Hi Jeroen, Thanks for your patch, compiles and checked in.
-/- We need to call analyse_one_frame() every 10ms as that's the internal frame rate of the core sinusoidal modeling inside Codec 2. Note the ptr into the input speech vector is offset by 80 samples (10ms) each time. We need the input speech sample driver to supply us with a 320 sample (40ms) input vector. Various states need to be updated even though we toss the output model parameters away for 3/4 of the frames in 700C. Just transmitting the model parameters 1 in every 4 frames is like "decimation in time" of any sampled sequence. At the decoder, to reconstruct the missing frames (say 2,3,4) we interpolate between need frames 1 and 5. So we could send a sequence of frames 1,5,9 or 2,6,10 ... either way you get a 40ms latency. -/- Yes it would be nice to try the same VQ ideas at a higher bit rate and hopefully higher quality. If anyone would like to attempt that I can show you how. Cheers, David On 15/01/17 12:20, Jeroen Vreeken wrote: > Hi David, > > The new samples sound really impressive. > I added support for the new mode to my DML code and hope to do some more > extensive testing soon. > I also made a small patch to get the 'energy' of a 700C frame. Hopefully > I got it about right... > > Looking at the codec2_encode_700c function I noticed that the indexes > are determined after just one call to the analyse_one_frame function and > that the other 3 frames are analysed after that, but don't influence the > indexes at all anymore. > I might be wrong, but to me it looks like this order introduces 30ms of > latency for no real reason... Would it not be better to just call > analyse_one_frame four times before creating the indexes? > > Another thing I was wondering about: Would this method also > significantly improve the modes with a higher bitrate? How good would a > '1300C' mode sound? > > Regards, > Jeroen > > On 01/13/2017 02:52 AM, David Rowe wrote: >> Hello Lists, >> >> Here is a blog post on the new, and somewhat experimental, Codec 2 700C >> mode: >> >> http://www.rowetel.com/?p=5373 >> >> Cheers, >> >> David >> >> >> >> ------------------------------------------------------------------------------ >> Developer Access Program for Intel Xeon Phi Processors >> Access to Intel Xeon Phi processor-based developer platforms. >> With one year of Intel Parallel Studio XE. >> Training and support from Colfax. >> Order your platform today. http://sdm.link/xeonphi >> _______________________________________________ >> Freetel-codec2 mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >> > > > > ------------------------------------------------------------------------------ > Developer Access Program for Intel Xeon Phi Processors > Access to Intel Xeon Phi processor-based developer platforms. > With one year of Intel Parallel Studio XE. > Training and support from Colfax. > Order your platform today. http://sdm.link/xeonphi > > > > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
