• Hardware Platform (Jetson / GPU) GPU
• DeepStream Version 6.0.1
• Issue Type( questions, new requirements, bugs) Question
I’m trying to translate deepstream_gst_metadata.c into Python code so that I can attach custom metadata in an appsrc element and extract it again after it has been passed through nvinfer. I found this related post which unfortunately doesn’t provide much help other than it should be possible in principle.
I don’t know how I can call pyds.gst_buffer_add_nvds_meta. How do I pass in Python functions for copying and releasing the metadata? My code below (excerpt) fails when pyds.gst_buffer_add_nvds_meta gets called due to incompatible function arguments.
I couldn’t find any example calling pyds.gst_buffer_add_nvds_meta from Python online. The example deepstream_test_4.py doesn’t help unfortunately because it’s not showing how you can add metadata before an nvstreammux element.
Could someone please help me with this? I would be grateful for any pointers.
VIDEOSRC_GST_META = pyds.nvds_get_user_meta_type("ORG.VIDEOSRC.GST_USER_META")
def videosrc_meta_copy(data: ctypes.pointer, user_data: ctypes.pointer):
pass
def videosrc_meta_release(data: ctypes.pointer, user_data: ctypes.pointer):
pass
def videosrc_gst_to_nvds_meta_transform(data: ctypes.pointer, user_data: ctypes.pointer):
pass
def videosrc_gst_to_nvds_meta_release(data: ctypes.pointer, user_data: ctypes.pointer):
pass
class VideoSrc(GstApp.AppSrc):
def __init__(self, url, *args, **kwargs):
logger.info("Creating VideoSrc element")
super().__init__(*args, **kwargs)
self._url = url
self._buffer_emitted = False
def do_need_data(self, need):
if self._buffer_emitted:
self.end_of_stream()
response = requests.get(self._url, allow_redirects=True)
buffer = Gst.Buffer.new_wrapped(response.content)
videosrc_meta = GstBufferInfo()
videosrc_meta.description = self._url.encode("utf-8")
meta = pyds.gst_buffer_add_nvds_meta(
buffer, videosrc_meta, None, videosrc_meta_copy, videosrc_meta_release
)
meta.meta_type = VIDEOSRC_GST_META
meta.gst_to_nvds_meta_transform_func = videosrc_gst_to_nvds_meta_transform
meta.gst_to_nvds_meta_release_func = videosrc_gst_to_nvds_meta_release
self.push_buffer(buffer)
self._buffer_emitted = True