ffmpeg -i marko-845-incar.wmv -f flv -s 320x240 -acodec mp3 flvs/wmv.flv FFmpeg version SVN-r5778, Copyright (c) 2000-2004 Fabrice Bellard configuration: --enable-shared --enable-mp3lame --enable-gpl --enable-faac --enable-faad --enable-a52 libavutil version: 49.0.0 libavcodec version: 51.10.0 libavformat version: 50.5.0 built on Jul 17 2006 05:21:50, gcc: 4.0.4 20060507 (prerelease) (Debian 4.0.3-3) marko-845-incar.wmv: I/O error occured Usually that means that input file is truncated and/or corrupted. carmio:/home/carmio/httpd# cd videos/ carmio:/home/carmio/httpd/videos# ffmpeg -i marko-845-incar.wmv -f flv -s 320x240 -acodec mp3 flvs/wmv.flv FFmpeg version SVN-r5778, Copyright (c) 2000-2004 Fabrice Bellard configuration: --enable-shared --enable-mp3lame --enable-gpl --enable-faac --enable-faad --enable-a52 libavutil version: 49.0.0 libavcodec version: 51.10.0 libavformat version: 50.5.0 built on Jul 17 2006 05:21:50, gcc: 4.0.4 20060507 (prerelease) (Debian 4.0.3-3) Seems that stream 1 comes from film source: 1000.00 (1000/1) -> 29.97 (30000/1001) Input #0, asf, from 'marko-845-incar.wmv': Duration: 00:00:29.7, start: 4.000000, bitrate: 529 kb/s Stream #0.0: Audio: wmav2, 44100 Hz, stereo, 64 kb/s Stream #0.1: Video: WMV3 / 0x33564D57, 320x240, 29.97 fps(r) Output #0, flv, to 'flvs/wmv.flv': Stream #0.0: Video: flv, yuv420p, 320x240, q=2-31, 200 kb/s, 29.97 fps(c) Stream #0.1: Audio: mp3, 44100 Hz, stereo, 64 kb/s Stream mapping: Stream #0.1 -> #0.0 Stream #0.0 -> #0.1 Unsupported codec (id=74) for input stream #0.1