the mapped buffer
pointers to the plane data
#GstVideoFrameFlags for the frame
id of the mapped frame. the id can for example be used to identify the frame in case of multiview video.
the #GstVideoInfo
mappings of the planes
pointer to metadata if any
Copy the contents from src to dest.
Note: Since: 1.18, dest dimensions are allowed to be
smaller than src dimensions.
a #GstVideoFrame
Copy the plane with index plane from src to dest.
Note: Since: 1.18, dest dimensions are allowed to be
smaller than src dimensions.
a #GstVideoFrame
a plane
Unmap the memory previously mapped with gst_video_frame_map.
Use info and buffer to fill in the values of frame. frame is usually
allocated on the stack, and you will pass the address to the #GstVideoFrame
structure allocated on the stack; gst_video_frame_map() will then fill in
the structures with the various video-specific information you need to access
the pixels of the video buffer. You can then use accessor macros such as
GST_VIDEO_FRAME_COMP_DATA(), GST_VIDEO_FRAME_PLANE_DATA(),
GST_VIDEO_FRAME_COMP_STRIDE(), GST_VIDEO_FRAME_PLANE_STRIDE() etc.
to get to the pixels.
GstVideoFrame vframe;
...
// set RGB pixels to black one at a time
if (gst_video_frame_map (&vframe, video_info, video_buffer, GST_MAP_WRITE)) {
guint8 *pixels = GST_VIDEO_FRAME_PLANE_DATA (vframe, 0);
guint stride = GST_VIDEO_FRAME_PLANE_STRIDE (vframe, 0);
guint pixel_stride = GST_VIDEO_FRAME_COMP_PSTRIDE (vframe, 0);
for (h = 0; h < height; ++h) {
for (w = 0; w < width; ++w) {
guint8 *pixel = pixels + h * stride + w * pixel_stride;
memset (pixel, 0, pixel_stride);
}
}
gst_video_frame_unmap (&vframe);
}
...
All video planes of buffer will be mapped and the pointers will be set in
frame->data.
The purpose of this function is to make it easy for you to get to the video pixels in a generic way, without you having to worry too much about details such as whether the video data is allocated in one contiguous memory chunk or multiple memory chunks (e.g. one for each plane); or if custom strides and custom plane offsets are used or not (as signalled by GstVideoMeta on each buffer). This function will just fill the #GstVideoFrame structure with the right values and if you use the accessor macros everything will just work and you can access the data easily. It also maps the underlying memory chunks for you.
a #GstVideoInfo
the buffer to map
#GstMapFlags
Use info and buffer to fill in the values of frame with the video frame
information of frame id.
When id is -1, the default frame is mapped. When id != -1, this function
will return %FALSE when there is no GstVideoMeta with that id.
All video planes of buffer will be mapped and the pointers will be set in
frame->data.
a #GstVideoInfo
the buffer to map
the frame id to map
#GstMapFlags
A video frame obtained from gst_video_frame_map()