Sensoray 2253 Windows - Manual (Page 37)

int enabled,
int devid,
int strmidx);
Enables capturing and insertion of closed-caption data into the stream.
Applies to H.264 only. When enabled, user data insertion will be overridden.
enabled
on or off setting.
devid
device id in the system (use 0 with a single board installed).
strmidx
stream index (0 or 1).
Video Output Functions
S2253_SetOverlay
MID2253_API int __stdcall S2253_SetOverlay (
MID2253_OVL_STRUCT *ovl,
unsigned char *data,
int devid);
This function controls overlays on the physical video output channel. It is not
used for overlays on the encoded or captured video stream. It uploads an
image to be overlaid on the video output frames. The device remembers the id
where each image was placed, allowing it to be moved later.
To move an existing overlay image, set the id, length to zero, the update field
to MID2253_OVERLAY_UPDATE_POSITION and the x and y offets to the new
position. Due to hardware limitations, the x offset may be limited to a multiple
of 2.
The transparent setting allows the overlay to have a transparency effect,
allowing the underlying video to be mixed with the image. When transparent is
set to “8”, the alpha channel in a 32-bit PNG or BMP will be used.
To hide an existing image, update the overlay (with specified id) with the
transparent field set to zero.
To display images, use the MID2253_OVERLAY_UPDATE_DISPLAY mask in the
ovl->update field. When updating multiple overlays at once, it is only
necessary (and more efficient to) set MID2253_OVERLAY_UPDATE_DISPLAY for
the last “id” to update.
Image overlays are destructive; moving or overlapping images will cause the
previous image to be overwritten by the rectangular region of the updated
image, regardless of the transparency setting.
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