RTSP Stream through GStreamer + STDOUT on Jetson Xavier AGX

play_rtsp_nvdec_jetson_agx.py

#!/usr/bin/python
"""
RTSP Stream Reader Class for Jetson Xavier AGX

Requirement : Jetpack, OpenCV 4.4 with CUDA-Enabled

Tested RTSP Stream from
- HIKVISION DS-2CD2021-IAX [1280*720 Main-Stream Selected]

CPU Used : 20-35% on Jetson AGX
GPU Used : 0-30% on Jetson AGX

# TEST COMMAND
gst-launch-1.0 rtspsrc \
location=rtsp://path_to_rtsp_stream latency=200 ! \
rtph264depay ! h264parse ! \
nvv4l2decoder drop-frame-interval=2 ! \
nvvideoconvert ! \
video/x-raw,width=1280,height=720,format=I420 ! \
queue ! nveglglessink window-x=0 window-y=0 window-width=1280 window-height=720

# References
CasiaFan/deepstream_gstreamer_decoding_with_python.py
- https://medium.com/@fanzongshaoxing/use-nvidia-deepstream-to-accelerate-h-264-video-stream-decoding-8f0fec764778
- https://gist.github.com/CasiaFan/684ec8c36624fb5ff61360c71ee9e4ec
I420 Convertsion
- https://github.com/ArduCAM/MIPI_Camera/blob/master/RPI/python/capture2opencv.py

Author : C3MX <tutorgaming@gmail.com>
Date : 6-May-2021
"""

############################################
# IMPORT
############################################
import subprocess
import numpy as np
import cv2

############################################
# GLOBAL PARAM
############################################
RTSP_PATH = "rtsp://path_to_rtsp_stream"
BUFFSIZE = 10
GSTREAMER_COMMAND = [
    "gst-launch-1.0",
    "rtspsrc" ,
    "location={}".format(RTSP_PATH), "latency=200", "!",
    "queue", "!",
    "rtph264depay", "!",
    "h264parse", "!",
    "nvv4l2decoder", "drop-frame-interval=2", "!",
    "nvvideoconvert", "!",
    "video/x-raw,format=(string)I420", "!",
    "queue", "!",
    "filesink", "location=/dev/stdout"
]

############################################
# CLASS
############################################
class StreamReader(object):
    """
    Class to Create RTSP Stream
    """
    def __init__(self):
        # Subprocess to use gstreamer PIPELINE
        self.gst_stream = subprocess.Popen(
            GSTREAMER_COMMAND,
            stdout=subprocess.PIPE,
            bufsize=BUFFSIZE,
        )
        # Video Config (use I420 Format)
        self.width = 1280
        self.height = 720
        self.receive_height = (self.height * 3) //2
        self.receive_width = self.width

        # Prepare the Stream
        # Removing Log Text from stdout
        LOG_LENGTH = 497
        RTSP_SRC_LENGTH = len(RTSP_PATH)
        self.gst_stream.stdout.read(LOG_LENGTH+RTSP_SRC_LENGTH)

        # Start the Stream process
        print("Init Complete - Begin Process !")
        self.receive_rtsp_loop()

    def receive_rtsp_loop(self):
        """
        Receive RTSP Stream directly from STDOUT
        """
        while True:
            # Read Stream from STDOUT
            image = self.gst_stream.stdout.read(int(self.receive_height*self.receive_width))
            image = np.fromstring(image, dtype=np.uint8).reshape((self.receive_height, self.receive_width))
            image = cv2.cvtColor(image, cv2.COLOR_YUV2BGR_I420)
            # Do Processing Here
            self.process(image)
            # Visualizing
            cv2.imshow("image", image)
            # End Condition
            if cv2.waitKey(5) & 0xFF == ord('q'):
                break
        # Close the Stream Sub-process
        self.gst_stream.terminate()
        cv2.destroyAllWindows()

    def process(self, input_image):
        """
        Do Some Image Processing Here :)
        """
        pass

############################################
# MAIN
############################################
STREAM = StreamReader()

play_rtsp_nvdec_videocapture_appsink.py

#!/usr/bin/python
"""
[OPENCV-VideoCapture-Based-GST-APPSINK]
RTSP Stream Reader Class for Jetson Xavier AGX
Requirement : Jetpack, OpenCV 4.4 with CUDA-Enabled

Tested RTSP Stream from
- HIKVISION DS-2CD2021-IAX [1280*720 Main-Stream Selected]

CPU Used : 20-35% on Jetson AGX with many thread spawned
GPU Used : 0-30% on Jetson AGX

Author : C3MX <tutorgaming@gmail.com>
Date : 6-May-2021
"""
import numpy as np
import cv2

RTSP_PATH = "rtsp://path_to_rtsp"
GSTREAMER_COMMAND = (
    "rtspsrc location={}".format(RTSP_PATH)+ " " + "latency=200 !" +
    "queue !"+ " " + "rtph264depay !" + " " +
    "h264parse !"+ " " +
    "nvv4l2decoder"+ " " + "drop-frame-interval=2"+ " " + "!"+ " " +
    "nvvideoconvert !" + " " +
    "video/x-raw,format=(string)I420"+ " " + "!"+ " " +
    "queue"+ " " + "!"+ " " +
    "appsink"
)
cap = cv2.VideoCapture(GSTREAMER_COMMAND, cv2.CAP_GSTREAMER)

while(True):
    # Capture frame-by-frame
    ret, frame = cap.read()
    # Our operations on the frame come here
    image = cv2.cvtColor(frame, cv2.COLOR_YUV2BGR_I420)
    # Display the resulting frame
    cv2.imshow('frame',image)
    if cv2.waitKey(10) & 0xFF == ord('q'):
        break

# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()

Thanks a lot!