--extract-audio doesn't seem to work.

[bat999]

Hi
I've tried using the --extract-audio option.
What happens is a new file is created 'whatever.aac' but it contains 0 bytes and the downloaded flv file gets deleted.
Am I using it correctly?
youtube-dl --extract-audio http://www.youtube.com/watch?v=2bQZ6l_cq5Y&feature=feedrec_grec_index

Version is 2011.02.25c
Ubuntu 9.10
FFmpeg version git-2bbec1e

[rg3]

I don't know what could be wrong. youtube-dl is supposed not to delete the video if ffprobe or ffmpeg fail to run or exit with error. I'd try the following:

• Use youtube-dl to download the video normally.
• Then, run "ffmpeg -y -i VIDEO_FILE -vn -acodec copy -f adts -- FILE.aac"
• Then, run "echo $?" (this will print the exit status of ffmpeg).

Take note of the ffmpeg output and its exit status, so we can investigate what goes wrong in the process.

[bat999]

Hi
Yes, I've extracted the aac from a downloaded video as per your command above.
When I enter echo $? this is the reply:-
ron@ubuntu:~$ echo $?
0

[rg3]

If that works, youtube-dl should work too, because that's the exact same command youtube-dl tries to run when extracting the audio from the video file. I just tried locally here, and I get:

-rw------- 1 rg3 users 3549345 Feb 27 17:46 2bQZ6l_cq5Y.aac

[bat999]

Yes, I also have the file 2bQZ6l_cq5Y.aac.
But it is empty, zero bytes.

[rg3]

I'll think about it a bit more and maybe I'll post some special version of the program to get more information. In the mean time, I suspect a very weird problem. If ffmpeg failed to run for some reason, the file wouldn't even be created. The fact that it exists and has zero bytes signals a very very strange problem. I don't know what could be wrong right now.

[rg3]

This version will print the ffmpeg command, and will not redirect its output, so you can see what ffmpeg is doing:

https://gist.github.com/baf002a3049c7861d2f2

[bat999]

OK thanks.
But the 2bQZ6l_cq5Y.aac file that you have, is it not zero bytes too?

[bat999]

I've pasted the terminal output.
ffmpeg started to convert, then it just hung there doing nothing:-
Press [q] to stop encoding

Here is the output:- http://pastebin.com/aPpRxPc3

[rg3]

I think you're confused. As you did not quote the URL, the shell interpreted the command as something to be launched in the background. The process probably finished, but you don't see the prompt appear.

[rg3]

About your previous question, no, my AAC file is not empty. I pasted the "ls -l" in a comment above.

[bat999]

"As you did not quote the URL"
Please explain what this means.

My command was:-
ron@ubuntu:~$ ./tester --extract-audio http://www.youtube.com/watch?v=2bQZ6l_cq5Y&feature=feedrec_grec_index

The URL is included there:-
"http://www.youtube.com/watch?v=2bQZ6l_cq5Y&feature=feedrec_grec_index"

What do you mean?

[rg3]

I mean to put the URL in quotes, as in:

./tester --extract-audio 'http://www.youtube.com/watch?v=2bQZ6l_cq5Y&feature=feedrec_grec_index'

[bat999]

Hi
Yes, the command does work properly when I enclose the URL in quotes.
That's the solution.

My excuse is that when I do normal downloads it's not necessary to use quotes. ;-)

Thanks for your patience.

[rg3]

No problem, I'm closing the issue since it's a non-issue.