manpagez: man pages & more
html files: gstreamer-libs-1.0
Home | html | info | man

GstCollectPads

GstCollectPads — manages a set of pads that operate in collect mode

Functions

void (*GstCollectDataDestroyNotify) ()
GstFlowReturn (*GstCollectPadsBufferFunction) ()
GstFlowReturn (*GstCollectPadsClipFunction) ()
gint (*GstCollectPadsCompareFunction) ()
gboolean (*GstCollectPadsEventFunction) ()
void (*GstCollectPadsFlushFunction) ()
gboolean (*GstCollectPadsQueryFunction) ()
GstFlowReturn (*GstCollectPadsFunction) ()
#define GST_COLLECT_PADS_STATE()
#define GST_COLLECT_PADS_STATE_IS_SET()
#define GST_COLLECT_PADS_STATE_SET()
#define GST_COLLECT_PADS_STATE_UNSET()
#define GST_COLLECT_PADS_GET_STREAM_LOCK()
#define GST_COLLECT_PADS_STREAM_LOCK()
#define GST_COLLECT_PADS_STREAM_UNLOCK()
#define GST_COLLECT_PADS_DTS()
#define GST_COLLECT_PADS_DTS_IS_VALID()
GstCollectPads * gst_collect_pads_new ()
GstCollectData * gst_collect_pads_add_pad ()
gboolean gst_collect_pads_remove_pad ()
void gst_collect_pads_start ()
void gst_collect_pads_stop ()
guint gst_collect_pads_available ()
guint gst_collect_pads_flush ()
GstBuffer * gst_collect_pads_peek ()
GstBuffer * gst_collect_pads_pop ()
GstBuffer * gst_collect_pads_read_buffer ()
GstBuffer * gst_collect_pads_take_buffer ()
GstFlowReturn gst_collect_pads_clip_running_time ()
gboolean gst_collect_pads_query_default ()
gboolean gst_collect_pads_event_default ()
gboolean gst_collect_pads_src_event_default ()
void gst_collect_pads_set_buffer_function ()
void gst_collect_pads_set_clip_function ()
void gst_collect_pads_set_compare_function ()
void gst_collect_pads_set_event_function ()
void gst_collect_pads_set_flush_function ()
void gst_collect_pads_set_query_function ()
void gst_collect_pads_set_flushing ()
void gst_collect_pads_set_function ()
void gst_collect_pads_set_waiting ()

Types and Values

Object Hierarchy

    GObject
    ╰── GInitiallyUnowned
        ╰── GstObject
            ╰── GstCollectPads

Includes

#include <gst/base/gstcollectpads.h>

Description

Manages a set of pads that operate in collect mode. This means that control is given to the manager of this object when all pads have data.

Functions

GstCollectDataDestroyNotify ()

void
(*GstCollectDataDestroyNotify) (GstCollectData *data);

A function that will be called when the GstCollectData will be freed. It is passed the pointer to the structure and should free any custom memory and resources allocated for it.

Parameters

data

the GstCollectData that will be freed

 

GstCollectPadsBufferFunction ()

GstFlowReturn
(*GstCollectPadsBufferFunction) (GstCollectPads *pads,
                                 GstCollectData *data,
                                 GstBuffer *buffer,
                                 gpointer user_data);

A function that will be called when a (considered oldest) buffer can be muxed. If all pads have reached EOS, this function is called with NULL buffer and NULL data .

Parameters

pads

the GstCollectPads that triggered the callback

 

data

the GstCollectData of pad that has received the buffer

 

buffer

the GstBuffer.

[transfer full]

user_data

user data passed to gst_collect_pads_set_buffer_function()

 

Returns

GST_FLOW_OK for success


GstCollectPadsClipFunction ()

GstFlowReturn
(*GstCollectPadsClipFunction) (GstCollectPads *pads,
                               GstCollectData *data,
                               GstBuffer *inbuffer,
                               GstBuffer **outbuffer,
                               gpointer user_data);

A function that will be called when inbuffer is received on the pad managed by data in the collectpad object pads .

The function should use the segment of data and the negotiated media type on the pad to perform clipping of inbuffer .

This function takes ownership of inbuffer and should output a buffer in outbuffer or return NULL in outbuffer if the buffer should be dropped.

Parameters

pads

a GstCollectPads

 

data

a GstCollectData

 

inbuffer

the input GstBuffer.

[transfer full]

outbuffer

the output GstBuffer

 

user_data

user data

 

Returns

a GstFlowReturn that corresponds to the result of clipping.


GstCollectPadsCompareFunction ()

gint
(*GstCollectPadsCompareFunction) (GstCollectPads *pads,
                                  GstCollectData *data1,
                                  GstClockTime timestamp1,
                                  GstCollectData *data2,
                                  GstClockTime timestamp2,
                                  gpointer user_data);

A function for comparing two timestamps of buffers or newsegments collected on one pad.

Parameters

pads

the GstCollectPads that is comparing the timestamps

 

data1

the first GstCollectData

 

timestamp1

the first timestamp

 

data2

the second GstCollectData

 

timestamp2

the second timestamp

 

user_data

user data passed to gst_collect_pads_set_compare_function()

 

Returns

Integer less than zero when first timestamp is deemed older than the second one. Zero if the timestamps are deemed equally old. Integer greater than zero when second timestamp is deemed older than the first one.


GstCollectPadsEventFunction ()

gboolean
(*GstCollectPadsEventFunction) (GstCollectPads *pads,
                                GstCollectData *pad,
                                GstEvent *event,
                                gpointer user_data);

A function that will be called while processing an event. It takes ownership of the event and is responsible for chaining up (to gst_collect_pads_event_default()) or dropping events (such typical cases being handled by the default handler).

Parameters

pads

the GstCollectPads that triggered the callback

 

pad

the GstPad that received an event

 

event

the GstEvent received

 

user_data

user data passed to gst_collect_pads_set_event_function()

 

Returns

TRUE if the pad could handle the event


GstCollectPadsFlushFunction ()

void
(*GstCollectPadsFlushFunction) (GstCollectPads *pads,
                                gpointer user_data);

A function that will be called while processing a flushing seek event.

The function should flush any internal state of the element and the state of all the pads. It should clear only the state not directly managed by the pads object. It is therefore not necessary to call gst_collect_pads_set_flushing nor gst_collect_pads_clear from this function.

Parameters

pads

a GstCollectPads

 

user_data

user data

 

Since: 1.4


GstCollectPadsQueryFunction ()

gboolean
(*GstCollectPadsQueryFunction) (GstCollectPads *pads,
                                GstCollectData *pad,
                                GstQuery *query,
                                gpointer user_data);

A function that will be called while processing a query. It takes ownership of the query and is responsible for chaining up (to events downstream (with gst_pad_event_default()).

Parameters

pads

the GstCollectPads that triggered the callback

 

pad

the GstPad that received an event

 

query

the GstEvent received

 

user_data

user data passed to gst_collect_pads_set_query_function()

 

Returns

TRUE if the pad could handle the event


GstCollectPadsFunction ()

GstFlowReturn
(*GstCollectPadsFunction) (GstCollectPads *pads,
                           gpointer user_data);

A function that will be called when all pads have received data.

Parameters

pads

the GstCollectPads that triggered the callback

 

user_data

user data passed to gst_collect_pads_set_function()

 

Returns

GST_FLOW_OK for success


GST_COLLECT_PADS_STATE()

#define GST_COLLECT_PADS_STATE(data)                 (((GstCollectData *) data)->state)

A flags word containing GstCollectPadsStateFlags flags set on this collected pad.

Parameters

data

a GstCollectData.

 

GST_COLLECT_PADS_STATE_IS_SET()

#define GST_COLLECT_PADS_STATE_IS_SET(data,flag)     !!(GST_COLLECT_PADS_STATE (data) & flag)

Gives the status of a specific flag on a collected pad.

Parameters

data

a GstCollectData.

 

flag

the GstCollectPadsStateFlags to check.

 

GST_COLLECT_PADS_STATE_SET()

#define GST_COLLECT_PADS_STATE_SET(data,flag)        (GST_COLLECT_PADS_STATE (data) |= flag)

Sets a state flag on a collected pad.

Parameters

data

a GstCollectData.

 

flag

the GstCollectPadsStateFlags to set.

 

GST_COLLECT_PADS_STATE_UNSET()

#define GST_COLLECT_PADS_STATE_UNSET(data,flag)      (GST_COLLECT_PADS_STATE (data) &= ~(flag))

Clears a state flag on a collected pad.

Parameters

data

a GstCollectData.

 

flag

the GstCollectPadsStateFlags to clear.

 

GST_COLLECT_PADS_GET_STREAM_LOCK()

#define GST_COLLECT_PADS_GET_STREAM_LOCK(pads) (&((GstCollectPads *)pads)->stream_lock)

Get the stream lock of pads . The stream lock is used to coordinate and serialize execution among the various streams being collected, and in protecting the resources used to accomplish this.

Parameters

pads

a GstCollectPads

 

GST_COLLECT_PADS_STREAM_LOCK()

#define GST_COLLECT_PADS_STREAM_LOCK(pads)     g_rec_mutex_lock(GST_COLLECT_PADS_GET_STREAM_LOCK (pads))

Lock the stream lock of pads .

Parameters

pads

a GstCollectPads

 

GST_COLLECT_PADS_STREAM_UNLOCK()

#define GST_COLLECT_PADS_STREAM_UNLOCK(pads)   g_rec_mutex_unlock(GST_COLLECT_PADS_GET_STREAM_LOCK (pads))

Unlock the stream lock of pads .

Parameters

pads

a GstCollectPads

 

GST_COLLECT_PADS_DTS()

#define GST_COLLECT_PADS_DTS(data)                   (((GstCollectData *) data)->ABI.abi.dts)

Returns the DTS that has been converted to running time when using gst_collect_pads_clip_running_time(). Unlike the value saved into the buffer, this value is of type gint64 and may be negative. This allow properly handling streams with frame reordering where the first DTS may be negative. If the initial DTS was not set, this value will be set to G_MININT64.

Parameters

data

A GstCollectData.

 

Since: 1.6


GST_COLLECT_PADS_DTS_IS_VALID()

#define GST_COLLECT_PADS_DTS_IS_VALID(data)          (GST_CLOCK_STIME_IS_VALID (GST_COLLECT_PADS_DTS (data)))

Check if running DTS value store is valid.

Parameters

data

A GstCollectData.

 

Since: 1.6


gst_collect_pads_new ()

GstCollectPads *
gst_collect_pads_new (void);

Create a new instance of GstCollectPads.

MT safe.

Returns

a new GstCollectPads, or NULL in case of an error.

[transfer full]


gst_collect_pads_add_pad ()

GstCollectData *
gst_collect_pads_add_pad (GstCollectPads *pads,
                          GstPad *pad,
                          guint size,
                          GstCollectDataDestroyNotify destroy_notify,
                          gboolean lock);

Add a pad to the collection of collect pads. The pad has to be a sinkpad. The refcount of the pad is incremented. Use gst_collect_pads_remove_pad() to remove the pad from the collection again.

You specify a size for the returned GstCollectData structure so that you can use it to store additional information.

You can also specify a GstCollectDataDestroyNotify that will be called just before the GstCollectData structure is freed. It is passed the pointer to the structure and should free any custom memory and resources allocated for it.

Keeping a pad locked in waiting state is only relevant when using the default collection algorithm (providing the oldest buffer). It ensures a buffer must be available on this pad for a collection to take place. This is of typical use to a muxer element where non-subtitle streams should always be in waiting state, e.g. to assure that caps information is available on all these streams when initial headers have to be written.

The pad will be automatically activated in push mode when pads is started.

MT safe.

Parameters

pads

the collectpads to use

 

pad

the pad to add.

[transfer none]

size

the size of the returned GstCollectData structure

 

destroy_notify

function to be called before the returned GstCollectData structure is freed.

[scope async]

lock

whether to lock this pad in usual waiting state

 

Returns

a new GstCollectData to identify the new pad. Or NULL if wrong parameters are supplied.

[nullable][transfer none]


gst_collect_pads_remove_pad ()

gboolean
gst_collect_pads_remove_pad (GstCollectPads *pads,
                             GstPad *pad);

Remove a pad from the collection of collect pads. This function will also free the GstCollectData and all the resources that were allocated with gst_collect_pads_add_pad().

The pad will be deactivated automatically when pads is stopped.

MT safe.

Parameters

pads

the collectpads to use

 

pad

the pad to remove.

[transfer none]

Returns

TRUE if the pad could be removed.


gst_collect_pads_start ()

void
gst_collect_pads_start (GstCollectPads *pads);

Starts the processing of data in the collect_pads.

MT safe.

Parameters

pads

the collectpads to use

 

gst_collect_pads_stop ()

void
gst_collect_pads_stop (GstCollectPads *pads);

Stops the processing of data in the collect_pads. this function will also unblock any blocking operations.

MT safe.

Parameters

pads

the collectpads to use

 

gst_collect_pads_available ()

guint
gst_collect_pads_available (GstCollectPads *pads);

Query how much bytes can be read from each queued buffer. This means that the result of this call is the maximum number of bytes that can be read from each of the pads.

This function should be called with pads STREAM_LOCK held, such as in the callback.

MT safe.

Parameters

pads

the collectpads to query

 

Returns

The maximum number of bytes queued on all pads. This function returns 0 if a pad has no queued buffer.


gst_collect_pads_flush ()

guint
gst_collect_pads_flush (GstCollectPads *pads,
                        GstCollectData *data,
                        guint size);

Flush size bytes from the pad data .

This function should be called with pads STREAM_LOCK held, such as in the callback.

MT safe.

Parameters

pads

the collectpads to query

 

data

the data to use

 

size

the number of bytes to flush

 

Returns

The number of bytes flushed This can be less than size and is 0 if the pad was end-of-stream.


gst_collect_pads_peek ()

GstBuffer *
gst_collect_pads_peek (GstCollectPads *pads,
                       GstCollectData *data);

Peek at the buffer currently queued in data . This function should be called with the pads STREAM_LOCK held, such as in the callback handler.

MT safe.

Parameters

pads

the collectpads to peek

 

data

the data to use

 

Returns

The buffer in data or NULL if no buffer is queued. should unref the buffer after usage.

[transfer full][nullable]


gst_collect_pads_pop ()

GstBuffer *
gst_collect_pads_pop (GstCollectPads *pads,
                      GstCollectData *data);

Pop the buffer currently queued in data . This function should be called with the pads STREAM_LOCK held, such as in the callback handler.

MT safe.

Parameters

pads

the collectpads to pop

 

data

the data to use

 

Returns

The buffer in data or NULL if no buffer was queued. You should unref the buffer after usage.

[transfer full][nullable]


gst_collect_pads_read_buffer ()

GstBuffer *
gst_collect_pads_read_buffer (GstCollectPads *pads,
                              GstCollectData *data,
                              guint size);

Get a subbuffer of size bytes from the given pad data .

This function should be called with pads STREAM_LOCK held, such as in the callback.

MT safe.

Parameters

pads

the collectpads to query

 

data

the data to use

 

size

the number of bytes to read

 

Returns

A sub buffer. The size of the buffer can be less that requested. A return of NULL signals that the pad is end-of-stream. Unref the buffer after use.

[transfer full][nullable]


gst_collect_pads_take_buffer ()

GstBuffer *
gst_collect_pads_take_buffer (GstCollectPads *pads,
                              GstCollectData *data,
                              guint size);

Get a subbuffer of size bytes from the given pad data . Flushes the amount of read bytes.

This function should be called with pads STREAM_LOCK held, such as in the callback.

MT safe.

Parameters

pads

the collectpads to query

 

data

the data to use

 

size

the number of bytes to read

 

Returns

A sub buffer. The size of the buffer can be less that requested. A return of NULL signals that the pad is end-of-stream. Unref the buffer after use.

[transfer full][nullable]


gst_collect_pads_clip_running_time ()

GstFlowReturn
gst_collect_pads_clip_running_time (GstCollectPads *pads,
                                    GstCollectData *cdata,
                                    GstBuffer *buf,
                                    GstBuffer **outbuf,
                                    gpointer user_data);

Convenience clipping function that converts incoming buffer's timestamp to running time, or clips the buffer if outside configured segment.

Since 1.6, this clipping function also sets the DTS parameter of the GstCollectData structure. This version of the running time DTS can be negative. G_MININT64 is used to indicate invalid value.

Parameters

pads

the collectpads to use

 

cdata

collect data of corresponding pad

 

buf

buffer being clipped

 

outbuf

output buffer with running time, or NULL if clipped.

[allow-none]

user_data

user data (unused)

 

gst_collect_pads_query_default ()

gboolean
gst_collect_pads_query_default (GstCollectPads *pads,
                                GstCollectData *data,
                                GstQuery *query,
                                gboolean discard);

Default GstCollectPads query handling that elements should always chain up to to ensure proper operation. Element might however indicate query should not be forwarded downstream.

Parameters

pads

the collectpads to use

 

data

collect data of corresponding pad

 

query

query being processed

 

discard

process but do not send event downstream

 

gst_collect_pads_event_default ()

gboolean
gst_collect_pads_event_default (GstCollectPads *pads,
                                GstCollectData *data,
                                GstEvent *event,
                                gboolean discard);

Default GstCollectPads event handling that elements should always chain up to to ensure proper operation. Element might however indicate event should not be forwarded downstream.

Parameters

pads

the collectpads to use

 

data

collect data of corresponding pad

 

event

event being processed

 

discard

process but do not send event downstream

 

gst_collect_pads_src_event_default ()

gboolean
gst_collect_pads_src_event_default (GstCollectPads *pads,
                                    GstPad *pad,
                                    GstEvent *event);

Default GstCollectPads event handling for the src pad of elements. Elements can chain up to this to let flushing seek event handling be done by GstCollectPads.

Parameters

pads

the GstCollectPads to use

 

pad

src GstPad that received the event

 

event

event being processed

 

Since: 1.4


gst_collect_pads_set_buffer_function ()

void
gst_collect_pads_set_buffer_function (GstCollectPads *pads,
                                      GstCollectPadsBufferFunction func,
                                      gpointer user_data);

Set the callback function and user data that will be called with the oldest buffer when all pads have been collected, or NULL on EOS. If a buffer is passed, the callback owns a reference and must unref it.

MT safe.

Parameters

pads

the collectpads to use

 

func

the function to set.

[scope call]

user_data

user data passed to the function.

[closure]

gst_collect_pads_set_clip_function ()

void
gst_collect_pads_set_clip_function (GstCollectPads *pads,
                                    GstCollectPadsClipFunction clipfunc,
                                    gpointer user_data);

Install a clipping function that is called right after a buffer is received on a pad managed by pads . See GstCollectPadsClipFunction for more info.

Parameters

pads

the collectpads to use

 

clipfunc

clip function to install.

[scope call]

user_data

user data to pass to clip_func

 

gst_collect_pads_set_compare_function ()

void
gst_collect_pads_set_compare_function (GstCollectPads *pads,
                                       GstCollectPadsCompareFunction func,
                                       gpointer user_data);

Set the timestamp comparison function.

MT safe.

Parameters

pads

the pads to use

 

func

the function to set.

[scope call]

user_data

user data passed to the function.

[closure]

gst_collect_pads_set_event_function ()

void
gst_collect_pads_set_event_function (GstCollectPads *pads,
                                     GstCollectPadsEventFunction func,
                                     gpointer user_data);

Set the event callback function and user data that will be called when collectpads has received an event originating from one of the collected pads. If the event being processed is a serialized one, this callback is called with pads STREAM_LOCK held, otherwise not. As this lock should be held when calling a number of CollectPads functions, it should be acquired if so (unusually) needed.

MT safe.

Parameters

pads

the collectpads to use

 

func

the function to set.

[scope call]

user_data

user data passed to the function

 

gst_collect_pads_set_flush_function ()

void
gst_collect_pads_set_flush_function (GstCollectPads *pads,
                                     GstCollectPadsFlushFunction func,
                                     gpointer user_data);

Install a flush function that is called when the internal state of all pads should be flushed as part of flushing seek handling. See GstCollectPadsFlushFunction for more info.

Parameters

pads

the collectpads to use

 

func

flush function to install.

[scope call]

user_data

user data to pass to func

 

Since: 1.4


gst_collect_pads_set_query_function ()

void
gst_collect_pads_set_query_function (GstCollectPads *pads,
                                     GstCollectPadsQueryFunction func,
                                     gpointer user_data);

Set the query callback function and user data that will be called after collectpads has received a query originating from one of the collected pads. If the query being processed is a serialized one, this callback is called with pads STREAM_LOCK held, otherwise not. As this lock should be held when calling a number of CollectPads functions, it should be acquired if so (unusually) needed.

MT safe.

Parameters

pads

the collectpads to use

 

func

the function to set.

[scope call]

user_data

user data passed to the function

 

gst_collect_pads_set_flushing ()

void
gst_collect_pads_set_flushing (GstCollectPads *pads,
                               gboolean flushing);

Change the flushing state of all the pads in the collection. No pad is able to accept anymore data when flushing is TRUE. Calling this function with flushing FALSE makes pads accept data again. Caller must ensure that downstream streaming (thread) is not blocked, e.g. by sending a FLUSH_START downstream.

MT safe.

Parameters

pads

the collectpads to use

 

flushing

desired state of the pads

 

gst_collect_pads_set_function ()

void
gst_collect_pads_set_function (GstCollectPads *pads,
                               GstCollectPadsFunction func,
                               gpointer user_data);

CollectPads provides a default collection algorithm that will determine the oldest buffer available on all of its pads, and then delegate to a configured callback. However, if circumstances are more complicated and/or more control is desired, this sets a callback that will be invoked instead when all the pads added to the collection have buffers queued. Evidently, this callback is not compatible with gst_collect_pads_set_buffer_function() callback. If this callback is set, the former will be unset.

MT safe.

Parameters

pads

the collectpads to use

 

func

the function to set.

[scope call]

user_data

user data passed to the function

 

gst_collect_pads_set_waiting ()

void
gst_collect_pads_set_waiting (GstCollectPads *pads,
                              GstCollectData *data,
                              gboolean waiting);

Sets a pad to waiting or non-waiting mode, if at least this pad has not been created with locked waiting state, in which case nothing happens.

This function should be called with pads STREAM_LOCK held, such as in the callback.

MT safe.

Parameters

pads

the collectpads

 

data

the data to use

 

waiting

boolean indicating whether this pad should operate in waiting or non-waiting mode

 

Types and Values

struct GstCollectPads

struct GstCollectPads {
  GSList        *data;                  /* list of CollectData items */
};

Collectpads object.

Members

GSList *data;

GList of GstCollectData managed by this GstCollectPads.

[element-type GstBase.CollectData]

struct GstCollectData

struct GstCollectData {
  /* with STREAM_LOCK of @collect */
  GstCollectPads        *collect;
  GstPad                *pad;
  GstBuffer             *buffer;
  guint                  pos;
  GstSegment             segment;

      gint64 dts;
};

Structure used by the collect_pads.

Members

GstCollectPads *collect;

owner GstCollectPads

 

GstPad *pad;

GstPad managed by this data

 

GstBuffer *buffer;

currently queued buffer.

 

guint pos;

position in the buffer

 

GstSegment segment;

last segment received.

 

gint64 dts;

the signed version of the DTS converted to running time. To access this memeber, use GST_COLLECT_PADS_DTS macro. (Since 1.6)

 

enum GstCollectPadsStateFlags

Members

GST_COLLECT_PADS_STATE_EOS

Set if collectdata's pad is EOS.

 

GST_COLLECT_PADS_STATE_FLUSHING

Set if collectdata's pad is flushing.

 

GST_COLLECT_PADS_STATE_NEW_SEGMENT

Set if collectdata's pad received a new_segment event.

 

GST_COLLECT_PADS_STATE_WAITING

Set if collectdata's pad must be waited for when collecting.

 

GST_COLLECT_PADS_STATE_LOCKED

Set collectdata's pad WAITING state must not be changed. GstCollectPadsStateFlags indicate private state of a collectdata('s pad).

 
© manpagez.com 2000-2018
Individual documents may contain additional copyright information.