This is an unusual feed format - one I have never encountered before.
They are sort of a series of podcast.  
Podcast are either MP3 or MPEG4. This one is in AAC/ADTS format in a M3U
playlist.

To skip to a time point LMS needs to know the duration and size.
To skip to a time in a streamed podcast - the server has to support a
byte range HTTP header (i.e Accept-Ranges: bytes)

With MP3, to skip to a timepoint, the byte offset position is estimated
by file size and proportion of duration and then get data from that byte
position - playing starts at a further offset after finding a frame
header.
With MPEG-4 with AAC codec, the MPEG4 format has an index in header
which indicate the byte offset for the timepoint so that byte position
to start playing is accurate.

The duration of MP3 podcast are specified in feed or in the header for
MPEG4/AAC.  

This stream has duration specified in the M3U format file and it is
AAC/ADTS format which means MP3 technique needs to be applied (estimate
position and then seek using http byte-range and then look for start of
AAC frame)  but AFAIK LMS does not implement seeked streaming for
AAC/ADTS only the MPEG4.  I have not looked at code nor debugged so I
could be wrong.

I looked at something similar a few years ago and decided it was too
much effort, however Philippe_44 made a lot of change last year to add
extra support for MPEG4 streaming. I think  the "new" code only
implemented support MEPG4 for AAC.

The question is whether is it possible to add ADTS support without
adding complexity or requiring significant changes as it is a niche
case.


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