Clipping in the DSP chain

2011-07-12 01:05:58

I use the Peak Meter visualization in fb2k to warn me when the output clips.  AFAIK this samples the final output after the DSP chain so I know my final output isn't clipping.

However, what happens if something early in my DSP chain is clipping and something late in the chain is attenuating the signal?  Does the first DSP preserve values above the clipping point so that it'll be ok as long as the final output doesn't clip?  Or does it clip off the peaks before sending the signal to the next DSP?  Does it depend on the DSP in question?

Is there a peak meter that acts as a DSP I can put anywhere in the DSP chain to visualize what's going on after any particular DSP?

Thanks

Clipping in the DSP chain

Reply #1 – 2011-07-12 02:16:45

All internal processing is performed in floating point, so there is no clipping going on whatsoever. Well, excluding some special cases, such as a Winamp DSP wrapper that I don't think is maintained anymore, which has to perform clipping because sample data must be converted to 16 bit integer format for processing and then back to floating point again.

All native DSP components should process entirely in floating point and not clip their own input or output at all. VST plug-in wrappers should not clip either, as the VST system works in floating point as well.

Clipping in the DSP chain

Reply #2 – 2011-07-12 04:59:18

Thanks.  Confirmed with some quick testing that the particular plugin I'm concerned about (foo_dsp_crossfeed) is passing signals beyond clipping intact.

Would still like to find a simple peak meter that I can plug into the DSP chain though.

Jimi Hendrix's albums keep making me wonder if my sound system's broken with its weird effects