If you create your own kind, you won't break anything, but you should contact Be Developer Support for guidance, so we can standardize given your needs.
The Be Book - Classes And Methods - The Media Kit
| Derived From: | – |
| Mix-in Classes: | – |
| Declared In: | be/media/ParameterGroup.h |
| Library: | libmedia.so |
| Allocation: | Constructor only |
| Class Overview | |
BParameterGroup();Rather than directly creating a BParameterGroup object via the new
operator, you should call
BParameterWeb::MakeGroup()
to create a top-level group, or
BParameterGroup::MakeGroup()
if you want to create a subgroup.
~BParameterGroup();You don't need to delete a BParameterGroup object; the
BParameterWeb
that owns it will do this for you when the web is deleted.
int32 CountGroups();Returns the number of subgroups in the group. This count doesn't subgroups nested within subgroups.
int32 CountParameters();Returns the number of
BParameters
in the group. This count doesn't include
BParameters
in subgroups.
BParameterGroup* GroupAt(int32 index);Returns the subgroup at the specified index within the BParameterGroup.
If the index is negative, or is greater than
CountGroups()-1,
NULL is returned.
BNullParameter* MakeNullParameter(int32 id,
media_type type,
const char* name,
const char* kind);Creates a new
BNullParameter
within the group, with the internal ID specified by id, which
should be unique within the
BParameterWeb
that owns the group.
The type of media data that travels through the null parameter is
indicated by type, which could be B_MEDIA_UNKNOWN_TYPE or
B_MEDIA_NO_TYPE. The parameter's name will be displayed by client
applications that display information about the node, and the parameter
has the specified kind.
B_WEB_PHYSICAL_INPUTThe parameter represents a physical input (such as a microphone jack or line input jack).
B_WEB_PHYSICAL_OUTPUTThe parameter represents a physical output (such as a line output jack or headphone jack).
B_WEB_LOGICAL_INPUTThe parameter represents a point at which bits of data are transferred between the computer and the A/V input hardware.
B_WEB_LOGICAL_OUTPUTThe parameter represents a point at which bits of data are transferred between the computer and the A/V output hardware.
B_WEB_ADC_CONVERTERThe parameter represents an analog to digital converter.
B_WEB_DAC_CONVERTERThe parameter represents a digital to analog converter.
B_WEB_BUFFER_INPUTThe parameter represents a media_input.
B_WEB_BUFFER_OUTPUTThe parameter represents a media_output.
B_GENERICThe parameter's kind isn't one of the above.
These kinds are used when a control panel needs to draw a signal flow diagram, so it can use the appropriate symbols for these points in the flow.
If you create your own kind, you won't break anything, but you should contact Be Developer Support for guidance, so we can standardize given your needs.
BDiscreteParameter* MakeDiscreteParameter(int32 id,
media_type type,
const char* name,
const char* kind);Creates a new
BDiscreteParameter
object and attaches it to the group. The
BDiscreteParameter
will have the specified internal id, which should be
unique within the
BParameterWeb
that owns the group.
The
BDiscreteParameter
will affect media data of the specified type, and
will have the specified name.
The kind of discrete parameter is specified by kind, and may be any of
the following values:
B_MUTEThe parameter represents a mute control; a value of 0 passes data through unchanged, while a value of 1 mutes the data.
B_ENABLEThe parameter represents an enable toggle; a value of 0 disables the function while a value of 1 enables it.
B_INPUT_MUXThe parameter represents an input MUX. The value specifies which input should pass through.
B_OUTPUT_MUXThe parameter represents an output MUX; the value specifies which output should receive the incoming data.
B_TUNER_CHANNELThe parameter represents a channel tuner (like a TV channel); the value indicates the channel number.
B_TRACKThe parameter's value indicates a track number.
B_RECSTATEThe parameter indicates whether the node is silent (0), playing (1), or recording (2).
B_SHUTTLE_MODEThe parameter indicates performance mode: -1 for backwards, 0 for stop, 1 for playing, and 2 for paused.
B_RESOLUTIONThe parameter indicates video or audio resolution.
B_COLOR_SPACEThe parameter indicates video color space.
B_FRAME_RATEThe parameter represents a selector for picking frame rate.
BContinuousParameter* MakeContinuousParameter(int32 id,
media_type type,
const char* name,
const char* kind,
const char* unit,
float minValue,
float maxValue,
float step);Creates a new
BContinuousParameter
object and attaches it to the group. The
BContinuousParameter
will have the specified internal id, which
should be unique within the
BParameterWeb
that owns the group.
The
BContinuousParameter
will affect media data of the specified type,
and will have the specified name.
The kind of parameter the
BContinuousParameter
represents is specified by
kind, and may be any of the following values:
B_MASTER_GAINThe parameter represents the main volume control.
B_GAINThe parameter represents a gain control.
B_BALANCEThe parameter represents a balance control.
B_FREQUENCYThe parameter represents a frequency, like a radio tuner.
B_LEVELThe parameter represents a level, as in EQ and effects.
B_SHUTTLE_SPEEDThe parameter represents playback speed. A value of 1.0 indicates normal speed; less than 1.0 is slower, greater than 1.0 is faster.
B_CROSSFADEThe parameter indicates a crossfade for mixing audio or video; 0 indicates that the the first of a pair of streams should be presented, 100 indicates that the other should be presented, and values in between indicate the degree of mixing that should occur.
B_COMPRESSIONThe parameter indicates compression ratio; the value is 0 for no compression, 99 for 100:1 compression.
B_QUALITYThe parameter indicates quality level; the value is 0 for maximum compression, 100 for no compression.
B_GOP_SIZEThe parameter indicates a "group of pictures" such as how many frames apart a keyframe should be inserted into a video stream.
B_TUNER_CHANNELThe parameter represents a channel tuner (like a TV channel); the value indicates the channel number.
The units of measurement are specified by
unit, and the parameter's value can range from
minValue to maxValue,
with a granularity of step.
const char* Name();Returns the name of the BParameterGroup. This name can be displayed to
the user; for example, it could be used as the label of a
BTab.
BParameter* ParameterAt(int32 index);Returns the
BParameter
at the specified index within the BParameterGroup.
If the index is negative, or is greater than
CountParameters()-1,
NULL is returned.
