Finding out what’s in an FLV
I must confess, I pay attention to my Tumblr dashboard about once a week and even then only if I’m not busy with other things. This in in sharp contrast to, for example, Twitter, which has a typical latency of about 30 seconds.
As such, I hadn’t noticed Paul Mison reblogging my lossless H.264+AAC FLV to MP4 container conversion tip (doesn’t that just roll off the tongue).
He commented…
Now all I need to do is find out how to tell what the composite formats of a given FLV are.
Well, seek no more. The quickest (and arguably dirtiest, as it technically bitches about it) method is possibly:
ffmpeg -i file.flv -an -vn
Which will give you output such as:
FFmpeg version SVN-r19356, Copyright (c) 2000-2009 Fabrice Bellard, et al.
configuration: --enable-gpl --enable-nonfree --enable-pthreads --enable-libfaac --enable-libfaad --enable-libmp3lame --enable-libtheora --enable-libx264 --enable-libxvid --enable-x11grab --prefix=/opt/txsuite
libavutil 50. 3. 0 / 50. 3. 0
libavcodec 52.32. 0 / 52.32. 0
libavformat 52.36. 0 / 52.36. 0
libavdevice 52. 2. 0 / 52. 2. 0
libswscale 0. 7. 1 / 0. 7. 1
built on Jul 6 2009 11:18:48, gcc: 4.3.2
Seems stream 0 codec frame rate differs from container frame rate: 50.00 (50/1) -> 25.00 (25/1)
Input #0, flv, from 'file.flv':
Duration: 00:28:37.05, start: 0.000000, bitrate: N/A
Stream #0.0: Video: h264, yuv420p, 832x468 [PAR 117:117 DAR 16:9], 25 tbr, 1k tbn, 50 tbc
Stream #0.1: Audio: aac, 48000 Hz, 2 channels, s16
At least one output file must be specified
You can do the same thing with mplayer, too, if you don’t have a retarded build:
mplayer -identify -frames 0 -vc null -vo null -ao null file.flv
