0dbfs
0dbfs — Sets the value of 0 decibels using full scale amplitude.
Performance
The default is 32767, so all existing orcs should work.
These calls should all work:
ipeak = 0dbfs
asig oscil 0dbfs, freq, 1 out asig * 0.3 * 0dbfs
and so on.
As for documentation: the usage should be obvious - the main thing is for people to start to code 0dbfs-relatively (and use the ampdbfs() opcodes a lot more!), rather than use explicit sample values.
Floats written to a file, when 0dbfs = 1, will in effect go through no range translation at all. So the numbers in the file are exactly what the orc says they are.
![[Note]](images/note.png)
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BIG NB |
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All the main sample formats are supported, but I haven't got around to dealing with the char formats. Probably it's straight-forward... I have tried to cover the main utils - adsyn, lpanal, etc. But there are bound to be things missing, sorry. Some of the parsing code is a bit grungy because I have a variable with a leading digit! |
Examples
Here is an example of the 0dbfs opcode. It uses the file 0dbfs.csd.
Example 22. Example of the 0dbfs opcode.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform ; Audio out Audio in No messages -odac -iadc -d ;;;RT audio I/O ; For Non-realtime ouput leave only the line below: ; -o 0dbfs.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> ; Initialize the global variables. sr = 44100 kr = 4410 ksmps = 10 nchnls = 1 ; Set the 0dbfs to the 16-bit maximum. 0dbfs = 32767 ; Instrument #1. instr 1 ; Linearly increase the amplitude value "kamp" from ; 0 to 1 over the duration defined by p3. kamp line 0, p3, 1 ; Generate a basic tone using our amplitude value. a1 oscil kamp, 440, 1 ; Multiply the basic tone (with its amplitude between ; 0 and 1) by the full-scale 0dbfs value. out a1 * 0dbfs endin </CsInstruments> <CsScore> ; Table #1, a sine wave. f 1 0 16384 10 1 ; Play Instrument #1 for three seconds. i 1 0 3 e </CsScore> </CsoundSynthesizer>
Here is another example of the 0dbfs opcode. It uses the file 0dbfs-1.csd. This example has exactly the same output as the previous example, but output samples should now be normalized between -1 and 1.
Example 23. Example of the 0dbfs opcode with maximum amplitude of 1.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform ; Audio out Audio in No messages -odac -iadc -d ;;;RT audio I/O ; For Non-realtime ouput leave only the line below: ; -o 0dbfs.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> ; Initialize the global variables. sr = 44100 kr = 4410 ksmps = 10 nchnls = 1 ; Set the 0dbfs to 1. 0dbfs = 1 ; Instrument #1. instr 1 ; Linearly increase the amplitude value "kamp" from ; -90 to p4 (in dBfs) over the duration defined by p3. kamp line -90, p3, p4 print ampdbfs(p4) ; Generate a basic tone using our amplitude value. a1 oscil ampdbfs(kamp), 440, 1 ; Since 0dbfs = 1 we don't need to multiply the output out a1 endin </CsInstruments> <CsScore> ; Table #1, a sine wave. f 1 0 16384 10 1 ; Play Instrument #1 for three seconds. i 1 0 3 -6 e </CsScore> </CsoundSynthesizer>