Re: [music-dsp] SOLA, PSOLA and WSOLA.
In essence WSOLA and SOLA are only for Time Scale Modification... WSOLA - Applies synchronization in the analysis stage of OLA, so input frames are selected based on waveform similarity, keeping the output at a constant rate! SOLA - Works like WSOLA but applies synchronization in the output, so a input frame are selected and the synchronism occurs at the output (where the input frame is more like the current output frame). As far as I know, these are the differences between SOLA and WSOLA I'd love to be right, lol. But if I am correct I have already seen several implementations of WSOLA running as SOLA (of course the two algorithms are very similar, they only have distinction if they will use correlation in the input or output). Regards, Eder On Tue, Feb 26, 2019 at 8:54 AM Ross Bencina wrote: > Hi Alex, > > > I can't understand the difference between SOLA, PSOLA and WSOLA. > > I'll attempt a partial answer: > > I think PSOLA and WSOLA are clearly distinct. > > PSOLA involves identifying a time varying pitch (fundamental frequency) > track for the input, segmenting the input signal into (possibly > overlapping) windowed grains which are synchronous to this fundamental > frequency (e.g. grains that are centered on glottal pulses) and then > altering the rate at which the grains are assembled in the output stream. > > WSOLA involves breaking the signal into grains using some method (e.g. > constant duration grains), then concatenating input grains to the output > stream with relative phase adjusted according to two criteria: (1) on > average, the input must be consumed at a rate that maintains the > timescaling factor; (2) the source material should be mixed (with > windowing) into the output stream in a way that minimizes local error > over the crossfade region (i.e. to minimize phase cancellation) -- if > the signal is strongly periodic, and the parameters are just right, this > will fairly nicely keep the period of the source waveform, but it lacks > sub-sample-accurate phase alignment I think. You can add enhancements > such as trying to avoid mixing the same transient into the output stream > more than once. > > Not sure what SOLA is. > > Ross. > ___ > dupswapdrop: music-dsp mailing list > music-dsp@music.columbia.edu > https://lists.columbia.edu/mailman/listinfo/music-dsp > > ___ dupswapdrop: music-dsp mailing list music-dsp@music.columbia.edu https://lists.columbia.edu/mailman/listinfo/music-dsp
Re: [music-dsp] SOLA, PSOLA and WSOLA.
Hi Alex, > I can't understand the difference between SOLA, PSOLA and WSOLA. I'll attempt a partial answer: I think PSOLA and WSOLA are clearly distinct. PSOLA involves identifying a time varying pitch (fundamental frequency) track for the input, segmenting the input signal into (possibly overlapping) windowed grains which are synchronous to this fundamental frequency (e.g. grains that are centered on glottal pulses) and then altering the rate at which the grains are assembled in the output stream. WSOLA involves breaking the signal into grains using some method (e.g. constant duration grains), then concatenating input grains to the output stream with relative phase adjusted according to two criteria: (1) on average, the input must be consumed at a rate that maintains the timescaling factor; (2) the source material should be mixed (with windowing) into the output stream in a way that minimizes local error over the crossfade region (i.e. to minimize phase cancellation) -- if the signal is strongly periodic, and the parameters are just right, this will fairly nicely keep the period of the source waveform, but it lacks sub-sample-accurate phase alignment I think. You can add enhancements such as trying to avoid mixing the same transient into the output stream more than once. Not sure what SOLA is. Ross. ___ dupswapdrop: music-dsp mailing list music-dsp@music.columbia.edu https://lists.columbia.edu/mailman/listinfo/music-dsp
Re: [music-dsp] SOLA, PSOLA and WSOLA.
� i often ask the same question and had thought at one time i knew the answer.� and then another paper comes out and muddies the water. i have most often thought that PSOLA means what i like to call "Lent's Algorithm" (that can also be credited to Hamon).� it's a pitch shifter that does not shift the formants or resonances of a vocal tone. and i thought that WSOLA is for time-scaling (so neither pitch nor formants are shifted), but when combined with resampling shifts pitch and formants together. so one paper that might help (or confuse) is�https://arxiv.org/pdf/1801.06492.pdf� and here is another�https://www.researchgate.net/publication/3567696_An_Overlap-Add_Technique_Based_on_Waveform_Similarity_WSOLA_for_High_Quality_Time-Scale_Modification_of_Speech . � i dunno how SOLA differs from PSOLA.� "Synchronous" to what? � and i can be totally wrong and am happy to be corrected. � r b-j Original Message ---- Subject: [music-dsp] SOLA, PSOLA and WSOLA. From: "Alex Dashevski" Date: Tue, February 26, 2019 2:09 am To: music-dsp@music.columbia.edu -- > I can't understand the difference between SOLA, PSOLA and WSOLA. > I have already understood how OLA works. > What is difference between PSOLA and Re-sampling with (SOLA or WSOLA) ? > What is difference between SOLA and WSOLA ? > I tried to search in google but I did not find any understandable > information > > Thanks, > Alex > ___ > dupswapdrop: music-dsp mailing list > music-dsp@music.columbia.edu > https://lists.columbia.edu/mailman/listinfo/music-dsp � � � -- r b-j� � � � � � � � � � � � �r...@audioimagination.com "Imagination is more important than knowledge." � � � � ___ dupswapdrop: music-dsp mailing list music-dsp@music.columbia.edu https://lists.columbia.edu/mailman/listinfo/music-dsp
[music-dsp] SOLA, PSOLA and WSOLA.
Hi, I can't understand the difference between SOLA, PSOLA and WSOLA. I have already understood how OLA works. What is difference between PSOLA and Re-sampling with (SOLA or WSOLA) ? What is difference between SOLA and WSOLA ? I tried to search in google but I did not find any understandable information Thanks, Alex ___ dupswapdrop: music-dsp mailing list music-dsp@music.columbia.edu https://lists.columbia.edu/mailman/listinfo/music-dsp
