Happy New Year. I’m learning the python API - I need to take a frame from the camera and access the frame to work with it via cv2 or pyds. I wrote a simple example but I keep getting the error “Input buffer number of surfaces (0) must be equal to mux->num_surfaces_per_frame (1)”.
#!/usr/bin/env python
# gst-launch-1.0 nvarguscamerasrc sensor_id=0 ! \
# 'video/x-raw(memory:NVMM),width=3264, height=2464, framerate=21/1, format=NV12' ! \
# nvvidconv flip-method=0 ! 'video/x-raw, width=3264, height=2464' ! \
# nvvidconv ! nvegltransform ! nveglglessink
import sys, gi
sys.path.append("../")
gi.require_version('Gst', '1.0')
from gi.repository import GObject, Gst
from common.bus_call import bus_call
from common.create_element_or_error import create_element_or_error
from common.FPS import GETFPS
import pyds
print(1)
import pyds
def osd_sink_pad_buffer_probe(pad,info,u_data):
frame_number=0
#Intiallizing object counter with 0.
gst_buffer = info.get_buffer()
if not gst_buffer:
print("Unable to get GstBuffer ")
return
# Retrieve batch metadata from the gst_buffer
# Note that pyds.gst_buffer_get_nvds_batch_meta() expects the
# C address of gst_buffer as input, which is obtained with hash(gst_buffer)
batch_meta = pyds.gst_buffer_get_nvds_batch_meta(hash(gst_buffer))
l_frame = batch_meta.frame_meta_list
while l_frame is not None:
try:
# Note that l_frame.data needs a cast to pyds.NvDsFrameMeta
# The casting is done by pyds.NvDsFrameMeta.cast()
# The casting also keeps ownership of the underlying memory
# in the C code, so the Python garbage collector will leave
# it alone.
frame_meta = pyds.NvDsFrameMeta.cast(l_frame.data)
except StopIteration:
break
frame_number=frame_meta.frame_num
# Acquiring a display meta object. The memory ownership remains in
# the C code so downstream plugins can still access it. Otherwise
# the garbage collector will claim it when this probe function exits.
display_meta=pyds.nvds_acquire_display_meta_from_pool(batch_meta)
display_meta.num_labels = 1
py_nvosd_text_params = display_meta.text_params[0]
# Setting display text to be shown on screen
# Note that the pyds module allocates a buffer for the string, and the
# memory will not be claimed by the garbage collector.
# Reading the display_text field here will return the C address of the
# allocated string. Use pyds.get_string() to get the string content.
py_nvosd_text_params.display_text = "Frame Number={}".format(frame_number)
# Now set the offsets where the string should appear
py_nvosd_text_params.x_offset = 10
py_nvosd_text_params.y_offset = 12
# Font , font-color and font-size
py_nvosd_text_params.font_params.font_name = "Serif"
py_nvosd_text_params.font_params.font_size = 10
# set(red, green, blue, alpha); set to White
py_nvosd_text_params.font_params.font_color.set(1.0, 1.0, 1.0, 1.0)
# Text background color
py_nvosd_text_params.set_bg_clr = 1
# set(red, green, blue, alpha); set to Black
py_nvosd_text_params.text_bg_clr.set(0.0, 0.0, 0.0, 1.0)
# Using pyds.get_string() to get display_text as string
print(pyds.get_string(py_nvosd_text_params.display_text))
pyds.nvds_add_display_meta_to_frame(frame_meta, display_meta)
try:
l_frame=l_frame.next
except StopIteration:
break
return Gst.PadProbeReturn.OK
def main():
# Standard GStreamer initialization
GObject.threads_init()
Gst.init(None)
# Create Pipeline Element
print("Creating Pipeline")
pipeline = Gst.Pipeline()
############################################
nvosd = Gst.ElementFactory.make("nvdsosd", "onscreendisplay")
if not nvosd:
sys.stderr.write(" Unable to create nvosd \n")
# Use convertor to convert from NV12 to RGBA as required by nvosd
nvvideoconvert = Gst.ElementFactory.make("nvvideoconvert", "convertor")
if not nvvideoconvert:
sys.stderr.write(" Unable to create nvvidconv \n")
nvstreammux = create_element_or_error("nvstreammux", "stream-muxer")
nvstreammux.set_property('width', 3264)
nvstreammux.set_property('height', 1848)
nvstreammux.set_property('batched-push-timeout', 4000000)
nvstreammux.set_property('batch-size', 1)
nvstreammux.set_property('sync-inputs', 1)
nvstreammux.set_property('num-surfaces-per-frame', 1)
############################################
# Create Elements
source = create_element_or_error("nvarguscamerasrc", "camera-source")
caps = create_element_or_error("capsfilter", "source-caps")
caps.set_property("caps", Gst.Caps.from_string("sensor_id=0"))
convertor = create_element_or_error('nvvidconv', 'converter')
caps = create_element_or_error("capsfilter", "convertor-caps")
caps.set_property("caps", Gst.Caps.from_string("video/x-raw(memory:NVMM), width=(int)3264, height=(int)1848, framerate=28/1, format=(string)NV12"))
nvvidconvsrc = Gst.ElementFactory.make("nvvideoconvert", "convertor_src2")
if not nvvidconvsrc:
sys.stderr.write(" Unable to create Nvvideoconvert \n")
convertors = create_element_or_error('nvvideoconvert', 'converters')
capsConverter = create_element_or_error("capsfilter", "convertors-capsConverter")
capsConverter.set_property("caps", Gst.Caps.from_string("video/x-raw(memory:NVMM), width=(int)3264, height=(int)1848, framerate=28/1, format=(string)RGBA"))
videocrops = create_element_or_error('videocrop', 'videocrops')
videocrops.set_property('top', 100)
videocrops.set_property('bottom', 100)
videocrops.set_property('left', 50)
videocrops.set_property('right', 150)
transform = create_element_or_error("nvegltransform", "nvegl-transform")
sink = create_element_or_error("nveglglessink", "egl-overlay")
sink.set_property('sync', False)
# Set Element Properties
# source.set_property('sensor-id', 0)
# Add Elemements to Pipielin
print("Adding elements to Pipeline")
pipeline.add(source)
pipeline.add(caps)
pipeline.add(convertor)
pipeline.add(capsConverter)
pipeline.add(convertors)
pipeline.add(nvvidconvsrc)
pipeline.add(videocrops)
pipeline.add(transform)
pipeline.add(nvstreammux)
pipeline.add(nvvideoconvert)
pipeline.add(nvosd)
pipeline.add(sink)
# Link the elements together:
print("Linking elements in the Pipeline")
source.link(caps)
caps.link(convertor)
convertor.link(capsConverter)
capsConverter.link(convertors)
#convertors.link(videocrop)
convertors.link(nvvidconvsrc)
# sinkpad = nvstreammux.get_request_pad("sink_0")
# if not sinkpad:
# sys.stderr.write(" Unable to get the sink pad of streammux \n")
# srcpad = nvvidconvsrc.get_static_pad("src")
# if not srcpad:
# sys.stderr.write(" Unable to get source pad of caps_vidconvsrc \n")
# srcpad.link(sinkpad)
# nvstreammux.link(nvosd)
nvvidconvsrc.link(nvosd)
#nvvideoconvert.link(transform)
nvosd.link(transform)
transform.link(sink)
# Create an event loop and feed gstreamer bus mesages to it
loop = GObject.MainLoop()
bus = pipeline.get_bus()
bus.add_signal_watch()
bus.connect ("message", bus_call, loop)
osdsinkpad = nvosd.get_static_pad("sink")
if not osdsinkpad:
sys.stderr.write(" Unable to get sink pad of nvosd \n")
#osdsinkpad.add_probe(Gst.PadProbeType.BUFFER, osd_sink_pad_buffer_probe, 0)
# Start play back and listen to events
print("Starting pipeline")
pipeline.set_state(Gst.State.PLAYING)
try:
loop.run()
except:
pass
# Cleanup
pipeline.set_state(Gst.State.NULL)
if __name__ == "__main__":
sys.exit(main())
**• Hardware Platform Jetson **
• DeepStream Version 6.0
• JetPack Version 4.6
• Issue Type questions