hypercube
12th October 2002, 12:34
I need technical help.
I made a dynamic Range Processor in VC++. Its behaviour is the same
as cooledit with:
Output Gain: 0 dB
Attack Time: 0 ms
Release Time: 0 dB
Level Detector:
Input Gain: 0dB
Attack Time: 0 ms
Release Time: 0 ms
Peak detection
Lookhahead time: 0 ms
so the result is not good. like Cooledit help say:
If the sum of the Attack and Release times is too short (less than 20 milliseconds total), audible effects (such as a “vibrating” sound) can be heard at around 1000 Hz/ms total. For example, if the Attack and Release times are each set to 5 milliseconds (making 10 milliseconds total), then a vibrating sound at 100Hz will be heard. Thus, a total value of about 30 milliseconds is about as low as you can go without introducing these effects.
is there anybody who can help me to implement attack time and release time ?
how it works ? :(
Here what my program do:
- take 1 signed 16 bit sample
- convert it into dB
- take the dynamic ratio to apply to this value (looking up in preset curve)
- apply dynamic ratio
- convert into signed 16 bit sample
- loop until end of WAV file...
I had tested some ideas to implement attack time and release time, but none works
properly. (fade in and fade out effect for example)
another question:
how to compute RMS energy with 16 signed samples ?
I made a dynamic Range Processor in VC++. Its behaviour is the same
as cooledit with:
Output Gain: 0 dB
Attack Time: 0 ms
Release Time: 0 dB
Level Detector:
Input Gain: 0dB
Attack Time: 0 ms
Release Time: 0 ms
Peak detection
Lookhahead time: 0 ms
so the result is not good. like Cooledit help say:
If the sum of the Attack and Release times is too short (less than 20 milliseconds total), audible effects (such as a “vibrating” sound) can be heard at around 1000 Hz/ms total. For example, if the Attack and Release times are each set to 5 milliseconds (making 10 milliseconds total), then a vibrating sound at 100Hz will be heard. Thus, a total value of about 30 milliseconds is about as low as you can go without introducing these effects.
is there anybody who can help me to implement attack time and release time ?
how it works ? :(
Here what my program do:
- take 1 signed 16 bit sample
- convert it into dB
- take the dynamic ratio to apply to this value (looking up in preset curve)
- apply dynamic ratio
- convert into signed 16 bit sample
- loop until end of WAV file...
I had tested some ideas to implement attack time and release time, but none works
properly. (fade in and fade out effect for example)
another question:
how to compute RMS energy with 16 signed samples ?