On Mon, Nov 16, 2015 at 1:20 PM, Hendrik Leppkes <h.lepp...@gmail.com> wrote: > On Mon, Nov 16, 2015 at 6:24 PM, Ganesh Ajjanagadde <gajja...@mit.edu> wrote: >> On Mon, Nov 16, 2015 at 9:48 AM, Daniel Serpell <dserp...@gmail.com> wrote: >>> Hi!, >>> >>> El Fri, Nov 13, 2015 at 11:42:30AM -0500, Ganesh Ajjanagadde escribio: >>>> Whoever wrote this stuff had a pretty bad libm - digits differ pretty >>>> quickly. >>> >>> They where correctly rounded to 24bit precision. I don't know if that >>> was intentional, so I can't comment on the correctness of the patch. >> >> Unless I am off here, doing things at 24 bits makes very little sense: >> float itself offers 32 bits > > Actually floats offer 23-bits of precision for the significand (with 8 > for mantissa and one sign bit) - 7-8 digits, so any more precision > than that couldn't be stored accurately anymore, so when using single > precision like this code, more precision is not needed.
Point taken. However, the general remark still applies: precision is being lost unnecessarily at an intermediate computation stage since it is anyway a static computation. > Maybe it was even specifically wanted to have values that are > represented accurately, but I do not know the history of this code > either. > > - Hendrik > _______________________________________________ > 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
