Using an iMX8MPLUS-BB, Yocto honister,
Gstreamer plugin that can write initially static data (RGBA) that is overlaid on video. Similar to what is described in
Basic tutorial 8: Short-cutting the pipeline (gstreamer.freedesktop.org)
The overlay on video will be a gst_video_overlay_rectangle
Gst_video_overlay_rectangle_new_raw(
GstBuffer * pixels,
gint render_x, render_y
gint render_width, render_height
GstVideoOVerlayFormatFlags flags)
In old Gstreamer 0.10 the GstBuffer structure was as follows and contained a pointer to the actual data, *data. And a Macro for access the pointer. Looks like what I need. But is old gstreamer
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;
/* ABI Added */
GFreeFunc free_func;
GstBuffer *parent;
/*< private >*/
gpointer _gst_reserved[GST_PADDING - 2];
};
GST_BUFFER_DATA (buffer)
The iMX8 used GStreamer Core Library version 1.18.5, where the structure of GstBuffer is a follows
struct _GstBuffer {
GstMiniObject mini_object;
/*< public >*/ /* with COW */
GstBufferPool *pool;
/* timestamp */
GstClockTime pts;
GstClockTime dts;
GstClockTime duration;
/* media specific offset */
guint64 offset;
guint64 offset_end;
};
It no longer provides the data pointer and uses GstBufferPool, I have investigated the GstBufferPool but have not found an obvious method to get the memory address, so is there a mechanism for obtaining a pointer to the memory address from the GstBufferPool ?
