| GStreamer 0.11 Core Reference Manual | ||||
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| Top | Description | Object Hierarchy | ||||
#include <gst/gst.h> struct GstProxyPad; struct GstGhostPad; GstPad * gst_ghost_pad_new (const gchar *name,GstPad *target); GstPad * gst_ghost_pad_new_no_target (const gchar *name,GstPadDirection dir); GstPad * gst_ghost_pad_new_from_template (const gchar *name,GstPad *target,GstPadTemplate *templ); GstPad * gst_ghost_pad_new_no_target_from_template (const gchar *name,GstPadTemplate *templ); gboolean gst_ghost_pad_set_target (GstGhostPad *gpad,GstPad *newtarget); GstPad * gst_ghost_pad_get_target (GstGhostPad *gpad); gboolean gst_ghost_pad_construct (GstGhostPad *gpad); void gst_ghost_pad_unlink_default (GstPad *pad); GstPadLinkReturn gst_ghost_pad_link_default (GstPad *pad,GstPad *peer); gboolean gst_ghost_pad_activate_pull_default (GstPad *pad,gboolean active); gboolean gst_ghost_pad_activate_push_default (GstPad *pad,gboolean active); gboolean gst_ghost_pad_internal_activate_push_default (GstPad *pad,gboolean active); gboolean gst_ghost_pad_internal_activate_pull_default (GstPad *pad,gboolean active); GstProxyPad * gst_proxy_pad_get_internal (GstProxyPad *pad); const GstQueryType * gst_proxy_pad_query_type_default (GstPad *pad); gboolean gst_proxy_pad_event_default (GstPad *pad,GstEvent *event); gboolean gst_proxy_pad_query_default (GstPad *pad,GstQuery *query); GstIterator * gst_proxy_pad_iterate_internal_links_default (GstPad *pad); GstFlowReturn gst_proxy_pad_chain_default (GstPad *pad,GstBuffer *buffer); GstFlowReturn gst_proxy_pad_chain_list_default (GstPad *pad,GstBufferList *list); GstFlowReturn gst_proxy_pad_getrange_default (GstPad *pad,guint64 offset,guint size,GstBuffer **buffer); GstCaps * gst_proxy_pad_getcaps_default (GstPad *pad,GstCaps *filter); gboolean gst_proxy_pad_acceptcaps_default (GstPad *pad,GstCaps *caps); void gst_proxy_pad_fixatecaps_default (GstPad *pad,GstCaps *caps); void gst_proxy_pad_unlink_default (GstPad *pad);
GObject +----GInitiallyUnowned +----GstObject +----GstPad +----GstProxyPad +----GstGhostPad
GObject +----GInitiallyUnowned +----GstObject +----GstPad +----GstProxyPad +----GstGhostPad
GhostPads are useful when organizing pipelines with GstBin like elements. The idea here is to create hierarchical element graphs. The bin element contains a sub-graph. Now one would like to treat the bin-element like any other GstElement. This is where GhostPads come into play. A GhostPad acts as a proxy for another pad. Thus the bin can have sink and source ghost-pads that are associated with sink and source pads of the child elements.
If the target pad is known at creation time, gst_ghost_pad_new() is the
function to use to get a ghost-pad. Otherwise one can use gst_ghost_pad_new_no_target()
to create the ghost-pad and use gst_ghost_pad_set_target() to establish the
association later on.
Note that GhostPads add overhead to the data processing of a pipeline.
Last reviewed on 2005-11-18 (0.9.5)
GstPad * gst_ghost_pad_new (const gchar *name,GstPad *target);
Create a new ghostpad with target as the target. The direction will be taken
from the target pad. target must be unlinked.
Will ref the target.
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the name of the new pad, or NULL to assign a default name. [allow-none] |
|
the pad to ghost. [transfer none] |
Returns : |
a new GstPad, or NULL in case of an error. [transfer full] |
GstPad * gst_ghost_pad_new_no_target (const gchar *name,GstPadDirection dir);
Create a new ghostpad without a target with the given direction.
A target can be set on the ghostpad later with the
gst_ghost_pad_set_target() function.
The created ghostpad will not have a padtemplate.
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the name of the new pad, or NULL to assign a default name. [allow-none] |
|
the direction of the ghostpad |
Returns : |
a new GstPad, or NULL in case of an error. [transfer full] |
GstPad * gst_ghost_pad_new_from_template (const gchar *name,GstPad *target,GstPadTemplate *templ);
Create a new ghostpad with target as the target. The direction will be taken
from the target pad. The template used on the ghostpad will be template.
Will ref the target.
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the name of the new pad, or NULL to assign a default name. [allow-none] |
|
the pad to ghost. [transfer none] |
|
the GstPadTemplate to use on the ghostpad. [transfer none] |
Returns : |
a new GstPad, or NULL in case of an error. [transfer full] |
Since 0.10.10
GstPad * gst_ghost_pad_new_no_target_from_template (const gchar *name,GstPadTemplate *templ);
Create a new ghostpad based on templ, without setting a target. The
direction will be taken from the templ.
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the name of the new pad, or NULL to assign a default name. [allow-none] |
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the GstPadTemplate to create the ghostpad from. [transfer none] |
Returns : |
a new GstPad, or NULL in case of an error. [transfer full] |
Since 0.10.10
gboolean gst_ghost_pad_set_target (GstGhostPad *gpad,GstPad *newtarget);
Set the new target of the ghostpad gpad. Any existing target
is unlinked and links to the new target are established. if newtarget is
NULL the target will be cleared.
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the GstGhostPad |
|
the new pad target. [transfer none][allow-none] |
Returns : |
TRUE if the new target could be set. This function can return FALSE when the internal pads could not be linked. [transfer full] |
GstPad * gst_ghost_pad_get_target (GstGhostPad *gpad);
Get the target pad of gpad. Unref target pad after usage.
|
the GstGhostPad |
Returns : |
the target GstPad, can be NULL if the ghostpad has no target set. Unref target pad after usage. [transfer full] |
gboolean gst_ghost_pad_construct (GstGhostPad *gpad);
Finish initialization of a newly allocated ghost pad.
This function is most useful in language bindings and when subclassing
GstGhostPad; plugin and application developers normally will not call this
function. Call this function directly after a call to g_object_new
(GST_TYPE_GHOST_PAD, "direction", dir, ..., NULL).
Since 0.10.22
void gst_ghost_pad_unlink_default (GstPad *pad);
Invoke the default unlink function of a ghost pad.
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the GstPad to link. |
Since 0.10.35
GstPadLinkReturn gst_ghost_pad_link_default (GstPad *pad,GstPad *peer);
Invoke the default link function of a ghost pad.
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the GstPad to link. |
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the GstPad peer |
Returns : |
GstPadLinkReturn of the operation |
Since 0.10.35
gboolean gst_ghost_pad_activate_pull_default (GstPad *pad,gboolean active);
Invoke the default activate pull function of a ghost pad.
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the GstPad to activate or deactivate. |
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whether the pad should be active or not. |
Returns : |
TRUE if the operation was successful. |
Since 0.10.35
gboolean gst_ghost_pad_activate_push_default (GstPad *pad,gboolean active);
Invoke the default activate push function of a ghost pad.
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the GstPad to activate or deactivate. |
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whether the pad should be active or not. |
Returns : |
TRUE if the operation was successful. |
Since 0.10.35
gboolean gst_ghost_pad_internal_activate_push_default (GstPad *pad,gboolean active);
Invoke the default activate push function of a proxy pad that is owned by a ghost pad.
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the GstPad to activate or deactivate. |
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whether the pad should be active or not. |
Returns : |
TRUE if the operation was successful. |
Since 0.10.35
gboolean gst_ghost_pad_internal_activate_pull_default (GstPad *pad,gboolean active);
Invoke the default activate pull function of a proxy pad that is owned by a ghost pad.
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the GstPad to activate or deactivate. |
|
whether the pad should be active or not. |
Returns : |
TRUE if the operation was successful. |
Since 0.10.35
GstProxyPad * gst_proxy_pad_get_internal (GstProxyPad *pad);
Get the internal pad of pad. Unref target pad after usage.
The internal pad of a GstGhostPad is the internally used pad of opposite direction, which is used to link to the target.
|
the GstProxyPad |
Returns : |
the target GstProxyPad, can be NULL. Unref target pad after usage. [transfer full] |
Since 0.10.35
const GstQueryType * gst_proxy_pad_query_type_default (GstPad *pad);
Invoke the default query type handler of the proxy pad.
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a GstPad. |
Returns : |
a zero-terminated array of GstQueryType. [transfer none][array zero-terminated=1] |
Since 0.10.35
gboolean gst_proxy_pad_event_default (GstPad *pad,GstEvent *event);
Invoke the default event of the proxy pad.
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a GstPad to push the event to. |
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the GstEvent to send to the pad. [transfer full] |
Returns : |
TRUE if the event was handled. |
Since 0.10.35
gboolean gst_proxy_pad_query_default (GstPad *pad,GstQuery *query);
Invoke the default query function of the proxy pad.
|
a GstPad to invoke the default query on. |
|
the GstQuery to perform. [transfer none] |
Returns : |
TRUE if the query could be performed. |
Since 0.10.35
GstIterator * gst_proxy_pad_iterate_internal_links_default
(GstPad *pad);
GstFlowReturn gst_proxy_pad_chain_default (GstPad *pad,GstBuffer *buffer);
Invoke the default chain function of the proxy pad.
|
a sink GstPad, returns GST_FLOW_ERROR if not. |
|
the GstBuffer to send, return GST_FLOW_ERROR if not. [transfer full] |
Returns : |
a GstFlowReturn from the pad. |
Since 0.10.35
GstFlowReturn gst_proxy_pad_chain_list_default (GstPad *pad,GstBufferList *list);
Invoke the default chain list function of the proxy pad.
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a sink GstPad, returns GST_FLOW_ERROR if not. |
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the GstBufferList to send, return GST_FLOW_ERROR if not. [transfer full] |
Returns : |
a GstFlowReturn from the pad. |
Since 0.10.35
GstFlowReturn gst_proxy_pad_getrange_default (GstPad *pad,guint64 offset,guint size,GstBuffer **buffer);
GstCaps * gst_proxy_pad_getcaps_default (GstPad *pad,GstCaps *filter);
Invoke the default getcaps function of the proxy pad.
|
a GstPad to get the capabilities of. |
|
a GstCaps filter. |
Returns : |
the caps of the pad with incremented ref-count. [transfer full] |
Since 0.10.35
gboolean gst_proxy_pad_acceptcaps_default (GstPad *pad,GstCaps *caps);
Invoke the default acceptcaps function of the proxy pad.
|
a GstPad to check |
|
a GstCaps to check on the pad |
Returns : |
TRUE if the pad can accept the caps. |
Since 0.10.35
void gst_proxy_pad_fixatecaps_default (GstPad *pad,GstCaps *caps);
Invoke the default fixatecaps function of the proxy pad.
Since 0.10.35