The Audio Input API provides a set of functions to directly manage the system audio input devices.

Required Header

#include <audio_io.h>

Overview

The Audio Input API provides a set of functions to record audio data (PCM format) from audio devices.

Related Features

This API is related with the following features:

http://tizen.org/feature/microphone

It is recommended to design feature related codes in your application for reliability.

You can check if a device supports the related features for this API by using System Information, thereby controlling the procedure of your application.

To ensure your application is only running on the device with specific features, please define the features in your manifest file using the manifest editor in the SDK.

More details on featuring your application can be found from Feature Element.

Functions
int	audio_in_create (int sample_rate, audio_channel_e channel, audio_sample_type_e type, audio_in_h *input)
	Creates an audio device instance and returns an input handle to record PCM (pulse-code modulation) data.
int	audio_in_create_loopback (int sample_rate, audio_channel_e channel, audio_sample_type_e type, audio_in_h *input)
	Creates an audio loopback device instance and returns an input handle to record PCM (pulse-code modulation) data.
int	audio_in_destroy (audio_in_h input)
	Releases the audio input handle and all its resources associated with an audio stream.
int	audio_in_prepare (audio_in_h input)
	Prepares reading audio input by starting buffering of audio data from the device.
int	audio_in_unprepare (audio_in_h input)
	Unprepares reading audio input by stopping buffering the audio data from the device.
int	audio_in_read (audio_in_h input, void *buffer, unsigned int length)
	Reads audio data from the audio input buffer.
int	audio_in_get_buffer_size (audio_in_h input, int *size)
	Gets the size to be allocated for the audio input buffer.
int	audio_in_get_sample_rate (audio_in_h input, int *sample_rate)
	Gets the sample rate of the audio input data stream.
int	audio_in_get_channel (audio_in_h input, audio_channel_e *channel)
	Gets the channel type of the audio input data stream.
int	audio_in_get_sample_type (audio_in_h input, audio_sample_type_e *type)
	Gets the sample audio format (8-bit or 16-bit) of the audio input data stream.
int	audio_in_set_interrupted_cb (audio_in_h input, audio_io_interrupted_cb callback, void *user_data)
	Registers a callback function to be invoked when the audio input handle is interrupted or the interrupt is completed.
int	audio_in_unset_interrupted_cb (audio_in_h input)
	Unregisters the callback function.
int	audio_in_ignore_session (audio_in_h input)
	Ignores session for input.
int	audio_in_set_stream_cb (audio_in_h input, audio_in_stream_cb callback, void *userdata)
	Sets an asynchronous(event) callback function to handle recording PCM (pulse-code modulation) data.
int	audio_in_unset_stream_cb (audio_in_h input)
	Unregisters the callback function.
int	audio_in_peek (audio_in_h input, const void *buffer, unsigned int length)
	peek from audio in buffer
int	audio_in_drop (audio_in_h input)
	drop peeked audio buffer.
Typedefs
typedef struct audio_in_s *	audio_in_h
	The audio input handle.
typedef void(*	audio_in_stream_cb )(audio_in_h handle, size_t nbytes, void *userdata)
	Called when audio input data is available in asynchronous(event) mode.

Typedef Documentation

typedef struct audio_in_s* audio_in_h

The audio input handle.

Since :: 2.3.1

typedef void(* audio_in_stream_cb)(audio_in_h handle, size_t nbytes, void *userdata)

Called when audio input data is available in asynchronous(event) mode.

Since :: 2.3.1

Remarks:: use audio_in_peek() to get audio in data inside callback, use audio_in_drop() after use of peeked data.

Parameters:

[in]	handle	The handle to the audio input
[in]	nbytes	The amount of available audio in data which can be peeked.
[in]	userdata	The user data passed from the callback registration function

See also:: audio_in_set_stream_cb()

Function Documentation

int audio_in_create	(	int	sample_rate,
		audio_channel_e	channel,
		audio_sample_type_e	type,
		audio_in_h *	input
	)

Creates an audio device instance and returns an input handle to record PCM (pulse-code modulation) data.

Since :: 2.3.1

Privilege Level:: public

Privilege:: http://tizen.org/privilege/recorder

This function is used for audio input initialization.

Remarks:: input must be released using audio_in_destroy().

Parameters:

[in]	sample_rate	The audio sample rate in 8000[Hz] ~ 48000[Hz]
[in]	channel	The audio channel type (mono or stereo)
[in]	type	The type of audio sample (8- or 16-bit)
[out]	input	An audio input handle is created on success

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_PERMISSION_DENIED	Permission denied
AUDIO_IO_ERROR_OUT_OF_MEMORY	Out of memory
AUDIO_IO_ERROR_DEVICE_NOT_OPENED	Device not opened
AUDIO_IO_ERROR_SOUND_POLICY	Sound policy error
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

See also:: audio_in_destroy()

int audio_in_create_loopback	(	int	sample_rate,
		audio_channel_e	channel,
		audio_sample_type_e	type,
		audio_in_h *	input
	)

Creates an audio loopback device instance and returns an input handle to record PCM (pulse-code modulation) data.

Since :: 2.3.1

Privilege Level:: public

Privilege:: http://tizen.org/privilege/recorder

This function is used for audio loopback input initialization.

Remarks:: input must be released using audio_in_destroy().

Parameters:

[in]	sample_rate	The audio sample rate in 8000[Hz] ~ 48000[Hz]
[in]	channel	The audio channel type, mono, or stereo
[in]	type	The type of audio sample (8- or 16-bit)
[out]	input	An audio input handle will be created, if successful

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_PERMISSION_DENIED	Permission denied
AUDIO_IO_ERROR_OUT_OF_MEMORY	Out of memory
AUDIO_IO_ERROR_DEVICE_NOT_OPENED	Device not opened
AUDIO_IO_ERROR_SOUND_POLICY	Sound policy error
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

See also:: audio_in_destroy()

int audio_in_destroy ( audio_in_h input )

Releases the audio input handle and all its resources associated with an audio stream.

Since :: 2.3.1

Parameters:

[in] input The handle to the audio input to destroy

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_DEVICE_NOT_CLOSED	Device not closed
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

See also:: audio_in_create()

int audio_in_drop ( audio_in_h input )

drop peeked audio buffer.

This function works correctly only with read, write callback. Otherwise it won't operate as intended.

Since :: 2.3.1

Remarks:: Works only in asynchronous(event) mode. This will remove audio in data from actual stream buffer. Use this if peeked data is not needed anymore.

Parameters:

[in] input The handle to the audio input

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_INVALID_OPERATION	Invalid operation
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

See also:: audio_in_peek()

int audio_in_get_buffer_size	(	audio_in_h	input,
		int *	size
	)

Gets the size to be allocated for the audio input buffer.

Since :: 2.3.1

Parameters:

[in]	input	The handle to the audio input
[out]	size	The buffer size (in bytes, the maximum size is 1 MB)

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

See also:: audio_in_read()

int audio_in_get_channel	(	audio_in_h	input,
		audio_channel_e *	channel
	)

Gets the channel type of the audio input data stream.

Since :: 2.3.1

The audio channel type defines whether the audio is mono or stereo.

Parameters:

[in]	input	The handle to the audio input
[out]	channel	The audio channel type

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

int audio_in_get_sample_rate	(	audio_in_h	input,
		int *	sample_rate
	)

Gets the sample rate of the audio input data stream.

Since :: 2.3.1

Parameters:

[in]	input	The handle to the audio input
[out]	sample_rate	The audio sample rate in Hertz (8000 ~ 48000)

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

int audio_in_get_sample_type	(	audio_in_h	input,
		audio_sample_type_e *	type
	)

Gets the sample audio format (8-bit or 16-bit) of the audio input data stream.

Since :: 2.3.1

Parameters:

[in]	input	The handle to the audio input
[out]	type	The audio sample type

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

int audio_in_ignore_session ( audio_in_h input )

Ignores session for input.

Since :: 2.3.1

Parameters:

[in] input The handle to the audio input

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_INVALID_OPERATION	Invalid operation
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

int audio_in_peek	(	audio_in_h	input,
		const void **	buffer,
		unsigned int *	length
	)

peek from audio in buffer

Since :: 2.3.1

This function works correctly only with read, write callback. Otherwise it won't operate as intended.

Remarks:: Works only in asynchronous(event) mode. This will just retrieve buffer pointer from audio in buffer. Drop after use.

Parameters:

[in]	input	The handle to the audio input
[out]	buffer	start buffer pointer of peeked audio in data
[in,out]	length	amount of audio in data to be peeked

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_INVALID_OPERATION	Invalid operation
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

See also:: audio_in_drop()

int audio_in_prepare ( audio_in_h input )

Prepares reading audio input by starting buffering of audio data from the device.

Since :: 2.3.1

Parameters:

[in] input The handle to the audio input

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

See also:: audio_in_unprepare()

int audio_in_read	(	audio_in_h	input,
		void *	buffer,
		unsigned int	length
	)

Reads audio data from the audio input buffer.

Since :: 2.3.1

Parameters:

[in]	input	The handle to the audio input
[out]	buffer	The PCM buffer address
[in]	length	The length of the PCM data buffer (in bytes)

Returns:: The number of read bytes on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_INVALID_BUFFER	Invalid buffer pointer
AUDIO_IO_ERROR_SOUND_POLICY	Sound policy error
AUDIO_IO_ERROR_INVALID_OPERATION	Invalid operation
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

Precondition:: audio_in_start_recording().

int audio_in_set_interrupted_cb	(	audio_in_h	input,
		audio_io_interrupted_cb	callback,
		void *	user_data
	)

Registers a callback function to be invoked when the audio input handle is interrupted or the interrupt is completed.

Since :: 2.3.1

Parameters:

[in]	input	The handle to the audio input
[in]	callback	The callback function to register
[in]	user_data	The user data to be passed to the callback function

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_INVALID_OPERATION	Invalid operation
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

Postcondition:: audio_io_interrupted_cb() will be invoked.

See also:: audio_in_unset_interrupted_cb(); audio_io_interrupted_cb()

int audio_in_set_stream_cb	(	audio_in_h	input,
		audio_in_stream_cb	callback,
		void *	userdata
	)

Sets an asynchronous(event) callback function to handle recording PCM (pulse-code modulation) data.

Since :: 2.3.1

callback will be called when you can read a PCM data. It might cause dead lock if change the state of audio handle in callback. (ex: audio_in_destroy, audio_in_prepare, audio_in_unprepare) Recommend to use as a VOIP only. Recommend not to hold callback too long.(it affects latency)

Remarks:: input must be created using audio_in_create().

Parameters:

[in]	input	An audio input handle
[in]	callback	notify stream callback when user can read data (audio_in_stream_cb)
[in]	userdata	user data to be retrieved when callback is called

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_OUT_OF_MEMORY	Out of memory
AUDIO_IO_ERROR_DEVICE_NOT_OPENED	Device not opened
AUDIO_IO_ERROR_SOUND_POLICY	Sound policy error
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

See also:: audio_out_set_stream_cb()

int audio_in_unprepare ( audio_in_h input )

Unprepares reading audio input by stopping buffering the audio data from the device.

Since :: 2.3.1

Parameters:

[in] input The handle to the audio input

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

See also:: audio_in_prepare()

int audio_in_unset_interrupted_cb ( audio_in_h input )

Unregisters the callback function.

Since :: 2.3.1

Parameters:

[in] input The handle to the audio input

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_INVALID_OPERATION	Invalid operation
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

See also:: audio_in_set_interrupted_cb()

int audio_in_unset_stream_cb ( audio_in_h input )

Unregisters the callback function.

Since :: 2.3.1

Parameters:

[in] input The handle to the audio input

Returns:: 0 on success, otherwise a negative error value

Return values:

AUDIO_IO_ERROR_NONE	Successful
AUDIO_IO_ERROR_INVALID_PARAMETER	Invalid parameter
AUDIO_IO_ERROR_INVALID_OPERATION	Invalid operation
AUDIO_IO_ERROR_NOT_SUPPORTED	Not supported

See also:: audio_in_set_interrupted_cb()

Required Header

Overview

Related Features

Functions

Typedefs

Typedef Documentation

Function Documentation