On Monday 04 June 2007 13:21, you wrote:
> At Mon, 4 Jun 2007 12:53:06 +0100,
> Alan Horstmann wrote:
> > Might it be worth adding a paragraph to 'OSS-Emulation.txt' (or.html), eg
> > as below? Apart from that I will close off on this issue now!
>
> Looks fine. Could you make a patch?
Patch attached and also for your html version in case useful.
Also just in case -signed-off etc though the content is from yourselves
anyway.
Alan
OSS-Emulation.txt-duplex-streams.diff
Add paragraph to the OSS document to clarify correct use of duplex streams.
Signed-off-by: Alan Horstmann <gineera@xxxxxxxxxxxxxxx>
--- alsa-kernel/Documentation/OSS-Emulation-orig.txt 2007-05-02 09:02:20.000000000 +0100
+++ alsa-kernel/Documentation/OSS-Emulation.txt 2007-06-04 20:50:51.000000000 +0100
@@ -278,6 +278,21 @@
image.
+Duplex Streams
+==============
+
+Note that when attempting to use a single device file for playback and
+capture, the OSS API provides no way to set the format, sample rate or
+number of channels different in each direction. Thus
+ io_handle = open("device", O_RDWR)
+will only function correctly if the values are the same in each direction.
+
+To use different values in the two directions, use both
+ input_handle = open("device", O_RDONLY)
+ output_handle = open("device", O_WRONLY)
+and set the values for the corresponding handle.
+
+
Unsupported Features
====================
--- OSS-Emulation-orig.html 2007-06-04 10:57:39.000000000 +0100
+++ OSS-Emulation.html 2007-06-04 21:18:54.000000000 +0100
@@ -381,6 +381,27 @@
<p>
+ <h2>Duplex Streams</h2>
+
+ <P>
+ Note that when attempting to use a single device file for playback
+ and capture, the OSS API provides no way to set the format, sample
+ rate or number of channels different in each direction. Thus
+<pre>
+ io_handle = open("device", O_RDWR)
+</pre>
+ will only function correctly if the values are the same in each
+ direction.
+ <P>
+ To use different values in the two directions, use both
+<pre>
+ input_handle = open("device", O_RDONLY)
+ output_handle = open("device", O_WRONLY)
+</pre>
+ and set values for the corresponding handle.
+
+
+ <p>
<h2>Unsupported Features</h2>
<h3>MMAP on ICE1712 driver</h3>
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