM</A>
<LI><A HREF="ossmodule.html#IDX88">AFMT_MPEG</A>
<LI><A HREF="ossmodule.html#IDX79">AFMT_MU_LAW</A>
<LI><A HREF="ossmodule.html#IDX84">AFMT_S16_BE</A>
<LI><A HREF="ossmodule.html#IDX83">AFMT_S16_LE</A>
<LI><A HREF="ossmodule.html#IDX85">AFMT_S8</A>
<LI><A HREF="ossmodule.html#IDX87">AFMT_U16_BE</A>
<LI><A HREF="ossmodule.html#IDX86">AFMT_U16_LE</A>
<LI><A HREF="ossmodule.html#IDX82">AFMT_U8</A>
</DIR>
<H2>c</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX67">CTRL_EXPRESSION</A>
<LI><A HREF="ossmodule.html#IDX68">CTRL_MAIN_VOLUME</A>
</DIR>
<H2>m</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX78">MIDI_CAP_MPU401</A>
</DIR>
<H2>s</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX103">SNDCARD_ADLIB</A>
<LI><A HREF="ossmodule.html#IDX121">SNDCARD_AWE32</A>
<LI><A HREF="ossmodule.html#IDX106">SNDCARD_GUS</A>
<LI><A HREF="ossmodule.html#IDX111">SNDCARD_GUS16</A>
<LI><A HREF="ossmodule.html#IDX107">SNDCARD_MPU401</A>
<LI><A HREF="ossmodule.html#IDX112">SNDCARD_MSS</A>
<LI><A HREF="ossmodule.html#IDX105">SNDCARD_PAS</A>
<LI><A HREF="ossmodule.html#IDX113">SNDCARD_PSS</A>
<LI><A HREF="ossmodule.html#IDX115">SNDCARD_PSS_MPU</A>
<LI><A HREF="ossmodule.html#IDX116">SNDCARD_PSS_MSS</A>
<LI><A HREF="ossmodule.html#IDX104">SNDCARD_SB</A>
<LI><A HREF="ossmodule.html#IDX108">SNDCARD_SB16</A>
<LI><A HREF="ossmodule.html#IDX109">SNDCARD_SB16MIDI</A>
<LI><A HREF="ossmodule.html#IDX114">SNDCARD_SSCAPE</A>
<LI><A HREF="ossmodule.html#IDX117">SNDCARD_SSCAPE_MSS</A>
<LI><A HREF="ossmodule.html#IDX118">SNDCARD_TRXPRO</A>
<LI><A HREF="ossmodule.html#IDX120">SNDCARD_TRXPRO_MPU</A>
<LI><A HREF="ossmodule.html#IDX119">SNDCARD_TRXPRO_SB</A>
<LI><A HREF="ossmodule.html#IDX110">SNDCARD_UART6850</A>
<LI><A HREF="ossmodule.html#IDX45">SOUND_CAP_EXCL_INPUT</A>
<LI><A HREF="ossmodule.html#IDX36">SOUND_DEVICE_LABELS</A>
<LI><A HREF="ossmodule.html#IDX37">SOUND_DEVICE_NAMES</A>
<LI><A HREF="ossmodule.html#IDX23">SOUND_MASK_ALTPCM</A>
<LI><A HREF="ossmodule.html#IDX5">SOUND_MASK_BASS</A>
<LI><A HREF="ossmodule.html#IDX19">SOUND_MASK_CD</A>
<LI><A HREF="ossmodule.html#IDX27">SOUND_MASK_IGAIN</A>
<LI><A HREF="ossmodule.html#IDX21">SOUND_MASK_IMIX</A>
<LI><A HREF="ossmodule.html#IDX15">SOUND_MASK_LINE</A>
<LI><A HREF="ossmodule.html#IDX31">SOUND_MASK_LINE1</A>
<LI><A HREF="ossmodule.html#IDX33">SOUND_MASK_LINE2</A>
<LI><A HREF="ossmodule.html#IDX35">SOUND_MASK_LINE3</A>
<LI><A HREF="ossmodule.html#IDX17">SOUND_MASK_MIC</A>
<LI><A HREF="ossmodule.html#IDX29">SOUND_MASK_OGAIN</A>
<LI><A HREF="ossmodule.html#IDX11">SOUND_MASK_PCM</A>
<LI><A HREF="ossmodule.html#IDX25">SOUND_MASK_RECLEV</A>
<LI><A HREF="ossmodule.html#IDX13">SOUND_MASK_SPEAKER</A>
<LI><A HREF="ossmodule.html#IDX9">SOUND_MASK_SYNTH</A>
<LI><A HREF="ossmodule.html#IDX7">SOUND_MASK_TREBLE</A>
<LI><A HREF="ossmodule.html#IDX3">SOUND_MASK_VOLUME</A>
<LI><A HREF="ossmodule.html#IDX22">SOUND_MIXER_ALTPCM</A>
<LI><A HREF="ossmodule.html#IDX4">SOUND_MIXER_BASS</A>
<LI><A HREF="ossmodule.html#IDX18">SOUND_MIXER_CD</A>
<LI><A HREF="ossmodule.html#IDX26">SOUND_MIXER_IGAIN</A>
<LI><A HREF="ossmodule.html#IDX20">SOUND_MIXER_IMIX</A>
<LI><A HREF="ossmodule.html#IDX14">SOUND_MIXER_LINE</A>
<LI><A HREF="ossmodule.html#IDX30">SOUND_MIXER_LINE1</A>
<LI><A HREF="ossmodule.html#IDX32">SOUND_MIXER_LINE2</A>
<LI><A HREF="ossmodule.html#IDX34">SOUND_MIXER_LINE3</A>
<LI><A HREF="ossmodule.html#IDX16">SOUND_MIXER_MIC</A>
<LI><A HREF="ossmodule.html#IDX1">SOUND_MIXER_NRDEVICES</A>
<LI><A HREF="ossmodule.html#IDX28">SOUND_MIXER_OGAIN</A>
<LI><A HREF="ossmodule.html#IDX10">SOUND_MIXER_PCM</A>
<LI><A HREF="ossmodule.html#IDX24">SOUND_MIXER_RECLEV</A>
<LI><A HREF="ossmodule.html#IDX12">SOUND_MIXER_SPEAKER</A>
<LI><A HREF="ossmodule.html#IDX8">SOUND_MIXER_SYNTH</A>
<LI><A HREF="ossmodule.html#IDX6">SOUND_MIXER_TREBLE</A>
<LI><A HREF="ossmodule.html#IDX2">SOUND_MIXER_VOLUME</A>
<LI><A HREF="ossmodule.html#IDX74">SYNTH_TYPE_FM</A>
<LI><A HREF="ossmodule.html#IDX76">SYNTH_TYPE_MIDI</A>
<LI><A HREF="ossmodule.html#IDX75">SYNTH_TYPE_SAMPLE</A>
</DIR>

</P>


<H1><A NAME="SEC35" HREF="ossmodule.html#TOC35">Function Index</A></H1>

<P>
<H2>b</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX69">bender_range on sequencer</A>
</DIR>
<H2>c</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX44">caps on mixer</A>
<LI><A HREF="ossmodule.html#IDX99">channels on audio</A>
<LI><A HREF="ossmodule.html#IDX64">chn_pressure on sequencer</A>
<LI><A HREF="ossmodule.html#IDX91">close on audio</A>
<LI><A HREF="ossmodule.html#IDX40">close on mixer</A>
<LI><A HREF="ossmodule.html#IDX52">close on sequencer</A>
<LI><A HREF="ossmodule.html#IDX66">control on sequencer</A>
<LI><A HREF="ossmodule.html#IDX59">ctrlrate on sequencer</A>
</DIR>
<H2>d</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX41">devmask on mixer</A>
</DIR>
<H2>e</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX71">expression on sequencer</A>
</DIR>
<H2>f</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX90">fileno on audio</A>
<LI><A HREF="ossmodule.html#IDX39">fileno on mixer</A>
<LI><A HREF="ossmodule.html#IDX51">fileno on sequencer</A>
<LI><A HREF="ossmodule.html#IDX95">format on audio</A>
</DIR>
<H2>g</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX96">get_formats on audio</A>
</DIR>
<H2>m</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX72">main_volume on sequencer</A>
<LI><A HREF="ossmodule.html#IDX77">midi_info</A>
<LI><A HREF="ossmodule.html#IDX56">midi_info on sequencer</A>
<LI><A HREF="ossmodule.html#IDX60">midiout on sequencer</A>
</DIR>
<H2>n</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX55">nrmidis on sequencer</A>
<LI><A HREF="ossmodule.html#IDX53">nrsynths on sequencer</A>
</DIR>
<H2>o</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX89">open_audio</A>
<LI><A HREF="ossmodule.html#IDX38">open_mixer</A>
<LI><A HREF="ossmodule.html#IDX50">open_sequencer</A>
</DIR>
<H2>p</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX65">panning on sequencer</A>
<LI><A HREF="ossmodule.html#IDX70">pitch_bend on sequencer</A>
<LI><A HREF="ossmodule.html#IDX94">post on audio</A>
</DIR>
<H2>q</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX97">query_format on audio</A>
</DIR>
<H2>r</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX101">read on audio</A>
<LI><A HREF="ossmodule.html#IDX48">read_channel on mixer</A>
<LI><A HREF="ossmodule.html#IDX46">read_recsrc on mixer</A>
<LI><A HREF="ossmodule.html#IDX42">recmask on mixer</A>
<LI><A HREF="ossmodule.html#IDX92">reset on audio</A>
</DIR>
<H2>s</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX61">set_patch on sequencer</A>
<LI><A HREF="ossmodule.html#IDX100">speed on audio</A>
<LI><A HREF="ossmodule.html#IDX62">start_note on sequencer</A>
<LI><A HREF="ossmodule.html#IDX57">start_timer on sequencer</A>
<LI><A HREF="ossmodule.html#IDX98">stereo on audio</A>
<LI><A HREF="ossmodule.html#IDX43">stereodevs on mixer</A>
<LI><A HREF="ossmodule.html#IDX63">stop_note on sequencer</A>
<LI><A HREF="ossmodule.html#IDX93">sync on audio</A>
<LI><A HREF="ossmodule.html#IDX73">synth_info</A>
<LI><A HREF="ossmodule.html#IDX54">synth_info on sequencer</A>
</DIR>
<H2>w</H2>
<DIR>
<LI><A HREF="ossmodule.html#IDX58">wait_time on sequencer</A>
<LI><A HREF="ossmodule.html#IDX102">write on audio</A>
<LI><A HREF="ossmodule.html#IDX49">write_channel on mixer</A>
<LI><A HREF="ossmodule.html#IDX47">write_recsrc on mixer</A>
</DIR>

</P>
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