ffmpeg: Proper way to encode ac3 to aac?

Question

I have actually encoded an audio file from ac3 to aac using ffmpeg native aac encoder but the issue is that the file is not playing correctly , more specifically i have played that file in different media player but most of them start from 19 seconds and in vlc it is not even starting till I seek to more than 19 seconds duration.

command i have used is :- ffmpeg -i source.mkv -map 0:a:0 -c:a aac audio.mp4.

Solution

That is the proper way.

Don't know if this will make a difference, try -b:a 400k and -strict experimental.

If you want audio only, convert to m4a or aac.

ffmpeg -i input.mkv -y -c:a aac -b:a 400k -map 0:a:0? -strict experimental output.mp4

Other encoders, may require compiling ffmpeg with use flags:

http://trac.ffmpeg.org/wiki/Encode/AAC

libfdk_aac

libfaac