From: Russell Kroll <rkroll@xxxxxxxxxxxx>
> There are a lot of things that can be decoded from the bitstream. What's
> available depends on the type of blocks being sent to us by the
> broadcaster. The most useful ones that come to mind right off are:
>
> - Program type (PTY) - News, Rock, other descriptions for what's on
> - Program name - 8 chars, usually a station's nickname ("MAGIC FM")
> - Radiotext - up to 64 chars, sometimes a song name (depends on source)
> - Clock - Assuming they have a good source, then you can sync from them
Possible with the PCM20 radio and used well by broadcasters.
> - Call sign - Kxxx or Wxxx in this country. Not sure for others...
Unknow to me and my card... (:
> Some of these elements occur more than others in the transmissions. The
> PTY, for example, is supposed to be in every type of block they send out.
> Things like the radiotext only show up once every few seconds.
This is completly one level deeper than what I can get from the PCM20.
> There are also interesting things like the traffic program / traffic
> announcement flags, which are genuinely useful when clueful broadcasters
> are in command. The intended purpose is to pause a CD or similar in order
> to let you hear their traffic report. Around here nobody actually uses
> it, so it's just a vaporware feature at best.
First: this kind of feature is in heavy use in Germany! And I can get
these flags. - What I dont know for sure is about the integration of
pre-RDS-standards on traffic announcement. Broadcasters (also?) send an
audible sign when the announcement starts and stops...
Here I intergrate unseen one of my novice questions: (:
Is it possible to extract RDS without hardware like with videotext? -
I've seen an interesting device which showed RDS (e.g. text) when
connected to the headphone-out of a standard radio!! As far as I
understood the spec this should be impossible...
> I can rig some code to parse the raw bits and turn it into useful data,
> but we'll need a clear structure for storing it. It would also be nice to
> be able to convey things directly to userspace for people with this card,
> since many of the blocks are defined by the broadcaster - that is, no
> existing format.
>
> Perhaps a series of types within the struct would be best... highlevel
> types like "program name" would be on both cards, but there could also be
> low level types like "3A open data application raw data" for the Cadet.
I would like this solution!
Bye,
Robert
