On Thu, Mar 10, 2016 at 11:21 AM, Rostislav Pehlivanov <atomnu...@gmail.com> wrote: > On 10 March 2016 at 01:55, Ganesh Ajjanagadde <gajja...@gmail.com> wrote: >> >> >> In fact, I personally have no idea why it is absolutely critical that >> a Hamming window is used, see 0cfdaf45c4 where Welch was used >> previously. At a first glance I think one can find a window that works >> and avoids libm, e.g Parzen or other polynomial windows. >> Rostislav, any thoughts? >> >> > Yes, though experiments the Hamming window was determined to work the best > with the TNS system. The Welch window was far too wide and caused > artifacts. The Prazen window seems too focused to let the LPC algorithm do > its job on correctly giving proper coefficients near the ends of the > window. The LPC coefficients are used by the decoder to shape the spectral > coefficients right before iDCT and after everything else, so it has big > implications on the quality. > I'll experiment with other types of windows, but I think the performance > penalty here is really worth it.
Thanks for clarifying. Agree it is probably not worth it. Pushed, thanks. > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
