问题：ffmpeg无法对IP组播进行处理，表现如下
[root@os01 /]# ffprobe udp://225.0.0.2:9000ffprobe version 2.7.1 Copyright (c) 2007-2015 the FFmpeg developers built with gcc 4.8.3 (GCC) 20140911 (Red Hat 4.8.3-9) configuration: --enable-gpl --enable-nonfree --enable-static --enable-pthreads libavutil 54. 27.100 / 54. 27.100 libavcodec 56. 41.100 / 56. 41.100 libavformat 56. 36.100 / 56. 36.100 libavdevice 56. 4.100 / 56. 4.100 libavfilter 5. 16.101 / 5. 16.101 libswscale 3. 1.101 / 3. 1.101 libswresample 1. 2.100 / 1. 2.100 libpostproc 53. 3.100 / 53. 3.100 （一直卡在这里）
而通过tcpdump抓包，是可以抓到组播流的
[root@os01 /]# tcpdump -ieno1 host 225.0.0.2 and port 9000tcpdump: verbose output suppressed, use -v or -vv for full protocol decodelistening on eno1, link-type EN10MB (Ethernet), capture size 65535 bytes09:03:35.745690 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 131609:03:35.759688 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 131609:03:35.763224 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 131609:03:35.766720 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 131609:03:35.770256 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 131609:03:35.773768 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 1316
查看route表如下
[root@os01 logs]# routeKernel IP routing tableDestination Gateway Genmask Flags Metric Ref Use Ifacedefault bogon 0.0.0.0 UG 100 0 0 eno4link-local 0.0.0.0 255.255.0.0 U 1003 0 0 eno2172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0172.28.1.0 0.0.0.0 255.255.255.0 U 100 0 0 eno3172.28.33.0 0.0.0.0 255.255.255.0 U 100 0 0 eno1172.28.34.0 0.0.0.0 255.255.255.0 U 0 0 0 eno2192.168.0.0 0.0.0.0 255.255.255.0 U 100 0 0 eno4192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
故，分析得出，上述问题是由route表中未配置组播地址导致，解决办法如下
[root@os01 logs]# route add -net 225.0.0.0 netmask 255.0.0.0 dev eno1
[root@os01 logs]# routeKernel IP routing tableDestination Gateway Genmask Flags Metric Ref Use Ifacedefault bogon 0.0.0.0 UG 100 0 0 eno4link-local 0.0.0.0 255.255.0.0 U 1003 0 0 eno2172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0172.28.1.0 0.0.0.0 255.255.255.0 U 100 0 0 eno3172.28.33.0 0.0.0.0 255.255.255.0 U 100 0 0 eno1172.28.34.0 0.0.0.0 255.255.255.0 U 0 0 0 eno2192.168.0.0 0.0.0.0 255.255.255.0 U 100 0 0 eno4192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0225.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eno1
再次验证ffmpeg:
[root@os01 logs]# ffprobe udp://225.0.0.2:9000ffprobe version 2.7.1 Copyright (c) 2007-2015 the FFmpeg developers built with gcc 4.8.3 (GCC) 20140911 (Red Hat 4.8.3-9) configuration: --enable-gpl --enable-nonfree --enable-static --enable-pthreads libavutil 54. 27.100 / 54. 27.100 libavcodec 56. 41.100 / 56. 41.100 libavformat 56. 36.100 / 56. 36.100 libavdevice 56. 4.100 / 56. 4.100 libavfilter 5. 16.101 / 5. 16.101 libswscale 3. 1.101 / 3. 1.101 libswresample 1. 2.100 / 1. 2.100 libpostproc 53. 3.100 / 53. 3.100[h264 @ 0x2ed1160] non-existing PPS 0 referenced Last message repeated 1 times[h264 @ 0x2ed1160] decode_slice_header error[h264 @ 0x2ed1160] no frame![h264 @ 0x2ed1160] non-existing PPS 0 referenced Last message repeated 1 times[h264 @ 0x2ed1160] decode_slice_header error[h264 @ 0x2ed1160] no frame![h264 @ 0x2ed1160] non-existing PPS 0 referenced Last message repeated 1 times