Xavier,<br><br>Its starting to get clearer, but I still have a couple questions as I am definetaly not doing the resynthesis correct yet (I am getting a periodic pitch.. not sound).<br><div class="gmail_quote"><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
The analysis window, which by default is a BlackmanHarris92<br>with a 75% overlap. You need to multiply by the<br>inverse of this window after the SFFT. </blockquote><div><br>sorry for having to ask, but what is an SFFT? If it is the same as an STFT or FFT, at which point do I do this? I was under the impression from one of Serra's publications that all I had to do with resynthesize the residual FFT, but don't have to do any more FFTing.
<br><br>If this is an IFFT, my attempt is on the right track, but I am still not getting a noise sound. I am windowing the residual IFFT by a 75% overlap and multiplying it by the BlackmanHarris92 window, then re-windowing the result with a 50% overlap and multiplying by a triangle window. But my result is pitched, and this changes if I change the overlap.
<br><br>Can anyone see what I am doing wrong?<br><br>regards,<br>rich <br><br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">And then a completely independent
<br>triangular window with a size equal to twice<br>the analysis hop and overlap 50%. This is the one in charge of getting a<br>smooth overlap and add process in place.<br><br>Hope it helps.<br><br>X<br><div class="Ih2E3d">
<br>Rich E wrote:<br>> Okay, I didn't think of looking for the overlap size by checking the<br>> timestamps, but that seems obvious now.. thanks! I have found there<br>> are many things preventing the SDIF files from being used in real-time
<br>> (such as the 1TRC frames not containing birth and death information).<br>> So I am already buffering the data in a format that can be used in<br>> real-time, so finding the overlap before sysnthesis-time shouldn't be
<br>> a problem.<br>><br>> However, I do not see the 1WIN matrix within the SMS-produced files.<br>> I assumed it is a triangle window with an overlap factor of 2 (this is<br>> the default settings in SMSTools), but of course this can be changed,
<br>> in which case I would not know how to find the windowing function.<br>> But I tried these settings without success (in comparison to<br>> SMSTools-produced residual sound), so I am still looking for the<br>
> correct ones.<br>> cheers,<br>> rich<br>> On Dec 14, 2007 6:30 PM, Richard Dobson<br>> <<a href="mailto:richarddobson@blueyonder.co.uk">richarddobson@blueyonder.co.uk</a><br></div><div><div></div><div class="Wj3C7c">
> <mailto:<a href="mailto:richarddobson@blueyonder.co.uk">richarddobson@blueyonder.co.uk</a>>> wrote:<br>><br>> Rich E wrote:<br>> > Okay, sorry for getting into too much pd stuff... I basically just
<br>> > need to know what needs to be done to the 1STF data before I can<br>> > synthesize it. Is it ready to go, or is windowing still necessary?<br>> > Should the frames be overlapped?<br>
> ><br>><br>> It's plain real/imaginary DFT data. SO in that sense yes it is<br>> ready to<br>> go straight into the IFFT. It will almost certainly require windowing.<br>> If you haven't already done so, you will neded to check the formal
<br>> definition of the 1STF format e.g. at:<br>><br>> <a href="http://www.cnmat.berkeley.edu/SDIF/FrameTypes.html#1STF" target="_blank">http://www.cnmat.berkeley.edu/SDIF/FrameTypes.html#1STF</a><br>>
<br>> SDIF is famous/notorious for being particularly "loose" about<br>> definitions and content. In short, each frame (matrix) is time-stamped<br>> (from the centre of the window, because they like doing things that
<br>> way), and you have to determine the overlap from that (which means you<br>> have to read at least two frames before you can start rendering,<br>> so this<br>> is not a true real-time streaming format; one would assume the
<br>> overlap<br>> is constant, but the format does not see the need to mandate it);<br>> there<br>> should be a 1WIN matrix that defines the window to use. Beyond<br>> that, all<br>> I can say is "good luck"!
<br>><br>><br>> Richard Dobson<br>><br>><br>><br>><br>><br>><br>> _______________________________________________<br>> CLAM mailing list<br></div></div>> <a href="mailto:CLAM@iua.upf.es">
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