CentOS中离线安装ffmpeg

1.下载安装包
ffmpeg-4.1.tar.xz
2.解压安装包：

tar -xvJf ffmpeg-4.1.tar.xz

3.编译安装： /programFiles/soft/ffmpeg 为自己指定的安装目录

./configure --enable-shared --prefix=/programFiles/soft/ffmpeg

提示错误：

nasm/yasm not found or too old. Use --disable-x86asm for a crippled build.

If you think configure made a mistake, make sure you are using the latest
version from Git.  If the latest version fails, report the problem to the
ffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net.
Include the log file "ffbuild/config.log" produced by configure as this will help
solve the problem.

安装gcc编译器

centos 执行

yum install gcc

ubuntu 执行

apt install gcc

安装yasm编译器：

centos 执行

yum install -y yasm

ubuntu 执行

apt install -y yasm

离线安装yasm：

wget http://www.tortall.net/projects/yasm/releases/yasm-1.3.0.tar.gz

tar zxvf yasm-1.3.0.tar.gz

cd yasm-1.3.0

./configure

make && make install

4.编译（编译时间比较长）和安装：

make && make install

5.遇到问题 -bash: make: command not found 的解决办法

一般出现这个提示，是因为安装系统的时候使用的是最小化mini安装，系统没有安装make、vim等常用命令，直接yum安装下即可。

yum -y install gcc automake autoconf libtool make

安装g++:

yum install gcc gcc-c++

6.修改文件/etc/ld.so.conf

vim /etc/ld.so.conf

include ld.so.conf.d/*.conf

将安装目录的lib包路径 /{make install的目录}/ffmpeg/lib 加入最后

/programFiles/soft/ffmpeg/lib/

使修改生效：

ldconfig

7.查看版本

/programFiles/soft/ffmpeg/bin/ffmpeg -version

8.配置环境变量

vim /etc/profile

在最后PATH添加环境变量（ /programFiles/soft/ffmpeg/bin 为安装目录）：

#set ffmpeg environment
PATH=$PATH:/programFiles/soft/ffmpeg/bin
export PATH

或者这么写：

#set ffmpeg env
export FFMPEG_HOME=/usr/bin/ffmpeg
export PATH=$PATH:${FFMPEG_HOME}/bin

使配置生效：

source /etc/profile 

9.查看环境变量是否配置成功

ffmpeg -version

参考资料：
https://www.cnblogs.com/wpjamer/p/ffmpeg.html
https://www.cnblogs.com/wintercloud/p/11162962.html

转码时候遇到问题 Unknown encoder 'libx264'

即，缺少libx264解码库，需要安装该库：

git clone http://git.videolan.org/git/x264.git && cd x264

./configure --enable-static --enable-shared

make && make install

FFMPEG使用NVIDIA的GPU硬件转码（使用N卡加速解码）

下载ffmpeg源码

sudo apt-get install build-essential yasm cmake libtool libc6 libc6-dev unzip wget libnuma1 libnuma-dev

正常编译配置（防止报错，根据提示加上--disable-x86asm）

./configure --prefix=/usr/local/ffmpeg --enable-shared --enable-yasm --enable-libx264 --enable-gpl --enable-pthreads --extra-cflags=-I/usr/local/x264/include --extra-ldflags=-L/usr/local/x264/lib --disable-x86asm

N卡加速编译配置

./configure --enable-nonfree -–enable-cuda-sdk –enable-libnpp --extra-cflags=-I/usr/local/cuda/include --extra-ldflags=-L/usr/local/cuda/lib64

编译和安装

make && make install

同分辨率转码, gpu加速转码，ddr在线模式

ffmpeg -y -vsync 0 -hwaccel cuvid -c:v h264_cuvid -i input.mp4 -c:a copy -c:v h264_nvenc -b:v 5M output.mp4

变分辨率转码：

ffmpeg -y -vsync 0 -hwaccel cuvid –resize 1280x720 -c:v h264_cuvid -i input.mp4 -c:a copy -c:v h264_nvenc -b:v 5M output.mp4

corp转码 (-crop (top)x(bottom)x(left)x(right))

ffmpeg -y -vsync 0 -hwaccel cuvid –crop 16x16x32x32 -c:v h264_cuvid -i input.mp4 -c:a copy -c:v h264_nvenc -b:v 5M output.mp4

scale_cuda filter 转码

ffmpeg -y -vsync 0 -hwaccel cuvid -c:v h264_cuvid -i input.mp4 -vf scale_cuda=1280:720 -c:a copy -c:v h264_nvenc -b:v 5M output.mp4

scale_npp filter 转码

ffmpeg -y -vsync 0 -hwaccel cuvid -c:v h264_cuvid -i input.mp4 -vf scale_npp=1280:720 -c:a copy -c:v h264_nvenc -b:v 5M output.mp4

1:N 转码

ffmpeg -y -vsync 0 -hwaccel cuvid -c:v h264_cuvid -i input.mp4 -vf scale_npp=1920:1080 -c:a copy -c:v h264_nvenc -b:v 5M output1.mp4 -vf scale_npp=1280:720 -c:a copy -c:v h264_nvenc -b:v 8M output2.mp4

yuv编码, 1:N 编码

ffmpeg -y -vsync 0 -pix_fmt yuv420p -s 1920x1080 -i input.yuv -filter_complex "[0:v]hwupload_cuda,split=4[o1][o2][o3][o4]" -map "[o1]" -c:v h264_nvenc -b:v 8M output1.mp4 -map "[o2]" -c:v h264_nvenc -b:v 10M output2.mp4 -map "[o3]" -c:v h264_nvenc -b:v 12M output3.mp4 -map "[o4]" -c:v h264_nvenc -b:v 14M output4.mp4

转码, 1:N 编码

ffmpeg -y -hwaccel cuvid –c:v h264_cuvid -i input1.mp4 -hwaccel cuvid –c:v h264_cuvid -i input2.mp4 -map 0:0 -vf scale_npp=640:480 –c:v h264_nvenc -b:v 1M output11.mp4 -map 0:0 -vf scale_npp=320:240 –c:v h264_nvenc -b:v 500k output12.mp4 -map 1:0 -vf scale_npp=1280:720 –c:v h264_nvenc -b:v 3M output21.mp4 -map 1:0 -vf scale_npp=640:480 –c:v h264_nvenc -b:v 2M output22.mp4

软解码，gpu resize，gpu编码

ffmpeg -y -init_hw_device cuda=foo:bar -filter_hw_device foo  -i input1.mp4 -i input2.mp4 -map 0:0 -vf hwupload,scale_npp=640:480 –c:v h264_nvenc -b:v 1M  output11.mp4 -map 0:0 -vf hwupload,scale_npp=320:240 –c:v h264_nvenc -b:v 500k  output12.mp4 -map 1:0 -vf hwupload,scale_npp=1280:720 –c:v h264_nvenc -b:v 2M output21.mp4 -map 1:0 -vf hwupload,scale_npp=640:480 –c:v h264_nvenc -b:v 1M output22.mp4

更多配置通过ffmpeg查看NVIDIA编码器和解码器属性配置

更多参考：
https://developer.nvidia.com/ffmpeg
h264_nvenc 编码器配置参考
Using_FFmpeg_with_NVIDIA_GPU_Hardware_Acceleration_v01.4.pdf