---
title: Install Opencv with ffmpeg on Ubuntu 20.04
date: 2020-10-26 10:31:11
tags:
- Ubuntu20.04
- OpenCV
- ffmpeg
- Issue
- Fixed
categories:
- FixedIssue
---

# OpenCV Installation

從 Ubuntu Repository 安裝 OpenCV

sudo apt update
sudo apt install libopencv-dev python3-opencv

上面的命令將安裝運行OpenCV所需的所有軟件包。

通過導入cv2模塊並印OpenCV版本來驗證安裝版本：

python3 -c "import cv2; print(cv2.__version__)"

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從 Source 安裝 OpenCV

安裝建構工具和依賴環境：

sudo apt install build-essential cmake git pkg-config libgtk-3-dev \
    libavcodec-dev libavformat-dev libswscale-dev libv4l-dev \
    libxvidcore-dev libx264-dev libjpeg-dev libpng-dev libtiff-dev \
    gfortran openexr libatlas-base-dev python3-dev python3-numpy \
    libtbb2 libtbb-dev libdc1394-22-dev libopenexr-dev \
    libgstreamer-plugins-base1.0-dev libgstreamer1.0-dev

Clone OpenCV’s and OpenCV contrib 資料庫:

mkdir ~/opencv_build && cd ~/opencv_build
git clone https://github.com/opencv/opencv.git
git clone https://github.com/opencv/opencv_contrib.git

下載完成後，創建一個build目錄，並進入至該目錄：

cd ~/opencv_build/opencv
mkdir -p build && cd build

使用CMake進行設置OpenCV建構：

cmake -D CMAKE_BUILD_TYPE=RELEASE \
    -D CMAKE_INSTALL_PREFIX=/usr/local \
    -D INSTALL_C_EXAMPLES=ON \
    -D INSTALL_PYTHON_EXAMPLES=ON \
    -D OPENCV_GENERATE_PKGCONFIG=ON \
    -D OPENCV_EXTRA_MODULES_PATH=~/opencv_build/opencv_contrib/modules \
    -D BUILD_EXAMPLES=ON ..

輸出會類似以下:

-- Configuring done
-- Generating done
-- Build files have been written to: /home/vagrant/opencv_build/opencv/build

開始編譯過程：

make -j8 #-j8 代表我有8線程的CPU

安裝Opencv:

sudo make install

驗證安裝版本
C++ bindings:

pkg-config --modversion opencv4

Python bindings:

python3 -c "import cv2; print(cv2.__version__)"

**Install ffmpeg**

因為OpenCV 是根據舊版的ffmpeg做開發
所以如果直接使用 apt-get install ffmpeg 會下載到最新版的ffmpeg
容易產生錯誤，所以以下我將以ffmpeg 2.8.14版本教學
親測有用!

ffmpeg官網下載安裝包

tar xvf ffmpeg-2.8.14.tar.bz2
cd ffmpeg-2.8.14
sudo apt-get install yasm 
./configure --host-cppflags=-fPIC --host-cflags=-fPIC --enable-shared
make
sudo make install

apt-get安裝相關的依賴庫

sudo apt-get install build-essential
sudo apt-get install cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev
sudo apt-get install python-dev python-numpy libtbb2 libtbb-dev libjpeg-dev libpng-dev libtiff-dev libjasper-dev libdc1394-22-dev # 處理圖像所需的包
sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev liblapacke-dev
sudo apt-get install libxvidcore-dev libx264-dev # 處理視頻所需的包
sudo apt-get install libatlas-base-dev gfortran # 優化opencv功能
sudo apt-get install ffmpeg

最後可以透過以下指令查看版本

ffmpeg -version

---
tags:
###### tags: Ubuntu20.04
###### tags: OpenCV
###### tags: ffmpeg
###### tags: Issue
###### tags: Fixed
---