SndDoubleBufferHeaderPtr
#include <Sound.h>
short dbhNumChannels; 2 0 number of sound
channels
short dbhSampleSize; 2 2 sample size, if
un compressed
short dbhCompressionID; 2 4 ID of compression
algorithm
short dbhPacketSize; 2 6 number of bits per
packet
Fixed dbhSampleRate; 4 8 sample rate procedure
typedef SndDoubleBufferHeader *SndDoubleBufferHeaderPtr;
Field descriptions
dbhNumChannels Indicates the number of channels for the sound (1 for
monophonic sound, 2 for stereo).
dbhSampleSize Indicates the sample size for the sound if the sound is
not compressed. If the sound is compressed,
dbhSampleSize should be set to 0. Samples that are
1-8 bits have a dbhSampleSize value of 8; samples that
are 9-16 bits have a dbhSampleSize value of 16.
Currently, only 8-bit samples are supported. For
further information on sample sizes, refer to the AIFF
specification.
dbhCompressionID Indicates the compression identification number of the
compression algorithm, if the sound is compressed. If
the sound is not compressed, dbhCompressionID should
be set to 0.
dbhPacketSize Indicates the packet size for the compression
algorithm specified by dbhCompressionID, if the sound
is compressed.
dbhSampleRate Indicates the sample rate for the sound. Note that the
sample rate is declared as a Fixed data type, but the most significant bit is not treated as a sign bit; instead,
that bit is interpreted as having the value 32,768.
dbhBufferPtr Indicates an array of two pointers, each of which
dbhDoubleBack Points to the application- defined routine that is called
when the double buffers are switched and the exhausted
buffer needs to be refilled.
The values for the dbhCompressionID, dbhNumChannels, and dbhPacketSize
fields are the same as those for the compressionID, numChannels, and
packetSize fields of the compressed sound header, respectively.
The dbhBufferPtr array contains pointers to two records of type Sound Manager switches until all the sound data has been sent into the buffers should both already contain a nonzero number of frames of data.