• DepthAI-v2

  • Flicker in video stream when modifying settings

I am using the script below to apply settings changes to an ispstream from an OAK-1 Max USB camera. I can change any combination of settings except for brightness and the stream behaves accordingly. But when I try to change brightness with any other setting, the resultant video has a strong flicker. This is a video I captured of the phenomenon.

$$
import time
from fractions import Fraction
import depthai as dai
import av

pipeline = dai.Pipeline()
camRgb = pipeline.create(dai.node.ColorCamera)
camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_4_K)
width, height = camRgb.getVideoSize()
camRgb.setFps(10)
imageManip = pipeline.create(dai.node.ImageManip)
frame_size = width * height * 1.5
imageManip.setMaxOutputFrameSize(int(frame_size))
imageManip.initialConfig.setFrameType(dai.ImgFrame.Type.NV12)
camRgb.isp.link(imageManip.inputImage)
videoEnc = pipeline.create(dai.node.VideoEncoder)
videoEnc.setDefaultProfilePreset(10, dai.VideoEncoderProperties.Profile.H264_MAIN)
imageManip.out.link(videoEnc.input)
xoutEnc = pipeline.create(dai.node.XLinkOut)
xoutEnc.setStreamName('video')
videoEnc.bitstream.link(xoutEnc.input)
controlIn = pipeline.create(dai.node.XLinkIn)
controlIn.setStreamName('control')
controlIn.out.link(camRgb.inputControl)
ctrl = dai.CameraControl()
with dai.Device(pipeline, dai.DeviceInfo("184430109118E1F400"), maxUsbSpeed=dai.UsbSpeed.HIGH) as device:
controlQueue = device.getInputQueue('control')
ctrl = dai.CameraControl()
###############

comment either one out to remove flicker

ctrl.setBrightness(-5)
ctrl.setSharpness(4)
################################
controlQueue.send(ctrl)
videoQueue = device.getOutputQueue('video', maxSize=30, blocking=True)
output_container = av.open("video.mp4", 'w')
stream = output_container.add_stream("h264", rate=Fraction(camRgb.getFps()))
stream.time_base = Fraction(1, 1000 * 1000)
start = time.time()
print("Recording...ctrl+c to stop\n")
try:
while True:
data = videoQueue.get().getData()
packet = av.Packet(data)
packet.pts = int((time.time() - start) * 1000 * 1000)
output_container.mux_one(packet)
except KeyboardInterrupt:
pass
output_container.close()
$$

  • jakaskerl replied to this.

  • Hi DanGoodrick
    Sorry, sent you a different script; was testing different configs and I sent you the one I though was working. The issue disappears if you put send under getData.

    data = videoQueue.get().getData()
inputQueue.send(control)

    I don't know why that happens, it doesn't really make sense to me but seems like it stems from the blocking get() call. We will try to fix this in V3.

    Thanks,
    Jaka

      DanGoodrick
      Set it either as initial control before running the pipeline, or keep it in the while True loop after the first image is received using .get().

      Thanks,
      Jaka

        7 days later

        I'm not sure how to set the brightness before running the pipeline. I used the device object to access getInputQueue("control"). This didn't fix the problem. The video still flickers.

        import time
from fractions import Fraction
import depthai as dai
import av

from rgb_camera_control import ids, get_log_level_obj, camera_models


def write_stream(cam_id, settings):
    pipeline = dai.Pipeline()
    camRgb = pipeline.create(dai.node.ColorCamera)
    camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_4_K)
    # camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_4000X3000)
    # camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_5312X6000)
    width, height = camRgb.getVideoSize()
    print(width, height)
    camRgb.setFps(settings["fps"])
    imageManip = pipeline.create(dai.node.ImageManip)
    frame_size = width * height * 3
    imageManip.setMaxOutputFrameSize(int(frame_size))
    imageManip.initialConfig.setFrameType(dai.ImgFrame.Type.NV12)
    camRgb.isp.link(imageManip.inputImage)
    videoEnc = pipeline.create(dai.node.VideoEncoder)
    videoEnc.setDefaultProfilePreset(settings["fps"], dai.VideoEncoderProperties.Profile.H264_MAIN)
    imageManip.out.link(videoEnc.input)
    xoutEnc = pipeline.create(dai.node.XLinkOut)
    xoutEnc.setStreamName('video')
    videoEnc.bitstream.link(xoutEnc.input)
    controlIn = pipeline.create(dai.node.XLinkIn)
    controlIn.setStreamName('control')
    controlIn.out.link(camRgb.inputControl)

    with dai.Device(pipeline, dai.DeviceInfo(ids[cam_id]), maxUsbSpeed=dai.UsbSpeed.HIGH) as device:
        device.setLogLevel(get_log_level_obj(settings["log_level"]))
        device.setLogOutputLevel(get_log_level_obj(settings["log_level"]))        
        controlQueue = device.getInputQueue('control')  # For sending control commands
        # apply_settings(controlQueue, settings)
        ctrl = dai.CameraControl()
        ctrl.setBrightness(-5)
        ctrl.setSharpness(2)
        controlQueue.send(ctrl)
        videoQueue = device.getOutputQueue('video', maxSize=30, blocking=True)
        output_container = av.open("video.mp4", 'w')
        stream = output_container.add_stream("h264", rate=Fraction(camRgb.getFps()))
        stream.time_base = Fraction(1, 1000 * 1000)
        start = time.time()
        print("Recording...ctrl+c to stop\n")
        try:
            while True:
                data = videoQueue.get().getData()
                ctrl.setBrightness(-5)
                controlQueue.send(ctrl)
                packet = av.Packet(data)
                packet.pts = int((time.time() - start) * 1000 * 1000)
                output_container.mux_one(packet)
        except KeyboardInterrupt:
            pass
        output_container.close()


if __name__ == "__main__":
    import json
    devices = dai.Device.getAllAvailableDevices()
    print(f"Found {len(devices)} devices")
    for i, device_info in enumerate(devices):
        ids[i+1] = device_info.getMxId()
    for id in ids:
        print(camera_models[ids[id]], ": ", ids[id])
    with open('settings.json', 'r') as f:
        settings = json.load(f)
    write_stream(2, settings)

          DanGoodrick

          camRgb.initialControl.(some control)

          Thanks,
          Jaka

            thanks for that tip, but setting the control before the pipeline didn't fix the problem.

            camRgb.initialControl.setBrightness(-5)

            camRgb.initialControl.setSharpness(2)

            yes I did. Is this not happening on your end? This is my script:

            import time
from fractions import Fraction
import depthai as dai
import av

fps = 30
pipeline = dai.Pipeline()
camRgb = pipeline.create(dai.node.ColorCamera)
camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_4_K)
width, height = camRgb.getVideoSize()
print(width, height)
camRgb.setFps(fps)
imageManip = pipeline.create(dai.node.ImageManip)
frame_size = width * height * 3
imageManip.setMaxOutputFrameSize(int(frame_size))
imageManip.initialConfig.setFrameType(dai.ImgFrame.Type.NV12)
camRgb.isp.link(imageManip.inputImage)

camRgb.initialControl.setBrightness(-5)
camRgb.initialControl.setSharpness(2)

videoEnc = pipeline.create(dai.node.VideoEncoder)
videoEnc.setDefaultProfilePreset(fps, dai.VideoEncoderProperties.Profile.H264_MAIN)
imageManip.out.link(videoEnc.input)
xoutEnc = pipeline.create(dai.node.XLinkOut)
xoutEnc.setStreamName('video')
videoEnc.bitstream.link(xoutEnc.input)
controlIn = pipeline.create(dai.node.XLinkIn)
controlIn.setStreamName('control')
controlIn.out.link(camRgb.inputControl)

with dai.Device(pipeline, dai.DeviceInfo("184430109118E1F400"), maxUsbSpeed=dai.UsbSpeed.HIGH) as device:
    # apply_settings(controlQueue, settings)
    videoQueue = device.getOutputQueue('video', maxSize=30, blocking=True)
    output_container = av.open("video.mp4", 'w')
    stream = output_container.add_stream("h264", rate=Fraction(camRgb.getFps()))
    stream.time_base = Fraction(1, 1000 * 1000)
    start = time.time()
    print("Recording...ctrl+c to stop\n")
    try:
        while True:
            data = videoQueue.get().getData()
            packet = av.Packet(data)
            packet.pts = int((time.time() - start) * 1000 * 1000)
            output_container.mux_one(packet)
    except KeyboardInterrupt:
        pass
    output_container.close()

              Hi DanGoodrick
              It looks to be a FW problem. The only way I found it works is if send the controls each iteration:

              with dai.Device(pipeline, dai.DeviceInfo(), maxUsbSpeed=dai.UsbSpeed.SUPER_PLUS) as device:
    # apply_settings(controlQueue, settings)
    inputQueue = device.getInputQueue('control')

    control = dai.CameraControl()
    control.setSharpness(-10)
    control.setBrightness(-2)

    videoQueue = device.getOutputQueue('video', maxSize=30, blocking=True)
    output_container = av.open("video.mp4", 'w')
    stream = output_container.add_stream("h264", rate=Fraction(camRgb.getFps()))
    stream.time_base = Fraction(1, 1000 * 1000)
    start = time.time()
    print("Recording...ctrl+c to stop\n")
    try:
        while True:
            inputQueue.send(control)
            data = videoQueue.get().getData()
            packet = av.Packet(data)
            packet.pts = int((time.time() - start) * 1000 * 1000)
            output_container.mux_one(packet)
    except KeyboardInterrupt:
        pass
    output_container.close()

              Thanks,
              Jaka

                I installed the dev branch and but get the same flickery result.

                (venv) bwadmin@proactive-sandy:~/luxonis$ pip show depthai
Name: depthai
Version: 2.28.0.0.dev0+d3b92a92782894b33015d97d435451ff35532d06

                  Hi DanGoodrick
                  Sorry, sent you a different script; was testing different configs and I sent you the one I though was working. The issue disappears if you put send under getData.

                  data = videoQueue.get().getData()
inputQueue.send(control)

                  I don't know why that happens, it doesn't really make sense to me but seems like it stems from the blocking get() call. We will try to fix this in V3.

                  Thanks,
                  Jaka