I've been examining the Winamp problem in more detail and I can confirm the findings in the other thread, thanks to PotPlayer's detailed format information.
General
...
Format : dash
Codec ID : dash (iso6/mp41)
...
Overall bit rate : 127 kb/s
...
Audio
ID : 1
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
...
Bit rate : 126 kb/s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 kHz
Frame rate : 43.066 FPS (1024 spf)
Compression mode : Lossy
...
Winamp supports the AAC/LC codec but it does not support the general Dynamic Adaptive Streaming over HTTP iso6/mp41 (container) format. The evidence is that it can play mp4 files with the same audio format and codec (Advanced Audio Codec / LC format with codec ID 40). In this case the container is formatted according to the MPEG-4 BASE Media / Version 2 with codec ID isom/mp42.
The mp4 files have the following general and audio formats:
General
...
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/mp42)
...
Overall bit rate mode : Variable
Overall bit rate : 358 kb/s
...
Video
...
Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
...
Bit rate mode : Variable
Bit rate : 96.0 kb/s
Maximum bit rate : 103 kb/s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 kHz
Frame rate : 43.066 FPS (1024 spf)
Compression mode : Lossy
Stream size : 5.37 MiB (27%)
Title : IsoMedia File Produced by Google, 5-11-2011
...
Since all the media players I could find on my PC support DASH I think it would be wise to add it to Winamp as well.
DASH support on other browsers & operating systems is available via Media Source Extensions (source:
https://en.wikipedia.org/wiki/Dynami...ming_over_HTTP).