GstBaseSrc

GstBaseSrc —

Synopsis


#include <gst/base/gstbasesrc.h>


            GstBaseSrc;
            GstBaseSrcClass;
enum        GstBaseSrcFlags;
gboolean    gst_base_src_is_live            (GstBaseSrc *src);
void        gst_base_src_set_live           (GstBaseSrc *src,
                                             gboolean live);
void        gst_base_src_set_format         (GstBaseSrc *src,
                                             GstFormat format);
#define     GST_BASE_SRC_PAD                (obj)

Object Hierarchy


  GObject
   +----GstObject
         +----GstElement
               +----GstBaseSrc
                     +----GstPushSrc

Description

Details

GstBaseSrc

typedef struct _GstBaseSrc GstBaseSrc;

The opaque GstBaseSrc data structure.

GstBaseSrcClass

typedef struct {
  GstElementClass parent_class;

  /* virtual methods for subclasses */

  /* get caps from subclass */
  GstCaps*      (*get_caps)     (GstBaseSrc *src);
  /* notify the subclass of new caps */
  gboolean      (*set_caps)     (GstBaseSrc *src, GstCaps *caps);

  /* decide on caps */
  gboolean      (*negotiate)    (GstBaseSrc *src);

  /* generate and send a newsegment */
  gboolean      (*newsegment)   (GstBaseSrc *src);

  /* start and stop processing, ideal for opening/closing the resource */
  gboolean      (*start)        (GstBaseSrc *src);
  gboolean      (*stop)         (GstBaseSrc *src);

  /* given a buffer, return start and stop time when it should be pushed
   * out. The base class will sync on the clock using these times. */
  void          (*get_times)    (GstBaseSrc *src, GstBuffer *buffer,
                                 GstClockTime *start, GstClockTime *end);

  /* get the total size of the resource in bytes */
  gboolean      (*get_size)     (GstBaseSrc *src, guint64 *size);

  /* check if the resource is seekable */
  gboolean      (*is_seekable)  (GstBaseSrc *src);
  /* unlock any pending access to the resource. subclasses should unlock
   * any function ASAP. */
  gboolean      (*unlock)       (GstBaseSrc *src);

  /* notify subclasses of an event */
  gboolean      (*event)        (GstBaseSrc *src, GstEvent *event);

  /* ask the subclass to create a buffer with offset and size */
  GstFlowReturn (*create)       (GstBaseSrc *src, guint64 offset, guint size,
		                 GstBuffer **buf);

  /* additions that change padding... */
  /* notify subclasses of a seek */
  gboolean      (*do_seek)      (GstBaseSrc *src, GstSegment *segment);
  /* notify subclasses of a query */
  gboolean      (*query)        (GstBaseSrc *src, GstQuery *query);

  /* check whether the source would support pull-based operation if
   * it were to be opened now. This vfunc is optional, but should be
   * implemented if possible to avoid unnecessary start/stop cycles.
   * The default implementation will open and close the resource to
   * find out whether get_range is supported and that is usually
   * undesirable. */
  gboolean      (*check_get_range) (GstBaseSrc *src);
} GstBaseSrcClass;

GstElementClass `parent_class`;	Element parent class
`get_caps` ()	Called to get the caps to report
`set_caps` ()	Notify subclass of changed output caps
`negotiate` ()	Negotiated the caps with the peer.
`newsegment` ()	Generate and send a new_segment event.
`start` ()	Start processing. Subclasses should open resources and prepare to produce data.
`stop` ()	Stop processing. Subclasses should use this to close resources.
`get_times` ()	Given a buffer, return the start and stop time when it should be pushed out. The base class will sync on the clock using these times.
`get_size` ()	Return the total size of the resource, in the configured format.
`is_seekable` ()	Check if the source can seek
`unlock` ()	Unlock any pending access to the resource. Subclasses should unblock any blocked function ASAP
`event` ()	Override this to implement custom event handling.
`create` ()	Ask the subclass to create a buffer with offset and size.
`do_seek` ()	Perform seeking on the resource to the indicated segment.
`query` ()	Handle a requested query.
`check_get_range` ()	Check whether the source would support pull-based operation if it were to be opened now. This vfunc is optional, but should be implemented if possible to avoid unnecessary start/stop cycles. The default implementation will open and close the resource to find out whether get_range is supported, and that is usually undesirable.

enum GstBaseSrcFlags

typedef enum {
  GST_BASE_SRC_STARTED           = (GST_ELEMENT_FLAG_LAST << 0),
  /* padding */
  GST_BASE_SRC_FLAG_LAST         = (GST_ELEMENT_FLAG_LAST << 2)
} GstBaseSrcFlags;

The GstElement flags that a basesrc element may have.

`GST_BASE_SRC_STARTED`	has source been started
`GST_BASE_SRC_FLAG_LAST`	offset to define more flags

gst_base_src_is_live ()

gboolean    gst_base_src_is_live            (GstBaseSrc *src);

Check if an element is in live mode.

`src` :	base source instance
Returns :	`TRUE` if element is in live mode.

gst_base_src_set_live ()

void        gst_base_src_set_live           (GstBaseSrc *src,
                                             gboolean live);

If the element listens to a live source, the livemode should be set to TRUE. This declares that this source can't seek.

`src` :	base source instance
`live` :	new live-mode

gst_base_src_set_format ()

void        gst_base_src_set_format         (GstBaseSrc *src,
                                             GstFormat format);

Sets the default format of the source. This will be the format used for sending NEW_SEGMENT events and for performing seeks.

If a format of GST_FORMAT_BYTES is set, the element will be able to operate in pull mode if the GstBaseSrc::is_seekable returns TRUE.

Since: 0.10.1

`src` :	base source instance
`format` :	the format to use

GST_BASE_SRC_PAD()

#define GST_BASE_SRC_PAD(obj)                 (GST_BASE_SRC_CAST (obj)->srcpad)

Gives the pointer to the GstPad object of the element.

obj : base source instance