gstreamer/libs/gst/base/gstbasesrc.h
Sebastian Dröge fae502056f basesrc: Make locking of the segment a bit more strict and update documentation
Updating the segment values must only be done while holding the
STREAM_LOCK and OBJECT_LOCK. This means, reading can be done as
long as one of them is held, not both, which removes some lock-unlock
blocks from performance critical code paths.

Also document, that gst_base_src_set_format() *must* be called in
states <= READY and add an assertion for this. Changing the format
later will completely mess up the segment information.
2010-02-12 14:58:42 +01:00

254 lines
9.8 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2005 Wim Taymans <wim@fluendo.com>
*
* gstbasesrc.h:
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef __GST_BASE_SRC_H__
#define __GST_BASE_SRC_H__
#include <gst/gst.h>
G_BEGIN_DECLS
#define GST_TYPE_BASE_SRC (gst_base_src_get_type())
#define GST_BASE_SRC(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_BASE_SRC,GstBaseSrc))
#define GST_BASE_SRC_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_BASE_SRC,GstBaseSrcClass))
#define GST_BASE_SRC_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_BASE_SRC, GstBaseSrcClass))
#define GST_IS_BASE_SRC(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_BASE_SRC))
#define GST_IS_BASE_SRC_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_BASE_SRC))
#define GST_BASE_SRC_CAST(obj) ((GstBaseSrc *)(obj))
/**
* GstBaseSrcFlags:
* @GST_BASE_SRC_STARTED: has source been started
* @GST_BASE_SRC_FLAG_LAST: offset to define more flags
*
* The #GstElement flags that a basesrc element may have.
*/
typedef enum {
GST_BASE_SRC_STARTED = (GST_ELEMENT_FLAG_LAST << 0),
/* padding */
GST_BASE_SRC_FLAG_LAST = (GST_ELEMENT_FLAG_LAST << 2)
} GstBaseSrcFlags;
typedef struct _GstBaseSrc GstBaseSrc;
typedef struct _GstBaseSrcClass GstBaseSrcClass;
typedef struct _GstBaseSrcPrivate GstBaseSrcPrivate;
/**
* GST_BASE_SRC_PAD:
* @obj: base source instance
*
* Gives the pointer to the #GstPad object of the element.
*/
#define GST_BASE_SRC_PAD(obj) (GST_BASE_SRC_CAST (obj)->srcpad)
/**
* GstBaseSrc:
* @element: the parent element.
*
* The opaque #GstBaseSrc data structure.
*/
struct _GstBaseSrc {
GstElement element;
/*< protected >*/
GstPad *srcpad;
/* available to subclass implementations */
/* MT-protected (with LIVE_LOCK) */
GMutex *live_lock;
GCond *live_cond;
gboolean is_live;
gboolean live_running;
/* MT-protected (with LOCK) */
gint blocksize; /* size of buffers when operating push based */
gboolean can_activate_push; /* some scheduling properties */
GstActivateMode pad_mode;
gboolean seekable; /* not used anymore */
gboolean random_access;
GstClockID clock_id; /* for syncing */
GstClockTime end_time;
/* MT-protected (with STREAM_LOCK *and* OBJECT_LOCK) */
GstSegment segment;
/* MT-protected (with STREAM_LOCK) */
gboolean need_newsegment;
guint64 offset; /* current offset in the resource, unused */
guint64 size; /* total size of the resource, unused */
gint num_buffers;
gint num_buffers_left;
/*< private >*/
union {
struct {
/* FIXME: those fields should be moved into the private struct */
gboolean typefind;
gboolean running;
GstEvent *pending_seek;
} ABI;
gpointer _gst_reserved[GST_PADDING_LARGE-1];
} data;
GstBaseSrcPrivate *priv;
};
/**
* GstBaseSrcClass:
* @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 (UNUSED)
* @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
* @unlock_stop: Clear the previous unlock request. Subclasses should clear
* any state they set during unlock(), such as clearing command queues.
* @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.
* @prepare_seek_segment: Prepare the GstSegment that will be passed to the
* do_seek vmethod for executing a seek request. Sub-classes should override
* this if they support seeking in formats other than the configured native
* format. By default, it tries to convert the seek arguments to the
* configured native format and prepare a segment in that format.
* Since: 0.10.13
* @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.
* @fixate: Called during negotiation if caps need fixating. Implement instead of
* setting a fixate function on the source pad.
*
* Subclasses can override any of the available virtual methods or not, as
* needed. At the minimum, the @create method should be overridden to produce
* buffers.
*/
struct _GstBaseSrcClass {
GstElementClass parent_class;
/*< public >*/
/* 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 (UNUSED) */
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);
/* called if, in negotiation, caps need fixating */
void (*fixate) (GstBaseSrc *src, GstCaps *caps);
/* Clear any pending unlock request, as we succeeded in unlocking */
gboolean (*unlock_stop) (GstBaseSrc *src);
/* Prepare the segment on which to perform do_seek(), converting to the
* current basesrc format. */
gboolean (*prepare_seek_segment) (GstBaseSrc *src, GstEvent *seek,
GstSegment *segment);
/*< private >*/
gpointer _gst_reserved[GST_PADDING_LARGE - 6];
};
GType gst_base_src_get_type (void);
GstFlowReturn gst_base_src_wait_playing (GstBaseSrc *src);
void gst_base_src_set_live (GstBaseSrc *src, gboolean live);
gboolean gst_base_src_is_live (GstBaseSrc *src);
void gst_base_src_set_format (GstBaseSrc *src, GstFormat format);
gboolean gst_base_src_query_latency (GstBaseSrc *src, gboolean * live,
GstClockTime * min_latency,
GstClockTime * max_latency);
void gst_base_src_set_blocksize (GstBaseSrc *src, gulong blocksize);
gulong gst_base_src_get_blocksize (GstBaseSrc *src);
void gst_base_src_set_do_timestamp (GstBaseSrc *src, gboolean timestamp);
gboolean gst_base_src_get_do_timestamp (GstBaseSrc *src);
gboolean gst_base_src_new_seamless_segment (GstBaseSrc *src, gint64 start, gint64 stop, gint64 position);
G_END_DECLS
#endif /* __GST_BASE_SRC_H__ */