A user uploaded a Quicktime video to my website the other day and the server ran into a problem transcoding it to FLV. I hit up #ffmpeg and it was suggested that I upgrade my install of FFMPEG and libfaad. Alrighty, no big deal, done it before. So first thing this morning was going to be update the sources and recompile.


Before I get on with that, first I’ll describe the environment. We’re running on RHEL4 and have an install of FFMPEG that works fine (aside from that 1 user uploaded video). The last upgrade of FFMPEG to get h264 support wasn’t done by me, but rather our sysadmin, when we actually had a sysadmin. I believe he used rpms for the libraries and compiled FFMPEG from the SVN repo.


So I did a quick search just to remind myself what libraries I needed and I came across this post about compiling on RHEL4, our distro. Perfect. I followed directions to a T (aside from upgrading SVN) and it compiled fine. Now, time to run a test transcode…



[root@140859-www1 ~]# /home/derek/ffmpeg_sources/ffmpeg/ffmpeg -y -i /media/v2-prod/atlas/8102/20206 -ab 64k -ar 22050 -b 700K -r 15 -y -s 640x480 -ac 1 -padtop -padbottom -s vga /home/derek/blah.flv
FFmpeg version SVN-r13977, Copyright (c) 2000-2008 Fabrice Bellard, et al.
configuration: –enable-libmp3lame –enable-libvorbis –enable-libfaac –enable-libfaad –enable-gpl –enable-libtheora –enable-libx264 –enable-shared
libavutil version: 49.7.0
libavcodec version: 51.57.2
libavformat version: 52.16.0
libavdevice version: 52.0.0
built on Jun 25 2008 14:49:55, gcc: 3.4.6 20060404 (Red Hat 3.4.6-9)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from ‘/media/v2-prod/atlas/8102/20206’:
Duration: 00:10:55.2, start: 0.000000, bitrate: 406 kb/s
Stream #0.0(und): Audio: mpeg4aac, 44100 Hz, stereo
Stream #0.1(und): Video: h264, yuv420p, 320x240 [PAR 0:1 DAR 0:1], 30.00 tb(r)
Output #0, flv, to ‘/home/derek/blah.flv’:
Stream #0.0(und): Video: flv, yuv420p, 640x480 [PAR 0:1 DAR 0:1], q=2-31, 700 kb/s, 15.00 tb(c)
Stream #0.1(und): Audio: libmp3lame, 22050 Hz, mono, 64 kb/s
Stream mapping:
Stream #0.1 -> #0.0
Stream #0.0 -> #0.1
Press [q] to stop encoding
/home/derek/ffmpeg_sources/ffmpeg/ffmpeg: symbol lookup error: /home/derek/ffmpeg_sources/ffmpeg/ffmpeg: undefined symbol: av_fifo_generic_write
You have new mail in /var/spool/mail/root

Well shit. Ok, so I hit up #ffmpeg again, but don’t get any help, so I try recompiling without any config options and it works fine. So I slowly start added on config options and it works until I add “–enable-share”, and which point it compiles a version of FFMPEG that throws the “undefined symbol” error. So that gives me a pretty good idea it has something to do with that. I go through the symlinks in the guide (linked above) and notice that /usr/lib/libavformat.so.50 is symlinked to a file that doesn’t exist. And that’s where I’m at now, kinda stumped. Am I missing libraries? how can I ensure any old libraries installed before are cleaned out and not conflicting with new ones? I’m a developer, not a linux admin. I know my way around the OS, but when it comes to this type of stuff, I’m stumped.


Any ideas? post a comment or email/gtalk me at drgath at gmail.com.