Jetson Nano(4GB), Xavier NX Developer Kitを使って4カメラでDeepStreamで遊ぶ


標準のJetson Nano(4GB) Developer Kitか、Jetson Xavier NX Developer Kitで4カメラから映像を取りこみ、4ラインでDeepStreamで処理するためのまとめ。

![IMG_2193.JPG](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/63450/251a62e4-3414-093e-67ac-885b5283785c.jpeg)

## 対応機種

- Jetson Nano (4GB)
- Jetson Xavier NX


## Imageの作成
 
JetPack 4.5.1をSDカードに焼き込みます
https://developer.nvidia.com/jetpack-sdk-45-archive

## Dockerの展開

[NVIDIA L4T ML](https://ngc.nvidia.com/catalog/containers/nvidia:l4t-ml)を起動します。

```
sudo docker run \
    --runtime=nvidia \
    -it \
    -v /tmp/.X11-unix:/tmp/.X11-unix \
    -v $HOME/data:/home/jetson/data \
    -e DISPLAY \
    -e QT_GRAPHICSSYSTEM=native \
    -e QT_X11_NO_MITSHM=1 \
    -v /var/run/dbus/system_bus_socket:/var/run/dbus/system_bus_socket:ro \
    -v /etc/localtime:/localtime:ro \
    -v /tmp/argus_socket:/tmp/argus_socket \
    -v /dev/:/dev/ \
    --privileged \
    --network=host \
nvcr.io/nvidia/deepstream-l4t:5.0.1-20.09-samples
```

## パッケージのアップデートと必要なパッケージのインストール

```
apt update
apt install libgstrtspserver-1.0-dev v4l-utils  vim python3-pip python3-gi python3-dev python3-gst-1.0 -y
```

## DeepStream Python Bindingをgit Clone


```
cd /opt/nvidia/deepstream/deepstream-5.0/sources
git clone https://github.com/NVIDIA-AI-IOT/deepstream_python_apps
cd deepstream_python_apps/apps/deepstream-test3
```

## サンプルの実行

Dockerではなく大本のUbuntuで、xhost +を実行し、画面へのアクセスを許可する。

```
xhost +
```

Dockerに戻り、画面の転送先を設定する

```
export DISPLAY=:1
```

```
python3 deepstream_test_3.py file:///opt/nvidia/deepstream/deepstream-5.0/samples/streams/sample_1080p_h264.mp4
```

![deepstream001.png](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/63450/0ee7ac5c-2ec5-57b9-ef6f-4e7711e0d1d5.png)


> Unable to create NvStreamMux

のエラーが発生する場合は、

キャッシュを消す

```
rm ~/.cache/gstreamer-1.0/registry*
```

参照 : [Unable to create NvStreamMux ,pgie, nvvidconv, nvosd]
(https://forums.developer.nvidia.com/t/unable-to-create-nvstreammux-pgie-nvvidconv-nvosd/170649)

## 4カメラ装着

CSIは2ポート、USBは3カメラ以上つなぐとうまくいかないので、CSI x 2 , USB x 2で4カメラ構成にする。

```
v4l2-ctl --list-device 

vi-output, imx219 9-0010 (platform:15c10000.vi:0):
	/dev/video0

vi-output, imx219 10-0010 (platform:15c10000.vi:2):
	/dev/video1

HD USB Camera (usb-3610000.xhci-2.1):
	/dev/video3

HD USB Camera (usb-3610000.xhci-2.3):
	/dev/video2
```

/dev/video3(USBカメラ)のプロファイルは以下の通り。ここは各自使用するカメラのコーデック、解像度、FPSをメモっておく。

```
v4l2-ctl -d /dev/video3 --list-formats-ext

ioctl: VIDIOC_ENUM_FMT
	Index       : 0
	Type        : Video Capture
	Pixel Format: 'MJPG' (compressed)
	Name        : Motion-JPEG
		Size: Discrete 640x360
			Interval: Discrete 0.004s (260.004 fps)
		Size: Discrete 1280x720
			Interval: Discrete 0.008s (120.000 fps)
		Size: Discrete 1920x1080
			Interval: Discrete 0.017s (60.000 fps)
```

2つのUSBカメラは、解像度とFPSとコーデックを装着するUSBカメラのスペックにあわせて、SampleプログラムのGStreamer周りを書き直す。

## ソース


deepstream_test_3.pyを下記のコードに書き直す

```
#!/usr/bin/env python3
################################################################################
# Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved.
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.
################################################################################

import sys
sys.path.append('../')
import gi
import configparser
gi.require_version('Gst', '1.0')
from gi.repository import GObject, Gst
from gi.repository import GLib
from ctypes import *
import time
import sys
import math
import platform
from common.is_aarch_64 import is_aarch64
from common.bus_call import bus_call
from common.FPS import GETFPS

import pyds

fps_streams={}

MAX_DISPLAY_LEN=64
PGIE_CLASS_ID_VEHICLE = 0
PGIE_CLASS_ID_BICYCLE = 1
PGIE_CLASS_ID_PERSON = 2
PGIE_CLASS_ID_ROADSIGN = 3
MUXER_OUTPUT_WIDTH=1280
MUXER_OUTPUT_HEIGHT=720
MUXER_BATCH_TIMEOUT_USEC=4000000
TILED_OUTPUT_WIDTH=1280 * 2
TILED_OUTPUT_HEIGHT=720 * 2
GST_CAPS_FEATURES_NVMM="memory:NVMM"
OSD_PROCESS_MODE= 0
OSD_DISPLAY_TEXT= 0
pgie_classes_str= ["Vehicle", "TwoWheeler", "Person","RoadSign"]

# tiler_sink_pad_buffer_probe  will extract metadata received on OSD sink pad
# and update params for drawing rectangle, object information etc.
def tiler_src_pad_buffer_probe(pad,info,u_data):
    frame_number=0
    num_rects=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

        '''
        print("Frame Number is ", frame_meta.frame_num)
        print("Source id is ", frame_meta.source_id)
        print("Batch id is ", frame_meta.batch_id)
        print("Source Frame Width ", frame_meta.source_frame_width)
        print("Source Frame Height ", frame_meta.source_frame_height)
        print("Num object meta ", frame_meta.num_obj_meta)
        '''
        frame_number=frame_meta.frame_num
        l_obj=frame_meta.obj_meta_list
        num_rects = frame_meta.num_obj_meta
        obj_counter = {
        PGIE_CLASS_ID_VEHICLE:0,
        PGIE_CLASS_ID_PERSON:0,
        PGIE_CLASS_ID_BICYCLE:0,
        PGIE_CLASS_ID_ROADSIGN:0
        }
        while l_obj is not None:
            try: 
                # Casting l_obj.data to pyds.NvDsObjectMeta
                obj_meta=pyds.NvDsObjectMeta.cast(l_obj.data)
            except StopIteration:
                break
            obj_counter[obj_meta.class_id] += 1
            try: 
                l_obj=l_obj.next
            except StopIteration:
                break
        """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]
        py_nvosd_text_params.display_text = "Frame Number={} Number of Objects={} Vehicle_count={} Person_count={}".format(frame_number, num_rects, vehicle_count, person)
        py_nvosd_text_params.x_offset = 10;
        py_nvosd_text_params.y_offset = 12;
        py_nvosd_text_params.font_params.font_name = "Serif"
        py_nvosd_text_params.font_params.font_size = 10
        py_nvosd_text_params.font_params.font_color.red = 1.0
        py_nvosd_text_params.font_params.font_color.green = 1.0
        py_nvosd_text_params.font_params.font_color.blue = 1.0
        py_nvosd_text_params.font_params.font_color.alpha = 1.0
        py_nvosd_text_params.set_bg_clr = 1
        py_nvosd_text_params.text_bg_clr.red = 0.0
        py_nvosd_text_params.text_bg_clr.green = 0.0
        py_nvosd_text_params.text_bg_clr.blue = 0.0
        py_nvosd_text_params.text_bg_clr.alpha = 1.0
        #print("Frame Number=", frame_number, "Number of Objects=",num_rects,"Vehicle_count=",vehicle_count,"Person_count=",person)
        pyds.nvds_add_display_meta_to_frame(frame_meta, display_meta)"""
        print("Frame Number=", frame_number, "Number of Objects=",num_rects,"Vehicle_count=",obj_counter[PGIE_CLASS_ID_VEHICLE],"Person_count=",obj_counter[PGIE_CLASS_ID_PERSON])

        # Get frame rate through this probe
        fps_streams["stream{0}".format(frame_meta.pad_index)].get_fps()
        try:
            l_frame=l_frame.next
        except StopIteration:
            break

    return Gst.PadProbeReturn.OK



def cb_newpad(decodebin, decoder_src_pad,data):
    print("In cb_newpad\n")
    caps=decoder_src_pad.get_current_caps()
    gststruct=caps.get_structure(0)
    gstname=gststruct.get_name()
    source_bin=data
    features=caps.get_features(0)

    # Need to check if the pad created by the decodebin is for video and not
    # audio.
    print("gstname=",gstname)
    if(gstname.find("video")!=-1):
        # Link the decodebin pad only if decodebin has picked nvidia
        # decoder plugin nvdec_*. We do this by checking if the pad caps contain
        # NVMM memory features.
        print("features=",features)
        if features.contains("memory:NVMM"):
            # Get the source bin ghost pad
            bin_ghost_pad=source_bin.get_static_pad("src")
            if not bin_ghost_pad.set_target(decoder_src_pad):
                sys.stderr.write("Failed to link decoder src pad to source bin ghost pad\n")
        else:
            sys.stderr.write(" Error: Decodebin did not pick nvidia decoder plugin.\n")

def decodebin_child_added(child_proxy,Object,name,user_data):
    print("Decodebin child added:", name, "\n")
    if(name.find("decodebin") != -1):
        Object.connect("child-added",decodebin_child_added,user_data)   
    if(is_aarch64() and name.find("nvv4l2decoder") != -1):
        print("Seting bufapi_version\n")
        Object.set_property("bufapi-version",True)

def create_source_bin(index,uri):
    print("Creating source bin")
    if uri == "/dev/video0" or uri == "/dev/video1":
        cam_type = 'CSI'
    else:
        cam_type = 'USB'
    # we need a jpegparser
    print("Creating JPEGParser \n")
    jpegparser = Gst.ElementFactory.make("jpegparse", "jpeg-parser")
    if not jpegparser:
        sys.stderr.write(" Unable to create jpeg parser \n")

    # Use nvjpegdec for hardware accelerated decode on GPU
    print("Creating Decoder \n")
    decoder = Gst.ElementFactory.make("jpegdec", "jpeg-decoder")
    if not decoder:
        sys.stderr.write(" Unable to create NvJPEG Decoder \n")

    if cam_type == 'CSI':
        nvv4l2decoder = Gst.ElementFactory.make("nvv4l2decoder", "nvv4l2")

    # Create a source GstBin to abstract this bin's content from the rest of the
    # pipeline
    bin_name="source-bin-%02d" %index
    print(bin_name)
    nbin=Gst.Bin.new(bin_name)
    if not nbin:
        sys.stderr.write(" Unable to create source bin \n")

    # Source element for reading from the uri.
    # We will use decodebin and let it figure out the container format of the
    # stream and the codec and plug the appropriate demux and decode plugins.

    # uri_decode_bin=Gst.ElementFactory.make("uridecodebin", "uri-decode-bin")
    # if not uri_decode_bin:
    #     sys.stderr.write(" Unable to create uri decode bin \n")
    # # We set the input uri to the source element
    # uri_decode_bin.set_property("uri",uri)
    print("Creating Source \n ")
    if cam_type == 'CSI':
        source = Gst.ElementFactory.make("nvarguscamerasrc", "src-elem")
    elif cam_type == 'USB':
        source = Gst.ElementFactory.make("v4l2src", "usb-cam-source")

    if not source:
        sys.stderr.write(" Unable to create source \n")

    if cam_type == 'USB':
        caps_v4l2src = Gst.ElementFactory.make("capsfilter", "v4l2src_caps")
        if not caps_v4l2src:
            sys.stderr.write("Could not create caps_v4l2src")
    
    # videoconvert to make sure a superset of raw formats are supported
    vidconvsrc = Gst.ElementFactory.make("videoconvert", "convertor_src1")
    if not vidconvsrc:
        sys.stderr.write(" Unable to create videoconvert \n")
    
    if cam_type == 'CSI':
        # Converter to scale the image
        nvvidconv_src = Gst.ElementFactory.make("nvvideoconvert", "convertor_src")
        if not nvvidconv_src:
            sys.stderr.write(" Unable to create nvvidconv_src \n")

    # nvvideoconvert to convert incoming raw buffers to NVMM Mem (NvBufSurface API)
    nvvidconvsrc = Gst.ElementFactory.make("nvvideoconvert", "convertor_src2")
    if not nvvidconvsrc:
        sys.stderr.write(" Unable to create Nvvideoconvert \n")
    
    caps_vidconvsrc = Gst.ElementFactory.make("capsfilter", "nvmm_caps")
    if not caps_vidconvsrc:
        sys.stderr.write(" Unable to create capsfilter \n")

    if cam_type == 'CSI':
        # Caps for NVMM and resolution scaling
        caps_nvvidconv_src = Gst.ElementFactory.make("capsfilter", "nvmm_caps2")
        if not caps_nvvidconv_src:
            sys.stderr.write(" Unable to create capsfilter \n")


    if cam_type == 'CSI':
        caps_nvvidconv_src.set_property('caps', Gst.Caps.from_string('video/x-raw(memory:NVMM), width=1280, height=720, framerate=60/1'))
        caps_vidconvsrc.set_property('caps', Gst.Caps.from_string("video/x-raw(memory:NVMM)"))
        print("_________________________________")
        print(f"{cam_type} Camera")
        source.set_property('bufapi-version', True)
        if uri == "/dev/video0":
            source.set_property('sensor-id', 1)
        if uri == "/dev/video1":
            source.set_property('sensor-id', 0)
        nbin.add(source)
        nbin.add(nvvidconv_src)
        nbin.add(caps_nvvidconv_src)
        nbin.add(vidconvsrc)
        nbin.add(nvvidconvsrc)
        nbin.add(caps_vidconvsrc)

        source.link(nvvidconv_src)
        nvvidconv_src.link(caps_nvvidconv_src)
        caps_nvvidconv_src.link(vidconvsrc)
        vidconvsrc.link(nvvidconvsrc)
        nvvidconvsrc.link(caps_vidconvsrc)
    elif cam_type == 'USB':
        caps_v4l2src.set_property('caps', Gst.Caps.from_string("image/jpeg, width=1280, height=720,framerate=120/1"))
        caps_vidconvsrc.set_property('caps', Gst.Caps.from_string("video/x-raw(memory:NVMM)"))
        print("_________________________________")
        print(f"{cam_type} Camera")
        source.set_property('device', uri)
        nbin.add(source)
        nbin.add(caps_v4l2src)
        nbin.add(jpegparser)
        nbin.add(decoder)
        nbin.add(vidconvsrc)
        nbin.add(nvvidconvsrc)
        nbin.add(caps_vidconvsrc)
        source.link(caps_v4l2src)
        caps_v4l2src.link(jpegparser)
        jpegparser.link(decoder)
        decoder.link(vidconvsrc)
        vidconvsrc.link(nvvidconvsrc)
        nvvidconvsrc.link(caps_vidconvsrc)

    # Connect to the "pad-added" signal of the decodebin which generates a
    # callback once a new pad for raw data has beed created by the decodebin
   
    # uri_decode_bin.connect("pad-added",cb_newpad,nbin)
    # uri_decode_bin.connect("child-added",decodebin_child_added,nbin)

    # We need to create a ghost pad for the source bin which will act as a proxy
    # for the video decoder src pad. The ghost pad will not have a target right
    # now. Once the decode bin creates the video decoder and generates the
    # cb_newpad callback, we will set the ghost pad target to the video decoder
    # src pad.

    # Gst.Bin.add(nbin,uri_decode_bin)

    srcpad = caps_vidconvsrc.get_static_pad("src")

    bin_pad=nbin.add_pad(Gst.GhostPad.new("src",srcpad))
    
    if not bin_pad:
        sys.stderr.write(" Failed to add ghost pad in source bin \n")
        return None
    return nbin


#For reference here is the code for setting up the pipelines and the linking for the app:

def main(args):
    # Check input arguments
    if len(args) < 2:
        sys.stderr.write("usage: %s <uri1> [uri2] ... [uriN]\n" % args[0])
        sys.exit(1)

    for i in range(0,len(args)-1):
        fps_streams["stream{0}".format(i)]=GETFPS(i)
        print(GETFPS(i))
    number_sources=len(args)-1

    # Standard GStreamer initialization
    GObject.threads_init()
    Gst.init(None)
    

    # Create gstreamer elements */
    # Create Pipeline element that will form a connection of other elements
    print("Creating Pipeline \n ")
    pipeline = Gst.Pipeline()
    is_live = False

    if not pipeline:
        sys.stderr.write(" Unable to create Pipeline \n")
    print("Creating streamux \n ")

    # Create nvstreammux instance to form batches from one or more sources.
    streammux = Gst.ElementFactory.make("nvstreammux", "Stream-muxer")
    if not streammux:
        sys.stderr.write(" Unable to create NvStreamMux \n")

    pipeline.add(streammux)
    for i in range(number_sources):
        print("===========================  Creating source_bin ",i," \n ")
        uri=args[i+1]
        # if uri_name.find("rtsp://") == 0 :
        is_live = True
        source_bin=create_source_bin(i, uri)
        if not source_bin:
            sys.stderr.write("Unable to create source bin \n")
        pipeline.add(source_bin)
        padname="sink_%u" %i
        sinkpad= streammux.get_request_pad(padname) 
        if not sinkpad:
            sys.stderr.write("Unable to create sink pad bin \n")
        srcpad=source_bin.get_static_pad("src")
        if not srcpad:
            sys.stderr.write("Unable to create src pad bin \n")
        srcpad.link(sinkpad)
    queue1=Gst.ElementFactory.make("queue","queue1")
    queue2=Gst.ElementFactory.make("queue","queue2")
    queue3=Gst.ElementFactory.make("queue","queue3")
    queue4=Gst.ElementFactory.make("queue","queue4")
    queue5=Gst.ElementFactory.make("queue","queue5")
    pipeline.add(queue1)
    pipeline.add(queue2)
    pipeline.add(queue3)
    pipeline.add(queue4)
    pipeline.add(queue5)
    print("Creating Pgie \n ")
    pgie = Gst.ElementFactory.make("nvinfer", "primary-inference")
    if not pgie:
        sys.stderr.write(" Unable to create pgie \n")
    print("Creating tiler \n ")
    tiler=Gst.ElementFactory.make("nvmultistreamtiler", "nvtiler")
    if not tiler:
        sys.stderr.write(" Unable to create tiler \n")
    print("Creating nvvidconv \n ")
    nvvidconv = Gst.ElementFactory.make("nvvideoconvert", "convertor")
    if not nvvidconv:
        sys.stderr.write(" Unable to create nvvidconv \n")
    print("Creating nvosd \n ")
    nvosd = Gst.ElementFactory.make("nvdsosd", "onscreendisplay")
    if not nvosd:
        sys.stderr.write(" Unable to create nvosd \n")
    nvosd.set_property('process-mode',OSD_PROCESS_MODE)
    nvosd.set_property('display-text',OSD_DISPLAY_TEXT)
    if(is_aarch64()):
        print("Creating transform \n ")
        transform=Gst.ElementFactory.make("nvegltransform", "nvegl-transform")
        if not transform:
            sys.stderr.write(" Unable to create transform \n")

    print("Creating EGLSink \n")
    sink = Gst.ElementFactory.make("nveglglessink", "nvvideo-renderer")
    #sink = Gst.ElementFactory.make("nvoverlaysink", "nvvideo-renderer")
    sink.set_property('sync', 0)
    if not sink:
        sys.stderr.write(" Unable to create egl sink \n")

    if is_live:
        print("Atleast one of the sources is live")
        streammux.set_property('live-source', 1)

    streammux.set_property('width', 1280)
    streammux.set_property('height', 720)
    streammux.set_property('batch-size', number_sources)
    streammux.set_property('batched-push-timeout', 4000000)
    pgie.set_property('config-file-path', "dstest3_pgie_config.txt")
    pgie_batch_size=pgie.get_property("batch-size")
    if(pgie_batch_size != number_sources):
        print("WARNING: Overriding infer-config batch-size",pgie_batch_size," with number of sources ", number_sources," \n")
        pgie.set_property("batch-size",number_sources)
    #tiler_rows=int(math.sqrt(number_sources))
    tiler_rows=2
    #tiler_columns=int(math.ceil((1.0*number_sources)/tiler_rows))
    tiler_columns=2
    tiler.set_property("rows",tiler_rows)
    tiler.set_property("columns",tiler_columns)
    tiler.set_property("width", TILED_OUTPUT_WIDTH)
    tiler.set_property("height", TILED_OUTPUT_HEIGHT)
    sink.set_property("qos",0)

    print("Adding elements to Pipeline \n")
    pipeline.add(pgie)
    pipeline.add(tiler)
    pipeline.add(nvvidconv)
    pipeline.add(nvosd)
    if is_aarch64():
        pipeline.add(transform)
    pipeline.add(sink)

    print("Linking elements in the Pipeline \n")
    streammux.link(queue1)
    queue1.link(pgie)
    pgie.link(queue2)
    queue2.link(tiler)
    tiler.link(queue3)
    queue3.link(nvvidconv)
    nvvidconv.link(queue4)
    queue4.link(nvosd)
    if is_aarch64():
        nvosd.link(queue5)
        queue5.link(transform)
        transform.link(sink)
    else:
        nvosd.link(queue5)
        queue5.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)
    tiler_src_pad=pgie.get_static_pad("src")
    if not tiler_src_pad:
        sys.stderr.write(" Unable to get src pad \n")
    else:
        tiler_src_pad.add_probe(Gst.PadProbeType.BUFFER, tiler_src_pad_buffer_probe, 0)

    # List the sources
    print("Now playing...")
    for i, source in enumerate(args):
        if (i != 0):
            print(i, ": ", source)

    print("Starting pipeline \n")
    # start play back and listed to events		
    pipeline.set_state(Gst.State.PLAYING)
    try:
        loop.run()
    except:
        pass
    # cleanup
    print("Exiting app\n")
    pipeline.set_state(Gst.State.NULL)

if __name__ == '__main__':
    sys.exit(main(sys.argv))

```

## USBカメラのパラメーター調整

```
elif cam_type == 'USB':
        caps_v4l2src.set_property('caps', Gst.Caps.from_string("image/jpeg, width=1280, height=720,framerate=120/1"))
```

の箇所はUSBカメラにパラメーターに応じて修正してください。
例えば、MJPEG, 1280x720, 30fpsのカメラを取り込む場合は、`framerate=30/1`のように修正します。

```
elif cam_type == 'USB':
        caps_v4l2src.set_property('caps', Gst.Caps.from_string("image/jpeg, width=1280, height=720,framerate=30/1"))
```

## 実行

GstreamerはCSIカメラのコードを先に実行すると、それ以降CSIカメラしか読めなくなってしまうため、先にUSBカメラを指定する。

```
python3 deepstream_test_3.py /dev/video2 /dev/video3 /dev/video0 /dev/video1 
```