* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
+
/**
* SECTION:gstbuffer
* @short_description: Data-passing buffer type, supporting sub-buffers.
* @see_also: #GstPad, #GstMiniObject
*
- * Buffers are the basic unit of data transfer in GStreamer. The GstBuffer type
- * provides all the state necessary to define a region of memory as part of a
- * stream. Sub-buffers are also supported, allowing a smaller region of a
+ * Buffers are the basic unit of data transfer in GStreamer. The #GstBuffer
+ * type provides all the state necessary to define a region of memory as part
+ * of a stream. Sub-buffers are also supported, allowing a smaller region of a
* buffer to become its own buffer, with mechanisms in place to ensure that
- * neither memory space goes away.
- *
- * Buffers are usually created with gst_buffer_new(). After a buffer has been
- * created one will typically allocate memory for it and set the size of the
+ * neither memory space goes away prematurely.
+ *
+ * Buffers are usually created with gst_buffer_new(). After a buffer has been
+ * created one will typically allocate memory for it and set the size of the
* buffer data. The following example creates a buffer that can hold a given
* video frame with a given width, height and bits per plane.
* <example>
* <programlisting>
* GstBuffer *buffer;
* gint size, width, height, bpp;
- *
* ...
- *
* size = width * height * bpp;
- *
* buffer = gst_buffer_new ();
* GST_BUFFER_SIZE (buffer) = size;
- * GST_BUFFER_MALLOCDATA (buffer) = g_alloc (size);
+ * GST_BUFFER_MALLOCDATA (buffer) = g_malloc (size);
* GST_BUFFER_DATA (buffer) = GST_BUFFER_MALLOCDATA (buffer);
* ...
* </programlisting>
* </example>
- *
- * Alternatively, use gst_buffer_new_and_alloc()
+ *
+ * Alternatively, use gst_buffer_new_and_alloc()
* to create a buffer with preallocated data of a given size.
- *
+ *
+ * The data pointed to by the buffer can be retrieved with the GST_BUFFER_DATA()
+ * macro. The size of the data can be found with GST_BUFFER_SIZE(). For buffers
+ * of size 0, the data pointer is undefined (usually NULL) and should never be used.
+ *
* If an element knows what pad you will push the buffer out on, it should use
* gst_pad_alloc_buffer() instead to create a buffer. This allows downstream
* elements to provide special buffers to write in, like hardware buffers.
- *
+ *
+ * A buffer has a pointer to a #GstCaps describing the media type of the data
+ * in the buffer. Attach caps to the buffer with gst_buffer_set_caps(); this
+ * is typically done before pushing out a buffer using gst_pad_push() so that
+ * the downstream element knows the type of the buffer.
+ *
+ * A buffer will usually have a timestamp, and a duration, but neither of these
+ * are guaranteed (they may be set to #GST_CLOCK_TIME_NONE). Whenever a
+ * meaningful value can be given for these, they should be set. The timestamp
+ * and duration are measured in nanoseconds (they are #GstClockTime values).
+ *
+ * A buffer can also have one or both of a start and an end offset. These are
+ * media-type specific. For video buffers, the start offset will generally be
+ * the frame number. For audio buffers, it will be the number of samples
+ * produced so far. For compressed data, it could be the byte offset in a
+ * source or destination file. Likewise, the end offset will be the offset of
+ * the end of the buffer. These can only be meaningfully interpreted if you
+ * know the media type of the buffer (the #GstCaps set on it). Either or both
+ * can be set to #GST_BUFFER_OFFSET_NONE.
+ *
* gst_buffer_ref() is used to increase the refcount of a buffer. This must be
* done when you want to keep a handle to the buffer after pushing it to the
* next element.
- *
+ *
* To efficiently create a smaller buffer out of an existing one, you can
* use gst_buffer_create_sub().
- *
- * If the plug-in wants to modify the buffer in-place, it should first obtain
+ *
+ * If a plug-in wants to modify the buffer data in-place, it should first obtain
* a buffer that is safe to modify by using gst_buffer_make_writable(). This
* function is optimized so that a copy will only be made when it is necessary.
- *
- * Several flags of the buffer can be set and unset with the GST_BUFFER_FLAG_SET()
- * and GST_BUFFER_FLAG_UNSET() macros. Use GST_BUFFER_FLAG_IS_SET() to test it
- * a certain #GstBufferFlag is set.
- *
- * Buffers can be efficiently merged into a larger buffer with gst_buffer_merge()
- * and gst_buffer_span() if the gst_buffer_is_span_fast() function returns TRUE.
- *
+ *
+ * A plugin that only wishes to modify the metadata of a buffer, such as the
+ * offset, timestamp or caps, should use gst_buffer_make_metadata_writable(),
+ * which will create a subbuffer of the original buffer to ensure the caller
+ * has sole ownership, and not copy the buffer data.
+ *
+ * Several flags of the buffer can be set and unset with the
+ * GST_BUFFER_FLAG_SET() and GST_BUFFER_FLAG_UNSET() macros. Use
+ * GST_BUFFER_FLAG_IS_SET() to test if a certain #GstBufferFlag is set.
+ *
+ * Buffers can be efficiently merged into a larger buffer with
+ * gst_buffer_merge() and gst_buffer_span() if the gst_buffer_is_span_fast()
+ * function returns TRUE.
+ *
* An element should either unref the buffer or push it out on a src pad
* using gst_pad_push() (see #GstPad).
- *
- * Buffers usually are freed by unreffing them with gst_buffer_unref().
- * Do not use gst_buffer_free() : this function effectively frees the buffer
- * regardless of the refcount, which is dangerous.
*
- * Last reviewed on August 12th, 2004 (0.8.5)
+ * Buffers are usually freed by unreffing them with gst_buffer_unref(). When
+ * the refcount drops to 0, any data pointed to by GST_BUFFER_MALLOCDATA() will
+ * also be freed.
*
+ * Last reviewed on August 11th, 2006 (0.10.10)
*/
#include "gst_private.h"
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+
#include "gstbuffer.h"
#include "gstinfo.h"
#include "gstutils.h"
#include "gstminiobject.h"
+#include "gstversion.h"
-
-static void gst_buffer_init (GTypeInstance * instance, gpointer g_class);
-static void gst_buffer_class_init (gpointer g_class, gpointer class_data);
static void gst_buffer_finalize (GstBuffer * buffer);
static GstBuffer *_gst_buffer_copy (GstBuffer * buffer);
+static GType _gst_buffer_type = 0;
-void
-_gst_buffer_initialize (void)
+/* buffer alignment in bytes
+ * an alignment of 8 would be the same as malloc() guarantees
+ */
+#ifdef HAVE_POSIX_MEMALIGN
+#if defined(BUFFER_ALIGNMENT_MALLOC)
+static size_t _gst_buffer_data_alignment = 8;
+#elif defined(BUFFER_ALIGNMENT_PAGESIZE)
+static size_t _gst_buffer_data_alignment = 0;
+#elif defined(BUFFER_ALIGNMENT)
+static size_t _gst_buffer_data_alignment = BUFFER_ALIGNMENT;
+#else
+#error "No buffer alignment configured"
+#endif
+
+static inline gboolean
+aligned_malloc (gpointer * memptr, guint size)
{
- gpointer ptr;
+ gint res;
+
+ res = posix_memalign (memptr, _gst_buffer_data_alignment, size);
+ return (res == 0);
+}
- gst_buffer_get_type ();
+#endif /* HAVE_POSIX_MEMALIGN */
+void
+_gst_buffer_initialize (void)
+{
/* the GstMiniObject types need to be class_ref'd once before it can be
* done from multiple threads;
* see http://bugzilla.gnome.org/show_bug.cgi?id=304551 */
- ptr = g_type_class_ref (GST_TYPE_BUFFER);
- g_type_class_unref (ptr);
+ g_type_class_ref (gst_buffer_get_type ());
+#ifdef HAVE_GETPAGESIZE
+#ifdef BUFFER_ALIGNMENT_PAGESIZE
+ _gst_buffer_data_alignment = getpagesize ();
+#endif
+#endif
}
-GType
-gst_buffer_get_type (void)
-{
- static GType _gst_buffer_type;
-
- if (G_UNLIKELY (_gst_buffer_type == 0)) {
- static const GTypeInfo buffer_info = {
- sizeof (GstBufferClass),
- NULL,
- NULL,
- gst_buffer_class_init,
- NULL,
- NULL,
- sizeof (GstBuffer),
- 0,
- gst_buffer_init,
- NULL
- };
-
- _gst_buffer_type = g_type_register_static (GST_TYPE_MINI_OBJECT,
- "GstBuffer", &buffer_info, 0);
- }
- return _gst_buffer_type;
+#define _do_init \
+{ \
+ _gst_buffer_type = g_define_type_id; \
}
+G_DEFINE_TYPE_WITH_CODE (GstBuffer, gst_buffer, GST_TYPE_MINI_OBJECT, _do_init);
+
static void
-gst_buffer_class_init (gpointer g_class, gpointer class_data)
+gst_buffer_class_init (GstBufferClass * klass)
{
- GstBufferClass *buffer_class = GST_BUFFER_CLASS (g_class);
-
- buffer_class->mini_object_class.copy =
- (GstMiniObjectCopyFunction) _gst_buffer_copy;
- buffer_class->mini_object_class.finalize =
+ klass->mini_object_class.copy = (GstMiniObjectCopyFunction) _gst_buffer_copy;
+ klass->mini_object_class.finalize =
(GstMiniObjectFinalizeFunction) gst_buffer_finalize;
-
}
static void
{
g_return_if_fail (buffer != NULL);
+ GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
+
/* free our data */
- if (buffer->malloc_data) {
- g_free (buffer->malloc_data);
- }
+ if (G_LIKELY (buffer->malloc_data))
+ buffer->free_func (buffer->malloc_data);
gst_caps_replace (&GST_BUFFER_CAPS (buffer), NULL);
+
+ if (buffer->parent)
+ gst_buffer_unref (buffer->parent);
+
+/* ((GstMiniObjectClass *) */
+/* gst_buffer_parent_class)->finalize (GST_MINI_OBJECT_CAST (buffer)); */
+}
+
+/**
+ * gst_buffer_copy_metadata:
+ * @dest: a destination #GstBuffer
+ * @src: a source #GstBuffer
+ * @flags: flags indicating what metadata fields should be copied.
+ *
+ * Copies the metadata from @src into @dest. The data, size and mallocdata
+ * fields are not copied.
+ *
+ * @flags indicate which fields will be copied. Use #GST_BUFFER_COPY_ALL to copy
+ * all the metadata fields.
+ *
+ * This function is typically called from a custom buffer copy function after
+ * creating @dest and setting the data, size, mallocdata.
+ *
+ * Since: 0.10.13
+ */
+void
+gst_buffer_copy_metadata (GstBuffer * dest, const GstBuffer * src,
+ GstBufferCopyFlags flags)
+{
+ g_return_if_fail (dest != NULL);
+ g_return_if_fail (src != NULL);
+
+ /* nothing to copy if the buffers are the same */
+ if (G_UNLIKELY (dest == src))
+ return;
+
+#if GST_VERSION_NANO == 1
+ /* we enable this extra debugging in git versions only for now */
+ g_warn_if_fail (gst_buffer_is_metadata_writable (dest));
+#endif
+
+ GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p", src, dest);
+
+ if (flags & GST_BUFFER_COPY_FLAGS) {
+ guint mask;
+
+ /* copy relevant flags */
+ mask = GST_BUFFER_FLAG_PREROLL | GST_BUFFER_FLAG_IN_CAPS |
+ GST_BUFFER_FLAG_DELTA_UNIT | GST_BUFFER_FLAG_DISCONT |
+ GST_BUFFER_FLAG_GAP | GST_BUFFER_FLAG_MEDIA1 |
+ GST_BUFFER_FLAG_MEDIA2 | GST_BUFFER_FLAG_MEDIA3;
+ GST_MINI_OBJECT_FLAGS (dest) |= GST_MINI_OBJECT_FLAGS (src) & mask;
+ }
+
+ if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
+ GST_BUFFER_TIMESTAMP (dest) = GST_BUFFER_TIMESTAMP (src);
+ GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
+ GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
+ GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
+ }
+
+ if (flags & GST_BUFFER_COPY_CAPS) {
+ gst_caps_replace (&GST_BUFFER_CAPS (dest), GST_BUFFER_CAPS (src));
+ }
}
static GstBuffer *
_gst_buffer_copy (GstBuffer * buffer)
{
GstBuffer *copy;
- guint mask;
g_return_val_if_fail (buffer != NULL, NULL);
/* create a fresh new buffer */
copy = gst_buffer_new ();
- GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p", buffer, copy);
-
- /* copy relevant flags */
- mask = GST_BUFFER_FLAG_PREROLL | GST_BUFFER_FLAG_IN_CAPS |
- GST_BUFFER_FLAG_DELTA_UNIT;
- GST_MINI_OBJECT (copy)->flags |= GST_MINI_OBJECT (buffer)->flags & mask;
-
/* we simply copy everything from our parent */
+#ifdef HAVE_POSIX_MEMALIGN
+ {
+ gpointer memptr = NULL;
+
+ if (G_LIKELY (buffer->size)) {
+ if (G_UNLIKELY (!aligned_malloc (&memptr, buffer->size))) {
+ /* terminate on error like g_memdup() would */
+ g_error ("%s: failed to allocate %u bytes", G_STRLOC, buffer->size);
+ } else {
+ memcpy (memptr, buffer->data, buffer->size);
+ }
+ }
+ copy->data = (guint8 *) memptr;
+ GST_BUFFER_FREE_FUNC (copy) = free;
+ }
+#else
copy->data = g_memdup (buffer->data, buffer->size);
+#endif
+
/* make sure it gets freed (even if the parent is subclassed, we return a
- normal buffer */
+ normal buffer) */
copy->malloc_data = copy->data;
-
copy->size = buffer->size;
- GST_BUFFER_TIMESTAMP (copy) = GST_BUFFER_TIMESTAMP (buffer);
- GST_BUFFER_DURATION (copy) = GST_BUFFER_DURATION (buffer);
- GST_BUFFER_OFFSET (copy) = GST_BUFFER_OFFSET (buffer);
- GST_BUFFER_OFFSET_END (copy) = GST_BUFFER_OFFSET_END (buffer);
-
- if (GST_BUFFER_CAPS (buffer))
- GST_BUFFER_CAPS (copy) = gst_caps_ref (GST_BUFFER_CAPS (buffer));
- else
- GST_BUFFER_CAPS (copy) = NULL;
+ gst_buffer_copy_metadata (copy, buffer, GST_BUFFER_COPY_ALL);
return copy;
}
static void
-gst_buffer_init (GTypeInstance * instance, gpointer g_class)
+gst_buffer_init (GstBuffer * buffer)
{
- GstBuffer *buffer;
-
- buffer = (GstBuffer *) instance;
-
GST_CAT_LOG (GST_CAT_BUFFER, "init %p", buffer);
GST_BUFFER_TIMESTAMP (buffer) = GST_CLOCK_TIME_NONE;
GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
+ GST_BUFFER_FREE_FUNC (buffer) = g_free;
}
/**
*
* Creates a newly allocated buffer without any data.
*
- * Returns: the new #GstBuffer.
- *
* MT safe.
+ *
+ * Returns: (transfer full): the new #GstBuffer.
*/
GstBuffer *
gst_buffer_new (void)
{
GstBuffer *newbuf;
- newbuf = (GstBuffer *) gst_mini_object_new (GST_TYPE_BUFFER);
+ newbuf = (GstBuffer *) gst_mini_object_new (_gst_buffer_type);
GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
* @size: the size of the new buffer's data.
*
* Creates a newly allocated buffer with data of the given size.
+ * The buffer memory is not cleared. If the requested amount of
+ * memory can't be allocated, the program will abort. Use
+ * gst_buffer_try_new_and_alloc() if you want to handle this case
+ * gracefully or have gotten the size to allocate from an untrusted
+ * source such as a media stream.
+ *
*
- * Returns: the new #GstBuffer.
+ * Note that when @size == 0, the buffer data pointer will be NULL.
*
* MT safe.
+ *
+ * Returns: (transfer full): the new #GstBuffer.
*/
GstBuffer *
gst_buffer_new_and_alloc (guint size)
newbuf = gst_buffer_new ();
+#ifdef HAVE_POSIX_MEMALIGN
+ {
+ gpointer memptr = NULL;
+
+ if (G_LIKELY (size)) {
+ if (G_UNLIKELY (!aligned_malloc (&memptr, size))) {
+ /* terminate on error like g_memdup() would */
+ g_error ("%s: failed to allocate %u bytes", G_STRLOC, size);
+ }
+ }
+ newbuf->malloc_data = (guint8 *) memptr;
+ GST_BUFFER_FREE_FUNC (newbuf) = free;
+ }
+#else
newbuf->malloc_data = g_malloc (size);
+#endif
GST_BUFFER_DATA (newbuf) = newbuf->malloc_data;
GST_BUFFER_SIZE (newbuf) = size;
+ GST_CAT_LOG (GST_CAT_BUFFER, "new %p of size %d", newbuf, size);
+
+ return newbuf;
+}
+
+/**
+ * gst_buffer_try_new_and_alloc:
+ * @size: the size of the new buffer's data.
+ *
+ * Tries to create a newly allocated buffer with data of the given size. If
+ * the requested amount of memory can't be allocated, NULL will be returned.
+ * The buffer memory is not cleared.
+ *
+ * Note that when @size == 0, the buffer data pointer will be NULL.
+ *
+ * MT safe.
+ *
+ * Returns: (transfer full): a new #GstBuffer, or NULL if the memory couldn't
+ * be allocated.
+ *
+ * Since: 0.10.13
+ */
+GstBuffer *
+gst_buffer_try_new_and_alloc (guint size)
+{
+ GstBuffer *newbuf;
+ guint8 *malloc_data;
+#ifdef HAVE_POSIX_MEMALIGN
+ gpointer memptr = NULL;
+
+ if (G_LIKELY (size)) {
+ if (G_UNLIKELY (!aligned_malloc (&memptr, size))) {
+ GST_CAT_WARNING (GST_CAT_BUFFER, "failed to allocate %d bytes", size);
+ return NULL;
+ }
+ }
+ malloc_data = (guint8 *) memptr;
+#else
+ malloc_data = g_try_malloc (size);
+
+ if (G_UNLIKELY (malloc_data == NULL && size != 0)) {
+ GST_CAT_WARNING (GST_CAT_BUFFER, "failed to allocate %d bytes", size);
+ return NULL;
+ }
+#endif
+
+ /* FIXME: there's no g_type_try_create_instance() in GObject yet, so this
+ * will still abort if a new GstBuffer structure can't be allocated */
+ newbuf = gst_buffer_new ();
+
+ GST_BUFFER_MALLOCDATA (newbuf) = malloc_data;
+ GST_BUFFER_DATA (newbuf) = malloc_data;
+ GST_BUFFER_SIZE (newbuf) = size;
+#ifdef HAVE_POSIX_MEMALIGN
+ GST_BUFFER_FREE_FUNC (newbuf) = free;
+#endif
+
+ GST_CAT_LOG (GST_CAT_BUFFER, "new %p of size %d", newbuf, size);
+
return newbuf;
}
/**
* gst_buffer_get_caps:
- * @buffer: a #GstBuffer to get the caps of.
+ * @buffer: a #GstBuffer.
*
* Gets the media type of the buffer. This can be NULL if there
- * is not media type attached to this buffer or when the media
- * type is the same as the previous received buffer.
- *
- * This function does not increment the refcount of the caps. The
- * caps pointer will therefore remain valid until the buffer is
- * unreffed.
+ * is no media type attached to this buffer.
*
- * Returns: the #GstCaps, or NULL if there was an error or there
- * were no caps on this buffer.
+ * Returns: (transfer full): a reference to the #GstCaps. unref after usage.
+ * Returns NULL if there were no caps on this buffer.
+ */
+/* this is not made atomic because if the buffer were reffed from multiple
+ * threads, it would have a refcount > 2 and thus be immutable.
*/
-/* FIXME can we make this threadsafe without a lock on the buffer?
- * We can use compare and swap and atomic reads. */
GstCaps *
gst_buffer_get_caps (GstBuffer * buffer)
{
+ GstCaps *ret;
+
g_return_val_if_fail (buffer != NULL, NULL);
- return GST_BUFFER_CAPS (buffer);
+ ret = GST_BUFFER_CAPS (buffer);
+
+ if (ret)
+ gst_caps_ref (ret);
+
+ return ret;
}
/**
* gst_buffer_set_caps:
- * @buffer: a #GstBuffer to set the caps of.
- * @caps: a #GstCaps to set.
+ * @buffer: a #GstBuffer.
+ * @caps: (transfer none): a #GstCaps.
*
- * Sets the media type on the buffer. The caps' refcount will
+ * Sets the media type on the buffer. The refcount of the caps will
* be increased and any previous caps on the buffer will be
* unreffed.
*/
-/* FIXME can we make this threadsafe without a lock on the buffer?
- * We can use compare and swap and atomic reads. Another idea is to
- * not attach the caps to the buffer but use an event to signal a caps
- * change. */
+/* this is not made atomic because if the buffer were reffed from multiple
+ * threads, it would have a refcount > 2 and thus be immutable.
+ */
void
gst_buffer_set_caps (GstBuffer * buffer, GstCaps * caps)
{
g_return_if_fail (buffer != NULL);
+ g_return_if_fail (caps == NULL || GST_CAPS_IS_SIMPLE (caps));
+
+#if GST_VERSION_NANO == 1
+ /* we enable this extra debugging in git versions only for now */
+ g_warn_if_fail (gst_buffer_is_metadata_writable (buffer));
+ /* FIXME: would be nice to also check if caps are fixed here, but expensive */
+#endif
gst_caps_replace (&GST_BUFFER_CAPS (buffer), caps);
}
-
-typedef struct _GstSubBuffer GstSubBuffer;
-typedef struct _GstSubBufferClass GstSubBufferClass;
-
-#define GST_TYPE_SUBBUFFER (gst_subbuffer_get_type())
-
-#define GST_IS_SUBBUFFER(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_SUBBUFFER))
-#define GST_SUBBUFFER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_SUBBUFFER, GstSubBuffer))
-
-struct _GstSubBuffer
-{
- GstBuffer buffer;
-
- GstBuffer *parent;
-};
-
-struct _GstSubBufferClass
-{
- GstBufferClass buffer_class;
-};
-
-static GstBufferClass *sub_parent_class;
-
-static void gst_subbuffer_init (GTypeInstance * instance, gpointer g_class);
-static void gst_subbuffer_class_init (gpointer g_class, gpointer class_data);
-static void gst_subbuffer_finalize (GstSubBuffer * buffer);
-
-static GType
-gst_subbuffer_get_type (void)
+/**
+ * gst_buffer_is_metadata_writable:
+ * @buf: a #GstBuffer
+ *
+ * Similar to gst_buffer_is_writable, but this only ensures that the
+ * refcount of the buffer is 1, indicating that the caller is the sole
+ * owner and can change the buffer metadata, such as caps and timestamps.
+ *
+ * Returns: TRUE if the metadata is writable.
+ */
+gboolean
+gst_buffer_is_metadata_writable (GstBuffer * buf)
{
- static GType _gst_subbuffer_type = 0;
-
- if (G_UNLIKELY (_gst_subbuffer_type == 0)) {
- static const GTypeInfo subbuffer_info = {
- sizeof (GstSubBufferClass),
- NULL,
- NULL,
- gst_subbuffer_class_init,
- NULL,
- NULL,
- sizeof (GstSubBuffer),
- 0,
- gst_subbuffer_init,
- NULL
- };
-
- _gst_subbuffer_type = g_type_register_static (GST_TYPE_BUFFER,
- "GstSubBuffer", &subbuffer_info, 0);
- }
- return _gst_subbuffer_type;
+ return (GST_MINI_OBJECT_REFCOUNT_VALUE (GST_MINI_OBJECT_CAST (buf)) == 1);
}
-static void
-gst_subbuffer_class_init (gpointer g_class, gpointer class_data)
+/**
+ * gst_buffer_make_metadata_writable:
+ * @buf: (transfer full): a #GstBuffer
+ *
+ * Similar to gst_buffer_make_writable, but does not ensure that the buffer
+ * data array is writable. Instead, this just ensures that the returned buffer
+ * is solely owned by the caller, by creating a subbuffer of the original
+ * buffer if necessary.
+ *
+ * After calling this function, @buf should not be referenced anymore. The
+ * result of this function has guaranteed writable metadata.
+ *
+ * Returns: (transfer full): a new #GstBuffer with writable metadata, which
+ * may or may not be the same as @buf.
+ */
+GstBuffer *
+gst_buffer_make_metadata_writable (GstBuffer * buf)
{
- GstBufferClass *buffer_class = GST_BUFFER_CLASS (g_class);
+ GstBuffer *ret;
- sub_parent_class = g_type_class_ref (GST_TYPE_BUFFER);
-
- buffer_class->mini_object_class.finalize =
- (GstMiniObjectFinalizeFunction) gst_subbuffer_finalize;
-}
+ if (gst_buffer_is_metadata_writable (buf)) {
+ ret = buf;
+ } else {
+ ret = gst_buffer_create_sub (buf, 0, GST_BUFFER_SIZE (buf));
-static void
-gst_subbuffer_finalize (GstSubBuffer * buffer)
-{
- gst_buffer_unref (buffer->parent);
+ gst_buffer_unref (buf);
+ }
- GST_MINI_OBJECT_CLASS (sub_parent_class)->finalize (GST_MINI_OBJECT (buffer));
+ return ret;
}
-static void
-gst_subbuffer_init (GTypeInstance * instance, gpointer g_class)
-{
-}
+#define GST_IS_SUBBUFFER(obj) (GST_BUFFER_CAST(obj)->parent != NULL)
/**
* gst_buffer_create_sub:
- * @parent: a parent #GstBuffer to create a subbuffer from.
- * @offset: the offset into parent #GstBuffer.
- * @size: the size of the new #GstBuffer sub-buffer (with size > 0).
+ * @parent: a #GstBuffer.
+ * @offset: the offset into parent #GstBuffer at which the new sub-buffer
+ * begins.
+ * @size: the size of the new #GstBuffer sub-buffer, in bytes.
*
- * Creates a sub-buffer from the parent at a given offset.
+ * Creates a sub-buffer from @parent at @offset and @size.
* This sub-buffer uses the actual memory space of the parent buffer.
- * This function will copy the offset and timestamp field when the
- * offset is 0, else they are set to _NONE.
- * The duration field of the new buffer are set to GST_CLOCK_TIME_NONE.
- *
- * Returns: the new #GstBuffer, or NULL if there was an error.
+ * This function will copy the offset and timestamp fields when the
+ * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
+ * #GST_BUFFER_OFFSET_NONE.
+ * If @offset equals 0 and @size equals the total size of @buffer, the
+ * duration and offset end fields are also copied. If not they will be set
+ * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
*
* MT safe.
+ *
+ * Returns: (transfer full): the new #GstBuffer or NULL if the arguments were
+ * invalid.
*/
GstBuffer *
gst_buffer_create_sub (GstBuffer * buffer, guint offset, guint size)
{
- GstSubBuffer *subbuffer;
+ GstBuffer *subbuffer;
GstBuffer *parent;
+ gboolean complete;
g_return_val_if_fail (buffer != NULL, NULL);
- g_return_val_if_fail (buffer->mini_object.refcount > 0, NULL);
- g_return_val_if_fail (size > 0, NULL);
+ g_return_val_if_fail (buffer->mini_object.refcount, NULL);
g_return_val_if_fail (buffer->size >= offset + size, NULL);
/* find real parent */
if (GST_IS_SUBBUFFER (buffer)) {
- parent = GST_SUBBUFFER (buffer)->parent;
+ parent = buffer->parent;
} else {
parent = buffer;
}
gst_buffer_ref (parent);
/* create the new buffer */
- subbuffer = (GstSubBuffer *) gst_mini_object_new (GST_TYPE_SUBBUFFER);
+ subbuffer = gst_buffer_new ();
subbuffer->parent = parent;
+ GST_BUFFER_FLAG_SET (subbuffer, GST_BUFFER_FLAG_READONLY);
GST_CAT_LOG (GST_CAT_BUFFER, "new subbuffer %p (parent %p)", subbuffer,
parent);
/* set the right values in the child */
- GST_BUFFER_DATA (GST_BUFFER_CAST (subbuffer)) = buffer->data + offset;
- GST_BUFFER_SIZE (GST_BUFFER_CAST (subbuffer)) = size;
+ GST_BUFFER_DATA (subbuffer) = buffer->data + offset;
+ GST_BUFFER_SIZE (subbuffer) = size;
+
+ if ((offset == 0) && (size == GST_BUFFER_SIZE (buffer))) {
+ /* copy all the flags except IN_CAPS */
+ GST_BUFFER_FLAG_SET (subbuffer, GST_BUFFER_FLAGS (buffer));
+ GST_BUFFER_FLAG_UNSET (subbuffer, GST_BUFFER_FLAG_IN_CAPS);
+ } else {
+ /* copy only PREROLL & GAP flags */
+ GST_BUFFER_FLAG_SET (subbuffer, (GST_BUFFER_FLAGS (buffer) &
+ (GST_BUFFER_FLAG_PREROLL | GST_BUFFER_FLAG_GAP)));
+ }
/* we can copy the timestamp and offset if the new buffer starts at
* offset 0 */
if (offset == 0) {
GST_BUFFER_TIMESTAMP (subbuffer) = GST_BUFFER_TIMESTAMP (buffer);
GST_BUFFER_OFFSET (subbuffer) = GST_BUFFER_OFFSET (buffer);
+ complete = (buffer->size == size);
} else {
GST_BUFFER_TIMESTAMP (subbuffer) = GST_CLOCK_TIME_NONE;
GST_BUFFER_OFFSET (subbuffer) = GST_BUFFER_OFFSET_NONE;
+ complete = FALSE;
}
- GST_BUFFER_DURATION (subbuffer) = GST_CLOCK_TIME_NONE;
- GST_BUFFER_OFFSET_END (subbuffer) = GST_BUFFER_OFFSET_NONE;
-
- GST_BUFFER_CAPS (subbuffer) = NULL;
+ if (complete) {
+ GstCaps *caps;
- return GST_BUFFER_CAST (subbuffer);
+ /* if we copied the complete buffer we can copy the duration,
+ * offset_end and caps as well */
+ GST_BUFFER_DURATION (subbuffer) = GST_BUFFER_DURATION (buffer);
+ GST_BUFFER_OFFSET_END (subbuffer) = GST_BUFFER_OFFSET_END (buffer);
+ if ((caps = GST_BUFFER_CAPS (buffer)))
+ gst_caps_ref (caps);
+ GST_BUFFER_CAPS (subbuffer) = caps;
+ } else {
+ GST_BUFFER_DURATION (subbuffer) = GST_CLOCK_TIME_NONE;
+ GST_BUFFER_OFFSET_END (subbuffer) = GST_BUFFER_OFFSET_NONE;
+ GST_BUFFER_CAPS (subbuffer) = NULL;
+ }
+ return subbuffer;
}
/**
* gst_buffer_is_span_fast:
- * @buf1: a first source #GstBuffer.
- * @buf2: the second source #GstBuffer.
+ * @buf1: the first #GstBuffer.
+ * @buf2: the second #GstBuffer.
*
* Determines whether a gst_buffer_span() can be done without copying
- * the contents, that is, whether the data areas are contiguous.
+ * the contents, that is, whether the data areas are contiguous sub-buffers of
+ * the same buffer.
*
+ * MT safe.
* Returns: TRUE if the buffers are contiguous,
* FALSE if a copy would be required.
- *
- * MT safe.
*/
gboolean
gst_buffer_is_span_fast (GstBuffer * buf1, GstBuffer * buf2)
{
g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
- g_return_val_if_fail (buf1->mini_object.refcount > 0, FALSE);
- g_return_val_if_fail (buf2->mini_object.refcount > 0, FALSE);
+ g_return_val_if_fail (buf1->mini_object.refcount, FALSE);
+ g_return_val_if_fail (buf2->mini_object.refcount, FALSE);
/* it's only fast if we have subbuffers of the same parent */
return (GST_IS_SUBBUFFER (buf1) &&
- GST_IS_SUBBUFFER (buf2) &&
- (GST_SUBBUFFER (buf1)->parent == GST_SUBBUFFER (buf2)->parent) &&
- ((buf1->data + buf1->size) == buf2->data));
+ GST_IS_SUBBUFFER (buf2) && (buf1->parent == buf2->parent)
+ && ((buf1->data + buf1->size) == buf2->data));
}
/**
* gst_buffer_span:
- * @buf1: a first source #GstBuffer to merge.
+ * @buf1: the first source #GstBuffer to merge.
* @offset: the offset in the first buffer from where the new
* buffer should start.
* @buf2: the second source #GstBuffer to merge.
* parent, and thus no copying is necessary. you can use
* gst_buffer_is_span_fast() to determine if a memcpy will be needed.
*
- * Returns: the new #GstBuffer that spans the two source buffers.
- *
* MT safe.
+ *
+ * Returns: (transfer full): the new #GstBuffer that spans the two source
+ * buffers, or NULL if the arguments are invalid.
*/
GstBuffer *
gst_buffer_span (GstBuffer * buf1, guint32 offset, GstBuffer * buf2,
GstBuffer *newbuf;
g_return_val_if_fail (buf1 != NULL && buf2 != NULL, NULL);
- g_return_val_if_fail (buf1->mini_object.refcount > 0, FALSE);
- g_return_val_if_fail (buf2->mini_object.refcount > 0, FALSE);
- g_return_val_if_fail (len > 0, NULL);
+ g_return_val_if_fail (buf1->mini_object.refcount, NULL);
+ g_return_val_if_fail (buf2->mini_object.refcount, NULL);
+ g_return_val_if_fail (len, NULL);
g_return_val_if_fail (len <= buf1->size + buf2->size - offset, NULL);
/* if the two buffers have the same parent and are adjacent */
if (gst_buffer_is_span_fast (buf1, buf2)) {
- GstBuffer *parent = GST_SUBBUFFER (buf1)->parent;
+ GstBuffer *parent = buf1->parent;
/* we simply create a subbuffer of the common parent */
newbuf = gst_buffer_create_sub (parent,
/* copy the second buffer's data across */
memcpy (newbuf->data + (buf1->size - offset), buf2->data,
len - (buf1->size - offset));
- /* if the offset is 0, the new buffer has the same timestamp as buf1 */
- if (offset == 0) {
- GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET (buf1);
- GST_BUFFER_TIMESTAMP (newbuf) = GST_BUFFER_TIMESTAMP (buf1);
- }
}
- /* if we completely merged the two buffers (appended), we can
- * calculate the duration too. Also make sure we's not messing with
- * invalid DURATIONS */
- if (offset == 0 && buf1->size + buf2->size == len) {
- if (GST_BUFFER_DURATION_IS_VALID (buf1) &&
- GST_BUFFER_DURATION_IS_VALID (buf2)) {
- /* add duration */
- GST_BUFFER_DURATION (newbuf) = GST_BUFFER_DURATION (buf1) +
- GST_BUFFER_DURATION (buf2);
- }
- if (GST_BUFFER_OFFSET_END_IS_VALID (buf2)) {
- /* add offset_end */
- GST_BUFFER_OFFSET_END (newbuf) = GST_BUFFER_OFFSET_END (buf2);
+ /* if the offset is 0, the new buffer has the same timestamp as buf1 */
+ if (offset == 0) {
+ GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET (buf1);
+ GST_BUFFER_TIMESTAMP (newbuf) = GST_BUFFER_TIMESTAMP (buf1);
+
+ /* if we completely merged the two buffers (appended), we can
+ * calculate the duration too. Also make sure we's not messing with
+ * invalid DURATIONS */
+ if (buf1->size + buf2->size == len) {
+ if (GST_BUFFER_DURATION_IS_VALID (buf1) &&
+ GST_BUFFER_DURATION_IS_VALID (buf2)) {
+ /* add duration */
+ GST_BUFFER_DURATION (newbuf) = GST_BUFFER_DURATION (buf1) +
+ GST_BUFFER_DURATION (buf2);
+ }
+ if (GST_BUFFER_OFFSET_END_IS_VALID (buf2)) {
+ /* add offset_end */
+ GST_BUFFER_OFFSET_END (newbuf) = GST_BUFFER_OFFSET_END (buf2);
+ }
}
}
projects / platform / upstream / gstreamer.git / blobdiff