3 ms·

This does not matter… 32bits is 32bits is 32bits.

by survirtual 4y ago

pavon 4y ago
You are not going to get good compression reinterpreting a 32-bit float as if the bits were an integer.
- survirtual 4y ago
  What? Most systems are 64bit now, I wouldn’t be doing signal processing on a system that wasn’t. If my signal has 32bits to work with during capture and my scratch space is 64bits during processing, I can assure you I am not losing any signal during conversion between int / float. What am I missing?
LeoPanthera 4y ago
It absolutely does matter when the compression algorithm is expecting audio in a certain format. If you put something else in those bits you will get worse, or no, compression, and might as well just use zip.
- survirtual 4y ago
  I must be missing something here, but last I checked 32bit float uses about 8bits for metadata —- positive / negative, exponent, etc. — leaving 24bits for signal storage. A 32bit uint can just store the bits of raw data and would allow for denser packing of bits. You can then do processing with a 64bit float after converting the int’s bits without loss. Pretty sure every ADC IC I looked at uses integers. During analog processing, using the term “float” is highly disingenuous for an analog waveform, and if an ADC spouts out an int, what float are we talking about here? I maybe have gone too deep in the weeds reading TI chip manuals and writing drivers for some adc chips for my 8 channel, 32bit, 192kHz recording system, and maybe I missed some nuances in what “32bit” means, but last I checked my audio is pretty solid even after converting the 32bit int to 64bit float during my signal processing. Audio engineering has been a massive pain because these people use different terms for basic things (great example is “phantom power” — it’s just a 48v, low-current power supply, but good luck finding a simple answer to that useless term) and there doesn’t seem to be any authoritative references to find answers, so I am sure I am missing something here.

This does not matter… 32bits is 32bits is 32bits.

pavon 4y ago

You are not going to get good compression reinterpreting a 32-bit float as if the bits were an integer.

survirtual 4y ago
What? Most systems are 64bit now, I wouldn’t be doing signal processing on a system that wasn’t. If my signal has 32bits to work with during capture and my scratch space is 64bits during processing, I can assure you I am not losing any signal during conversion between int / float. What am I missing?

LeoPanthera 4y ago

It absolutely does matter when the compression algorithm is expecting audio in a certain format. If you put something else in those bits you will get worse, or no, compression, and might as well just use zip.

survirtual 4y ago
I must be missing something here, but last I checked 32bit float uses about 8bits for metadata —- positive / negative, exponent, etc. — leaving 24bits for signal storage. A 32bit uint can just store the bits of raw data and would allow for denser packing of bits. You can then do processing with a 64bit float after converting the int’s bits without loss. Pretty sure every ADC IC I looked at uses integers. During analog processing, using the term “float” is highly disingenuous for an analog waveform, and if an ADC spouts out an int, what float are we talking about here? I maybe have gone too deep in the weeds reading TI chip manuals and writing drivers for some adc chips for my 8 channel, 32bit, 192kHz recording system, and maybe I missed some nuances in what “32bit” means, but last I checked my audio is pretty solid even after converting the 32bit int to 64bit float during my signal processing. Audio engineering has been a massive pain because these people use different terms for basic things (great example is “phantom power” — it’s just a 48v, low-current power supply, but good luck finding a simple answer to that useless term) and there doesn’t seem to be any authoritative references to find answers, so I am sure I am missing something here.