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AAC ripped from Youtube unplayable

Started by terbenel, March 24, 2013, 12:08:13 am

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terbenel

Note: the audio in most Youtube videos with 360p+ resolution is AAC 64k/128k.

When I rip the AAC using Avidemux 2.5.6 (Audio > Save audio), I'm unable to play the output file (tried Potplayer and MPC-HC.) I've read that AAC tracks need an MP4 container, but I'm not sure how to do that in Avidemux. And now that I've ripped the audio, Avidemux doesn't recognize the output.

styrol

Do not use Avidemux if you simply wanna get a M4A audio file, it cannot output it.

Try Audacity (Audio Editor), XMedia Recode (video and audio converter/ripper).

Or on commandline using ffmpeg:
ffmpeg -i "input.mp4" -c:a copy -strict experimental -vn -sn -threads 8 -y "output.m4a"

terbenel

Thanks for the tips. I found that using ffmpeg directly worked best for my purposes. Except that I dropped some of the switches you've indicated as they're specific to encoding.

This was sufficient to extract playable AAC from Youtube FLV/MP4 sources:
ffmpeg -i "input.mp4" -c:a copy -vn "output.m4a"

dare2die

Sorry for bumping this old thread.


I'm still new to "non-gui" usage. How do i run the command line for FFmpeg? (Online tutorials assume you know what a command line is...)

Clicking on "ff-prompt.bat" after downloading FFmpeg, i get a ">"

where do i add in your stated: ffmpeg -i "visionvideo.mp4" -c:a copy -vn "output.aac"

What do i type in to locate the video file i want to extract the audio from?

Thanks for all advice!

snork

February 19, 2014, 07:47:28 pm #4 Last Edit: February 19, 2014, 08:07:33 pm by snork
Hej,

that someone else must explain, I never used ffmpeg directly/ through commandline.
I don't even know if that "ff-prompt.bat" called for Windows-default-commandline, or did it bring it's own shell ?


I can only offer a quick&dirty workaround, only to be used if the audiotrack in the final video does NOT need to be AAC.

I had a problem somewhat similar to the original poster's, trying to rip AAC from one mp4 file (French) and add it to other mp4 file (German) as secondary audiotrack.
I got nowhere with this problem with avidemux, until I resorted to this trick :
- I loaded the (French) video, did Video:copy, and audio:encode with lame(mp3)
- Then I loaded that new video and did "save audio", saved as french.mp3.
- Then I loaded the German-language file, and could choose the mp3-file as (secondary) audio-track. (menu : Audio -> select track)

Now it plays fine in VLC, and I can easily switch to and fro German/ French. :)

- I did not try, as I was happy then, but maybe I could have loaded the Videofile with mp3 soundtrack, and then encode it again with video:copy and  audio encode:AAC.
That would of course be two unnecessary re-encodings, so loosing somewhat in quality. So in the first step, I would then probably have reencoded the audio as/to PCM (beware - filmsoundtrack files in PCM get large, in the gigabyte range) that doesn't work for me, no PCM output. :(

Quote from: styrol on March 24, 2013, 09:39:43 am
Do not use Avidemux if you simply wanna get a M4A audio file, it cannot output it.


Could you add this to somewhere in the wiki ? it is valuable info, maybe keeping more users from trying to do so ?

dare2die

Thanks for your reply! It's nice when others answer our questions!

However, mp3 is not an option for me as (being particular) i want to losslessly copy the audio. I do not want to degrade the audio by transcoding.

I'll have to start look for alternatives...

dare2die

Hmmm, i think i've figured it out. I am such a noob! :P

Turns out all you need to do is to use the Windows default command line, found in Accessories. I assumed it was a "special" command line found somewhere inside the ffmpeg folder.

Me wishes there was a GUI for everything! XD

snork

hehe, me too, I assumed that might be possible, with the prompt not being c:\here\and\there>  :D

and, yes, I am often a bit tolerant towards audio "technical quality". One has to, when you like older African music. (wornout vinyl, and evenmorewornout tapes)

Good luck then with it.

styrol

February 19, 2014, 08:46:58 pm #8 Last Edit: February 19, 2014, 08:49:42 pm by styrol
Quote from: dare2die on February 19, 2014, 08:11:32 pm
Me wishes there was a GUI for everything!

That's why I recommended software with a GUI (internally using FFmpeg and other components), if you are not familiar to CLI:
Quote from: styrolTry Audacity (Audio Editor), XMedia Recode (video and audio converter/ripper).

And there is a program named WinFF which is a simple GUI to FFmpeg (only). IMHO XMedia Recode is the most powerful and easy-to-use software what converting on the windows platform is concerned.

STFU

If you just want to rip the .aac out of a flash based file, you can use  FLV Extract, this is not gonna work for .webm files off course, but if you want to rip the audio straight from youtube there are javacripts out there that can do that & present you with a download link, no conversions. Then when want put the audio & vdeo together you can also do that with mp4box, wich is a commandline utility but has numerous GUI's  availible.

dare2die

Thanks for all replies! I will check out the other softwares mentioned...

But as for the (hijacked by me) topic, i think everything is solved for now!


P.s. Now that i know how to use ffmpeg through command line, suddenly everything seems so easy. I losslessly extracted AAC audio from an MP4.

P.s.s. Tip for others, in Windows command line, you can actually DRAG & DROP files or folder locations. U don't have to type out the WHOLE path of each file/folder (like i was doing...).