On Sat, 2 Feb 2002, Richard W.E. Furse wrote: > Perhaps we should include a flag on LADSPA plugins indicating that the > plugin is non-linear and therefore cares about input level, plus a > recommendation that such plugins expect peak amplitude around 1. This gives
Just stating that 0dB level is 1.0f, and adding [-32767,32767] -> [-1.0,1.0] scaling to applyplugin, is not a bad option either. For a host to do on-demand scaling of audio data, it would have to maintain knowledge of the original fixed-point value range while traversing through the plugin network. Might save a few cycles, but doesn't sound like a very good design idea to me. > I don't think this should be much more than a recommendation - some plugins > inevitably mess around with peak levels and forcing plugins to keep to these > levels (a) breaks relative scaling when processing two channels of stereo in > parallel and (b) is very artificial and (c) inefficient - a chain of linear > plugins may mess around with signal amplitude quite badly and it'll be much > more efficient to renormalise at one point in the chain rather than on each > plugin. Absolutely. In networks of plugins, normalization should only be done when changing to/from fixed value range representation, or inside plugins (limiters and others). -- http://www.eca.cx Audio software for Linux!
