gstreamer/gst-libs/gst/video/gstvideometa.c
Jan Schmidt d18aa5b741 video: Make gst_buffer_get_video_meta() a real function, Return lowest id
Instead of returning the first video meta found on a buffer, return the
one with the lowest id (which is usually the same thing, except on
multi-view buffers)
2015-05-30 01:11:47 +10:00

754 lines
21 KiB
C

/* GStreamer
* Copyright (C) <2011> Wim Taymans <wim.taymans@gmail.com>
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "gstvideometa.h"
#include <string.h>
static gboolean
gst_video_meta_transform (GstBuffer * dest, GstMeta * meta,
GstBuffer * buffer, GQuark type, gpointer data)
{
GstVideoMeta *dmeta, *smeta;
guint i;
smeta = (GstVideoMeta *) meta;
if (GST_META_TRANSFORM_IS_COPY (type)) {
GstMetaTransformCopy *copy = data;
if (!copy->region) {
/* only copy if the complete data is copied as well */
dmeta =
(GstVideoMeta *) gst_buffer_add_meta (dest, GST_VIDEO_META_INFO,
NULL);
if (!dmeta)
return FALSE;
dmeta->buffer = dest;
GST_DEBUG ("copy video metadata");
dmeta->flags = smeta->flags;
dmeta->format = smeta->format;
dmeta->id = smeta->id;
dmeta->width = smeta->width;
dmeta->height = smeta->height;
dmeta->n_planes = smeta->n_planes;
for (i = 0; i < dmeta->n_planes; i++) {
dmeta->offset[i] = smeta->offset[i];
dmeta->stride[i] = smeta->stride[i];
}
dmeta->map = smeta->map;
dmeta->unmap = smeta->unmap;
}
}
return TRUE;
}
GType
gst_video_meta_api_get_type (void)
{
static volatile GType type = 0;
static const gchar *tags[] =
{ GST_META_TAG_VIDEO_STR, GST_META_TAG_MEMORY_STR,
GST_META_TAG_VIDEO_COLORSPACE_STR,
GST_META_TAG_VIDEO_SIZE_STR, NULL
};
if (g_once_init_enter (&type)) {
GType _type = gst_meta_api_type_register ("GstVideoMetaAPI", tags);
g_once_init_leave (&type, _type);
}
return type;
}
/* video metadata */
const GstMetaInfo *
gst_video_meta_get_info (void)
{
static const GstMetaInfo *video_meta_info = NULL;
if (g_once_init_enter (&video_meta_info)) {
const GstMetaInfo *meta =
gst_meta_register (GST_VIDEO_META_API_TYPE, "GstVideoMeta",
sizeof (GstVideoMeta), (GstMetaInitFunction) NULL,
(GstMetaFreeFunction) NULL, gst_video_meta_transform);
g_once_init_leave (&video_meta_info, meta);
}
return video_meta_info;
}
/**
* gst_buffer_get_video_meta:
* @buffer: a #GstBuffer
*
* Find the #GstVideoMeta on @buffer with the lowest @id.
*
* Buffers can contain multiple #GstVideoMeta metadata items when dealing with
* multiview buffers.
*
* Returns: the #GstVideoMeta with lowest id (usually 0) or %NULL when there
* is no such metadata on @buffer.
*/
GstVideoMeta *
gst_buffer_get_video_meta (GstBuffer * buffer)
{
gpointer state = NULL;
GstVideoMeta *out = NULL;
GstMeta *meta;
const GstMetaInfo *info = GST_VIDEO_META_INFO;
while ((meta = gst_buffer_iterate_meta (buffer, &state))) {
if (meta->info->api == info->api) {
GstVideoMeta *vmeta = (GstVideoMeta *) meta;
if (vmeta->id == 0)
return vmeta; /* Early out for id 0 */
if (out == NULL || vmeta->id < out->id)
out = vmeta;
}
}
return out;
}
/**
* gst_buffer_get_video_meta_id:
* @buffer: a #GstBuffer
* @id: a metadata id
*
* Find the #GstVideoMeta on @buffer with the given @id.
*
* Buffers can contain multiple #GstVideoMeta metadata items when dealing with
* multiview buffers.
*
* Returns: the #GstVideoMeta with @id or %NULL when there is no such metadata
* on @buffer.
*/
GstVideoMeta *
gst_buffer_get_video_meta_id (GstBuffer * buffer, gint id)
{
gpointer state = NULL;
GstMeta *meta;
const GstMetaInfo *info = GST_VIDEO_META_INFO;
while ((meta = gst_buffer_iterate_meta (buffer, &state))) {
if (meta->info->api == info->api) {
GstVideoMeta *vmeta = (GstVideoMeta *) meta;
if (vmeta->id == id)
return vmeta;
}
}
return NULL;
}
static gboolean
default_map (GstVideoMeta * meta, guint plane, GstMapInfo * info,
gpointer * data, gint * stride, GstMapFlags flags)
{
guint idx, length;
gsize offset, skip;
GstBuffer *buffer = meta->buffer;
offset = meta->offset[plane];
/* find the memory block for this plane, this is the memory block containing
* the plane offset. FIXME use plane size */
if (!gst_buffer_find_memory (buffer, offset, 1, &idx, &length, &skip))
goto no_memory;
if (!gst_buffer_map_range (buffer, idx, length, info, flags))
goto cannot_map;
*stride = meta->stride[plane];
*data = (guint8 *) info->data + skip;
return TRUE;
/* ERRORS */
no_memory:
{
GST_DEBUG ("plane %u, no memory at offset %" G_GSIZE_FORMAT, plane, offset);
return FALSE;
}
cannot_map:
{
GST_DEBUG ("cannot map memory range %u-%u", idx, length);
return FALSE;
}
}
static gboolean
default_unmap (GstVideoMeta * meta, guint plane, GstMapInfo * info)
{
GstBuffer *buffer = meta->buffer;
gst_buffer_unmap (buffer, info);
return TRUE;
}
/**
* gst_buffer_add_video_meta:
* @buffer: a #GstBuffer
* @flags: #GstVideoFrameFlags
* @format: a #GstVideoFormat
* @width: the width
* @height: the height
*
* Attaches GstVideoMeta metadata to @buffer with the given parameters and the
* default offsets and strides for @format and @width x @height.
*
* This function calculates the default offsets and strides and then calls
* gst_buffer_add_video_meta_full() with them.
*
* Returns: the #GstVideoMeta on @buffer.
*/
GstVideoMeta *
gst_buffer_add_video_meta (GstBuffer * buffer,
GstVideoFrameFlags flags, GstVideoFormat format, guint width, guint height)
{
GstVideoMeta *meta;
GstVideoInfo info;
gst_video_info_set_format (&info, format, width, height);
meta =
gst_buffer_add_video_meta_full (buffer, flags, format, width,
height, info.finfo->n_planes, info.offset, info.stride);
return meta;
}
/**
* gst_buffer_add_video_meta_full:
* @buffer: a #GstBuffer
* @flags: #GstVideoFrameFlags
* @format: a #GstVideoFormat
* @width: the width
* @height: the height
* @n_planes: number of planes
* @offset: offset of each plane
* @stride: stride of each plane
*
* Attaches GstVideoMeta metadata to @buffer with the given parameters.
*
* Returns: the #GstVideoMeta on @buffer.
*/
GstVideoMeta *
gst_buffer_add_video_meta_full (GstBuffer * buffer,
GstVideoFrameFlags flags, GstVideoFormat format, guint width,
guint height, guint n_planes, gsize offset[GST_VIDEO_MAX_PLANES],
gint stride[GST_VIDEO_MAX_PLANES])
{
GstVideoMeta *meta;
guint i;
meta =
(GstVideoMeta *) gst_buffer_add_meta (buffer, GST_VIDEO_META_INFO, NULL);
if (!meta)
return NULL;
meta->flags = flags;
meta->format = format;
meta->id = 0;
meta->width = width;
meta->height = height;
meta->buffer = buffer;
meta->n_planes = n_planes;
for (i = 0; i < n_planes; i++) {
meta->offset[i] = offset[i];
meta->stride[i] = stride[i];
GST_LOG ("plane %d, offset %" G_GSIZE_FORMAT ", stride %d", i, offset[i],
stride[i]);
}
meta->map = default_map;
meta->unmap = default_unmap;
return meta;
}
/**
* gst_video_meta_map:
* @meta: a #GstVideoMeta
* @plane: a plane
* @info: a #GstMapInfo
* @data: the data of @plane
* @stride: the stride of @plane
* @flags: @GstMapFlags
*
* Map the video plane with index @plane in @meta and return a pointer to the
* first byte of the plane and the stride of the plane.
*
* Returns: TRUE if the map operation was successful.
*/
gboolean
gst_video_meta_map (GstVideoMeta * meta, guint plane, GstMapInfo * info,
gpointer * data, gint * stride, GstMapFlags flags)
{
g_return_val_if_fail (meta != NULL, FALSE);
g_return_val_if_fail (meta->map != NULL, FALSE);
g_return_val_if_fail (plane < meta->n_planes, FALSE);
g_return_val_if_fail (info != NULL, FALSE);
g_return_val_if_fail (data != NULL, FALSE);
g_return_val_if_fail (stride != NULL, FALSE);
g_return_val_if_fail (meta->buffer != NULL, FALSE);
g_return_val_if_fail (!(flags & GST_MAP_WRITE)
|| gst_buffer_is_writable (meta->buffer), FALSE);
return meta->map (meta, plane, info, data, stride, flags);
}
/**
* gst_video_meta_unmap:
* @meta: a #GstVideoMeta
* @plane: a plane
* @info: a #GstMapInfo
*
* Unmap a previously mapped plane with gst_video_meta_map().
*
* Returns: TRUE if the memory was successfully unmapped.
*/
gboolean
gst_video_meta_unmap (GstVideoMeta * meta, guint plane, GstMapInfo * info)
{
g_return_val_if_fail (meta != NULL, FALSE);
g_return_val_if_fail (meta->unmap != NULL, FALSE);
g_return_val_if_fail (plane < meta->n_planes, FALSE);
g_return_val_if_fail (info != NULL, FALSE);
return meta->unmap (meta, plane, info);
}
static gboolean
gst_video_crop_meta_transform (GstBuffer * dest, GstMeta * meta,
GstBuffer * buffer, GQuark type, gpointer data)
{
GstVideoCropMeta *dmeta, *smeta;
if (GST_META_TRANSFORM_IS_COPY (type)) {
smeta = (GstVideoCropMeta *) meta;
dmeta = gst_buffer_add_video_crop_meta (dest);
GST_DEBUG ("copy crop metadata");
dmeta->x = smeta->x;
dmeta->y = smeta->y;
dmeta->width = smeta->width;
dmeta->height = smeta->height;
} else if (GST_VIDEO_META_TRANSFORM_IS_SCALE (type)) {
GstVideoMetaTransform *trans = data;
gint ow, oh, nw, nh;
smeta = (GstVideoCropMeta *) meta;
dmeta = gst_buffer_add_video_crop_meta (dest);
ow = GST_VIDEO_INFO_WIDTH (trans->in_info);
nw = GST_VIDEO_INFO_WIDTH (trans->out_info);
oh = GST_VIDEO_INFO_HEIGHT (trans->in_info);
nh = GST_VIDEO_INFO_HEIGHT (trans->out_info);
GST_DEBUG ("scaling crop metadata %dx%d -> %dx%d", ow, oh, nw, nh);
dmeta->x = (smeta->x * nw) / ow;
dmeta->y = (smeta->y * nh) / oh;
dmeta->width = (smeta->width * nw) / ow;
dmeta->height = (smeta->height * nh) / oh;
GST_DEBUG ("crop offset %dx%d -> %dx%d", smeta->x, smeta->y, dmeta->x,
dmeta->y);
GST_DEBUG ("crop size %dx%d -> %dx%d", smeta->width, smeta->height,
dmeta->width, dmeta->height);
}
return TRUE;
}
GType
gst_video_crop_meta_api_get_type (void)
{
static volatile GType type = 0;
static const gchar *tags[] =
{ GST_META_TAG_VIDEO_STR, GST_META_TAG_VIDEO_SIZE_STR,
GST_META_TAG_VIDEO_ORIENTATION_STR, NULL
};
if (g_once_init_enter (&type)) {
GType _type = gst_meta_api_type_register ("GstVideoCropMetaAPI", tags);
g_once_init_leave (&type, _type);
}
return type;
}
const GstMetaInfo *
gst_video_crop_meta_get_info (void)
{
static const GstMetaInfo *video_crop_meta_info = NULL;
if (g_once_init_enter (&video_crop_meta_info)) {
const GstMetaInfo *meta =
gst_meta_register (GST_VIDEO_CROP_META_API_TYPE, "GstVideoCropMeta",
sizeof (GstVideoCropMeta), (GstMetaInitFunction) NULL,
(GstMetaFreeFunction) NULL, gst_video_crop_meta_transform);
g_once_init_leave (&video_crop_meta_info, meta);
}
return video_crop_meta_info;
}
/**
* gst_video_meta_transform_scale_get_quark:
*
* Get the #GQuark for the "gst-video-scale" metadata transform operation.
*
* Returns: a #GQuark
*/
GQuark
gst_video_meta_transform_scale_get_quark (void)
{
static GQuark _value = 0;
if (_value == 0) {
_value = g_quark_from_static_string ("gst-video-scale");
}
return _value;
}
GType
gst_video_gl_texture_upload_meta_api_get_type (void)
{
static volatile GType type = 0;
static const gchar *tags[] =
{ GST_META_TAG_VIDEO_STR, GST_META_TAG_MEMORY_STR, NULL };
if (g_once_init_enter (&type)) {
GType _type =
gst_meta_api_type_register ("GstVideoGLTextureUploadMetaAPI", tags);
g_once_init_leave (&type, _type);
}
return type;
}
static void
gst_video_gl_texture_upload_meta_free (GstMeta * meta, GstBuffer * buffer)
{
GstVideoGLTextureUploadMeta *vmeta = (GstVideoGLTextureUploadMeta *) meta;
if (vmeta->user_data_free)
vmeta->user_data_free (vmeta->user_data);
}
static gboolean
gst_video_gl_texture_upload_meta_transform (GstBuffer * dest, GstMeta * meta,
GstBuffer * buffer, GQuark type, gpointer data)
{
GstVideoGLTextureUploadMeta *dmeta, *smeta;
smeta = (GstVideoGLTextureUploadMeta *) meta;
if (GST_META_TRANSFORM_IS_COPY (type)) {
GstMetaTransformCopy *copy = data;
if (!copy->region) {
/* only copy if the complete data is copied as well */
dmeta =
(GstVideoGLTextureUploadMeta *) gst_buffer_add_meta (dest,
GST_VIDEO_GL_TEXTURE_UPLOAD_META_INFO, NULL);
if (!dmeta)
return FALSE;
dmeta->texture_orientation = smeta->texture_orientation;
dmeta->n_textures = smeta->n_textures;
memcpy (dmeta->texture_type, smeta->texture_type,
sizeof (smeta->texture_type[0]) * 4);
dmeta->buffer = dest;
dmeta->upload = smeta->upload;
dmeta->user_data = smeta->user_data;
dmeta->user_data_copy = smeta->user_data_copy;
dmeta->user_data_free = smeta->user_data_free;
if (dmeta->user_data_copy)
dmeta->user_data = dmeta->user_data_copy (dmeta->user_data);
}
}
return TRUE;
}
const GstMetaInfo *
gst_video_gl_texture_upload_meta_get_info (void)
{
static const GstMetaInfo *info = NULL;
if (g_once_init_enter (&info)) {
const GstMetaInfo *meta =
gst_meta_register (GST_VIDEO_GL_TEXTURE_UPLOAD_META_API_TYPE,
"GstVideoGLTextureUploadMeta",
sizeof (GstVideoGLTextureUploadMeta),
NULL,
gst_video_gl_texture_upload_meta_free,
gst_video_gl_texture_upload_meta_transform);
g_once_init_leave (&info, meta);
}
return info;
}
/**
* gst_buffer_add_video_gl_texture_upload_meta:
* @buffer: a #GstBuffer
* @upload: the function to upload the buffer to a specific texture ID
* @user_data: user data for the implementor of @upload
* @user_data_copy: function to copy @user_data
* @user_data_free: function to free @user_data
*
* Attaches GstVideoGLTextureUploadMeta metadata to @buffer with the given
* parameters.
*
* Returns: the #GstVideoGLTextureUploadMeta on @buffer.
*/
GstVideoGLTextureUploadMeta *
gst_buffer_add_video_gl_texture_upload_meta (GstBuffer * buffer,
GstVideoGLTextureOrientation texture_orientation, guint n_textures,
GstVideoGLTextureType texture_type[4], GstVideoGLTextureUpload upload,
gpointer user_data, GBoxedCopyFunc user_data_copy,
GBoxedFreeFunc user_data_free)
{
GstVideoGLTextureUploadMeta *meta;
g_return_val_if_fail (buffer != NULL, NULL);
g_return_val_if_fail (upload != NULL, NULL);
g_return_val_if_fail (n_textures > 0 && n_textures < 5, NULL);
meta =
(GstVideoGLTextureUploadMeta *) gst_buffer_add_meta (buffer,
GST_VIDEO_GL_TEXTURE_UPLOAD_META_INFO, NULL);
if (!meta)
return NULL;
meta->texture_orientation = texture_orientation;
meta->n_textures = n_textures;
memcpy (meta->texture_type, texture_type, sizeof (texture_type[0]) * 4);
meta->buffer = buffer;
meta->upload = upload;
meta->user_data = user_data;
meta->user_data_copy = user_data_copy;
meta->user_data_free = user_data_free;
return meta;
}
/**
* gst_video_gl_texture_upload_meta_upload:
* @meta: a #GstVideoGLTextureUploadMeta
* @texture_id: the texture IDs to upload to
*
* Uploads the buffer which owns the meta to a specific texture ID.
*
* Returns: %TRUE if uploading succeeded, %FALSE otherwise.
*/
gboolean
gst_video_gl_texture_upload_meta_upload (GstVideoGLTextureUploadMeta * meta,
guint texture_id[4])
{
g_return_val_if_fail (meta != NULL, FALSE);
return meta->upload (meta, texture_id);
}
/* Region of Interest Meta implementation *******************************************/
GType
gst_video_region_of_interest_meta_api_get_type (void)
{
static volatile GType type;
static const gchar *tags[] =
{ GST_META_TAG_VIDEO_STR, GST_META_TAG_VIDEO_ORIENTATION_STR,
GST_META_TAG_VIDEO_SIZE_STR, NULL
};
if (g_once_init_enter (&type)) {
GType _type =
gst_meta_api_type_register ("GstVideoRegionOfInterestMetaAPI", tags);
GST_INFO ("registering");
g_once_init_leave (&type, _type);
}
return type;
}
static gboolean
gst_video_region_of_interest_meta_transform (GstBuffer * dest, GstMeta * meta,
GstBuffer * buffer, GQuark type, gpointer data)
{
GstVideoRegionOfInterestMeta *dmeta, *smeta;
if (GST_META_TRANSFORM_IS_COPY (type)) {
smeta = (GstVideoRegionOfInterestMeta *) meta;
GST_DEBUG ("copy region of interest metadata");
dmeta =
gst_buffer_add_video_region_of_interest_meta_id (dest,
smeta->roi_type, smeta->x, smeta->y, smeta->w, smeta->h);
dmeta->id = smeta->id;
dmeta->parent_id = smeta->parent_id;
} else if (GST_VIDEO_META_TRANSFORM_IS_SCALE (type)) {
GstVideoMetaTransform *trans = data;
gint ow, oh, nw, nh;
ow = GST_VIDEO_INFO_WIDTH (trans->in_info);
nw = GST_VIDEO_INFO_WIDTH (trans->out_info);
oh = GST_VIDEO_INFO_HEIGHT (trans->in_info);
nh = GST_VIDEO_INFO_HEIGHT (trans->out_info);
GST_DEBUG ("scaling region of interest metadata %dx%d -> %dx%d", ow, oh, nw,
nh);
smeta = (GstVideoRegionOfInterestMeta *) meta;
dmeta =
gst_buffer_add_video_region_of_interest_meta_id (dest,
smeta->roi_type, (smeta->x * nw) / ow, (smeta->y * nh) / oh,
(smeta->w * nw) / ow, (smeta->h * nh) / oh);
dmeta->id = smeta->id;
dmeta->parent_id = smeta->parent_id;
GST_DEBUG ("region of interest (id:%d, parent id:%d) offset %dx%d -> %dx%d",
smeta->id, smeta->parent_id, smeta->x, smeta->y, dmeta->x, dmeta->y);
GST_DEBUG ("region of interest size %dx%d -> %dx%d", smeta->w, smeta->h,
dmeta->w, dmeta->h);
}
return TRUE;
}
static gboolean
gst_video_region_of_interest_meta_init (GstMeta * meta, gpointer params,
GstBuffer * buffer)
{
GstVideoRegionOfInterestMeta *emeta = (GstVideoRegionOfInterestMeta *) meta;
emeta->id = 0;
emeta->parent_id = 0;
emeta->x = emeta->y = emeta->w = emeta->h = 0;
return TRUE;
}
static void
gst_video_region_of_interest_meta_free (GstMeta * meta, GstBuffer * buffer)
{
// nothing to do
}
const GstMetaInfo *
gst_video_region_of_interest_meta_get_info (void)
{
static const GstMetaInfo *meta_info = NULL;
if (g_once_init_enter (&meta_info)) {
const GstMetaInfo *mi =
gst_meta_register (GST_VIDEO_REGION_OF_INTEREST_META_API_TYPE,
"GstVideoRegionOfInterestMeta",
sizeof (GstVideoRegionOfInterestMeta),
gst_video_region_of_interest_meta_init,
gst_video_region_of_interest_meta_free,
gst_video_region_of_interest_meta_transform);
g_once_init_leave (&meta_info, mi);
}
return meta_info;
}
/**
* gst_buffer_get_video_region_of_interest_meta_id:
* @buffer: a #GstBuffer
* @id: a metadata id
*
* Find the #GstVideoRegionOfInterestMeta on @buffer with the given @id.
*
* Buffers can contain multiple #GstVideoRegionOfInterestMeta metadata items if
* multiple regions of interests are marked on a frame.
*
* Returns: the #GstVideoRegionOfInterestMeta with @id or %NULL when there is
* no such metadata on @buffer.
*/
GstVideoRegionOfInterestMeta *
gst_buffer_get_video_region_of_interest_meta_id (GstBuffer * buffer, gint id)
{
gpointer state = NULL;
GstMeta *meta;
const GstMetaInfo *info = GST_VIDEO_REGION_OF_INTEREST_META_INFO;
while ((meta = gst_buffer_iterate_meta (buffer, &state))) {
if (meta->info->api == info->api) {
GstVideoRegionOfInterestMeta *vmeta =
(GstVideoRegionOfInterestMeta *) meta;
if (vmeta->id == id)
return vmeta;
}
}
return NULL;
}
/**
* gst_buffer_add_video_region_of_interest_meta:
* @buffer: a #GstBuffer
* @roi_type: Type of the region of interest (e.g. "face")
* @x: X position
* @y: Y position
* @w: width
* @h: height
*
* Attaches #GstVideoRegionOfInterestMeta metadata to @buffer with the given
* parameters.
*
* Returns: the #GstVideoRegionOfInterestMeta on @buffer.
*/
GstVideoRegionOfInterestMeta *
gst_buffer_add_video_region_of_interest_meta (GstBuffer * buffer,
const gchar * roi_type, guint x, guint y, guint w, guint h)
{
return gst_buffer_add_video_region_of_interest_meta_id (buffer,
g_quark_from_string (roi_type), x, y, w, h);
}
/**
* gst_buffer_add_video_region_of_interest_meta_id:
* @buffer: a #GstBuffer
* @roi_type: Type of the region of interest (e.g. "face")
* @x: X position
* @y: Y position
* @w: width
* @h: height
*
* Attaches #GstVideoRegionOfInterestMeta metadata to @buffer with the given
* parameters.
*
* Returns: the #GstVideoRegionOfInterestMeta on @buffer.
*/
GstVideoRegionOfInterestMeta *
gst_buffer_add_video_region_of_interest_meta_id (GstBuffer * buffer,
GQuark roi_type, guint x, guint y, guint w, guint h)
{
GstVideoRegionOfInterestMeta *meta;
g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
meta = (GstVideoRegionOfInterestMeta *) gst_buffer_add_meta (buffer,
GST_VIDEO_REGION_OF_INTEREST_META_INFO, NULL);
meta->roi_type = roi_type;
meta->x = x;
meta->y = y;
meta->w = w;
meta->h = h;
return meta;
}