Copyright ©1995 by NeXT Computer, Inc.  All Rights Reserved.

Sound Functions

Accessing Sound Devices and Hardware Access sound devices

	int	SNDAcquire(int soundResource, int priority, int preempt, int timeout,  SNDNegotiationFun negFun, void *arg, port_t *devicePort, port_t *ownerPort)
	int	SNDReset(int soundResource, port_t devicePort, port_t ownerPort)
	int	SNDRelease(int soundResource, port_t *devicePort, port_t *ownerPort)

Reserve sound devices for recording or playback

	int	SNDReserve(int soundResource, int priority)
	int	SNDUnreserve(int soundResource)

Set the host computer for subsequent playback or recording

int

SNDSetHost(char *newHostname)

Sound playback utilities

	int	SNDSetVolume(int left, int right)
	int	SNDGetVolume(int *left, int *right)
	int	SNDSetMute(int speakerOn)
	int	SNDGetMute(int *speakerOn)
	int	SNDSetFilter(int filterOn)
	int	SNDGetFilter(int *filterOn)

Recording and Playing Play a soundfile

int SNDPlaySoundfile(char *path, int priority)

Recording and playing a sound

	int	SNDStartPlaying(SNDSoundStruct *sound, int tag, int priority, int preempt, SNDNotificationFun beginFun, SNDNotificationFun endFun)
	int	SNDVerifyPlayable(SNDSoundStruct *sound)
	int	SNDStartRecording(SNDSoundStruct *sound, int tag, int priority, int preempt, SNDNotificationFun beginFun, SNDNotificationFun endFun)
	int	SNDStartRecordingFile(char *fileName, SNDSoundStruct *sound, int tag, int priority, int preempt, SNDNotificationFun beginFun, SNDNotificationFun endFun)
	int	SNDStop(int tag)
	int	SNDWait(int tag)
	int	SNDSamplesProcessed(int tag)
	int	SNDModifyPriority(int tag, int newPriority)

Reading and Writing Soundfiles Read a sound from a file

	int	SNDReadSoundfile(char *path, SNDSoundStruct **sound)
	int	SNDRead(int fd, SNDSoundStruct **sound)
	int	SNDReadHeader(int fd, SNDSoundStruct **sound)
	int	SNDReadDSPfile(char *path, SNDSoundStruct **sound, char *info)

Write a sound to a file

	int	SNDWriteSoundfile(char *path, SNDSoundStruct *sound)
	int	SNDWrite(int fd, SNDSoundStruct *sound)
	int	SNDWriteHeader(int fd, SNDSoundStruct *sound)

Accessing Sound Data Create and free a sound structure

	int	SNDAlloc(SNDSoundStruct **sound, int dataSize, int dataFormat, int samplingRate, int channelCount, int infoSize)
	int	SNDFree(SNDSoundStruct *sound)

Gain access to sampled sound data

int

SNDGetDataPointer(SNDSoundStruct *sound, char **ptr, int *size, int *width)

Measure samples in a sound

	int	SNDSampleCount(SNDSoundStruct *sound)
	int	SNDBytesToSamples(int byteCount, int channelCount, int dataFormat)
	int	SNDSamplesToBytes(int sampleCount, int channelCount, int dataFormat)

Accessing the DSP Boot the DSP

int

SNDBootDSP(port_t *devicePort, port_t *ownerPort, SNDSoundStruct *dspCore)

Run the DSP

int

SNDRunDSP(SNDSoundStruct *dspCore, char *toDSP, int toCount, int toWidth, int toBufferSize, char **fromDSP, int *fromCount, int fromWidth, int negotiationTimeout, int flushTimeout, int conversionTimeout)

Compressing Sound Data Compress or decompress a sound

int

SNDCompressSound(SNDSoundStruct *fromSound, SNDSoundStruct **toSound, BOOL bitFaithful, int compressionAmount)

Query for frequency bands used by Audio Transform Compression

	int	SNDGetNumberOfATCBands(int *numBands)
	int	SNDGetATCBandFrequencies(int numBands, float *centerFreqs)
	int	SNDGetATCBandwidths(int numBands, float *bandwidths)

Speed up or slow down playback of ATC sound

	int	SNDDropATCSamples(int numSamples, int bySamples)
	int	SNDInsertATCSamples(int numSamples, int bySamples)

Modify volume or equalization for ATC playback

	int	SNDSetATCGain(float level)
	int	SNDGetATCGain(float *level)
	int	SNDSetATCEqualizerGains(int numBands, float *gains)
	int	SNDGetATCEqualizerGains(int numBands, float *gains)
	int	SNDScaleATCEqualizerGains(int numBands, float *gainScalars)

Set or get ATC parameters

	int	SNDSetATCSquelchThresholds(int numBands, float *thresholds)
	int	SNDGetATCSquelchThresholds(int numBands, float *thresholds)
	int	SNDUseDefaultATCSquelchThresholds(void)

Set and get compression attributes used in recording

	int	SNDSetCompressionOptions(SNDSoundStruct *sound, int bitFaithful, int compressionAmount)
	int	SNDGetCompressionOptions(SNDSoundStruct *sound, int *bitFaithful, int *compressionAmount)

Converting Sound Data Convert between logarithmic and linear units

	float	SNDConvertDecibelsToLinear(float dB)
	float	SNDConvertLinearToDecibels(float linear)

Convert a sound's attributes

	int	SNDConvertSound(SNDSoundStruct *fromSound, SNDSoundStruct **toSound)
	unsigned char	SNDMulaw(short linearValue)
	short	SNDiMulaw(unsigned char mulawValue)

Editing Sound Data Copy all or part of a sound

	int	SNDCopySound(SNDSoundStruct **toSound, SNDSoundStruct *fromSound)
	int	SNDCopySamples(SNDSoundStruct **toSound, SNDSoundStruct *fromSound, int startSample, int sampleCount)

Edit a sampled sound

	int	SNDInsertSamples(SNDSoundStruct *toSound, SNDSoundStruct *fromSound, int startSample)
	int	SNDDeleteSamples(SNDSoundStruct *sound, int startSample, int sampleCount)
	int	SNDCompactSamples(SNDSoundStruct **toSound, SNDSoundStruct *fromSound)

Sound Errors Describe a sound error

char

*SNDSoundError(int err)