How to convert mjpg file type to mpeg or flv?

Question

I`ve already asked how to do it with ffmpeg but nobody replied. Maybe anybody know how to convert from mjpeg format? Do not suggest to use virtual dub to convert to avi as all it does is putting mjpeg inside avi container and I need to convert from mjpeg to some other format like mpeg or flv.

Answer 1

Your problem with that file is actually the audio sampling rate, 11024 Hz isn't supported by MP3. Easy enough to fix:

ffmpeg -i MVI_2130.avi -ar 11025 test.flv

Of course, there are a lot of quality options you may want to set, such as the video (-vb) and audio (-ab) bitrates.

The ffmpeg output actually told you this:

FFmpeg version SVN-r19468, Copyright (c) 2000-2009 Fabrice Bellard, et al.
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Output #0, flv, to 'test.flv':
    Stream #0.0: Video: flv, yuv420p, 320x240, q=2-31, 200 kb/s, 90k tbn, 15 tbc
    Stream #0.1: Audio: libmp3lame, 11024 Hz, 1 channels, s16, 64 kb/s
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Error while opening encoder for output stream #0.1 - […]

Note how the error was with stream #0.1, which is the audio stream. It (unfortunately!) doesn't tell you that the sample rate is wrong; you just have to know what your output codec is capable of. And for mp3, that's 8000, 11025, 12000, 22050, 24000, 32000, 44100, and 48000 Hz according to Wikipedia.