问题：对摄像机进行推流时报错
解决：摄像头默认参数配置是h264则不会报错。如果出现如下报错，是因为摄像头是h265，FFmpeg是无法直接转成flv的
方法：
ffmpeg -rtsp_transport tcp -i rtsp://user:password@ip:port/Streaming/channels/101 -c:v libx264 -ar 22050 -f flv rtmp://127.0.0.1:1935/live/mystream
ffmpeg -rtsp_transport tcp -i rtsp://user:password@ip:port/Streaming/channels/101 -f flv -s 640x360 -b:v 512k -b:a 128k -r 25 -ar 22050 rtmp://127.0.0.1:1935/live
这时如果报错：Unknown encoder 'libx264' 则需要重新编译安装ffmpeg
git clone https://gitee.com/xiao2327/x264.git
cd x264
./configure --prefix=/usr/local/x264/ --includedir=/usr/local/include --libdir=/usr/local/lib --enable-shared
make
sudo make install
git clone https://gitee.com/mirrors/ffmpeg.git
cd ffmpeg
./configure --prefix=/usr/local/ffmpeg --enable-gpl --enable-shared --enable-libx264
make clean
make
sudo make install
参考：
https://www.jianshu.com/p/547dca89dd43
https://blog.csdn.net/yuxielea/article/details/103146362
https://www.cnblogs.com/blackhumour2018/p/9400415.html
https://stackoverflow.com/questions/44236871/error-while-opening-encoder-for-output-stream-00