afGetInstIDs(3dm) afGetInstIDs(3dm)
afGetInstIDs - get a list of instrument configurations from an
AFfilehandle
#include <dmedia/audiofile.h>
int afGetInstIDs(AFfilehandle file, int *instids)
file expects an AFfilehandle structure, created when an audio file
was opened by a call to afOpenFile(3dm).
instids an array of integer locations used to return a list of (unique)
positive instrument ID's which can be used to reference the
sampler configurations in a file. For an AIFF/AIFF-C file,
this array will return the ID AF_DEFAULT_INST if there is an
instrument chunk. If you pass a null instids array to
afGetInstIDs(), it simply returns the number of sampler
configurations stored in the audio file.
afGetInstIDs() returns a nonnegative integer count of the number of
instrument configurations in the file, or -1 in case of error.
For AIFF-C and AIFF files, this value is always either 0 or 1. The value
varies in other file formats, so it is important to use this routine to
check the inst count prior to handing it a pointer to an array.
Typically, afGetInstIDs() is called twice. The first time you pass it a
null instids array, and just check the return value. The return value
tells you how large an instids array to allocate, which you in turn pass
back to afGetInstIDs() to obtain a list of unique positive instrument ID
values. You can then use these ID's to reference the various instrument
configurations in the file.
For example, you pass an instrument ID to afGetInstParamLong(3dm) to
obtain the values of the individual instrument parameters such as gain,
base note, and velocity range.
This function may return more than one inst, unlike the one fixed INST in
AIFF/AIFF-C files. Other currently supported file formats have different
inst configurations than AIFF/AIFF-C.
In the case of INST parameters it is important to be able to query at
runtime the capabilities of a given file format. An application can use
afQuery(3dm) to determine whether a given file format supports INST
chunks, and if so, the maximum number allowed. Apps should also be
written to expect and ignore instrument configurations or instrument
parameters they do not understand.
Page 1
afGetInstIDs(3dm) afGetInstIDs(3dm)
afOpenFile(3dm), afInitInstIDs(3dm), afGetInstParamLong(3dm)
afGetInstIDs(3dm) afGetInstIDs(3dm)
afGetInstIDs - get a list of instrument configurations from an
AFfilehandle
#include <dmedia/audiofile.h>
int afGetInstIDs(AFfilehandle file, int *instids)
file expects an AFfilehandle structure, created when an audio file
was opened by a call to afOpenFile(3dm).
instids an array of integer locations used to return a list of (unique)
positive instrument ID's which can be used to reference the
sampler configurations in a file. For an AIFF/AIFF-C file,
this array will return the ID AF_DEFAULT_INST if there is an
instrument chunk. If you pass a null instids array to
afGetInstIDs(), it simply returns the number of sampler
configurations stored in the audio file.
afGetInstIDs() returns a nonnegative integer count of the number of
instrument configurations in the file, or -1 in case of error.
For AIFF-C and AIFF files, this value is always either 0 or 1. The value
varies in other file formats, so it is important to use this routine to
check the inst count prior to handing it a pointer to an array.
Typically, afGetInstIDs() is called twice. The first time you pass it a
null instids array, and just check the return value. The return value
tells you how large an instids array to allocate, which you in turn pass
back to afGetInstIDs() to obtain a list of unique positive instrument ID
values. You can then use these ID's to reference the various instrument
configurations in the file.
For example, you pass an instrument ID to afGetInstParamLong(3dm) to
obtain the values of the individual instrument parameters such as gain,
base note, and velocity range.
This function may return more than one inst, unlike the one fixed INST in
AIFF/AIFF-C files. Other currently supported file formats have different
inst configurations than AIFF/AIFF-C.
In the case of INST parameters it is important to be able to query at
runtime the capabilities of a given file format. An application can use
afQuery(3dm) to determine whether a given file format supports INST
chunks, and if so, the maximum number allowed. Apps should also be
written to expect and ignore instrument configurations or instrument
parameters they do not understand.
Page 1
afGetInstIDs(3dm) afGetInstIDs(3dm)
afOpenFile(3dm), afInitInstIDs(3dm), afGetInstParamLong(3dm)
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