diff --git a/gst-libs/gst/video/gstvideoaffinetransformationmeta.h b/gst-libs/gst/video/gstvideoaffinetransformationmeta.h index 3838a01da3..f1ee62982f 100644 --- a/gst-libs/gst/video/gstvideoaffinetransformationmeta.h +++ b/gst-libs/gst/video/gstvideoaffinetransformationmeta.h @@ -45,6 +45,13 @@ typedef gboolean (*GstVideoAffineTransformationGetMatrix) (GstVideoAffineTransfo * matrix. The transformation matrix can be composed with * gst_video_affine_transformation_meta_apply_matrix(). * + * The vertices operated on are all in the range 0 to 1, not in + * Normalized Device Coordinates (-1 to +1). Transforming points in this space + * are assumed to have an origin at (0.5, 0.5, 0.5) in a left-handed coordinate + * system with the x-axis moving horizontally (positive values to the right), + * the y-axis moving vertically (positive values up the screen) and the z-axis + * perpendicular to the screen (positive values into the screen). + * * Since: 1.8 */