gstreamer/gst/gstbuffer.h
Wim Taymans 67bd9529d0 buffer: remove subbuffer subclass
Move the parent buffer pointer into the GstBuffer struct so that we can
remove the subbuffer class and type. This is interesting because it allows us to
more naturally implement methods to get the real type and parent
of a subbuffer (See #545501).
It should also be slightly faster because there is no extra object hierarchy to
initialize and free.
2009-12-26 00:02:17 +01:00

505 lines
17 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstbuffer.h: Header for GstBuffer object
*
* 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_BUFFER_H__
#define __GST_BUFFER_H__
#include <gst/gstminiobject.h>
#include <gst/gstclock.h>
#include <gst/gstcaps.h>
G_BEGIN_DECLS
typedef struct _GstBuffer GstBuffer;
typedef struct _GstBufferClass GstBufferClass;
/**
* GST_BUFFER_TRACE_NAME:
*
* The name used for tracing memory allocations.
*/
#define GST_BUFFER_TRACE_NAME "GstBuffer"
#define GST_TYPE_BUFFER (gst_buffer_get_type())
#define GST_IS_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_BUFFER))
#define GST_IS_BUFFER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_BUFFER))
#define GST_BUFFER_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_BUFFER, GstBufferClass))
#define GST_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_BUFFER, GstBuffer))
#define GST_BUFFER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_BUFFER, GstBufferClass))
#define GST_BUFFER_CAST(obj) ((GstBuffer *)(obj))
/**
* GST_BUFFER_FLAGS:
* @buf: a #GstBuffer.
*
* A flags word containing #GstBufferFlag flags set on this buffer.
*/
#define GST_BUFFER_FLAGS(buf) GST_MINI_OBJECT_FLAGS(buf)
/**
* GST_BUFFER_FLAG_IS_SET:
* @buf: a #GstBuffer.
* @flag: the #GstBufferFlag to check.
*
* Gives the status of a specific flag on a buffer.
*/
#define GST_BUFFER_FLAG_IS_SET(buf,flag) GST_MINI_OBJECT_FLAG_IS_SET (buf, flag)
/**
* GST_BUFFER_FLAG_SET:
* @buf: a #GstBuffer.
* @flag: the #GstBufferFlag to set.
*
* Sets a buffer flag on a buffer.
*/
#define GST_BUFFER_FLAG_SET(buf,flag) GST_MINI_OBJECT_FLAG_SET (buf, flag)
/**
* GST_BUFFER_FLAG_UNSET:
* @buf: a #GstBuffer.
* @flag: the #GstBufferFlag to clear.
*
* Clears a buffer flag.
*/
#define GST_BUFFER_FLAG_UNSET(buf,flag) GST_MINI_OBJECT_FLAG_UNSET (buf, flag)
/**
* GST_BUFFER_DATA:
* @buf: a #GstBuffer.
*
* A pointer to the data element of this buffer.
*/
#define GST_BUFFER_DATA(buf) (GST_BUFFER_CAST(buf)->data)
/**
* GST_BUFFER_SIZE:
* @buf: a #GstBuffer.
*
* The size in bytes of the data in this buffer.
*/
#define GST_BUFFER_SIZE(buf) (GST_BUFFER_CAST(buf)->size)
/**
* GST_BUFFER_TIMESTAMP:
* @buf: a #GstBuffer.:
*
* The timestamp in nanoseconds (as a #GstClockTime) of the data in the buffer.
* Value will be %GST_CLOCK_TIME_NONE if the timestamp is unknown.
*
*/
#define GST_BUFFER_TIMESTAMP(buf) (GST_BUFFER_CAST(buf)->timestamp)
/**
* GST_BUFFER_DURATION:
* @buf: a #GstBuffer.
*
* The duration in nanoseconds (as a #GstClockTime) of the data in the buffer.
* Value will be %GST_CLOCK_TIME_NONE if the duration is unknown.
*/
#define GST_BUFFER_DURATION(buf) (GST_BUFFER_CAST(buf)->duration)
/**
* GST_BUFFER_CAPS:
* @buf: a #GstBuffer.
*
* The caps for this buffer.
*/
#define GST_BUFFER_CAPS(buf) (GST_BUFFER_CAST(buf)->caps)
/**
* GST_BUFFER_OFFSET:
* @buf: a #GstBuffer.
*
* The offset in the source file of the beginning of this buffer.
*/
#define GST_BUFFER_OFFSET(buf) (GST_BUFFER_CAST(buf)->offset)
/**
* GST_BUFFER_OFFSET_END:
* @buf: a #GstBuffer.
*
* The offset in the source file of the end of this buffer.
*/
#define GST_BUFFER_OFFSET_END(buf) (GST_BUFFER_CAST(buf)->offset_end)
/**
* GST_BUFFER_MALLOCDATA:
* @buf: a #GstBuffer.
*
* A pointer to any data allocated for this buffer using g_malloc(). If this is
* non-NULL, this memory will be freed at the end of the buffer's lifecycle
* (i.e. when its refcount becomes zero).
*/
#define GST_BUFFER_MALLOCDATA(buf) (GST_BUFFER_CAST(buf)->malloc_data)
/**
* GST_BUFFER_FREE_FUNC:
* @buf: a #GstBuffer.
*
* A pointer to a function that will be called on the buffer's malloc_data when
* this buffer is finalized. Defaults to g_free().
*
* Note that the free function only affects the buffer's malloc_data; if the
* buffer's malloc_data is %NULL, the function will not be called.
*
* Since: 0.10.22
*/
#define GST_BUFFER_FREE_FUNC(buf) (GST_BUFFER_CAST(buf)->free_func)
/**
* GST_BUFFER_OFFSET_NONE:
*
* Constant for no-offset return results.
*/
#define GST_BUFFER_OFFSET_NONE ((guint64)-1)
/**
* GST_BUFFER_DURATION_IS_VALID:
* @buffer: a #GstBuffer
*
* Tests if the duration is known.
*/
#define GST_BUFFER_DURATION_IS_VALID(buffer) (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DURATION (buffer)))
/**
* GST_BUFFER_TIMESTAMP_IS_VALID:
* @buffer: a #GstBuffer
*
* Tests if the timestamp is known.
*/
#define GST_BUFFER_TIMESTAMP_IS_VALID(buffer) (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_TIMESTAMP (buffer)))
/**
* GST_BUFFER_OFFSET_IS_VALID:
* @buffer: a #GstBuffer
*
* Tests if the start offset is known.
*/
#define GST_BUFFER_OFFSET_IS_VALID(buffer) (GST_BUFFER_OFFSET (buffer) != GST_BUFFER_OFFSET_NONE)
/**
* GST_BUFFER_OFFSET_END_IS_VALID:
* @buffer: a #GstBuffer
*
* Tests if the end offset is known.
*/
#define GST_BUFFER_OFFSET_END_IS_VALID(buffer) (GST_BUFFER_OFFSET_END (buffer) != GST_BUFFER_OFFSET_NONE)
/**
* GST_BUFFER_IS_DISCONT:
* @buffer: a #GstBuffer
*
* Tests if the buffer marks a discontinuity in the stream.
*
* Since: 0.10.9
*/
#define GST_BUFFER_IS_DISCONT(buffer) (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DISCONT))
/**
* GstBufferFlag:
* @GST_BUFFER_FLAG_READONLY: the buffer is read-only. This means the data of
* the buffer should not be modified. The metadata might still be modified.
* @GST_BUFFER_FLAG_PREROLL: the buffer is part of a preroll and should not be
* displayed.
* @GST_BUFFER_FLAG_DISCONT: the buffer marks a discontinuity in the stream.
* This typically occurs after a seek or a dropped buffer from a live or
* network source.
* @GST_BUFFER_FLAG_IN_CAPS: the buffer has been added as a field in a #GstCaps.
* @GST_BUFFER_FLAG_GAP: the buffer has been created to fill a gap in the
* stream and contains media neutral data (elements can switch to optimized code
* path that ignores the buffer content).
* @GST_BUFFER_FLAG_DELTA_UNIT: this unit cannot be decoded independently.
* @GST_BUFFER_FLAG_MEDIA1: a flag whose use is specific to the caps of the buffer.
* Since: 0.10.23
* @GST_BUFFER_FLAG_MEDIA2: a flag whose use is specific to the caps of the buffer.
* Since: 0.10.23
* @GST_BUFFER_FLAG_MEDIA3: a flag whose use is specific to the caps of the buffer.
* Since: 0.10.23
* @GST_BUFFER_FLAG_LAST: additional flags can be added starting from this flag.
*
* A set of buffer flags used to describe properties of a #GstBuffer.
*/
typedef enum {
GST_BUFFER_FLAG_READONLY = GST_MINI_OBJECT_FLAG_READONLY,
GST_BUFFER_FLAG_PREROLL = (GST_MINI_OBJECT_FLAG_LAST << 0),
GST_BUFFER_FLAG_DISCONT = (GST_MINI_OBJECT_FLAG_LAST << 1),
GST_BUFFER_FLAG_IN_CAPS = (GST_MINI_OBJECT_FLAG_LAST << 2),
GST_BUFFER_FLAG_GAP = (GST_MINI_OBJECT_FLAG_LAST << 3),
GST_BUFFER_FLAG_DELTA_UNIT = (GST_MINI_OBJECT_FLAG_LAST << 4),
GST_BUFFER_FLAG_MEDIA1 = (GST_MINI_OBJECT_FLAG_LAST << 5),
GST_BUFFER_FLAG_MEDIA2 = (GST_MINI_OBJECT_FLAG_LAST << 6),
GST_BUFFER_FLAG_MEDIA3 = (GST_MINI_OBJECT_FLAG_LAST << 7),
GST_BUFFER_FLAG_LAST = (GST_MINI_OBJECT_FLAG_LAST << 8)
} GstBufferFlag;
/**
* GstBuffer:
* @mini_object: the parent structure
* @data: pointer to the buffer data
* @size: size of buffer data
* @timestamp: timestamp of the buffer, can be #GST_CLOCK_TIME_NONE when the
* timestamp is not known or relevant.
* @duration: duration in time of the buffer data, can be #GST_CLOCK_TIME_NONE
* when the duration is not known or relevant.
* @caps: the #GstCaps describing the data format in this buffer
* @offset: a media specific offset for the buffer data.
* For video frames, this is the frame number of this buffer.
* For audio samples, this is the offset of the first sample in this buffer.
* For file data or compressed data this is the byte offset of the first
* byte in this buffer.
* @offset_end: the last offset contained in this buffer. It has the same
* format as @offset.
* @malloc_data: a pointer to the allocated memory associated with this buffer.
* When the buffer is freed, this data will freed with @free_func.
* @free_func: a custom function that will be called with @malloc_data, defaults
* to g_free(). Since 0.10.22.
* @parent: the parent buffer if this is a subbuffer. Since 0.10.26.
*
* The structure of a #GstBuffer. Use the associated macros to access the public
* variables.
*/
struct _GstBuffer {
GstMiniObject mini_object;
/*< public >*/ /* with COW */
/* pointer to data and its size */
guint8 *data;
guint size;
/* timestamp */
GstClockTime timestamp;
GstClockTime duration;
/* the media type of this buffer */
GstCaps *caps;
/* media specific offset */
guint64 offset;
guint64 offset_end;
guint8 *malloc_data;
/* ABI Added */
GFreeFunc free_func;
GstBuffer *parent;
/*< private >*/
gpointer _gst_reserved[GST_PADDING - 2];
};
struct _GstBufferClass {
GstMiniObjectClass mini_object_class;
};
GType gst_buffer_get_type (void);
/* allocation */
GstBuffer * gst_buffer_new (void);
GstBuffer * gst_buffer_new_and_alloc (guint size);
GstBuffer * gst_buffer_try_new_and_alloc (guint size);
/**
* gst_buffer_set_data:
* @buf: a #GstBuffer
* @data: The data (a #guint8 *) to set on the buffer.
* @size: The size (in bytes, as a #guint) of the data being set.
*
* A convenience function to set the data and size on a buffer.
* This will replace any existing data pointer set on this buffer, but will
* not change GST_BUFFER_MALLOCDATA(), if any. Callers should ensure that
* GST_BUFFER_MALLOCDATA() is non-NULL, or should free that and set it to NULL.
*
* No checks are done on the data or size arguments passed.
*/
#define gst_buffer_set_data(buf, data, size) \
G_STMT_START { \
GST_BUFFER_DATA (buf) = data; \
GST_BUFFER_SIZE (buf) = size; \
} G_STMT_END
/* refcounting */
/**
* gst_buffer_ref:
* @buf: a #GstBuffer.
*
* Increases the refcount of the given buffer by one.
*
* Note that the refcount affects the writeability
* of @buf and its metadata, see gst_buffer_is_writable() and
* gst_buffer_is_metadata_writable(). It is
* important to note that keeping additional references to
* GstBuffer instances can potentially increase the number
* of memcpy operations in a pipeline.
*
* Returns: @buf
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC GstBuffer * gst_buffer_ref (GstBuffer * buf);
#endif
static inline GstBuffer *
gst_buffer_ref (GstBuffer * buf)
{
return (GstBuffer *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (buf));
}
/**
* gst_buffer_unref:
* @buf: a #GstBuffer.
*
* Decreases the refcount of the buffer. If the refcount reaches 0, the buffer
* will be freed. If GST_BUFFER_MALLOCDATA() is non-NULL, this pointer will
* also be freed at this time.
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC void gst_buffer_unref (GstBuffer * buf);
#endif
static inline void
gst_buffer_unref (GstBuffer * buf)
{
gst_mini_object_unref (GST_MINI_OBJECT_CAST (buf));
}
/* copy buffer */
/**
* gst_buffer_copy:
* @buf: a #GstBuffer.
*
* Create a copy of the given buffer. This will also make a newly allocated
* copy of the data the source buffer contains.
*
* Returns: a new copy of @buf.
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC GstBuffer * gst_buffer_copy (const GstBuffer * buf);
#endif
static inline GstBuffer *
gst_buffer_copy (const GstBuffer * buf)
{
return GST_BUFFER (gst_mini_object_copy (GST_MINI_OBJECT_CAST (buf)));
}
/**
* GstBufferCopyFlags:
* @GST_BUFFER_COPY_FLAGS: flag indicating that buffer flags should be copied
* @GST_BUFFER_COPY_TIMESTAMPS: flag indicating that buffer timestamp, duration,
* offset and offset_end should be copied
* @GST_BUFFER_COPY_CAPS: flag indicating that buffer caps should be copied
*
* A set of flags that can be provided to the gst_buffer_copy_metadata()
* function to specify which metadata fields should be copied.
*
* Since: 0.10.13
*/
typedef enum {
GST_BUFFER_COPY_FLAGS = (1 << 0),
GST_BUFFER_COPY_TIMESTAMPS = (1 << 1),
GST_BUFFER_COPY_CAPS = (1 << 2)
} GstBufferCopyFlags;
/**
* GST_BUFFER_COPY_ALL:
*
* Combination of all possible fields that can be copied with
* gst_buffer_copy_metadata().
*
* Since: 0.10.13
*/
#define GST_BUFFER_COPY_ALL (GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS | GST_BUFFER_COPY_CAPS)
/* copies metadata into newly allocated buffer */
void gst_buffer_copy_metadata (GstBuffer *dest, const GstBuffer *src,
GstBufferCopyFlags flags);
/**
* gst_buffer_is_writable:
* @buf: a #GstBuffer
*
* Tests if you can safely write data into a buffer's data array or validly
* modify the caps and timestamp metadata. Metadata in a GstBuffer is always
* writable, but it is only safe to change it when there is only one owner
* of the buffer - ie, the refcount is 1.
*/
#define gst_buffer_is_writable(buf) gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (buf))
/**
* gst_buffer_make_writable:
* @buf: a #GstBuffer
*
* Makes a writable buffer from the given buffer. If the source buffer is
* already writable, this will simply return the same buffer. A copy will
* otherwise be made using gst_buffer_copy().
*/
#define gst_buffer_make_writable(buf) GST_BUFFER_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (buf)))
/* Ensure that the metadata of the buffer is writable, even if the buffer data
* isn't */
gboolean gst_buffer_is_metadata_writable (GstBuffer *buf);
GstBuffer* gst_buffer_make_metadata_writable (GstBuffer *buf);
/**
* gst_buffer_replace:
* @obuf: pointer to a pointer to a #GstBuffer to be replaced.
* @nbuf: pointer to a #GstBuffer that will replace the buffer pointed to by
* @obuf.
*
* Modifies a pointer to a #GstBuffer to point to a different #GstBuffer. The
* modification is done atomically (so this is useful for ensuring thread safety
* in some cases), and the reference counts are updated appropriately (the old
* buffer is unreffed, the new is reffed).
*
* Either @nbuf or the #GstBuffer pointed to by @obuf may be NULL.
*/
#define gst_buffer_replace(obuf,nbuf) \
G_STMT_START { \
GstBuffer **___obufaddr = (GstBuffer **)(obuf); \
gst_mini_object_replace ((GstMiniObject **)___obufaddr, \
GST_MINI_OBJECT_CAST (nbuf)); \
} G_STMT_END
GstCaps* gst_buffer_get_caps (GstBuffer *buffer);
void gst_buffer_set_caps (GstBuffer *buffer, GstCaps *caps);
/* creating a subbuffer */
GstBuffer* gst_buffer_create_sub (GstBuffer *parent, guint offset, guint size);
/* span, two buffers, intelligently */
gboolean gst_buffer_is_span_fast (GstBuffer *buf1, GstBuffer *buf2);
GstBuffer* gst_buffer_span (GstBuffer *buf1, guint32 offset, GstBuffer *buf2, guint32 len);
/**
* gst_value_set_buffer:
* @v: a #GValue to receive the data
* @b: a #GstBuffer to assign to the GstValue
*
* Sets @b as the value of @v. Caller retains reference to buffer.
*/
#define gst_value_set_buffer(v,b) gst_value_set_mini_object(v, GST_MINI_OBJECT_CAST(b))
/**
* gst_value_take_buffer:
* @v: a #GValue to receive the data
* @b: a #GstBuffer to assign to the GstValue
*
* Sets @b as the value of @v. Caller gives away reference to buffer.
*/
#define gst_value_take_buffer(v,b) gst_value_take_mini_object(v, GST_MINI_OBJECT_CAST(b))
/**
* gst_value_get_buffer:
* @v: a #GValue to query
*
* Receives a #GstBuffer as the value of @v. Does not return a reference to
* the buffer, so the pointer is only valid for as long as the caller owns
* a reference to @v.
*/
#define gst_value_get_buffer(v) GST_BUFFER_CAST (gst_value_get_mini_object(v))
G_END_DECLS
#endif /* __GST_BUFFER_H__ */