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GStreamer 1.0 Core Reference Manual | |
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| Top | Description | Object Hierarchy | ||||
#include <gst/gst.h>
GstPreset;
struct GstPresetInterface;
gchar ** gst_preset_get_preset_names (GstPreset *preset);
gchar ** gst_preset_get_property_names (GstPreset *preset);
gboolean gst_preset_load_preset (GstPreset *preset,
const gchar *name);
gboolean gst_preset_save_preset (GstPreset *preset,
const gchar *name);
gboolean gst_preset_rename_preset (GstPreset *preset,
const gchar *old_name,
const gchar *new_name);
gboolean gst_preset_delete_preset (GstPreset *preset,
const gchar *name);
gboolean gst_preset_set_meta (GstPreset *preset,
const gchar *name,
const gchar *tag,
const gchar *value);
gboolean gst_preset_get_meta (GstPreset *preset,
const gchar *name,
const gchar *tag,
gchar **value);
gboolean gst_preset_set_app_dir (const gchar *app_dir);
const gchar * gst_preset_get_app_dir (void);
This interface offers methods to query and manipulate parameter preset sets. A preset is a bunch of property settings, together with meta data and a name. The name of a preset serves as key for subsequent method calls to manipulate single presets. All instances of one type will share the list of presets. The list is created on demand, if presets are not used, the list is not created.
The interface comes with a default implementation that serves most plugins.
Wrapper plugins will override most methods to implement support for the
native preset format of those wrapped plugins.
One method that is useful to be overridden is gst_preset_get_property_names().
With that one can control which properties are saved and in which order.
The default implementation supports presets located in a system directory, application specific directory and in the users home directory. When getting a list of presets individual presets are read and overlaid in 1) system, 2) application and 3) user order. Whenever an earlier entry is newer, the later entries will be updated.
struct GstPresetInterface {
GTypeInterface parent;
/* methods */
gchar** (*get_preset_names) (GstPreset *preset);
gchar** (*get_property_names) (GstPreset *preset);
gboolean (*load_preset) (GstPreset *preset, const gchar *name);
gboolean (*save_preset) (GstPreset *preset, const gchar *name);
gboolean (*rename_preset) (GstPreset *preset, const gchar *old_name,
const gchar *new_name);
gboolean (*delete_preset) (GstPreset *preset, const gchar *name);
gboolean (*set_meta) (GstPreset *preset, const gchar *name,
const gchar *tag, const gchar *value);
gboolean (*get_meta) (GstPreset *preset, const gchar *name,
const gchar *tag, gchar **value);
};
GstPreset interface.
GTypeInterface |
parent interface type. |
| virtual method to get list of presets | |
| virtual methods to get properties that are persistent | |
| virtual methods to load a preset into properties | |
| virtual methods to save properties into a preset | |
| virtual methods to rename a preset | |
| virtual methods to remove a preset | |
| virtual methods to set textual meta data to a preset | |
| virtual methods to get textual meta data from a preset |
gchar ** gst_preset_get_preset_names (GstPreset *preset);
Get a copy of preset names as a NULL terminated string array.
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a GObject that implements GstPreset |
Returns : |
list with names, ue g_strfreev() after usage. [transfer full][array zero-terminated=1][element-type gchar*]
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Since 0.10.20
gchar ** gst_preset_get_property_names (GstPreset *preset);
Get a the names of the GObject properties that can be used for presets.
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a GObject that implements GstPreset |
Returns : |
an
array of property names which should be freed with g_strfreev() after use. [transfer full][array zero-terminated=1][element-type gchar*]
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Since 0.10.20
gboolean gst_preset_load_preset (GstPreset *preset,const gchar *name);
Load the given preset.
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a GObject that implements GstPreset |
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preset name to load |
Returns : |
TRUE for success, FALSE if e.g. there is no preset with that name
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Since 0.10.20
gboolean gst_preset_save_preset (GstPreset *preset,const gchar *name);
Save the current object settings as a preset under the given name. If there
is already a preset by this name it will be overwritten.
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a GObject that implements GstPreset |
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preset name to save |
Returns : |
TRUE for success, FALSE
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Since 0.10.20
gboolean gst_preset_rename_preset (GstPreset *preset,const gchar *old_name,const gchar *new_name);
Renames a preset. If there is already a preset by the new_name it will be
overwritten.
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a GObject that implements GstPreset |
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current preset name |
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new preset name |
Returns : |
TRUE for success, FALSE if e.g. there is no preset with old_name
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Since 0.10.20
gboolean gst_preset_delete_preset (GstPreset *preset,const gchar *name);
Delete the given preset.
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a GObject that implements GstPreset |
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preset name to remove |
Returns : |
TRUE for success, FALSE if e.g. there is no preset with that name
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Since 0.10.20
gboolean gst_preset_set_meta (GstPreset *preset,const gchar *name,const gchar *tag,const gchar *value);
Sets a new value for an existing meta data item or adds a new item. Meta
data tag names can be something like e.g. "comment". Supplying NULL for the
value will unset an existing value.
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a GObject that implements GstPreset |
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preset name |
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meta data item name |
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new value |
Returns : |
TRUE for success, FALSE if e.g. there is no preset with that name
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Since 0.10.20
gboolean gst_preset_get_meta (GstPreset *preset,const gchar *name,const gchar *tag,gchar **value);
Gets the value for an existing meta data tag. Meta data tag names can be
something like e.g. "comment". Returned values need to be released when done.
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a GObject that implements GstPreset |
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preset name |
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meta data item name |
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value. [out callee-allocates] |
Returns : |
TRUE for success, FALSE if e.g. there is no preset with that name
or no value for the given tag
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Since 0.10.20
gboolean gst_preset_set_app_dir (const gchar *app_dir);
Sets an extra directory as an absolute path that should be considered when looking for presets. Any presets in the application dir will shadow the system presets.
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the application specific preset dir |
Returns : |
TRUE for success, FALSE if the dir already has been set |
Since 0.10.36