Hello Glen, I haven't measured codec 2 enc/dec alone on the STM32F4 for some time. On the SM1000 it's the complete FreeDV 1600 stack we tend to measure (modem, protocol, codec).
Danilo from the mcHF team recently reported 17.3ms for Codec 2 1600 decode on 40ms frames. IIRC the encoder uses less. I'd expect 3200 to be a fraction higher as it's doing bit unpacking, LSP decoding more often, but still run full duplex comfortably in real time. I used codec2-dev/stm/codec2_profile.c to profile the code when I initially ported to real time. This could be modified to run 3200. If you are interested in pushing any of your changes into codec2 SVN, they need to be verified against the current code base, for example shown to be bit exact or withing a small tolerance of the current code. Let me know if you want to work on this testing. Danilo and the mcHF worked with me on this approach with fantastic results. Changing FFT sizes would lead to output that is very hard to verify, so I don't recommend it if you goal is code optimisation. -/- One change I'm discussing with the mCHF guys is using a real input N/2 size FFT rather than the current complex N point FFT. That would help a lot and would be close to bit exact. If anyone is interested in working on that please let me know - it can be developed on an x86. When I originally ported codec 2 to the STM32 platform 3 years ago I didn't find any significant improvements using the STM library FFTs (see codec2-dev/src/fft_test.c). IIRC another guy tried them again a few months ago, with just a slight improvement. I think he posted his results to this mailing list. If you can send me a fft_test.c style unit test that runs on a Discovery and demonstrates significant improvements over kiss_fft I'd be happy to try it. Cheers, David On 16/09/16 07:21, glen english wrote: > All : Has anyone got any rough numbers on codec2 perf on the Sm1000 > stm32f4 style platform ? > > David : do you have any feel for how much precision in the FFTs is(are) > enough ? > A guess is fine. Your guesses are better than most people's facts. > > > > > > ------------------------------------------------------------------------------ > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > ------------------------------------------------------------------------------ _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
