axfer: add text for compatibility loss of sw parameter in libasound backend

At present, some options for software parameters have actual effects in
cases neither mmap operation nor timer-based scheduling model is used.
For mmap operation, backward compatibility  to aplay(1) is lost.

This commit adds descriptions about it.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Sakamoto 2018-12-21 20:48:44 +09:00 committed by Takashi Iwai
parent 0edb6ec765
commit 1c2315010c

View file

@ -684,6 +684,42 @@ effect to use PCM buffer aligned to non\-interleaved order if a target device
supports. As of 2018, PCM buffer of non\-interleaved order is hardly used by supports. As of 2018, PCM buffer of non\-interleaved order is hardly used by
sound devices. sound devices.
.TP
.I \-A, \-\-avail\-min
This option indicates threshold to wake up blocked process in a unit of
audio data frame. Against aplay(1) implementation, this option has no effect
with
.I \-\-mmap
option as well as
.I timer
of
.I \-\-sched\-model
option.
.TP
.I \-R, \-\-start\-delay
This option indicates threshold to start prepared PCM substream in a unit of
audio data frame. Against aplay(1) implementation, this option has no effect
with
.I \-\-mmap
option as well as
.I timer
of
.I \-\-sched\-model
option.
.TP
.I \-T, \-\-stop\-delay
This option indicates threshold to stop running PCM substream in a unit of
audio data frame. Against aplay(1) implementation, this option has no effect
with
.I \-\-mmap
option as well as
.I timer
of
.I \-\-sched\-model
option.
.TP .TP
.I \-\-max\-file\-time=# .I \-\-max\-file\-time=#
This option is unsupported. In aplay(1) implementation, the option has an This option is unsupported. In aplay(1) implementation, the option has an