Posted 2024-04-19Updated 2025-12-03a few seconds read (About 95 words)

如果是在wsl，檢查一下nameserver設定，確認DNS伺服器有沒有正確設定。
https://geekdudes.wordpress.com/2022/11/16/windows-subsistem-for-linux-make-etc-resolv-conf-changes-permanent/
在網路很糟的情況下可以重複apt update，有mismatch的部分會慢慢被校正。
更改鏡像網站
https://note.drx.tw/2012/01/mirror.html

https://blog.miniasp.com/post/2019/02/19/Ubuntu-apt-update-hash-sum-mismatch#google_vignette

Posted 2024-04-19Updated 2025-12-038 minutes read (About 1134 words)

Setup Deepstream C development enviornment with CMake and VSCode

2024/07/05更新

安裝C/C++、CMake 、CMake Tools extension
C/C++的IntelliSense直接選compile_commands.json
https://code.visualstudio.com/docs/cpp/configure-intellisense

launch.json

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "(gdb) Launch",
            "type": "cppdbg",
            "request": "launch",
            "program": "${command:cmake.launchTargetPath}",
            "args": ["-c", "licenceplate_nvmultiurisrcbin.txt"],
            "stopAtEntry": false,
            "cwd": "${workspaceFolder}",
            "environment": [],
            "externalConsole": false,
            "MIMode": "gdb",
            "setupCommands": [
                {
                    "description": "Enable pretty-printing for gdb",
                    "text": "-enable-pretty-printing",
                    "ignoreFailures": true
                },
                {
                    "description": "Set Disassembly Flavor to Intel",
                    "text": "-gdb-set disassembly-flavor intel",
                    "ignoreFailures": true
                }
            ]
        }
    ]
}

查看char *完整內容

https://stackoverflow.com/questions/52721440/how-to-expand-an-array-while-debugging-in-visual-studio-code

2024/07/05前舊方法

Prequirements

CMake > 3.25

sudo apt-get update
sudo apt-get install ca-certificates gpg wget
test -f /usr/share/doc/kitware-archive-keyring/copyright ||
wget -O - https://apt.kitware.com/keys/kitware-archive-latest.asc 2>/dev/null | gpg --dearmor - | sudo tee /usr/share/keyrings/kitware-archive-keyring.gpg >/dev/null

# For Ubuntu Jammy Jellyfish (22.04):
echo 'deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ jammy main' | sudo tee /etc/apt/sources.list.d/kitware.list >/dev/null
sudo apt-get update

# For Ubuntu Focal Fossa (20.04):
echo 'deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ focal main' | sudo tee /etc/apt/sources.list.d/kitware.list >/dev/null
sudo apt-get update

test -f /usr/share/doc/kitware-archive-keyring/copyright ||
sudo rm /usr/share/keyrings/kitware-archive-keyring.gpg

sudo apt-get install kitware-archive-keyring

sudo apt-get install cmake

VSCode
clangd
1
sudo apt-get install clangd-12

package to run this example

1 2	sudo apt-get install libgstreamer-plugins-base1.0-dev libgstreamer1.0-dev \ libgstrtspserver-1.0-dev libx11-dev libjson-glib-dev libyaml-cpp-dev

Setup VSCode for development

install VSCode extension
CodeLLDB、clangd 、CMake 、CMake Tools
Note: Do not install C/C++ extension pack from Microsoft
copy deepstream-test5 to your workspace
deepstream-test5 is a complete example to modify deepstream-app，this will take the advantage of the module design of deepstream-app. You can add probe to customize the app. It have good config parser and error handling, those will save many effort.
Following our workspace is in the copy of deepstream-test5 folder.

1	cp -r /opt/nvidia/deepstream/deepstream/apps/sample_apps/deepstream-test5/* /path/to/your/workspace

create launch.json and task.json
create launch.json and task.json for compile and debug

tasks.json use CMake to build

{
  "version": "2.0.0",
  "tasks": [
        {
            "type": "cmake",
            "label": "CMake: build",
            "command": "build",
            "targets": [
                "all"
            ],
            "group": "build",
            "problemMatcher": [],
            "detail": "CMake template build task"
        }
    ]
}

launch.json call task in task json to build

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "type": "lldb",
            "request": "launch",
            "name": "Debug",
            "program": "${workspaceFolder}/deepstream-test5",//the path of the executable file deepstream-test5
            "args": ["-c", "configs/test5_config_file_src_infer.txt"],//arg for deepstream-test5
            "cwd": "${workspaceFolder}",//指定工作目錄
            "preLaunchTask": "CMake: build"
        }
    ]
}
```  


create settings.json for clangd to read compile_commands.json. clangd can generate code navigator.
```json
{
    "cmake.sourceDirectory": "${workspaceFolder}",
    "cmake.generator": "Unix Makefiles",
    "clangd.arguments": [
        "--compile-commands-dir=${workspaceFolder}/build",
        "--background-index",
        "-j=8",
        "--query-driver=/usr/bin/clang++",
        "--clang-tidy",
        "--clang-tidy-checks=performance-*,bugprone-*",
        "--all-scopes-completion",
        "--completion-style=detailed",
        "--function-arg-placeholders",
        "--header-insertion=iwyu",
        "--pch-storage=memory",
    ],
}

Create CMAKELists.txt
Create CMakeLists.txt under the workspace folder, CMake will help you find CUDA and nvcc, no more CUDA_VER env variable needed even in jetson.
In this example，we need to compile deepstream-app first and use the object file in our project.So we use ExternalProject_Add to do this.

We need to change the permission for deepstream-app source folder in order to compile the deepstream-app.

1	sudo chmod -R 777 /opt/nvidia/deepstream/deepstream/sources/apps/

cmake_minimum_required(VERSION 3.25)
project(deepstream-test5 LANGUAGES C CXX) #project(deepstream-test5 LANGUAGES CUDA C CXX)
set(CMAKE_CXX_STANDARD 14)
set (CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
set(CMAKE_BUILD_TYPE Debug)
find_package(PkgConfig REQUIRED)
pkg_check_modules(PKGS REQUIRED uuid x11 gstreamer-video-1.0 json-glib-1.0 gstreamer-1.0 gstreamer-rtsp-server-1.0 yaml-cpp)
find_package(CUDAToolkit)
message("CUDA_VER is ${CUDAToolkit_VERSION_MAJOR}.${CUDAToolkit_VERSION_MINOR}")

if(NOT DEFINED CMAKE_CUDA_STANDARD)
    set(CMAKE_CUDA_STANDARD 11)
    set(CMAKE_CUDA_STANDARD_REQUIRED True)
endif()

SET(DEEPSTREAMAPP
    /opt/nvidia/deepstream/deepstream/sources/apps
)

include(ExternalProject)
ExternalProject_Add(deepstreamapp  
    SOURCE_DIR ${DEEPSTREAMAPP}/sample_apps/deepstream-app 
    CONFIGURE_COMMAND ""
    INSTALL_COMMAND ""
    DOWNLOAD_COMMAND ""
    BUILD_COMMAND export CUDA_VER=${CUDAToolkit_VERSION_MAJOR}.${CUDAToolkit_VERSION_MINOR} && make
    BUILD_IN_SOURCE true
)

file(GLOB_RECURSE  DEEPSTREAMAPPCOMMONOBJ "/opt/nvidia/deepstream/deepstream/sources/apps/apps-common/src/*.o")
file(GLOB_RECURSE  DEEPSTREAMAPPOBJ "/opt/nvidia/deepstream/deepstream/sources/apps/sample_apps/deepstream-app/*.o")

list(REMOVE_ITEM DEEPSTREAMAPPOBJ "/opt/nvidia/deepstream/deepstream/sources/apps/sample_apps/deepstream-app/deepstream_app_main.o")

message(DEEPSTREAMAPPCOMMONOBJ="${DEEPSTREAMAPPCOMMONOBJ}")
message(DEEPSTREAMAPPOBJ="${DEEPSTREAMAPPOBJ}")


SET(OBJS
    ${DEEPSTREAMAPPCOMMONOBJ}
    ${DEEPSTREAMAPPOBJ}
    /opt/nvidia/deepstream/deepstream/sources/apps/apps-common/src/deepstream_config_file_parser.o
    )   

SET_SOURCE_FILES_PROPERTIES(
  ${OBJS}
  PROPERTIES
  EXTERNAL_OBJECT true
  GENERATED true
)


add_executable(${PROJECT_NAME}
    ${OBJS}
    deepstream_utc.c
    deepstream_test5_app_main.c
)

target_include_directories(${PROJECT_NAME} PRIVATE
    ${PKGS_INCLUDE_DIRS}
    ${CMAKE_CUDA_TOOLKIT_INCLUDE_DIRECTORIES}
    /opt/nvidia/deepstream/deepstream/sources/apps/apps-common/includes
    /opt/nvidia/deepstream/deepstream/sources/includes
    /opt/nvidia/deepstream/deepstream/sources/apps/sample_apps/deepstream-app
    ${CMAKE_CURRENT_SOURCE_DIR}/cparse
    ${CMAKE_CURRENT_SOURCE_DIR}
)

target_link_libraries(${PROJECT_NAME} PRIVATE
    ${PKGS_LIBRARIES}
    CUDA::cuda_driver
    nvds_utils nvdsgst_helper m nvdsgst_meta nvds_meta stdc++
    nvbufsurface nvbufsurftransform nvds_batch_jpegenc uuid jpeg png nvds_yml_parser
    nvdsgst_smartrecord nvds_msgbroker nvdsgst_customhelper
    pthread 
    PRIVATE CUDA::cudart
)

target_link_directories(${PROJECT_NAME} PRIVATE
    /opt/nvidia/deepstream/deepstream/lib/
)

target_link_options(${PROJECT_NAME} PRIVATE -Wl,-rpath,/opt/nvidia/deepstream/deepstream/lib/)

build project
click the build button in VSCode and select the gcc compiler.
start debug and make a breakpoint
code navigation
example project
https://github.com/jenhaoyang/deepstream-startup

Posted 2024-04-17Updated 2025-12-03a few seconds read (About 14 words)

nohup使用教學

1	nohup command >logfile.txt 2>&1 &

參考

https://blog.csdn.net/xiaojin21cen/article/details/88991768

Posted 2024-04-17Updated 2025-12-03a few seconds read (About 19 words)

用bash讓程式壞掉的時候自動重啟

until myserver; do
    echo "Server 'myserver' crashed with exit code $?.  Respawning.." >&2
    sleep 1
done

參考:

https://stackoverflow.com/a/697064/22299707

Posted 2024-04-17Updated 2025-12-03a few seconds read (About 27 words)

update-alternatives管理軟體版本

1	update-alternatives --display cuda

1	update-alternatives --config cuda

參考:

https://www.baeldung.com/linux/update-alternatives-command
https://then.tw/switch-gcc-versions-with-update-alternatives/

Posted 2024-03-12Updated 2025-12-03a few seconds read (About 90 words)

Ubuntu22遠端桌面設定

xrdp設定

https://vegastack.com/tutorials/how-to-install-xrdp-server-on-ubuntu-22-04/
https://dic.vbird.tw/linux_server/unit06.php

注意

如果安裝Ubuntu的時候就已經是安裝Desktop版本，就不需要另外安裝xfce
使用遠端桌面的時候，要登入的帳號不可以在遠端的電腦已經登入，因此必須要把AutoLogin關閉

Posted 2024-03-12Updated 2025-12-03a few seconds read (About 21 words)

ssh經過跳板機的連線方式

Host Target
  HostName 192.168.8.71
  User user1
  ProxyJump JumpServer

Host JumpServer
  HostName 192.168.8.149
  User jumpuser

參考

https://city.shaform.com/zh/2017/10/28/ssh-proxycommand/

Posted 2024-02-26Updated 2025-12-03a minute read (About 126 words)

apt離線安裝套件的方法

https://www.jinnsblog.com/2020/11/linux-ubuntu-offline-install-package.html#google_vignette

1
2
3

apt-get clean #先清除不必要的檔案
apt-get install --download-only --reinstall $(apt-cache depends --recurse --no-recommends --no-suggests --no-conflicts --no-breaks --no-replaces --no-enhances 套件名稱 | grep "^\w" | sort -u)  #下載的套件會被儲存到/var/cache/apt/archives資料夾，會同時下載相依套件，而且就算已經安裝過這個指令也會進行下載
sudo dpkg -i *.deb #把整個archives資料夾移動到離線的主機中必且安裝

Posted 2024-02-19Updated 2025-12-03a few seconds read (About 62 words)

讓docker pull回復上次失敗的下載

解決方法

https://github.com/docker/for-linux/issues/1187#issuecomment-1570501567

1 2	sudo mkdir /etc/docker sudo gedit /etc/docker/daemon.json

加入這個屬性

1
2
3

{
    "features": {"containerd-snapshotter": true}
}

1	sudo systemctl restart docker

自動重新下載docker image

1	while ! docker pull nvcr.io/nvidia/deepstream:6.4-gc-triton-devel; do sleep .1; done && echo OK

Posted 2024-02-01Updated 2025-12-03a minute read (About 208 words)

串流相關知識

RTP/RTCP

跟TCP和UDP一樣為傳輸層協議
規範RFC3350
RTCP (RTP Control Protocol)專門用來處理服務品質(Qos)
RTP可以選擇用UDP或是TCP來進行傳輸

https://mark-lin.com/posts/20180912/(主要)
http://albert-oma.blogspot.com/2012/05/rtp.html

bps(bit Per Second)

位元率 (bps) = 採樣率(hz) x 採樣大小(bit) x 通道

編碼

將raw檔轉換壓縮

聲音編碼

例如MP3和AAC

色彩顏色編碼RGB與YUV

影像編碼H26X和VPX

主流有H264和VP8

封裝

將聲音和影像編碼後的結果放進容器的過程

容器

用來盛裝編碼，一種編碼可以放進各種容器，例如MP3編碼可以放進.mp3、.mp4、.avi容器裡面

網路協議

https://www.jianshu.com/p/9f3e879a4c9c

DTS和PTS

https://blog.csdn.net/aggie4628/article/details/130440133