hell its a normal file.
and dash is this:
http://en.wikipedia.org/wiki/Dynamic...ming_over_HTTP
If you download a file, you download all dash parts and mux the dash parts together into in this case the m4a container. Thats how downloaders do it. Thats why for example jdownloader 2 needs ffmpeg for the dash videos of youtube.
But I tested out with jdownloader 2 and apparently Winamp can read m4a container.
At least the m4a could opened by winamp. And on youtube it was a dash video as well.
a raw aac stream works as well.
Maybe he downloads it wrong then?
edit:
Tried his videolink but the video was deleted:
http://abload.de/img/unbenannt162hlpgi.png
edit2:
here mediainfo of a m4a by jdownloader 2.
code:
Allgemein
Vollständiger Name : D:\JDownloader\downloads\Cliff Lin - Total Annihilation (256 kbit_s).m4a
Format : MPEG-4
Format-Profil : Base Media
Codec-ID : isom
Dateigröße : 5,63 MiB
Dauer : 3min 5s
Modus der Gesamtbitrate : konstant
Gesamte Bitrate : 255 Kbps
Kodierendes Programm : Lavf55.21.102
Audio
ID : 1
Format : AAC
Format/Info : Advanced Audio Codec
Format-Profil : LC
Codec-ID : 40
Dauer : 3min 5s
Bitraten-Modus : konstant
Bitrate : 254 Kbps
Kanäle : 2 Kanäle
Kanal-Positionen : Front: L R
Samplingrate : 44,1 KHz
Stream-Größe : 5,60 MiB (99%)