[LAD] [ann] CAPS 0.4.5

[David Robillard]

On 30/03/11 07:40 AM, Stefano D'Angelo wrote:
> 2011/3/30 David Robillard<d at drobilla.net>:
>    
>> On 29/03/11 02:59 PM, Tim Goetze wrote:
>>      
>>> [Philipp �berbacher]
>>>
>>>
>>>        
>>>> Excerpts from Stefano D'Angelo's message of 2011-03-28 22:59:46 +0200:
>>>>
>>>>          
>>>>> This means, if you change the port signature and maintain the same
>>>>> UniqueID, we would have incompatibilities in the LV2 world. If you
>>>>> create a new plugin or don't touch ports, instead, everything's fine.
>>>>>
>>>>> Stefano
>>>>>
>>>>>            
>>>> I'd say you'd even have incompatibilities in LADSPA world. Even fixes in
>>>> LADSPA plugins would sometimes need a new ID (This was discussed a while
>>>> ago regarding a LADSPA that has an unintuitive port order).
>>>>
>>>>          
>>> Lacking sufficient knowledge of all the LADSPA hosts out there, I'm
>>> unable to judge how many will cope with the addition of a port to an
>>> existing plugin and how many will not.
>>>
>>>        
>> /Adding/ a port is probably fine, since hosts can just use the default value
>> or connect it to silence.
>>
>> However, "adding" here really means "appending": the new ports must be added
>> on to the end of the ports (by index). Definitely do NOT change existing
>> indices for ports, that will definitely break a lot of things in horrible
>> ways! It's not even possible to properly cope with that situation.
>>      
> Mmm.. so I could maybe add the port number to the URI and add
> dc:replaces, like this:
>
> <urn:ladspa:1234:5>  a lv2:Plugin ; dc:replaces<urn:ladspa:1234>  .
>
>    
You could to this, but the URI is changed, and that URI doesn't adhere 
to the standard LADSPA URI scheme (don't do that).
> Yet, I should send patches to those plugin authors providing both LV2
> and LADSPA versions of their plugins (the same holds true for DSSI, I
> guess).
>
> At the moment I don't seem to be able to come up with a better solution. :-S
>
>    
In LV2, the way to do this correctly is to add a connectionOptional 
port, and the URI does not have to change. You would have to special 
case this, I suppose.

We could also just port CAPS :)

-dr