ffmpeg and the 'unable to find suitable output' error

I'm trying to convert a large MKV to an old-school AVI file.

I'm trying this:

ffmpeg -i video.mkv -s -codec:v mpeg4 -bf 1 -b 2567k -mbd 2 -g 300 -flags cgop -acodec copy video.avi

but I get

[NULL @ 0x7fa0d901e600] Unable to find a suitable output format for 'mpeg4' mpeg4: Invalid argument

Long version of ffmpeg's message...

ffmpeg version 2.1.3 Copyright (c) 2000-2013 the FFmpeg developers built on Feb 4 2014 17:53:32 with Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn) configuration: --prefix=/usr/local/Cellar/ffmpeg/2.1.3 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-nonfree --enable- hardcoded-tables --enable-avresample --enable-vda --cc=clang --host-cflags= --host-ldflags= --enable-libx264 --enable-libfaac --enable-libmp3lame --enable-libxvid libavutil 52. 48.101 / 52. 48.101 libavcodec 55. 39.101 / 55. 39.101 libavformat 55. 19.104 / 55. 19.104 libavdevice 55. 5.100 / 55. 5.100 libavfilter 3. 90.100 / 3. 90.100 libavresample 1. 1. 0 / 1. 1. 0 libswscale 2. 5.101 / 2. 5.101 libswresample 0. 17.104 / 0. 17.104 libpostproc 52. 3.100 / 52. 3.100
Input #0, matroska,webm, from ‘video.mkv': Metadata: creation_time : 2011-05-11 09:25:47 Duration: 00:49:01.35, start: 0.000000, bitrate: 2851 kb/s Stream #0:0(eng): Video: h264 (High), yuv420p(tv, bt709), 1280x720, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default) Stream #0:1(eng): Audio: ac3, 48000 Hz, 5.1(side), fltp, 384 kb/s (default) (forced) Stream #0:2(eng): Subtitle: subrip
[NULL @ 0x7fa0d901e600] Unable to find a suitable output format for 'mpeg4'
mpeg4: Invalid argument

Any idea what's going on?

EDIT: I intended to use ffmpeg after DivX Converter - both on Mac and Windows - would fail at various points trying to transcode a video to DivX Home Theater profile. The closest I got was shlck's answer. It threw up only warnings (rather than errors.) In any case, I couldn't get the video to play on the DVD player (it would freeze every 10 seconds for about 6 seconds). If you've found this question while trying to research the creation of a DivX Home Theater profile-compatible video, you could possibly use this string as a starting point to figure out what's wrong, and post a new follow up question to SU:

ffmpeg -i video.mkv -s 720x406 -codec:v mpeg4 -bf 1 -b:v 2567k -mbd 2 -g 300 -flags cgop -sc_threshold 1000000000 -acodec copy video.avi

(In the end I gave the old DVD player away).

1 Answer

You have a lonely -s option there. It misses its argument.

You should specify the size you want or leave it out entirely – otherwise it will not interpret -codec:v correctly and assume mpeg4 is your output filename.

Additionally, use -b:v instead of just -b – it's ambiguous.

ffmpeg -i video.mkv -s 1280x720 -codec:v mpeg4 -bf 1 -b:v 2567k -mbd 2 -g 300 -flags cgop -acodec copy video.avi