[LAD] Re : Saving plugin presets

[Stefan Kost]

Paul Davis schrieb:
> On Wed, 2009-01-21 at 23:07 +0200, Stefan Kost wrote:
> 
>> Seems to be a nice library, but it looks already too capable for the task at
>> hand. The idea is to agree on a simple format, so that we don't add a hidden
>> dependency for a certain library to parse it. Therefore no xml, rdf etc..
> 
> No, no, and a hundred times no. This is the code needed in ardour to
> load a named preset:

I got ensure in a previous thread, that the rdf approach is flawed, as you can't
get a list of presets for each plugin. I got no answer how its supposed to work.
What an application would want to do is:
* scan LADSPA_PATH for plugins
* get the rdf blob for each
* build a list of presets for each plugin

If I just got it wrong and this is how its supposed to work, we don't need
anything, but a pointer to code that does this.

Stefan

> 
> ---------------------------------------------------------------
> bool
> Plugin::load_preset(const string preset_label)
> {
> 	lrdf_defaults* defs =
> lrdf_get_setting_values(presets[preset_label].c_str());
> 
> 	if (defs) {
> 		for (uint32_t i = 0; i < (uint32_t) defs->count; ++i) {
> 			// The defs->items[i].pid < defs->count check is to work around 
> 			// a bug in liblrdf that saves invalid values into the presets file.
> 			if (((uint32_t) defs->items[i].pid < (uint32_t) defs->count) &&
> parameter_is_input (defs->items[i].pid)) {
> 				set_parameter(defs->items[i].pid, defs->items[i].value);
> 			}
> 		}
> 		lrdf_free_setting_values(defs);
> 	}
> 
> 	return true;
> }
> ----------------------------------------------------------------------
> 
> The ONLY reason that Ardour would ever switch to some other "format" is
> if there is similarly easy way of loading presets. This means a
> pre-existing "library" (at the very least, 2 function) to get the
> load/save done.
> 
> This means, as I said a few days ago, that the core question is not what
> format to use, but where these functions are supposed to live.
> 
> Right now, most linux distro's have liblrdf (the library ardour uses) as
> a package. What is the actual problem with this format (other than that
> its essentially illegible to regular humans) ? What problem is solved by
> using some other format/library.
> 
> Note that, just for comparison, Apple AU's have their presets stored as
> XML. The contents are opaque to everything except the plugin (even
> though they are technically human-readable. 
> 
>