[asterisk-dev] codecs.conf code for Opus and SILK?

[Matt Fredrickson]

Hey Alex,

Good to see you here on the mailing list, as well as on gerrit, and
hope you have been doing well :-)

On Thu, Dec 15, 2016 at 10:23 AM, Alexander Traud
<pabstraud at compuserve.com> wrote:
> Since Asterisk 13.12, Digium offers those audio codecs thanks to commercial but free transcoding modules. Those are closed source. Is it possible to get (just) the code related to loading the configuration file codecs.conf?

I'm going to say 'no' for now.  If you're concerned about it being
challenging to write code to interpret Asterisk's conf files, there
are examples of how to do so all over the Asterisk source tree - most
channel drivers load .conf files and parse them and might be one place
to start looking for examples.  If you have questions about a
particular codec option that you don't understand, we can answer any
questions about it that might clarify its function as well.

> You know, I have open-source modules of those audio-codecs available on <https://github.com/traud?tab=repositories&q=asterisk>. If I implement the same codecs.conf code, users could switch between to/from the Digium variant more easily, especially macOS users. Any chance?

That's certainly an avenue that you as an independent developer can
pursue, if you'd like and would probably be very nice for any users of
both codec modules :-)

>> pass-through including fmtp negotiation (level 1)
>>  |   pass-through plus library detection in ./configure (level 2)
>>  |   |   transcoding module in codecs/codec_* (level 3)
>>  |   |   |
>> [x] [x] [x] GSM-EFR; GSM-FR is available already
>> [x] [x] [x] AMR
>> [x] [x] [x] AMR-WB
>
> A small follow-up on that E-mail from last year. I submitted Codec 2 and iLBC 20 into Asterisk and it got included.
>
> I did not add GSM-EFR or AMR(-WB) because users might get confused that those are available only as pass-through but not as transcoding modules. If somebody has an idea how to advertise this fact correctly to users (like a message somewhere: "you can download a transcoding module from xyz"), any ideas are welcome.
>
> Since Asterisk 13.12, menuselect offers the ability to download binary modules. Could that be extended to download source code files? In that case, users could download such a transcoding module via menuselect.
>
>
>
> By the way, just to make a bit of advertisement, last month I added a transcoding module for the successor of AMR-WB to my GitHub as well: 3GPP Enhanced Voice Services (EVS) <https://github.com/traud/asterisk-evs>. Hopefully that is useful not only to me.

>From our standpoint, it's probably not a good idea for us to be openly
endorsing or linking to codecs that could lead back to us (as
benevolent stewards over the project) being perceived as aiding or
abetting in codec patent infringement, particularly with regards to
some of the commonly used mobile codecs (AMR and kin).  I think that
given how long it's taken us to get a sanctioned version of the opus
codec out there, it's not going to be surprising that my answer to
your question is 'no' for now.

I *sincerely* apologize for that answer :-(  I'm sure that it is
disheartening to hear, but the liability impact of a legal mistake to
us, as a business, is potentially a lot larger than to you as an
individual.

-- 
Matthew Fredrickson
Digium, Inc. | Engineering Manager | Asterisk Open Source Lead
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA