> Chuck made me think it was a bit more than 24 bits, > now it seems Miller says it's more likely to be 20 bits :)
or I just got that way wrong and miller wasn't talking about this at all... so I stick to chuck's answer. cheers 2015-04-23 12:55 GMT-03:00 Alexandre Torres Porres <por...@gmail.com>: > I know there's a parallel discussion about human hearing and what audio > cards can get there. But I'm just trying to get one simple fact clear, that > is the bit depth of audio in Pd :) > > Leaving the human hearing or audio cards aside, some DAW (like Pro Tools > or Ardour) do operate on audio files that are actual 32 bit resolution. I > guess the idea is to keep quantization error as low as possible when > mixing, normalizing, processing, filtering, mastering and everything. Then > you can convert it to, say, 24 bit high quality audio afterwards for > distribution - I guess this is the standard for highest digital audio these > days, meaning that it's pointless to have a final audio that's higher than > that, but then, 32 bit dac seem to be showing up already as chuck pointed > out, but I digress. Moreover, you can also convert it to 16 bit CD quality > afterwards, or even just make some MP3 or whatever... > > Not to get into the discussion if dealing with 32 bits internally on a DAW > is really important or worth the hassle (and not even getting into the deal > with new 32 bit dac), the fact is that 32 bit audio exists out there for > some time now. They do have this 32 bits option, or even more maybe... (not > sure if they're pushing it to 64 yet, but it doesn't matter). > > So, I always knew Pd was "32 bit", and knowing the above, I was misled to > think Pd was just like Pro Tools or Ardour, that it could process audio in > 32 bit. But I was thinking about it these days and it hit me that you just > can't say Pd processes audio like Ardour and Pro Tools do on 32 bit > precision. > > Bottom line, you can't! > > So this made me wonder what the heck that precision would be... > > Chuck made me think it was a bit more than 24 bits, now it seems Miller > says it's more likely to be 20 bits :) > > cheers > > > > 2015-04-23 12:25 GMT-03:00 Miller Puckette <m...@ucsd.edu>: > > I get 1 000 000 = 2^19.9 so a 20 bit dynamic range. >> >> I don't think A/D/A hardware ever gets better than about 110 dB dtnamic >> range though. >> >> cheers >> Miller >> >> On Thu, Apr 23, 2015 at 05:20:51PM +0200, Cyrille Henry wrote: >> > >> > >> > Le 23/04/2015 16:41, Alexandre Torres Porres a écrit : >> > >Yep, nice indeed, I guess I learned - in short and in layman's >> undetailed terms - that audio output is ~24bits (a bit higher, but much >> higher for smaller numbers). >> > > >> > >Moreover, digital audio cards won't likely have more than 24 bit >> precision for many years to come, so it's just way more than enough. >> > The human ear is usually consider to be sensible from 0dB to 120dB, so >> a range of 10^(12/2) between the smallest and biggest amplitude. >> > i.e from 1 to 1 000 000, or from 1 to 2^13.8 >> > so, the human ear sensitivity can be considered to be about 14 bits. >> > 16 bits diffusion should be enough. >> > 24 bits diffusion is already overkill. >> > >> > cheers >> > c >> > >> > > >> > >thanks >> > > >> > > >> > >2015-04-23 6:43 GMT-03:00 Julian Brooks <jbee...@gmail.com <mailto: >> jbee...@gmail.com>>: >> > > >> > > Nice. Thanks Chuck, I learnt something. >> > > >> > > On 22 April 2015 at 23:45, Charles Z Henry <czhe...@gmail.com >> <mailto:czhe...@gmail.com>> wrote: >> > > >> > > On Wed, Apr 22, 2015 at 5:11 PM, Alexandre Torres Porres >> > > <por...@gmail.com <mailto:por...@gmail.com>> wrote: >> > > >> > > > So I start with this idea that the audio (values from -1 to >> 1) can't be in >> > > > full 32 bit float resolution, it's less. I don't see why >> that is "wrong". >> > > > And then, from it, my first question here was: "what is the >> audio resolution >> > > > then?". I'm still clueless here about this answer. >> > > > >> > > > Moreover, is it more or less than what 24 bit audio cards >> handle? >> > > >> > > Let me try: >> > > >> > > 32-bit floating point numbers have 24 bits of precision. >> Always. The >> > > remaining 8 bits are just for the sign and exponent. When the >> > > amplitude of the signals decrease, you don't lose any >> precision in >> > > floating-point. The value of the least significant bit (LSB) >> gets >> > > proportionally smaller. >> > > >> > > However, the output of a 24-bit soundcard always has a fixed >> > > quantization. The LSB is always the same size. Smaller >> numbers have >> > > less precision. >> > > >> > > The mismatch occurs when converting from the 32-bit floats to >> the >> > > 24-bit fixed point numbers. Now, the smaller numbers aren't as >> > > precise anymore. They get rounded to the nearest number in >> the 24-bit >> > > fixed point system. >> > > >> > > So, yes, the resolution (of small numbers) in floating point >> (internal >> > > to Pd) is finer than the resolution of those numbers when >> output >> > > (driver/DAC). >> > > >> > > Also, the 24-bit fixed point format is for values between -1 >> and 1. >> > > That means that numbers between 0 and 1 have just 23 bits. In >> 32-bit >> > > math, the numbers between 0.5 and 1 still have 24 bits of >> precision >> > > (the sign is held elsewhere). That means that Pd's internal >> > > resolution is finer than the soundcard resolution for all >> numbers >> > > between -1 and 1. >> > > >> > > Chuck >> > > >> > > _______________________________________________ >> > > Pd-list@lists.iem.at <mailto:Pd-list@lists.iem.at> mailing >> list >> > > UNSUBSCRIBE and account-management -> >> http://lists.puredata.info/listinfo/pd-list >> > > >> > > >> > > >> > > >> > > >> > >_______________________________________________ >> > >Pd-list@lists.iem.at mailing list >> > >UNSUBSCRIBE and account-management -> >> http://lists.puredata.info/listinfo/pd-list >> > > >> > >> > _______________________________________________ >> > Pd-list@lists.iem.at mailing list >> > UNSUBSCRIBE and account-management -> >> http://lists.puredata.info/listinfo/pd-list >> >> _______________________________________________ >> Pd-list@lists.iem.at mailing list >> UNSUBSCRIBE and account-management -> >> http://lists.puredata.info/listinfo/pd-list >> > >
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