afInitMiscIDs(3dm)afInitMiscIDs(3dm)NAME
afInitMiscIDs, afInitMiscType, afInitMiscSize - initialize the list of
miscellaneous data chunk ID's in an AFfilesetup file configuration
structure, initialize the chunk type and number of data bytes for a given
miscellaneous chunk.
SYNOPSIS
#include <dmedia/audiofile.h>
void afInitMiscIDs(AFfilesetup setup, int miscids[], int nmisc)
void afInitMiscType(AFfilesetup setup, int chunkid, int type)
void afInitMiscSize(AFfilesetup setup, int chunkid, int size)
PARAMETER
setup is an AFfilesetup structure, previously created by a call to
afNewFileSetup().
miscids
is an array of (unique) positive integer ID's which are used to
reference miscellaneous data chunks in a new audio file after it
is created by passing setup to afOpenFile(3dm).
nmisc The total number of miscellaneous chunks in the file
configuration. See the audio file format man pages aifc(4),
next(4), wave(4), bicsf(4), and sounddesigner2(4) for format-
specific information.
chunkid
is one of the chunk ID's from the miscids list.
type is an integer constant which denotes a valid chunk type for the
file format being configured with setup.
size is a nonnegative integer value indicating the number of bytes to
be allocated in the file header for data in the chunk given by
chunkid.
DESCRIPTIONafInitMiscIDs() initializes a list of unique miscellaneous chunk ID's
which are used to reference various file format dependent data chunks in
an audio file created by passing setup to afOpenFile(3dm).
After you specify the list of ID's, you have to specify a chunk type and
a chunk data area size for each of the ID's by calling afInitMiscType()
and afInitMiscSize().
The current valid miscellaneous data types are:
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afInitMiscIDs(3dm)afInitMiscIDs(3dm)
AF_MISC_COPY Copyright string
AF_MISC_AUTH Author/artist string
AF_MISC_NAME Name string
AF_MISC_ANNO AIFF/AIFF-C annotation string
AF_MISC_MIDI AIFF/AIFF-C MIDI system exclusive data
AF_MISC_APPL AIFF/AIFF-C application-specific data
AF_MISC_PCMMAP PCM mapping information (for future use)
AF_MISC_NeXT NeXT file info chunk
AF_MISC_IRCAM_PEAKAMP
BICSF peak amplitude sfcode
AF_MISC_COMMENT Text comment string. The tags AF_MISC_IRCAM_COMMENT
and AF_MISC_ICMT are also allowed for this type, though
this chunk is supported by several file types.
AF_MISC_ICRD Creation date string. This is usually of the form
"YYYY-MM-DD".
AF_MISC_ISFT Software name string. Usually set to the name of the
software package which created the sound.
AF_MISC_UNRECOGNIZED
unrecognized data chunk
For AIFF-C (and AIFF) files, you do not need to worry about the "trailing
zero pad byte" required at the end of chunks with odd numbers of data
bytes. The library hides this implementation detail from applications.
When an application creates an audio file by passing setup to
afOpenFile(3dm), the header for the file is written out with zero-filled
areas reserved for each of the various requested miscellaneous data
types.
You use the routine afWriteMisc(3dm) to write data into the chunks after
the file has be opened. The application is responsible for managing the
contents of the header space reserved for each chunk of miscellaneous
data.
For example, if the application reserves 1000 bytes of space for MIDI
exclusive data, then the application needs make sure that any bytes which
aren't used for meaningful data are filled with MIDI no-op messages
instead.
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afInitMiscIDs(3dm)afInitMiscIDs(3dm)CAVEATS
The Audio File Library will continue to expand the number of supported
file formats and misc types. The ability of these file formats to store
various kinds and numbers of miscellaneous chunks will vary. See
afGetMiscIDs(3dm) for some important notes about handling this situation.
SEE ALSOafNewFileSetup(3dm), afOpenFile(3dm), afWriteMisc(3dm)
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