Audio APIs

Note

Audio interface is currently only supported on RDA8910 chipset.

Example Usage

    #include <audio.h>

    /* Play an MP3 file from sdcard */
    audio_file_play("/sd/file.mp3", AUDIO_PLAY_LOCAL, NULL);

    /* Play an MP3 file from sdcard during call */
    audio_file_play("/sd/file.mp3", AUDIO_PLAY_VOICE, NULL);

/* set volume */
audio_set_volume(100);

/* play DTMF tone */
audio_play_dtmf("1234", 500, false, NULL);

/* Record from MIC */
audio_record_start("/fs/record.amr", AUDIO_REC_TYPE_MIC, AUDIO_QUALITY_MEDIUM, 5000, NULL);

/* Record voice call */
audio_record_start("/fs/call_record.amr", AUDIO_REC_TYPE_VOICE, AUDIO_QUALITY_MEDIUM, 0, NULL);

API Reference

Header File

Source: include/audio.h

#include <audio.h>

Functions

int audio_set_outputchannel(uint32_t ch)

Set output channel for Audio playback.

Parameters:: ch – output channel audio_out_e
Returns:: 0 for success, error code otherwise

int audio_get_outputchannel(void)

Get current output channel audio_out_e.

Returns:: output channel

int audio_set_inputchannel(uint32_t ch)

Set audio input channel for recording.

Parameters:: ch – input channel value audio_in_e
Returns:: 0 for success, error code otherwise

int audio_get_inputchannel(void)

Get current input channel for recording audio_in_e.

Returns:: audio input channel

int audio_set_volume(int vol)

Set playback volume. Volume level should in [0, 100]. 0 is the minimal volume, and 100 is the maximum volume. It is possible that the supported volume levels is not 100. And then the output is the same for multiple vol.

Parameters:: vol – Volume level between 0 to 100
Returns:: 0 for success, error code otherwise

int audio_get_volume(void)

Get current playback volume level.

Returns:: volume level between 0 to 100

int audio_set_callvolume(int vol)

Set volume level for voice call between 0 to 100. 0 is the minimal volume, and 100 is the maximum volume. It is possible that the supported volume levels is not 100. And then the output is the same for multiple vol.

Parameters:: vol – volume level between 0 to 100
Returns:: 0 for success, error code otherwise

int audio_get_callvolume(void)

Get current voice call volume.

Returns:: volume level between 0 to 100

int audio_set_mute(int mute)

mute or unmute audio output device. This setting won’t be stored, the initial value is always unmute.

Parameters:: mute – true for mute, false for unmute
Returns:: 0 for success, error code otherwise

int audio_get_mute(void)

check whether audio output device is muted

Returns:: true if mute, false if unmute

int audio_play_dtmf(const char *tone, unsigned duration, int block, audio_statuscb_f cb)

Play DTMF tone.

Parameters:

tone – DTMF string with valid DTMF characters (0-9,*,#,A,B,C,D)
duration – Duration of DTMF tone in milliseconds, 100 to 1000ms.
block – True to block till playback finishes, false for non-blocking call
cb – Callback function for playback status events

Returns:

0 for success, error code otherwise

int audio_file_play(const char *file, int path, audio_statuscb_f cb)

Play audio file. Supported audio file types: Raw PCM file Wav file MP3 audio file AMR audio file.

Parameters:

file – Filesystem path of audio file to play
path – Aduio output path audio_play_e
cb – Callback function for playback status events

Returns:

0 for success, error code otherwise

int audio_file_pause(void)

Pause audio file player.

Returns:: 0 for success, error code otherwise

int audio_file_resume(void)

Resume audio file player.

Returns:: 0 for success, error code otherwise

int audio_file_stop(void)

Stop audio file player.

Returns:: 0 for success, error code otherwise

int audio_record_start(const char *fname, int path, int quality, int duration, audio_statuscb_f cb)

Start audio recorder.

Parameters:

fname – Filename to store
path – Audio recorder path audio_rec_e
quality – Audio encoder quality audio_qual_e
duration – duration of recording in ms, 0 for continuous recording until stopped or call ends
cb – Callback function for recorder status events

Returns:

0 for success, error code otherwise

int audio_record_pause(void)

Pause audio recorder.

Returns:: 0 for success, error code otherwise

int audio_record_resume(void)

Resume audio recorder.

Returns:: 0 for success, error code otherwise

int audio_record_stop(void)

Stop audio recorder.

Returns:: 0 for success, error code otherwise

Type Definitions

typedef void (*audio_statuscb_f)(int ev): Audio event callback.

Enumerations

enum audio_out_e

Audio output channel list.

Values:

enumerator AUDIO_OUTPUT_RECEIVER: receiver

enumerator AUDIO_OUTPUT_HEADPHONE: headphone

enumerator AUDIO_OUTPUT_SPEAKER: speaker

enum audio_in_e

Audio input channel list.

Values:

enumerator AUDIO_INPUT_MAINMIC: main mic

enumerator AUDIO_INPUT_AUXMIC: auxilary mic

enumerator AUDIO_INPUT_DUALMIC: dual mic

enumerator AUDIO_INPUT_HPMIC_L: headphone mic left

enumerator AUDIO_INPUT_HPMIC_R: headphone mic right

enum audio_play_e

Audio playback path select.

Values:

enumerator AUDIO_PLAY_LOCAL: Play to local audio path

enumerator AUDIO_PLAY_VOICE: Play to uplink remote during voice call

enum audio_rec_e

Audio recorder path select.

Values:

enumerator AUDIO_REC_TYPE_MIC: Record from microphone.

enumerator AUDIO_REC_TYPE_VOICE: Record for voice call. The recorded stream is the mixed with uplink and downlink channels

enum audio_qual_e

Values:

enumerator AUDIO_QUALITY_LOW: quality low

enumerator AUDIO_QUALITY_MEDIUM: quality medium

enumerator AUDIO_QUALITY_HIGH: quality high

enumerator AUDIO_QUALITY_BEST: quality best