Re: a common DVB infrastructure

["Jared D. McNeill" <jmcneill%invisible.ca@localhost>]

Manu Abraham wrote:
> Hi All,
>
> About myself: i do some freelance development with regards to DVB, as of
> till date it has been with regards to Linux-DVB as a whole.

Welcome Manu, and thanks for your interest in NetBSD!

> Intention:
>
> I do write this post in the regards that a cross platform DVB API can
> exist, which can be used under other platforms as well.
>
> This platform should eventually be backward compatible for existing
> systems.
>
>
> I do understand that, for an older system it can be made practical to
> have a compatible layer to do a translation. But in the case of a newer
> system, there will be newer parameters etc.
>
> In such a case, in the case of a newer system, what about the usability
> with existing applications, as they need to select something new.
>
> In the case of older systems, i was made aware that proplib is used with
> BSD with a key-tag approach which sounds practical. In the case of Linux
> this is not available. As far as i have asked people around they do not
> prefer a library to interface with the kernel IOCTL's but would like to
> use the ioctl's directly. This has been seen with the ALSA driver
> subsystem under Linux, where people do hate that userspace library.
>
> This is one case where i am lost.

I think comparing proplib to the ALSA libraries is unfair. In this 
situation, proplib merely manages encoding and decoding messages, in 
essence a wrapper around ioctl. From the application writer perspective 
instead of reading back say a "struct dvb_mumble", you would receive a 
prop_dictionary_t that you can query. Likewise, to send data to the 
kernel, you simply create a prop_dictionary_t and fill it in.

> Another aspect is the area where the GPL vs BSD licenses do clash.
> For example some vendors (hardware manufacturers) do state the work
> being done with their support be GPL'd. This happens to exist for some
> new drivers that i happen to work upon.

GPL drivers can be made functional, with a few caveats:

  1. We (or people who use NetBSD as a base for their own systems)
     cannot distribute binaries that include your GPL'd device drivers.
     This is a restriction of GPL, not our license.
  2. We could theoretically ship source-only drivers, but that is only
     really useful for end users of our system.

To achieve end-user support these drivers could be shipped as kmods, but 
at the end of the day I think the best approach is to have talks with 
these vendors and ask them to reconsider.

Cheers,
Jared