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| author | Alan Horstmann <gineera@aspect135.co.uk> | 2007-06-04 23:11:23 +0200 |
|---|---|---|
| committer | Jaroslav Kysela <perex@suse.cz> | 2007-07-20 11:11:23 +0200 |
| commit | 1919de0a9e939ef4f9453ef1630ca1345991e144 (patch) | |
| tree | 019b662d29a7f6c278c4ea6f4ad8bbd562bf74f6 /Documentation/sound | |
| parent | 3b194401a31b8df9a07a1850e3fe44fc7ba832a4 (diff) | |
| download | lwn-1919de0a9e939ef4f9453ef1630ca1345991e144.tar.gz lwn-1919de0a9e939ef4f9453ef1630ca1345991e144.zip | |
[ALSA] More description on duplex streams with OSS emulation
Add paragraph to the OSS document to clarify correct use of duplex streams.
Signed-off-by: Alan Horstmann <gineera@aspect135.co.uk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Diffstat (limited to 'Documentation/sound')
| -rw-r--r-- | Documentation/sound/alsa/OSS-Emulation.txt | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/Documentation/sound/alsa/OSS-Emulation.txt b/Documentation/sound/alsa/OSS-Emulation.txt index ec2a02541d5b..bfa0c9aacb4b 100644 --- a/Documentation/sound/alsa/OSS-Emulation.txt +++ b/Documentation/sound/alsa/OSS-Emulation.txt @@ -278,6 +278,21 @@ current mixer configuration by reading and writing the whole file 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 ==================== |