Re-index AAC track?

[stranno]

I am trying to extract AAC from Youtube video using MP4Box but it have been extracted without the index and audio players doesnt recognize the lenght and i cannot seek around.

Any way to reindex the track without converting it (lossing quality)?

Not much quality from Youtube but is the only free source for a track i want.

[leghorn]

If you have your YT file as flv:
Get the latest FLV Extract v2+, extract audio, remux to mp4/m4a, and maybe check "to audio only". Hit start and things are good.

[stranno]

Its MP4 container .

[AlanHK]

Try MP3DirectCut.
It can also open and edit AAC losslessly.
Get libfaad2.dll from http://rarewares.org/aac-decoders.php and put it in the program folder so it can read AAC.

Then just open the file and resave it.

[El Heggunte]

Try ffmpeg instead:

ffmpeg -i input.mp4 -vn -acodec copy output.mp4

[stranno]

MP3DirectCut keeps the track without the seek info and ffmpeg do exactly the same dump as mp4box, so no seek info or time info.

[poisondeathray]

what "audio players" are you using ?

[stranno]

what "audio players" are you using ?

foobar2000

[El Heggunte]

That's weird, over here foobar2000 has never had issues with MP4s or AAC streams

You could post a MediaInfo report about those MP4 files from YouTube,

also you could try other versions of foobar2000
(mine is 0.9.6.9, FWIW ---
--- I don't like the 1.x versions, but only because they apparently are not optimized for performance).

[poisondeathray]

and/or maybe the audio is messed up? or maybe you didn't download it properly?

how about providing the youtube link

[El Heggunte]

Hmmm, I've run some tests on some AACs demuxed from YouTube's videos, and ffmpeg is unable to remux them to MP4s

I had to use muxer.exe from the L-Smash package:

( http://sada5.sakura.ne.jp/files/index.php?folder=TC1TTUFTSA== )

muxer -i input.aac -o output.mp4

[poisondeathray]

Hmmm, I've run some tests on some AACs demuxed from YouTube's videos, and ffmpeg is unable to remux them to MP4s

If you don't demux them, it works fine, correct?

I think you need -absf aac_adtstoasc for demuxed aac input for ffmpeg

[El Heggunte]

....
I think you need -absf aac_adtstoasc for demuxed aac input for ffmpeg

Your thoughts are right

Pay attention, evil devilopers , ONLY ME has the right to complicate things