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mixer.4 and mixer.8: Fix mandoc -Tlint errors.

Submitted by:		christos@
Differential Revision:	https://reviews.freebsd.org/D34603
Sponsored by:		NVIDIA Networking
This commit is contained in:
Hans Petter Selasky 2022-03-20 20:13:00 +01:00
parent f250ff5ff3
commit bde8460272
2 changed files with 90 additions and 81 deletions

View File

@ -22,7 +22,7 @@
.\" $FreeBSD$
.\"
.Dd March 18, 2022
.Dd March 19, 2022
.Dt MIXER 3
.Os
.Sh NAME
@ -40,7 +40,7 @@
.Nm mixer_mod_recsrc ,
.Nm mixer_get_dunit ,
.Nm mixer_set_dunit ,
.Nm mixer_get_mode,
.Nm mixer_get_mode ,
.Nm mixer_get_nmixers ,
.Nm MIX_ISDEV ,
.Nm MIX_ISMUTE ,
@ -64,7 +64,7 @@ Mixer library (libmixer, -lmixer)
.Ft int
.Fn mixer_add_ctl "struct mix_dev *parent" "int id" "const char *name" \
"int (*mod)(struct mix_dev *d, void *p)" \
"int (*print)(struct mix_dev *d, void *p)
"int (*print)(struct mix_dev *d, void *p)"
.Ft int
.Fn mixer_add_ctl_s "mix_ctl_t *ctl"
.Ft int
@ -105,7 +105,6 @@ The
library allows userspace programs to access and manipulate OSS sound mixers in
a simple way.
.Ss Mixer
.Pp
A mixer is described by the following structure:
.Bd -literal
struct mixer {
@ -141,16 +140,19 @@ The fields are follows:
.It Fa devs
A tail queue structure containing all supported mixer devices.
.It Fa dev
A pointer to the currently selected device. The device is one of the elements in
A pointer to the currently selected device.
The device is one of the elements in
.Ar devs .
.It Fa mi
OSS information about the mixer. Look at the definition of the
OSS information about the mixer.
Look at the definition of the
.Ft oss_mixerinfo
structure in
.In sys/soundcard.h
to see its fields.
.It Fa ci
OSS audio card information. This structure is also defined in
OSS audio card information.
This structure is also defined in
.In sys/soundcard.h .
.It Fa name
Path to the mixer (e.g /dev/mixer0).
@ -158,40 +160,43 @@ Path to the mixer (e.g /dev/mixer0).
File descriptor returned when the mixer is opened in
.Fn mixer_open .
.It Fa unit
Audio card unit. Since each mixer device maps to a pcmX device,
Audio card unit.
Since each mixer device maps to a pcmX device,
.Ar unit
is always equal to the number of that pcmX device. For example, if the audio
device's number is 0 (i.e pcm0), then
is always equal to the number of that pcmX device.
For example, if the audio device's number is 0 (i.e pcm0), then
.Ar unit
is 0 as well. This number is useful when checking if the mixer's audio
card is the default one.
is 0 as well.
This number is useful when checking if the mixer's audio card is the default one.
.It Fa ndev
Number of devices in
.Ar devs .
.It Fa devmask
Bit mask containing all supported devices for the mixer. For example
if device 10 is supported, then the 10th bit in the mask will be set. By default,
Bit mask containing all supported devices for the mixer.
For example, if device 10 is supported, then the 10th bit in the mask will be set.
By default,
.Fn mixer_open
stores only the supported devices in devs, so it's very unlikely this mask will
stores only the supported devices in devs, so it is very unlikely this mask will
be needed.
.It Fa mutemask
Bit mask containing all muted devices. The logic is the same as with
Bit mask containing all muted devices.
The logic is the same as with
.Ar devmask .
.It Fa recmask
Bit mask containing all recording devices. Again, same logic as with the
other masks.
Bit mask containing all recording devices.
Again, same logic as with the other masks.
.It Fa recsrc
Bit mask containing all recording sources. Yes, same logic again.
Bit mask containing all recording sources.
Yes, same logic again.
.It Fa mode
Bit mask containing the supported modes for this audio device. It holds the value
of the
Bit mask containing the supported modes for this audio device.
It holds the value of the
.Ar dev.pcm.X.mode
sysctl.
.It Fa f_default
Flag which tells whether the mixer's audio card is the default one.
.El
.Ss Mixer device
.Pp
Each mixer device stored in a mixer is described as follows:
.Bd -literal
struct mix_dev {
@ -217,7 +222,8 @@ The fields are follows:
.It Fa parent_mixer
Pointer to the mixer the device is attached to.
.It Fa name
Device name given by the OSS API. Devices can have one of the following names:
Device name given by the OSS API.
Devices can have one of the following names:
.Bd -ragged
vol, bass, treble, synth, pcm, speaker, line, mic, cd, mix,
pcm2, rec, igain, ogain, line1, line2, line3, dig1, dig2, dig3,
@ -229,10 +235,11 @@ Device's index in the SOUND_MIXER_NRDEVICES macro defined in
This number is used to check against the masks defined in the
.Ar mixer
structure.
.It Fa left, right
Left and right-ear volumes. Although the OSS API stores volumes in integers from
0-100, we normalize them to 32-bit floating point numbers. However, the volumes
can be denormalized using the
.It Fa left right
Left and right-ear volumes.
Although the OSS API stores volumes in integers from 0-100, \
we normalize them to 32-bit floating point numbers.
However, the volumes can be denormalized using the
.Ar MIX_VOLDENORM
macro if needed.
.It Fa nctl
@ -241,9 +248,8 @@ Number of user-defined mixer controls associated with the device.
A tail queue containing user-defined mixer controls.
.El
.Ss User-defined mixer controls
.Pp
Each mixer device can have user-defined controls. The control structure
is defined as follows:
Each mixer device can have user-defined controls.
The control structure is defined as follows:
.Bd -literal
struct mix_ctl {
struct mix_dev *parent_dev; /* parent device */
@ -260,41 +266,46 @@ The fields are follows:
.It Fa parent_dev
Pointer to the device the control is attached to.
.It Fa id
Control ID assigned by the caller. Even though the library will
report it, care has to be taken to not give a control the same ID in case
the caller has to choose controls using their ID.
Control ID assigned by the caller.
Even though the library will report it, care has to be taken to not give \
a control the same ID in case the caller has to choose controls using their ID.
.It Fa name
Control name. As with
Control name.
As with
.Ar id ,
the caller has to make sure the same name is not used more than once.
.It Fa mod
Function pointer to a control modification function. As in
Function pointer to a control modification function.
As in
.Xr mixer 8 ,
each mixer control's values can be modified. For example, if we have a
volume control, the
each mixer control's values can be modified.
For example, if we have a volume control, the
.Ar mod
function will be responsible for handling volume changes.
.It Fa print
Function pointer to a control print function.
.El
.Ss Opening and closing the mixer
.Pp
The application must first call the
.Fn mixer_open
function to obtain a handle to the device, which is used as an argument
in most other functions and macros. The parameter
function to obtain a handle to the device, which is used as an argument \
in most other functions and macros.
The parameter
.Ar name
specifies the path to the mixer. OSS mixers are stored under
specifies the path to the mixer.
OSS mixers are stored under
.Ar /dev/mixerN
where
.Ar N
is the number of the mixer device. Each device maps to an actual
is the number of the mixer device.
Each device maps to an actual
.Ar pcm
audio card, so
.Ar /dev/mixer0
is the mixer for
.Ar pcm0 ,
and so on. If
and so on.
If
.Ar name
is
.Ar NULL
@ -305,30 +316,30 @@ opens the default mixer (hw.snd.default_unit).
.Pp
The
.Fn mixer_close
function frees resources and closes the mixer device. It's a good practice to
always call it when the application is done using the mixer.
function frees resources and closes the mixer device.
It is a good practice to always call it when the application is done using the mixer.
.Ss Manipulating the mixer
.Pp
The
.Fn mixer_get_dev
and
.Fn mixer_get_dev_byname
functions select a mixer device, either by its number or by its name
respectively. The mixer structure keeps a list of all the devices, but only
one can be manipulated at a time. Each time a new device is to be manipulated,
one of the two functions has to be called.
functions select a mixer device, either by its number or by its name respectively.
The mixer structure keeps a list of all the devices, but only \
one can be manipulated at a time.
Each time a new device is to be manipulated, one of the two functions has to be called.
.Pp
The
.Fn mixer_set_vol
function changes the volume of the selected mixer device. The
function changes the volume of the selected mixer device.
The
.Ar vol
parameter is a structure that stores the left and right volumes of a given
device. The allowed volume values are between MIX_VOLMIN (0.0) and
MIX_VOLMAX (1.0).
parameter is a structure that stores the left and right volumes of a given device.
The allowed volume values are between MIX_VOLMIN (0.0) and MIX_VOLMAX (1.0).
.Pp
The
.Fn mixer_set_mute
function modifies the mute of a selected device. The
function modifies the mute of a selected device.
The
.Ar opt
parameter has to be one of the following options:
.Bl -tag -width MIX_TOGGLEMUTE -offset indent
@ -342,8 +353,9 @@ Toggle the device's mute (e.g mute if unmuted and unmute if muted).
.Pp
The
.Fn mixer_mod_recsrc
function modifies a recording device. The selected device has to be
a recording device, otherwise the function will fail. The
function modifies a recording device.
The selected device has to be a recording device, otherwise the function will fail.
The
.Ar opt
parameter has to be one of the following options:
.Bl -tag -width MIX_REMOVERECSRC -offset indent
@ -361,16 +373,17 @@ The
.Fn mixer_get_dunit
and
.Fn mixer_set_dunit
functions get and set the default audio card in the system. Although this is
not really a mixer feature, it's useful to have instead of having to use
the
functions get and set the default audio card in the system.
Although this is not really a mixer feature, it is useful to have instead of \
having to use the
.Xr sysctl 3
controls.
.Pp
The
.Fn mixer_get_mode
function returns the playback/recording mode of the audio device the mixer
belongs to. The available values are the following:
function returns the playback/recording mode of the audio device the mixer \
belongs to.
The available values are the following:
.Bl -tag -width "MIX_STATUS_PLAY | MIX_STATUS_REC" -offset indent
.It Dv MIX_STATUS_NONE
Neither playback nor recording.
@ -388,9 +401,9 @@ function returns the total number of mixer devices in the system.
.Pp
The
.Fn MIX_ISDEV
macro checks if a device is actually a valid device for a given mixer. It's very
unlikely that this macro will ever be needed since the library stores only
valid devices by default.
macro checks if a device is actually a valid device for a given mixer.
It is very unlikely that this macro will ever be needed since the library \
stores only valid devices by default.
.Pp
The
.Fn MIX_ISMUTE
@ -406,8 +419,8 @@ macro checks if a device is a recording source.
.Pp
The
.Fn MIX_VOLNORM
macro normalizes a value to 32-bit floating point number. It's used
to normalize the volumes read from the OSS API.
macro normalizes a value to 32-bit floating point number.
It is used to normalize the volumes read from the OSS API.
.Pp
The
.Fn MIX_VOLDENORM
@ -415,7 +428,6 @@ macro denormalizes the left and right volumes stores in the
.Ft mix_dev
structure.
.Ss Defining and using mixer controls
.Pp
The
.Fn mix_add_ctl
function creates a control and attaches it to the device specified in the
@ -428,7 +440,7 @@ function does the same thing as with
.Fn mix_add_ctl
but the caller passes a
.Ft mix_ctl_t *
structure instead of each field as a seperate argument.
structure instead of each field as a separate argument.
.Pp
The
.Fn mixer_remove_ctl
@ -438,7 +450,8 @@ The
.Fn mixer_get_ctl
function searches for a control in the device specified in the
.Ar d
argument and returns a pointer to it. The search is done using the control's ID.
argument and returns a pointer to it.
The search is done using the control's ID.
.Pp
The
.Fn mixer_get_ctl_byname
@ -446,7 +459,6 @@ function is the same as with
.Fn mixer_get_ctl
but the search is done using the control's name.
.Sh RETURN VALUES
.Pp
The
.Fn mixer_open
function returns the newly created handle on success and NULL on failure.
@ -530,10 +542,10 @@ TAILQ_FOREACH(dp, &m->devs, devs) {
(void)mixer_close(m);
.Ed
.Sh SEE ALSO
.Xr mixer 8 ,
.Xr sound 4 ,
.Xr queue 3 ,
.Xr sysctl 3 ,
.Xr queue 3
.Xr sound 4 ,
.Xr mixer 8
and
.Xr errno 2
.Sh AUTHORS

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@ -21,7 +21,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd March 13, 2022
.Dd March 18, 2022
.Dt MIXER 8
.Os
.Sh NAME
@ -54,8 +54,7 @@ Print the values for all mixer devices available in the system
Change the default audio card to
.Ar unit .
The unit has to be an integer value.
To see what unit values are available, look
at the number each mixer device has by running
To see what unit values are available, look at the number each mixer device has by running
.Nm .
.It Fl f Ar device
Open
@ -129,12 +128,10 @@ The optional
and/or
.Ar rvol
values have to be specified.
The values have to be normalized 32-bit floats,
from 0.0 to 1.0 inclusivly.
The values have to be normalized 32-bit floats, from 0.0 to 1.0 inclusively.
If no
.Ql \&.
character is present, the value is treated
like a percentage, for backwards compatibility.
character is present, the value is treated like a percentage, for backwards compatibility.
If the left or right volume values are prefixed with
.Cm +
or