[Spice-devel] Bug#603699: ITP: celt051 -- The CELT codec v0.5.1

[Gerd Hoffmann]

On 11/17/10 13:04, Ron wrote:
>
> Hi Hans,
>
> Hans de Goede writes:
>> The if at all part depends on if it will be doable without too much
>> pain to support both celt-0.5.1 and celt "1.0" in the same binary.

Should work without major trouble, the symbols exported by the shared 
library have a versioned prefix.

>> This is important to us as we care a lot about protocol
>> compatibility.
>
> Are you seriously telling me that you have no plan whatsoever for how
> to transition from a random snapshot of an experimental codec,

We can transition just fine.  server + client can signal supported 
codecs using capabilities.  We can even support something completely 
different such as ogg or mp3 (once the patents are expired).  We just 
don't want transition from one random celt snapshot to another random 
celt snapshot and the next random celt snapshot next year.

 > But so far, all have accepted this _is_ an experimental
> codec, and they must be prepared to move with it.  The interested app
> maintainers and upstream discussed this, and we settled on 0.7.1 as the
> next stable epoch for things that want broad interoperability.

We settled on 0.5.1 for interoperability.

/me figures the latest celt version is 0.9.1.  The web page lists both 
0.5.1 and 0.7.1 in the "provided mainly for historical reasons" section. 
  So you picked a random snapshot too, just another one.

> Are you aware there may never be a celt 1.0?  We have roughly 2 years
> from today before any version of spice will have a chance to be even
> considered for the next Debian stable release - and if things go as
> expected, it will not include any version of celt at all.  There will
> instead be a new (and standardised) codec that was spawned from it and
> merged with other codec work.

When celt merges with others and gets renamed in that process -- no 
problem.  Once the bitstream format is stable we'll happily support it. 
  But even then we will not drop celt 0.5.1 support to maintain 
compatibility with older installations.

> If that means an update to the spice bitstream protocol, now might be a
> good time to explore one.

Isn't going to happen.

If you don't want package celt 0.5.1 -- fine.  You can patch your spice 
server and client to just not signal the celt capability, and they will 
interoperate just fine with everybody else using raw uncompressed audio. 
  But IMHO it would be stupid to not support audio compression in your 
spice packages.  That is your call though.

cheers,
   Gerd