Rewrite the description of setparameters() so it actually reflects the

code (which has also been recently overhauled, so that it can be
documented without embarassment).

'error' has been renamed to 'OSSAudioError'.

Minor wordsmithing.

Doc/lib/libossaudiodev.tex

@@ -49,14 +49,17 @@ recent versions of FreeBSD.
 
 \module{ossaudiodev} defines the following variables and functions:
 
-\begin{excdesc}{error}
+\begin{excdesc}{OSSAudioError}
 This exception is raised on certain errors.  The argument is a string
 describing what went wrong.
 
 (If \module{ossaudiodev} receives an error from a system call such as
 \cfunction{open()}, \cfunction{write()}, or \cfunction{ioctl()}, it
 raises \exception{IOError}.  Errors detected directly by
-\module{ossaudiodev} result in \exception{ossaudiodev.error}.)
+\module{ossaudiodev} result in \exception{OSSAudioError}.)
+
+(For backwards compatibility, the exception class is also available as
+\code{ossaudiodev.error}.)
 \end{excdesc}
 
 \begin{funcdesc}{open}{\optional{device, }mode}
@@ -201,8 +204,8 @@ of
 \constant{AFMT_QUERY}.  
 \end{methoddesc}
 
-\begin{methoddesc}[audio device]{channels}{num_channels}
-Set the number of output channels to \var{num_channels}.  A value of 1
+\begin{methoddesc}[audio device]{channels}{nchannels}
+Set the number of output channels to \var{nchannels}.  A value of 1
 indicates monophonic sound, 2 stereophonic.  Some devices may have more
 than 2 channels, and some high-end devices may not support mono.
 Returns the number of channels the device was set to.
@@ -241,16 +244,33 @@ might use this after playing a spot sound effect, before waiting for
 user input, or before doing disk I/O.
 \end{methoddesc}
 
-Convenience methods
+The following convenience methods combine several ioctls, or one ioctl
+and some simple calculations.
+
+\begin{methoddesc}[audio device]{setparameters}
+  {format, nchannels, samplerate \optional{, strict=False}}
 
-\begin{methoddesc}[audio device]{setparameters}{samplerate,num_channels,format,emulate}
-Initialise the sound device in one method.  \var{samplerate},
-\var{channels} and \var{format} should be as specified in the
-\method{speed()}, \method{channels()} and \method{setfmt()}
-methods.  If \var{emulate} is true, attempt to find the closest matching
-format instead, otherwise raise ValueError if the device does not
-support the format.  The default is to raise ValueError on unsupported
-formats.
+Set the key audio sampling parameters---sample format, number of
+channels, and sampling rate---in one method call.  \var{format}, 
+\var{nchannels}, and \var{samplerate} should be as specified in the
+\method{setfmt()}, \method{channels()}, and \method{speed()} 
+methods.  If \var{strict} is true, \method{setparameters()} checks to
+see if each parameter was actually set to the requested value, and
+raises \exception{OSSAudioError} if not.  Returns a tuple (\var{format},
+\var{nchannels}, \var{samplerate}) indicating the parameter values that
+were actually set by the device driver (i.e., the same as the return
+valus of \method{setfmt()}, \method{channels()}, and \method{speed()}).
+
+For example,
+\begin{verbatim}
+  (fmt, channels, rate) = dsp.setparameters(fmt, channels, rate)
+\end{verbatim}
+is equivalent to
+\begin{verbatim}
+  fmt = dsp.setfmt(fmt)
+  channels = dsp.channels(channels)
+  rate = dsp.rate(channels)
+\end{verbatim}
 \end{methoddesc}
 
 \begin{methoddesc}[audio device]{bufsize}{}