def do_transform_ip(self, buffer: Gst.Buffer) -> Gst.FlowReturn:
if self.model is None:
Gst.warning(
f"No model speficied for {self}. Plugin working in passthrough mode"
)
return Gst.FlowReturn.OK
try:
# Convert Gst.Buffer to np.ndarray
image = utils.gst_buffer_with_caps_to_ndarray(
buffer, self.sinkpad.get_current_caps())
# model inference
objects = self.model.process_single(image)
Gst.debug(
f"Frame id ({buffer.pts // buffer.duration}). Detected {str(objects)}"
)
# write objects to as Gst.Buffer's metadata
# Explained: http://lifestyletransfer.com/how-to-add-metadata-to-gstreamer-buffer-in-python/
gst_meta_write(buffer, objects)
except Exception as err:
logging.error("Error %s: %s", self, err)
return Gst.FlowReturn.OK
def do_transform_ip(self, buffer: Gst.Buffer):
try:
caps = self.sinkpad.get_current_caps()
image = utils.gst_buffer_with_caps_to_ndarray(buffer, caps)
detections = self.process(image)
gst_meta_write(buffer, detections)
except Exception as err:
Gst.error(f'Error {self}: {traceback.format_exc()}')
return Gst.FlowReturn.OK
def test_metadata():
np_buffer = np.random.randint(low=0,
high=255,
size=(HEIGHT, WIDTH, 3),
dtype=np.uint8)
gst_buffer = gst.ndarray_to_gst_buffer(np_buffer)
from gstreamer.gst_objects_info_meta import gst_meta_write, gst_meta_get, gst_meta_remove
objects = [
{
'class_name': "person",
'bounding_box': [8, 10, 100, 100],
'confidence': 0.6,
'track_id': 1
},
{
'class_name': "person",
'bounding_box': [10, 9, 120, 110],
'confidence': 0.67,
'track_id': 2
},
]
# no metadata at the beginning
assert len(gst_meta_get(gst_buffer)) == 0
# write metadata
gst_meta_write(gst_buffer, objects)
# read metadata
meta_objects = gst_meta_get(gst_buffer)
assert len(gst_meta_get(gst_buffer)) == len(objects)
for gst_meta_obj, py_obj in zip(meta_objects, objects):
for key, val in py_obj.items():
if isinstance(gst_meta_obj[key], float):
assert math.isclose(gst_meta_obj[key], val, rel_tol=1e-07)
else:
assert gst_meta_obj[key] == val
# remove metadata
gst_meta_remove(gst_buffer)
assert len(gst_meta_get(gst_buffer)) == 0