[linux-audio-dev] LV2 buffersize extensions (was: LADSPA...)

Steve Harris steve at plugin.org.uk
Mon Jan 29 17:22:38 UTC 2007

On 29 Jan 2007, at 16:51, Florian Schmidt wrote:

> On Monday 29 January 2007 09:08, Steve Harris wrote:
>> Ah, well the host is not supposed to change port values during run()
>> anyway, the idea in LADSPA (and LV2) is that the host should chop the
>> run() block where port values change. In practice not all hosts do
>> that, some just pick a suitably small block size, eg. 32 frames and
>> quantise the changes to that rate.
> Hi, let me chime in because it kidna fits into the subject.
> I have defined two (very very simple LV2 extensions):
> "The extension’s URI is
> http://tapas.affenbande.org/lv2/ext/fixed-buffersize
> All that a plugin needs to check is whether a host feature with  
> this URI
> exists and the data will be a uint32 containing the buffersize.
> The host is only allowed to call the plugin’s run function with a  
> buffersize
> equal to the one specified by the host feature.
> There’s a second extension:
> http://tapas.affenbande.org/lv2/ext/power-of-two-buffersize
> which is identical to above but with the additional requirement  
> that the fixed
> buffersize has to be a power of two."

Great idea. I've got some plugins that will benefit a lot by this. We  
should link to known extensions on the http://lv2plug.in/ site.

FWIW, my provisional plan was to wait until it seemed like time for a  
LV2 1.1 (hopefully not too soon :), then roll all the "popular"  
extensions into that.
It doesn't make a huge amount of difference whether their included or  
not though.

Before you ask, no I don't have a definition for "popular".

- Steve

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