64BIT 定點 是內部運算, 是引擎的計算方式.....以bob 10多的不斷測試, 它最終還是選擇了定點運算, 他並不是否定浮點運算, 只是他認為定點較適合 audio , 正如 pt hd也是用 48bit 定點內部運運算..根據bob的觀測和試驗, 浮點計算的 round-off error (rounding error) 對音頻會做成 harsh 和所謂 digital 的聲音
http://en.wikipedia.org/wiki/Round-off_error
bob 建議盡量減少用浮點計算的插件, 雖然定點計算也同樣會出錯, 相對來說會較少, 但插件的優劣還視乎開發人的功力, 也得使用者自己去判斷。
If you dive deep into the use of floating point math you will find many buried areas that create round-off errors inside the FPU directly... these artifacts are the very reason Floating Point math is not a good choice for audio math... the audio seems to be continually degraded randomly along the way thru the engine... this is pretty noticably audible to many people that are HEARING the sound of digital... in my opinion.
I have tripped over examples in the 15 years of coding SAW where the same math calculation gives different and false results depending on the exact values of the variables in that calculation... one set of numbers results in a round-up of the result and another set results in a round-down... same equation, different numbers... therefore making it very difficult to actually have the code consistently interpret the results and in many cases branch to the wrong code segment based on a zero result not testing TRUE.
I have decided on integer math handled in a special way to preserve high orders of equivalent decimal data without these random issues... the results... much smoother audio quality... in many people's opinion... and definitely much higher performance.
It's a very tricky subject and does require you to dive deep in at the assembly level to see these issues... it seems many programmers do not code at this level anymore and many don't seem to question these issues at all, and simply make generic function calls to generic code libraries and accept the results they are handed... or simply repeat something they read in a magazine or programming book... I have tested and tested and made my decisions based on thousands of hours of trying many different techniques... SAWStudio is the result... but it is also well known that my views are not the generally accepted views of the industry... oh well...
Bob L
很多daw 都要借助第三方插件來完成工作, 因為本身調音台的效果不太好, 也是讓人以為必須要用本身以外的插件才可達到好的結果...也引導了市場有這個趨向, 當然第三方的效果器也有高水準的, 但要大量用似乎變成了一個潮流,
Its a myth... to some degree... in fact, the use of floating point math, in my opinion, can cause signal degradation due to the floating point math rounding errors that are very difficult if not impossible to control... this is why I use high res integer math in SAW.
You shouold have no issues in SAWStudio with fader moves or any of the internal summing and processing math... in fact the only place I use floating point is in the eq... and that is specifically hand coded to avaoid the floating point math chip problems... and I use floats only on very specific instructions at very specific points in the calculation process.
Feel free to mix away in SAWStudio... but realize... when inserting VST and DX plugs... you now give in to switching the datapath back and forth to floating point and run the risk of introducing whatever artifacts those plugs may produce because of it.
Bob L
saw 支持所有 vst/vsti 插件, duende ssl 當然也不例外.....