gstreamer/gst/gstbuffer.h

485 lines
16 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.
*
* 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;
GFreeFunc free_func;
/*< private >*/
gpointer _gst_reserved[GST_PADDING - 1];
};
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)
{
/* not using a macro here because gcc-4.1 will complain
* if the return value isn't used (because of the cast) */
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.
*/
#define gst_buffer_unref(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.
*/
#define gst_buffer_copy(buf) GST_BUFFER_CAST (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 #GstValue 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 #GstValue 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 #GstValue to qeury
*
* 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__ */