I'd like to propose a new Audiolibrary.
In a way that the old still exists, but marked as "deprecated".
The new name could be <Audio48> or similar, and more or less a copy of the old, with some important details changed.
- With 44.1kHz we see more and more limitations:
:On Teensy3 (uses 44117.6417Hz), SPDIF is on the upper end of allowed tolerance, and we see problems with USB ("klicks", etc)
ADAT changes the frequency to 44100 without any information and ignores all other parts of the library.
:On Teensy4 (uses 44100Hz) we will run into problems with ADC and PWM. This is partly my fault because a year ago I believed NXP when they said the IMXRT is great for exact timing of audio. Well it is - but not for ADC, PWM or other timers - they just can not run from the Audio PLL. The only _reliable_ chance is to use 44117Hz again (See problems above) -however, a change on this point would mean to create compatibility problems and new problems with new devices like s/pdif-in. I have no idea how to solve that.
Using 48KHz would solve all these problems and create only one new: Existing 44.1kHz encoded wav-files (or mp3) are not compatible anymore and need a re-encoding. This does not hurt.
A "new" library (well, basicially the old one!) would give the chance to change a few things more:
- User-selectable "SD"-library (The one from Bill Greiman is faster)
- Introduce the possibility to use other dataformats (float) later.
I know, _now_ is not the time to do something like this - but it would be good to add it to the "Roadmap" - midterm. We have enough experienced users who can work on this and would like to do it. So PJRC (Paul) does not need to do much - but he should give the OK for this and maybe support it a little bit by answering some questions or decide the details.
In a way that the old still exists, but marked as "deprecated".
The new name could be <Audio48> or similar, and more or less a copy of the old, with some important details changed.
- With 44.1kHz we see more and more limitations:
:On Teensy3 (uses 44117.6417Hz), SPDIF is on the upper end of allowed tolerance, and we see problems with USB ("klicks", etc)
ADAT changes the frequency to 44100 without any information and ignores all other parts of the library.
:On Teensy4 (uses 44100Hz) we will run into problems with ADC and PWM. This is partly my fault because a year ago I believed NXP when they said the IMXRT is great for exact timing of audio. Well it is - but not for ADC, PWM or other timers - they just can not run from the Audio PLL. The only _reliable_ chance is to use 44117Hz again (See problems above) -however, a change on this point would mean to create compatibility problems and new problems with new devices like s/pdif-in. I have no idea how to solve that.
Using 48KHz would solve all these problems and create only one new: Existing 44.1kHz encoded wav-files (or mp3) are not compatible anymore and need a re-encoding. This does not hurt.
A "new" library (well, basicially the old one!) would give the chance to change a few things more:
- User-selectable "SD"-library (The one from Bill Greiman is faster)
- Introduce the possibility to use other dataformats (float) later.
I know, _now_ is not the time to do something like this - but it would be good to add it to the "Roadmap" - midterm. We have enough experienced users who can work on this and would like to do it. So PJRC (Paul) does not need to do much - but he should give the OK for this and maybe support it a little bit by answering some questions or decide the details.
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