Clemens Ladisch wrote: > > Abramo Bagnara wrote: > > min & max are interchanged indeed. My bad... > > Oh, there's no problem with using _max instead of _min -- I just > noticed that the code for _max writes 0 for unsigned 16/24/32-bit > values ... ;o)
Fixed now in CVS. > > > Use of 32/64 bits for 24/32 bit is wanted. Take in account that this > > function is called on mix results (where I need to avoid wrap before > > normalization). > > Then it should use bigger types for 8/16 bits, too. Checking for a type > to overflow its own valid range seems to be rather pointless to me. It *does* use bigger types. > > > > > And the summing/normalization code in pcm_route.c treats the sample as > > > > if it were unsigned. > > > > Be careful here. Use of signed vs. unsigned was an hard decision. > > Can you point me exactly where you see a problem? > > In the following code snippet > > add_int64_att: > sum.as_sint64 += (u_int64_t) sample * ttp->as_int; > > each of the three variables has a signed integer type. Converting > the sample from int32_t to u_int64_t would give wrong results for > negative values, e.g., the sample -1 (0xffffffff) would be converted > to 4294967295 (0x00000000ffffffff). > > The following code > > norm_int: > if (sum.as_sint64 > (u_int32_t)0xffffffff) > sample = (u_int32_t)0xffffffff; > else > sample = sum.as_sint64; > > doesn't check for negative values of sum.as_sint64. Additionally, > using 0xffffffff in case of overflow results in sample == -1. > > These code snippets would be correct if the sample would be unsigned, > but my point was that this isn't the case. I've just checked: this has been broken by Jaroslav with CVS version 1.55. I'd like to restore the original behaviour I wrote (that used unsigned for efficiency reason), but I don't understand what Jaroslav tried to solve. Jaroslav? -- Abramo Bagnara mailto:[EMAIL PROTECTED] Opera Unica Phone: +39.546.656023 Via Emilia Interna, 140 48014 Castel Bolognese (RA) - Italy ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Stuff, things, and much much more. http://thinkgeek.com/sf _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
