ALaw/uLaw sample formats
------------------------

This driver does not support the ALaw/uLaw sample formats.
ALaw is the default mode when opening a sound device
using OSS/Free. The reason for the lack of support is
that the hardware does not support these formats, and adding
conversion routines to the kernel would lead to very ugly
code in the presence of the mmap interface to the driver.
And since xquake uses mmap, mmap is considered important :-)
and no sane application uses ALaw/uLaw these days anyway.
In short, playing a Sun .au file as follows:

cat my_file.au > /dev/dsp

does not work. Instead, you may use the play script from
Chris Bagwell's sox-12.14 package (available from the URL
below) to play many different audio file formats.
The script automatically determines the audio format
and does do audio conversions if necessary.
http://home.sprynet.com/sprynet/cbagwell/projects.html


Blocking vs. nonblocking IO
---------------------------

Unlike OSS/Free this driver honours the O_NONBLOCK file flag
not only during open, but also during read and write.
This is an effort to make the sound driver interface more
regular. Timidity has problems with this; a patch
is available from http://www.ife.ee.ethz.ch/~sailer/linux/pciaudio.html.
(Timidity patched will also run on OSS/Free).


MIDI UART
---------

The driver supports a simple MIDI UART interface, with
no ioctl's supported.


MIDI synthesizer
----------------

This soundcard does not have any hardware MIDI synthesizer;
MIDI synthesis has to be done in software. To allow this
the driver/soundcard supports two PCM (/dev/dsp) interfaces.
The second one goes to the mixer "synth" setting and supports
only a limited set of sampling rates (44100, 22050, 11025, 5512).
By setting lineout to 1 on the driver command line
(eg. insmod es1370 lineout=1) it is even possible on some
cards to convert the LINEIN jack into a second LINEOUT jack, thus
making it possible to output four independent audio channels!

There is a freely available software package that allows
MIDI file playback on this soundcard called Timidity.
See http://www.cgs.fi/~tt/timidity/.



Thomas Sailer
sailer@ife.ee.ethz.ch
