On Sat, Apr 25, 2015 at 08:35:56PM +0200, Albert Graef wrote: > > Question: I tried a demo product which did polyphony, with similar > > latency as my app, which claimed to have a full version with > > near-zero latency. > > > > Is this actually possible? > > Sounds like snake oil to me, but don't take my word for it.
Sound very unlikely. One problem with polyphonic pitch detection is two or more notes that share a number of harmonic frequencies and start at the same time. This will occur with many chords that contain simple intervals like octave and fifth. It is possible to detect which harmonics are shared (they will have a different amplitude / phase profile) but this requires tracking them for some time and hence additional latency. I suspect the same is even true for human perception. If we hear a perfect fifth chord we may have the impression to have detected that it consist of two notes immediately. But there are many examples of our brain playing tricks and 'backdating' the result of an observation which has actually taken more time than we think. Real-time polyphonic pitch detection is still a research topic, just look at the publication dates of some of papers already mentioned. For a guitar it may be easier than the general case due to the restriced frequency range of each string and in general a clear attack of each note. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) _______________________________________________ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev