测试环境：
Ubuntu14.04 LTS Desktop
ffmpeg version 3.3.3
命令行运行：
ffmpeg -i rtsp://admin:12345@10.0.10.19:554/Streaming/Channels/101 -fflags flush_packets -max_delay 1 -an -flags -global_header -hls_time 1 -hls_list_size 3 -hls_wrap 3 -vcodec copy -y /var/www/video/channel101.m3u8