Re: LF: Testing Audioinjector Octo with RPi3

[Paul Nicholson <vlf0403@abelian.org>]

> I could easily add support for uncompressed data via raw TCP
> (or even UDP) again,

Well I'm wondering what the best way is to get the signal
stream out of the Pi and into SL.  rawtcp:// works already
and receives the vorbis compressed stream.

Eg, vlf6 can be read from the stream server using
rawtcp://78.46.38.217:4406

But it can lose a dB or two on a weak signal through the
compression.  The weak signal is buried deep in the noise
and vorbis encodes the background noise using just a few
bits. [*]

So for it to work best, SL needs to pull down uncompressed
signal.  It doesn't have to read the vlfrx-tools block header
which tells the sample rate, format and number of channels
and timestamp.  It can do if it wants to, but really it only
needs to stream the raw samples, without protocol, without
headers, no block boundaries, just an endless stream of frames.

I couldn't remember if SL could do that already.  I have
a vague memory of you and Jacek doing something along those
lines a few years ago.

It would have to be TCP - it would go horribly wrong when
UDP drops a packet.

[*] That's with the typical 80kbps of the variable rate
stream we usually use for WAN streaming.  I've never actually
measured the loss on a LAN where a much higher bit rate could
be used.

--
Paul Nicholson
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