copy-mode extract of audio from youtube flv video

moob8 · 12-06-2006, 07:27 PM

I would like to extract the audio from a youtube (.flv) file without re-encoding it. When I play the video with mplayer and watch the console (text) output I see that the audio is in mp3 form. Despite this, I cannot extract that to an mp3 file (attempts using mencoder and also with transcode). I can use transcode to extract the audio but only in a way converts it to PCM ... which is not what I want.

By the way, extracting just the video part (no sound) in copy-mode (not-re-encoding) is easy:

Code:

mencoder -of avi -nosound -ovc copy in.flv -o out_just_vid.avi

David the H. · 12-07-2006, 01:39 PM

Try this:

'ffmpeg -i inputfile.flv -f mp3 -vn -acodec copy ouputfile.mp3'

That should do it for most files.

Apparently there are some microphone-recorded .flv files that use a proprietary codec that doesn't have any open source support. I don't know how common those are in the wild.

osor · 12-07-2006, 06:12 PM

The easiest and most elegant (IMO) way is:

Code:

mplayer -dumpaudio in.flv

This should leave a file called stream.dump in the original audio format (perhaps mp3), just extracted from the flv container.

moob8 · 12-07-2006, 08:23 PM

David The H. and osor, I tried both your methods and both worked! Not only that, the files produced by the two methods are identical. Most excellent! Thank you both! Yay!

fakie_flip · 05-01-2008, 01:58 AM

Quote:

Originally Posted by moob8

David The H. and osor, I tried both your methods and both worked! Not only that, the files produced by the two methods are identical. Most excellent! Thank you both! Yay!

How come neither worked for me

Code:

[root@localhost tmp]# ffmpeg -i video.flv -f mp3 -vn -acodec copy carsounds2.mp3 
FFmpeg version SVN-r10703, Copyright (c) 2000-2007 Fabrice Bellard, et al.
  configuration: --prefix=/usr --incdir=/usr/include/ffmpeg --libdir=/usr/lib64 --shlibdir=/usr/lib64 --mandir=/usr/share/man --arch=x86_64 --extra-cflags=-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic --enable-liba52 --enable-libfaac --enable-libfaad --enable-libgsm --enable-libmp3lame --enable-libogg --enable-libtheora --enable-libvorbis --enable-libxvid --enable-libx264 --enable-pp --enable-pthreads --disable-static --enable-shared --enable-gpl --disable-debug --disable-opts --disable-strip
  libavutil version: 49.5.0
  libavcodec version: 51.45.0
  libavformat version: 51.14.0
  built on Oct 18 2007 03:18:27, gcc: 4.1.2 20070925 (Red Hat 4.1.2-31)

Seems stream 0 codec frame rate differs from container frame rate: 1000.00 (1000/1) -> 25.00 (25/1)
Input #0, flv, from 'video.flv':
  Duration: 00:09:58.7, start: 0.000000, bitrate: 56 kb/s
  Stream #0.0: Video: flv, yuv420p, 320x240, 25.00 fps(r)
  Stream #0.1: Audio: mp3, 22050 Hz, mono, 56 kb/s
Output #0, mp3, to 'carsounds2.mp3':
  Stream #0.0: Audio: libmp3lame, 22050 Hz, mono, 56 kb/s
Stream mapping:
  Stream #0.1 -> #0.0
Press [q] to stop encoding
size=    4188kB time=598.8 bitrate=  57.3kbits/s    
video:0kB audio:4188kB global headers:0kB muxing overhead 0.000746%
[root@localhost tmp]#

Code:

[chris@localhost tmp]$ mplayer -dumpaudio video.flv 
MPlayer 1.0rc2-4.1.2 (C) 2000-2007 MPlayer Team
CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ (Family: 15, Model: 43, Stepping: 1)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing video.flv.
libavformat file format detected.
[lavf] Video stream found, -vid 0
[lavf] Audio stream found, -aid 1
VIDEO:  [FLV1]  320x240  0bpp  25.000 fps    0.0 kbps ( 0.0 kbyte/s)
Core dumped ;)

Exiting... (End of file)
[chris@localhost tmp]$

Dumping only the video has worked, but that's not what I want. Please help.

fakie_flip · 05-01-2008, 02:02 AM

I'm trying to get the audio only from here. I've already got the video.flv from that youtube site. Please help.

http://www.youtube.com/watch?v=Ejb8QOyjz-E&

I tried putting together some of my own commands just as a test. Here are the results.

Code:

[root@localhost tmp]# mencoder -novideo -ovc copy video.flv -o ultimatecarsounds2.mp3
MEncoder 1.0rc2-4.1.2 (C) 2000-2007 MPlayer Team
CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ (Family: 15, Model: 43, Stepping: 1)
CPUflags: Type: 15 MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.

WARNING: OUTPUT FILE FORMAT IS _AVI_. See -of help.
success: format: 0  data: 0x0 - 0x16ed37e
libavformat file format detected.
[lavf] Video stream found, -vid 0
[lavf] Audio stream found, -aid 1
Video stream is mandatory!

Exiting...
[root@localhost tmp]#

That indicates the audio is there!

fakie_flip · 05-01-2008, 03:03 AM

Nevermind, problem solved. I used Avidemux.

bruce384 · 06-23-2008, 12:29 AM

To get the audio from a bunch of .flv files I use

for i in *.flv; do ffmpeg -i $i -f mp3 -vn -acodec copy $i.mp3 ;done

By the way; this linuxquestions format is a pain in the ass. Try to log in and then find the question you were trying to answer is nuts. The thread disappeared after I loged in.

bruce

David the H. · 06-23-2008, 02:45 AM

Quote:

Originally Posted by bruce384

By the way; this linuxquestions format is a pain in the ass. Try to log in and then find the question you were trying to answer is nuts. The thread disappeared after I loged in.

Open up a new tab or window, log-in there, then go back to your original tab and hit refresh. Problem solved.

jschiwal · 04-13-2009, 01:35 AM

Fakie_Flip: The video you posted is an mp4 file and not a flash video. It uses aac codec rather than mp3.

I was able to extract the audio easily with: ffmpeg -i Ultimate_Car_Sounds__Part_II.mp4 -vn -acodec copy ucs.m4a

I could have transcoded it to another audio format/codec.

Generally I will first play the source with "ffmpeg -identify <video_file>" and study the text output for what make up the video and audio streams. You can't go by the extension. It just indicates the container.

nancy0903 · 07-17-2009, 01:30 AM

but i usually chose Audio Recorder

David the H. · 07-17-2009, 03:14 AM

Edit: deleted.

I should've noticed this was an older thread. I'd already replied to this one.

bijukn · 01-11-2010, 07:23 AM

use winff

eay · 02-14-2010, 02:11 AM

I know this is an old thread, but I found a solution over at UbuntuForums and thought I would post it here, too:

http://ubuntuforums.org/showpost.php...1&postcount=14

cheers,

ethan

random-tux · 08-18-2011, 05:23 PM

This way seems to work well (and one can see fast video meanwile ;-) ):

mplayer -ao pcm input.flv -ao pcm:file="output.wav"