Hello Rick, Currently the pitch is quantised in the log domain by Jean-Marc's joint pitch-energy quantiser. Jean-Marc has written up the design on his blog. I am not sure if that could be modified to match musical notes.
Also I am not sure if the pitch estimator has the resolution or ability to estimate pitch at the reqd resolution. Rick - if you are really keen on this, pls feel free to code it up and submit a patch. If its sounds the same as the current pitch quantiser and uses the same number of bits but does a better job with music its fine with me to include it. Cheers, David On Fri, 2012-06-01 at 10:30 +0200, Rick van Rein wrote: > Hello, > > In the past I've proposed to capture musical notes in Codec2 in a better > way; David's response was that this was still open, but I am now seeing > so much implementation work that makes it more and more involved to change > things. So I'm trying to "reopen" the issue, before it's too late. > > Codec2 encodes the base frequency of the voice on a linear scale, with a > somewhat rough resolution. The scale will probably sound just as well > if it is a logarithmic scale, which also happens to match workings of > our hearing. > > The experience of singing through a telephone would be dramatically > impacted by the choice of scale. If frequencies are rounded off to > the nearest match on a linear scale, then they are bound to be off-pitch. > On the other hand, if musical halftones (or perhaps halfway these) were > used as a rounded value, then Codec2 would pass musical tones at the > perfect pitch -- the roundoff could actually improve the song ;-) > > Two subsequent musical halfnotes are a factor of 12'th root of 2 apart, > so 12 such halfnotes make up a factor 2 or an octave. The frequency > 440 Hz is defined as an A. Using step sizes of the 24'th root of 2 > or 1.0293022366434921 should give a comparable experience, but be > friendly to music. It is also slightly more compact. > > Am I the only one who would find it a pitty if we missed out on this, > if the only reason would be the existing implementations in the field? > > > Thanks, > > Rick van Rein > OpenFortress > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
