ximagesink: use memory to store XImage info

Store the extra XImage information in the GstMemory instead of metadata.
This commit is contained in:
Wim Taymans 2013-02-26 16:02:41 +01:00
parent 1504153012
commit 1056304aad
3 changed files with 233 additions and 168 deletions

View file

@ -46,39 +46,6 @@ struct _GstXImageBufferPoolPrivate
gboolean need_alignment;
};
static void gst_ximage_meta_free (GstXImageMeta * meta, GstBuffer * buffer);
/* ximage metadata */
GType
gst_ximage_meta_api_get_type (void)
{
static volatile GType type;
static const gchar *tags[] =
{ "memory", "size", "colorspace", "orientation", NULL };
if (g_once_init_enter (&type)) {
GType _type = gst_meta_api_type_register ("GstXImageMetaAPI", tags);
g_once_init_leave (&type, _type);
}
return type;
}
const GstMetaInfo *
gst_ximage_meta_get_info (void)
{
static const GstMetaInfo *ximage_meta_info = NULL;
if (g_once_init_enter (&ximage_meta_info)) {
const GstMetaInfo *meta =
gst_meta_register (GST_XIMAGE_META_API_TYPE, "GstXImageMeta",
sizeof (GstXImageMeta), (GstMetaInitFunction) NULL,
(GstMetaFreeFunction) gst_ximage_meta_free,
(GstMetaTransformFunction) NULL);
g_once_init_leave (&ximage_meta_info, meta);
}
return ximage_meta_info;
}
/* X11 stuff */
static gboolean error_caught = FALSE;
@ -93,16 +60,171 @@ gst_ximagesink_handle_xerror (Display * display, XErrorEvent * xevent)
return 0;
}
static GstXImageMeta *
gst_buffer_add_ximage_meta (GstBuffer * buffer, GstXImageBufferPool * xpool)
static GstMemory *
gst_ximage_memory_alloc (GstAllocator * allocator, gsize size,
GstAllocationParams * params)
{
return NULL;
}
static void
gst_ximage_memory_free (GstAllocator * allocator, GstMemory * gmem)
{
GstXImageMemory *mem = (GstXImageMemory *) gmem;
GstXImageSink *ximagesink;
if (gmem->parent)
goto sub_mem;
ximagesink = mem->sink;
GST_DEBUG_OBJECT (ximagesink, "free memory %p", mem);
/* Hold the object lock to ensure the XContext doesn't disappear */
GST_OBJECT_LOCK (ximagesink);
/* We might have some buffers destroyed after changing state to NULL */
if (ximagesink->xcontext == NULL) {
GST_DEBUG_OBJECT (ximagesink, "Destroying XImage after XContext");
#ifdef HAVE_XSHM
/* Need to free the shared memory segment even if the x context
* was already cleaned up */
if (mem->SHMInfo.shmaddr != ((void *) -1)) {
shmdt (mem->SHMInfo.shmaddr);
}
#endif
goto beach;
}
g_mutex_lock (&ximagesink->x_lock);
#ifdef HAVE_XSHM
if (ximagesink->xcontext->use_xshm) {
if (mem->SHMInfo.shmaddr != ((void *) -1)) {
GST_DEBUG_OBJECT (ximagesink, "XServer ShmDetaching from 0x%x id 0x%lx",
mem->SHMInfo.shmid, mem->SHMInfo.shmseg);
XShmDetach (ximagesink->xcontext->disp, &mem->SHMInfo);
XSync (ximagesink->xcontext->disp, FALSE);
shmdt (mem->SHMInfo.shmaddr);
mem->SHMInfo.shmaddr = (void *) -1;
}
if (mem->ximage)
XDestroyImage (mem->ximage);
} else
#endif /* HAVE_XSHM */
{
if (mem->ximage) {
XDestroyImage (mem->ximage);
}
}
XSync (ximagesink->xcontext->disp, FALSE);
g_mutex_unlock (&ximagesink->x_lock);
beach:
GST_OBJECT_UNLOCK (ximagesink);
gst_object_unref (mem->sink);
sub_mem:
g_slice_free (GstXImageMemory, mem);
}
static gpointer
ximage_memory_map (GstXImageMemory * mem, gsize maxsize, GstMapFlags flags)
{
return mem->ximage->data + mem->parent.offset;
}
static gboolean
ximage_memory_unmap (GstXImageMemory * mem)
{
return TRUE;
}
static GstXImageMemory *
ximage_memory_share (GstXImageMemory * mem, gssize offset, gsize size)
{
GstXImageMemory *sub;
GstMemory *parent;
/* We can only share the complete memory */
if (offset != 0)
return NULL;
if (size != -1 && size != mem->size)
return NULL;
/* find the real parent */
if ((parent = mem->parent.parent) == NULL)
parent = (GstMemory *) mem;
if (size == -1)
size = mem->parent.size - offset;
/* the shared memory is always readonly */
sub = g_slice_new (GstXImageMemory);
gst_memory_init (GST_MEMORY_CAST (sub), GST_MINI_OBJECT_FLAGS (parent) |
GST_MINI_OBJECT_FLAG_LOCK_READONLY, mem->parent.allocator,
&mem->parent, mem->parent.maxsize, mem->parent.align,
mem->parent.offset + offset, size);
sub->sink = mem->sink;
sub->ximage = mem->ximage;
sub->SHMInfo = mem->SHMInfo;
sub->x = mem->x;
sub->y = mem->y;
sub->width = mem->width;
sub->height = mem->height;
return sub;
}
typedef GstAllocator GstXImageMemoryAllocator;
typedef GstAllocatorClass GstXImageMemoryAllocatorClass;
GType ximage_memory_allocator_get_type (void);
G_DEFINE_TYPE (GstXImageMemoryAllocator, ximage_memory_allocator,
GST_TYPE_ALLOCATOR);
#define GST_XIMAGE_ALLOCATOR_NAME "ximage"
#define GST_TYPE_XIMAGE_MEMORY_ALLOCATOR (ximage_memory_allocator_get_type())
#define GST_IS_XIMAGE_MEMORY_ALLOCATOR(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_XIMAGE_MEMORY_ALLOCATOR))
static void
ximage_memory_allocator_class_init (GstXImageMemoryAllocatorClass * klass)
{
GstAllocatorClass *allocator_class;
allocator_class = (GstAllocatorClass *) klass;
allocator_class->alloc = gst_ximage_memory_alloc;
allocator_class->free = gst_ximage_memory_free;
}
static void
ximage_memory_allocator_init (GstXImageMemoryAllocator * allocator)
{
GstAllocator *alloc = GST_ALLOCATOR_CAST (allocator);
alloc->mem_type = GST_XIMAGE_ALLOCATOR_NAME;
alloc->mem_map = (GstMemoryMapFunction) ximage_memory_map;
alloc->mem_unmap = (GstMemoryUnmapFunction) ximage_memory_unmap;
alloc->mem_share = (GstMemoryShareFunction) ximage_memory_share;
/* fallback copy and is_span */
GST_OBJECT_FLAG_SET (allocator, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC);
}
static GstMemory *
ximage_memory_alloc (GstXImageBufferPool * xpool)
{
GstXImageSink *ximagesink;
int (*handler) (Display *, XErrorEvent *);
gboolean success = FALSE;
GstXContext *xcontext;
GstXImageMeta *meta;
gint width, height, align = 15, offset;
GstXImageBufferPoolPrivate *priv;
GstXImageMemory *mem;
priv = xpool->priv;
ximagesink = xpool->sink;
@ -111,20 +233,19 @@ gst_buffer_add_ximage_meta (GstBuffer * buffer, GstXImageBufferPool * xpool)
width = priv->padded_width;
height = priv->padded_height;
meta =
(GstXImageMeta *) gst_buffer_add_meta (buffer, GST_XIMAGE_META_INFO,
NULL);
#ifdef HAVE_XSHM
meta->SHMInfo.shmaddr = ((void *) -1);
meta->SHMInfo.shmid = -1;
#endif
meta->x = priv->align.padding_left;
meta->y = priv->align.padding_top;
meta->width = GST_VIDEO_INFO_WIDTH (&priv->info);
meta->height = GST_VIDEO_INFO_HEIGHT (&priv->info);
meta->sink = gst_object_ref (ximagesink);
mem = g_slice_new (GstXImageMemory);
GST_DEBUG_OBJECT (ximagesink, "creating image %p (%dx%d)", buffer,
#ifdef HAVE_XSHM
mem->SHMInfo.shmaddr = ((void *) -1);
mem->SHMInfo.shmid = -1;
#endif
mem->x = priv->align.padding_left;
mem->y = priv->align.padding_top;
mem->width = GST_VIDEO_INFO_WIDTH (&priv->info);
mem->height = GST_VIDEO_INFO_HEIGHT (&priv->info);
mem->sink = gst_object_ref (ximagesink);
GST_DEBUG_OBJECT (ximagesink, "creating image %p (%dx%d)", mem,
width, height);
g_mutex_lock (&ximagesink->x_lock);
@ -135,10 +256,10 @@ gst_buffer_add_ximage_meta (GstBuffer * buffer, GstXImageBufferPool * xpool)
#ifdef HAVE_XSHM
if (xcontext->use_xshm) {
meta->ximage = XShmCreateImage (xcontext->disp,
mem->ximage = XShmCreateImage (xcontext->disp,
xcontext->visual,
xcontext->depth, ZPixmap, NULL, &meta->SHMInfo, width, height);
if (!meta->ximage || error_caught) {
xcontext->depth, ZPixmap, NULL, &mem->SHMInfo, width, height);
if (!mem->ximage || error_caught) {
g_mutex_unlock (&ximagesink->x_lock);
/* Reset error flag */
@ -160,27 +281,27 @@ gst_buffer_add_ximage_meta (GstBuffer * buffer, GstXImageBufferPool * xpool)
}
/* we have to use the returned bytes_per_line for our shm size */
meta->size = meta->ximage->bytes_per_line * meta->ximage->height;
mem->size = mem->ximage->bytes_per_line * mem->ximage->height;
GST_LOG_OBJECT (ximagesink,
"XShm image size is %" G_GSIZE_FORMAT ", width %d, stride %d",
meta->size, width, meta->ximage->bytes_per_line);
mem->size, width, mem->ximage->bytes_per_line);
/* get shared memory */
meta->SHMInfo.shmid =
shmget (IPC_PRIVATE, meta->size + align, IPC_CREAT | 0777);
if (meta->SHMInfo.shmid == -1)
mem->SHMInfo.shmid =
shmget (IPC_PRIVATE, mem->size + align, IPC_CREAT | 0777);
if (mem->SHMInfo.shmid == -1)
goto shmget_failed;
/* attach */
meta->SHMInfo.shmaddr = shmat (meta->SHMInfo.shmid, NULL, 0);
if (meta->SHMInfo.shmaddr == ((void *) -1))
mem->SHMInfo.shmaddr = shmat (mem->SHMInfo.shmid, NULL, 0);
if (mem->SHMInfo.shmaddr == ((void *) -1))
goto shmat_failed;
/* now we can set up the image data */
meta->ximage->data = meta->SHMInfo.shmaddr;
meta->SHMInfo.readOnly = FALSE;
mem->ximage->data = mem->SHMInfo.shmaddr;
mem->SHMInfo.readOnly = FALSE;
if (XShmAttach (xcontext->disp, &meta->SHMInfo) == 0)
if (XShmAttach (xcontext->disp, &mem->SHMInfo) == 0)
goto xattach_failed;
XSync (xcontext->disp, FALSE);
@ -188,70 +309,70 @@ gst_buffer_add_ximage_meta (GstBuffer * buffer, GstXImageBufferPool * xpool)
/* Now that everyone has attached, we can delete the shared memory segment.
* This way, it will be deleted as soon as we detach later, and not
* leaked if we crash. */
shmctl (meta->SHMInfo.shmid, IPC_RMID, NULL);
shmctl (mem->SHMInfo.shmid, IPC_RMID, NULL);
GST_DEBUG_OBJECT (ximagesink, "XServer ShmAttached to 0x%x, id 0x%lx",
meta->SHMInfo.shmid, meta->SHMInfo.shmseg);
mem->SHMInfo.shmid, mem->SHMInfo.shmseg);
} else
no_xshm:
#endif /* HAVE_XSHM */
{
guint allocsize;
meta->ximage = XCreateImage (xcontext->disp,
mem->ximage = XCreateImage (xcontext->disp,
xcontext->visual,
xcontext->depth, ZPixmap, 0, NULL, width, height, xcontext->bpp, 0);
if (!meta->ximage || error_caught)
if (!mem->ximage || error_caught)
goto create_failed;
/* upstream will assume that rowstrides are multiples of 4, but this
* doesn't always seem to be the case with XCreateImage() */
if ((meta->ximage->bytes_per_line % 4) != 0) {
if ((mem->ximage->bytes_per_line % 4) != 0) {
GST_WARNING_OBJECT (ximagesink, "returned stride not a multiple of 4 as "
"usually assumed");
}
/* we have to use the returned bytes_per_line for our image size */
meta->size = meta->ximage->bytes_per_line * meta->ximage->height;
mem->size = mem->ximage->bytes_per_line * mem->ximage->height;
/* alloc a bit more for unexpected strides to avoid crashes upstream.
* FIXME: if we get an unrounded stride, the image will be displayed
* distorted, since all upstream elements assume a rounded stride */
allocsize =
GST_ROUND_UP_4 (meta->ximage->bytes_per_line) * meta->ximage->height;
GST_ROUND_UP_4 (mem->ximage->bytes_per_line) * mem->ximage->height;
meta->ximage->data = g_malloc (allocsize + align);
mem->ximage->data = g_malloc (allocsize + align);
GST_LOG_OBJECT (ximagesink,
"non-XShm image size is %" G_GSIZE_FORMAT " (alloced: %u), width %d, "
"stride %d", meta->size, allocsize, width,
meta->ximage->bytes_per_line);
"stride %d", mem->size, allocsize, width, mem->ximage->bytes_per_line);
XSync (xcontext->disp, FALSE);
}
if ((offset = ((guintptr) meta->ximage->data & align)))
if ((offset = ((guintptr) mem->ximage->data & align)))
offset = (align + 1) - offset;
GST_DEBUG_OBJECT (ximagesink, "memory %p, align %d, offset %d",
meta->ximage->data, align, offset);
mem->ximage->data, align, offset);
/* Reset error handler */
error_caught = FALSE;
XSetErrorHandler (handler);
gst_buffer_append_memory (buffer,
gst_memory_new_wrapped (GST_MEMORY_FLAG_NO_SHARE, meta->ximage->data,
meta->size + align, offset, meta->size, NULL, NULL));
gst_memory_init (GST_MEMORY_CAST (mem), 0, xpool->allocator,
NULL, mem->size + align, align, offset, mem->size);
g_mutex_unlock (&ximagesink->x_lock);
success = TRUE;
beach:
if (!success)
meta = NULL;
if (!success) {
g_slice_free (GstXImageMemory, mem);
mem = NULL;
}
return meta;
return GST_MEMORY_CAST (mem);
/* ERRORS */
create_failed:
@ -275,7 +396,7 @@ shmget_failed:
("Failed to create output image buffer of %dx%d pixels",
width, height),
("could not get shared memory of %" G_GSIZE_FORMAT " bytes",
meta->size));
mem->size));
goto beach;
}
shmat_failed:
@ -285,13 +406,13 @@ shmat_failed:
("Failed to create output image buffer of %dx%d pixels",
width, height), ("Failed to shmat: %s", g_strerror (errno)));
/* Clean up the shared memory segment */
shmctl (meta->SHMInfo.shmid, IPC_RMID, NULL);
shmctl (mem->SHMInfo.shmid, IPC_RMID, NULL);
goto beach;
}
xattach_failed:
{
/* Clean up the shared memory segment */
shmctl (meta->SHMInfo.shmid, IPC_RMID, NULL);
shmctl (mem->SHMInfo.shmid, IPC_RMID, NULL);
g_mutex_unlock (&ximagesink->x_lock);
GST_ELEMENT_ERROR (ximagesink, RESOURCE, WRITE,
@ -302,62 +423,6 @@ xattach_failed:
#endif
}
static void
gst_ximage_meta_free (GstXImageMeta * meta, GstBuffer * buffer)
{
GstXImageSink *ximagesink;
ximagesink = meta->sink;
GST_DEBUG_OBJECT (ximagesink, "free meta on buffer %p", buffer);
/* Hold the object lock to ensure the XContext doesn't disappear */
GST_OBJECT_LOCK (ximagesink);
/* We might have some buffers destroyed after changing state to NULL */
if (ximagesink->xcontext == NULL) {
GST_DEBUG_OBJECT (ximagesink, "Destroying XImage after XContext");
#ifdef HAVE_XSHM
/* Need to free the shared memory segment even if the x context
* was already cleaned up */
if (meta->SHMInfo.shmaddr != ((void *) -1)) {
shmdt (meta->SHMInfo.shmaddr);
}
#endif
goto beach;
}
g_mutex_lock (&ximagesink->x_lock);
#ifdef HAVE_XSHM
if (ximagesink->xcontext->use_xshm) {
if (meta->SHMInfo.shmaddr != ((void *) -1)) {
GST_DEBUG_OBJECT (ximagesink, "XServer ShmDetaching from 0x%x id 0x%lx",
meta->SHMInfo.shmid, meta->SHMInfo.shmseg);
XShmDetach (ximagesink->xcontext->disp, &meta->SHMInfo);
XSync (ximagesink->xcontext->disp, FALSE);
shmdt (meta->SHMInfo.shmaddr);
meta->SHMInfo.shmaddr = (void *) -1;
}
if (meta->ximage)
XDestroyImage (meta->ximage);
} else
#endif /* HAVE_XSHM */
{
if (meta->ximage) {
XDestroyImage (meta->ximage);
}
}
XSync (ximagesink->xcontext->disp, FALSE);
g_mutex_unlock (&ximagesink->x_lock);
beach:
GST_OBJECT_UNLOCK (ximagesink);
gst_object_unref (meta->sink);
}
#ifdef HAVE_XSHM
/* This function checks that it is actually really possible to create an image
using XShm */
@ -576,16 +641,18 @@ ximage_buffer_pool_alloc (GstBufferPool * pool, GstBuffer ** buffer,
GstXImageBufferPoolPrivate *priv = xpool->priv;
GstVideoInfo *info;
GstBuffer *ximage;
GstXImageMeta *meta;
GstMemory *mem;
info = &priv->info;
ximage = gst_buffer_new ();
meta = gst_buffer_add_ximage_meta (ximage, xpool);
if (meta == NULL) {
mem = ximage_memory_alloc (xpool);
if (mem == NULL) {
gst_buffer_unref (ximage);
goto no_buffer;
}
gst_buffer_append_memory (ximage, mem);
if (priv->add_metavideo) {
GST_DEBUG_OBJECT (pool, "adding GstVideoMeta");
/* these are just the defaults for now */
@ -615,6 +682,7 @@ gst_ximage_buffer_pool_new (GstXImageSink * ximagesink)
pool = g_object_new (GST_TYPE_XIMAGE_BUFFER_POOL, NULL);
pool->sink = gst_object_ref (ximagesink);
pool->allocator = g_object_new (GST_TYPE_XIMAGE_MEMORY_ALLOCATOR, NULL);
GST_LOG_OBJECT (pool, "new XImage buffer pool %p", pool);
@ -653,6 +721,7 @@ gst_ximage_buffer_pool_finalize (GObject * object)
if (priv->caps)
gst_caps_unref (priv->caps);
gst_object_unref (pool->sink);
gst_object_unref (pool->allocator);
G_OBJECT_CLASS (gst_ximage_buffer_pool_parent_class)->finalize (object);
}

View file

@ -39,33 +39,27 @@
G_BEGIN_DECLS
typedef struct _GstXImageMeta GstXImageMeta;
typedef struct _GstXImageMemory GstXImageMemory;
typedef struct _GstXImageBufferPool GstXImageBufferPool;
typedef struct _GstXImageBufferPoolClass GstXImageBufferPoolClass;
typedef struct _GstXImageBufferPoolPrivate GstXImageBufferPoolPrivate;
#include "ximagesink.h"
GType gst_ximage_meta_api_get_type (void);
#define GST_XIMAGE_META_API_TYPE (gst_ximage_meta_api_get_type())
const GstMetaInfo * gst_ximage_meta_get_info (void);
#define GST_XIMAGE_META_INFO (gst_ximage_meta_get_info())
#define gst_buffer_get_ximage_meta(b) ((GstXImageMeta*)gst_buffer_get_meta((b),GST_XIMAGE_META_API_TYPE))
/**
* GstXImageMeta:
* @simagesink: a reference to the our #GstXImageSink
* GstXImageMemory:
* @sink: a reference to the our #GstXImageSink
* @ximage: the XImage of this buffer
* @width: the width in pixels of XImage @ximage
* @height: the height in pixels of XImage @ximage
* @size: the size in bytes of XImage @ximage
*
* Subclass of #GstMeta containing additional information about an XImage.
* Subclass of #GstMemory containing additional information about an XImage.
*/
struct _GstXImageMeta
struct _GstXImageMemory
{
GstMeta meta;
GstMemory parent;
/* Reference to the ximagesink we belong to */
GstXImageSink *sink;
@ -92,6 +86,7 @@ struct _GstXImageBufferPool
GstBufferPool bufferpool;
GstXImageSink *sink;
GstAllocator *allocator;
GstXImageBufferPoolPrivate *priv;
};

View file

@ -228,7 +228,7 @@ gst_ximagesink_xwindow_draw_borders (GstXImageSink * ximagesink,
static gboolean
gst_ximagesink_ximage_put (GstXImageSink * ximagesink, GstBuffer * ximage)
{
GstXImageMeta *meta;
GstXImageMemory *mem;
GstVideoCropMeta *crop;
GstVideoRectangle src, dst, result;
gboolean draw_border = FALSE;
@ -269,21 +269,21 @@ gst_ximagesink_ximage_put (GstXImageSink * ximagesink, GstBuffer * ximage)
}
}
meta = gst_buffer_get_ximage_meta (ximage);
mem = (GstXImageMemory *) gst_buffer_peek_memory (ximage, 0);
crop = gst_buffer_get_video_crop_meta (ximage);
if (crop) {
src.x = crop->x + meta->x;
src.y = crop->y + meta->y;
src.x = crop->x + mem->x;
src.y = crop->y + mem->y;
src.w = crop->width;
src.h = crop->height;
GST_LOG_OBJECT (ximagesink,
"crop %dx%d-%dx%d", crop->x, crop->y, crop->width, crop->height);
} else {
src.x = meta->x;
src.y = meta->y;
src.w = meta->width;
src.h = meta->height;
src.x = mem->x;
src.y = mem->y;
src.w = mem->width;
src.h = mem->height;
}
dst.w = ximagesink->xwindow->width;
dst.h = ximagesink->xwindow->height;
@ -304,7 +304,7 @@ gst_ximagesink_ximage_put (GstXImageSink * ximagesink, GstBuffer * ximage)
ximage, 0, 0, result.x, result.y, result.w, result.h,
ximagesink->xwindow->width, ximagesink->xwindow->height);
XShmPutImage (ximagesink->xcontext->disp, ximagesink->xwindow->win,
ximagesink->xwindow->gc, meta->ximage, src.x, src.y, result.x, result.y,
ximagesink->xwindow->gc, mem->ximage, src.x, src.y, result.x, result.y,
result.w, result.h, FALSE);
} else
#endif /* HAVE_XSHM */
@ -314,7 +314,7 @@ gst_ximagesink_ximage_put (GstXImageSink * ximagesink, GstBuffer * ximage)
ximage, 0, 0, result.x, result.y, result.w, result.h,
ximagesink->xwindow->width, ximagesink->xwindow->height);
XPutImage (ximagesink->xcontext->disp, ximagesink->xwindow->win,
ximagesink->xwindow->gc, meta->ximage, src.x, src.y, result.x, result.y,
ximagesink->xwindow->gc, mem->ximage, src.x, src.y, result.x, result.y,
result.w, result.h);
}
@ -1295,14 +1295,15 @@ gst_ximagesink_show_frame (GstVideoSink * vsink, GstBuffer * buf)
{
GstFlowReturn res;
GstXImageSink *ximagesink;
GstXImageMeta *meta;
GstXImageMemory *mem;
GstBuffer *to_put = NULL;
ximagesink = GST_XIMAGESINK (vsink);
meta = gst_buffer_get_ximage_meta (buf);
if (meta && meta->sink == ximagesink) {
if (gst_buffer_n_memory (buf) == 1
&& (mem = (GstXImageMemory *) gst_buffer_peek_memory (buf, 0))
&& g_strcmp0 (mem->parent.allocator->mem_type, "ximage") == 0
&& mem->sink == ximagesink) {
/* If this buffer has been allocated using our buffer management we simply
put the ximage which is in the PRIVATE pointer */
GST_LOG_OBJECT (ximagesink, "buffer from our pool, writing directly");