問題：ffmpeg無法對IP組播進行處理，表現如下
[root@os01 /]# ffprobe udp://225.0.0.2:9000 ffprobe 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
（一直卡在這裡）
而通過tcpdump抓包，是可以抓到組播流的
[root@os01 /]# tcpdump -ieno1 host 225.0.0.2 and port 9000 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eno1, link-type EN10MB (Ethernet), capture size 65535 bytes 09:03:35.745690 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 1316 09:03:35.759688 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 1316 09:03:35.763224 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 1316 09:03:35.766720 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 1316 09:03:35.770256 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 1316 09:03:35.773768 IP bogon.37266 > 225.0.0.2.cslistener: UDP, length 1316
檢視route表如下
[root@os01 logs]# route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface default bogon 0.0.0.0 UG 100 0 0 eno4 link-local 0.0.0.0 255.255.0.0 U 1003 0 0 eno2 172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0 172.28.1.0 0.0.0.0 255.255.255.0 U 100 0 0 eno3 172.28.33.0 0.0.0.0 255.255.255.0 U 100 0 0 eno1 172.28.34.0 0.0.0.0 255.255.255.0 U 0 0 0 eno2 192.168.0.0 0.0.0.0 255.255.255.0 U 100 0 0 eno4 192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
故，分析得出，上述問題是由route表中未配置組播地址導致，解決辦法如下
[root@os01 logs]# route add -net 225.0.0.0 netmask 255.0.0.0 dev eno1
[root@os01 logs]# route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface default bogon 0.0.0.0 UG 100 0 0 eno4 link-local 0.0.0.0 255.255.0.0 U 1003 0 0 eno2 172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0 172.28.1.0 0.0.0.0 255.255.255.0 U 100 0 0 eno3 172.28.33.0 0.0.0.0 255.255.255.0 U 100 0 0 eno1 172.28.34.0 0.0.0.0 255.255.255.0 U 0 0 0 eno2 192.168.0.0 0.0.0.0 255.255.255.0 U 100 0 0 eno4 192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0 225.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eno1
再次驗證ffmpeg:
[root@os01 logs]# ffprobe udp://225.0.0.2:9000 ffprobe 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