How can I extract audio from FLV?

Question

I need to extract the audio from a FLV file recorded using FMS. I used the SPEEX coded in my flash application that streams the audio and video to FMS.

I have tried using FFMPEG, with no luck. This is the -i outputs of my FLV:

FFmpeg version SVN-rUNKNOWN, Copyright (c) 2000-2007 Fabrice Bellard, et al. configuration: --enable-gpl --enable-pp --enable-swscaler --enable-pthreads --enable-libvorbis --enable-libtheora --enable-libogg --enable-libgsm --enable-dc1394 --disable-debug --enable-shared --prefix=/usr libavutil version: 1d.49.3.0 libavcodec version: 1d.51.38.0 libavformat version: 1d.51.10.0 built on Apr 23 2010 15:11:13, gcc: 4.2.4 (Ubuntu 4.2.4-1ubuntu3) [flv @ 0xb7ed7110]Unsupported audio codec (b) [flv @ 0xb7ed7110]Unsupported audio codec (b) Input #0, flv, from 'm.flv': Duration: 00:00:05.0, start: 0.000000, bitrate: N/A Stream #0.0: Video: flv, yuv420p, 288x203, 1000.00 fps(r) Stream #0.1: Audio: 0x000b, 11025 Hz, mono

I need a command line utility, since this will be executed from a server.

Thanks in advance.

Any chance I could have a copy of your FLV? I am trying to find any working example of Speex contained in an FLV, to debug my app. All the examples I can find are broken. See my question. — finnw

kagali-san kagali-san · Accepted Answer · 2010-10-06T21:16:50

Typical flv:

flv @ 0x152ba80]Estimating duration from bitrate, this may be inaccurate [lavf] stream 0: video (flv), -vid 0 [lavf] stream 1: audio (mp3), -aid 0 VIDEO: [FLV1] 320x240 0bpp 25.000 fps 250.3 kbps (30.6 kbyte/s)

To read this, ffmpeg must be compiled with additional options:

  --enable-gpl --enable-nonfree --enable-libmp3lame

Then,

ffmpeg -i flvfile 1.mp3

How can I extract audio from FLV?

2 Answers