Rick,
Before I get to my reply - if my memory serves me the post I was responding to was actually an original post in a new thread, created by Ben Helweg. That thread had nothing to do with the device(s) we were talking about specifically in this thread that convert to 32-bit float. I'm talking about this one:
viewtopic.php?p=626949#p626949Hopefully with that context what I wrote is more clear.
rick.lang wrote:Mattias, not disagreeing with your recommendation but I would think the argument that your software is converting to 24bit fixed
I don't think the software is doing that, I think it's the hardware that delivers whatever it is capable of via drivers to the software. And most converters aren't capable of converting to 32-bits, either float or fixed. So the output of the converter is going to be at most 24-bit fixed in most cases.
rick.lang wrote:and saving that as 32bit float must be incorrect or your software in question isn’t taking advantage of the 32bit float capabilities. Not that I know what’s happening, but it’s fraudulent software if it’s not recording different values for the exponent depending on the loudness received from the analog-to-digital circuits which are recorded data 32bit float. My reading of what Sound Devices dies is that the exponent varies if needed to preserve the full dynamic range available to it. Otherwise there is no point beyond marketing.
Yes, but the Sound Devices is a.. well.. device, not a software interfacing with a device.
Once a signal has been converted to
one fixed point value I don't really see how you can extrapolate what is no longer there. So if the converter outputs a 24-bit fixed signal there is then nothing the software can do to gain anything back, and that includes storing it as 32-bit float. It's essentially going to be the same 24-bit signal (clipped or not) stored within that 32-bit float file.
The reason a software could still save 32-bit float despite not receiving that from a converter is that for a long time most DAWs operated at 32-bit float internally when doing summing. So stored 24-bit fixed files would be converted on-the-fly to 32-bit float, get processed, and then get converted back to 24-bit fixed for output to the converter again so we could hear it. So since the internal working size is 32-bit float it actually makes some sense to allow for files to be stored as 32-bit float as well. You could for example imagine a case where you process files and you want to interchange them with another person using a different computer. By storing that processed file as a float file you retain whatever it is and lose nothing from conversion (not saying any "loss" is of significance either though). But this would most often still be a 24-bit input file, processed and stored in 32-bit float 'temporarily', and then in the end get output in fixed format again.
Since the OP was talking about a consumer device, and we have to take into account the tremendous amounts of converters out there for anything from phones to TVs to laptops to professional converters, it most likely was a converter that output a 24-bit fixed point signal. That is a different thing from how a software then decides to store it.
Looking at it from a different perspective:- I've seen very few converters over the past 20 years advertising 32-bit conversion, either fixed or float, and surely they would have if they were capable of it... and
- I've seen the ability to store audio files at 32-bit float for at least a decade or two, and that thus wouldn't have been possible without either a) the previous point being wrong, or b) the gist of what I'm saying being true.
PS: Sorry for all the words...