docs/build_ffmpeg.md

# 基于Ubuntu源码编译ffmpeg
## 编译SDL2
```shell
https://github.com/libsdl-org/SDL/releases/tag/release-2.30.8 # 下载源码
cd sdl/source/folder
./configure --prefix=/usr/local
make
sudo make install
```
## 安装ffmpeg依赖
1. 安装包管理工具 aptitude
   aptitude 与 apt-get一样，是 Debian 系中功能极其强大的包管理工具。 与 apt-get 不同的是，aptitude 在处理依赖问题上更佳一些，当 aptitude 在删除一个包时，会同时删除本身所依赖的包。
    ```shell
    sudo apt install aptitude
    ```
2. 安装 yasm、nasm
   yasm、nasm 是两个汇编器，编译 FFmpeg 需要用到。
   安装命令：
    ```shell
    sudo aptitude install yasm nasm
    ```
3. 其他依赖
   FFmpeg 的安装依赖许多库（如，音频编码库，音频解码库，视频编解码库等），这里不介绍每个库的具体作用，按照命令安装即可。
    ```shell
    sudo apt-get install libgmp3-dev
    sudo apt install pkg-config
    sudo apt install gnutls-bin
    sudo aptitude install libaom-dev
    sudo aptitude install libass-dev
    sudo aptitude install libbluray-dev
    sudo aptitude install libfdk-aac-dev
    sudo aptitude install libmp3lame-dev
    sudo aptitude install libopencore-amrnb-dev
    sudo aptitude install libopencore-amrwb-dev
    sudo aptitude install libopenmpt-dev
    sudo aptitude install libopus-dev
    sudo aptitude install libshine-dev
    sudo aptitude install libsnappy-dev
    sudo aptitude install libsoxr-dev
    sudo aptitude install libspeex-dev
    sudo aptitude install libtheora-dev
    sudo aptitude install libtwolame-dev
    sudo aptitude install libvo-amrwbenc-dev
    sudo aptitude install llibvpx-dev
    sudo aptitude install libwavpack-dev
    sudo aptitude install libwebp-dev
    sudo aptitude install libx264-dev
    sudo aptitude install libx265-dev
    sudo aptitude install libxvidcore-dev
    sudo aptitude install liblzma-dev
    ```
## 编译ffmpeg
1. 从官网下载源码
2. 进入根目录编译
    ```shell
    ./configure --enable-shared --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-iconv --enable-libass --enable-libbluray --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame 
   --enable-libvpx  --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-lzma --enable-zlib --enable-gmp 
   --enable-libvorbis --enable-libvo-amrwbenc --enable-libspeex --enable-libxvid 
   --enable-libaom --enable-libopenmpt --enable-libfdk-aac 
   --enable-nonfree --enable-nvdec --enable-cuda --enable-cuvid
   # 其中 --enable-gpl --enable-libx264 --enable-libx265 --enable-sdl2 必不可少
   # 由于需要硬件英伟达显卡加速编解码 -enable-nvdec --enable-cuda --enable-cuvid
   # 其他的要是编译不过，就把他删除掉
   make
   sudo make install
    ```
   如果需要硬件英伟达显卡加速编解码，需要安装相关依赖
    ```shell
    sudo apt install libdssialsacompat-dev
    git clone https://git.videolan.org/git/ffmpeg/nv-codec-headers.git
    cd nv-codec-headers
    make
    sudo make install
   ```