The Audio Metadata API provides functions to get information about audio items.

Required Header

#include <media_content.h>

Overview

The Audio Metadata API provides functions to get information about stored audio files. Its purpose is twofold:

to provide information about audio content
to organize audio content logically (grouping)

API provides functions that allow to check attributes of audio files. Following information about audio content is provided:

Attribute	Filter Keyword	Comments
album	MEDIA_ALBUM	Get from metadata if exist.
artist	MEDIA_ARTIST	Get from metadata if exist.
album_artist	MEDIA_ALBUM_ARTIST	Get from metadata if exist.
genre	MEDIA_GENRE	Get from metadata if exist.
composer	MEDIA_COMPOSER	Get from metadata if exist.
year	MEDIA_YEAR	Get from metadata if exist.
recorded_date	MEDIA_RECORDED_DATE	Get from metadata if exist. if not, same as modified time.
copyright		Get from metadata if exist.
track_num	MEDIA_TRACK_NUM	Get from metadata if exist.
bit_rate		Bitrate
bitpersample		Bit per sample
sample_rate		Samplerate
channel		Channel
duration	MEDIA_DURATION	Duration
rating		Get from metadata if exist.

For getting the audio handle (audio_meta_h) from the media information (media_info_h), call media_info_get_audio() function.
For getting the information related to audio files stored in the device, call the respective get functions e.g. to get the artist of a audio, call audio_meta_get_artist() function and to get bitrate of a audio, call audio_meta_get_bit_rate() function and so on.
When the audio handle is no longer needed, it should be destroyed by calling audio_meta_destroy() function.

Functions
int	audio_meta_clone (audio_meta_h *dst, audio_meta_h src)
	Clones the audio metadata.
int	audio_meta_destroy (audio_meta_h audio)
	Destroys the audio metadata.
int	audio_meta_get_media_id (audio_meta_h audio, char **media_id)
	Gets the ID of the media of the given audio metadata.
int	audio_meta_get_album (audio_meta_h audio, char **album)
	Gets the album of the given audio metadata.
int	audio_meta_get_artist (audio_meta_h audio, char **artist)
	Gets the artist of the given audio metadata.
int	audio_meta_get_album_artist (audio_meta_h audio, char **album_artist)
	Gets the album artist of the given audio metadata.
int	audio_meta_get_genre (audio_meta_h audio, char **genre)
	Gets the genre of the given audio metadata.
int	audio_meta_get_composer (audio_meta_h audio, char **composer)
	Gets the composer of the given audio metadata.
int	audio_meta_get_year (audio_meta_h audio, char **year)
	Gets the year of the given audio metadata.
int	audio_meta_get_recorded_date (audio_meta_h audio, char **recorded_date)
	Gets the recorded date of the given audio metadata.
int	audio_meta_get_copyright (audio_meta_h audio, char **copyright)
	Gets the copyright notice of the given audio metadata.
int	audio_meta_get_track_num (audio_meta_h audio, char **track_num)
	Gets the track number of the given audio metadata.
int	audio_meta_get_bit_rate (audio_meta_h audio, int *bit_rate)
	Gets the bitrate of the given audio metadata in bitrate per second.
int	audio_meta_get_bitpersample (audio_meta_h audio, int *bitpersample)
	Gets bit per sample of the given audio metadata.
int	audio_meta_get_sample_rate (audio_meta_h audio, int *sample_rate)
	Gets the sample rate of the given audio metadata.
int	audio_meta_get_channel (audio_meta_h audio, int *channel)
	Gets the channel of the given audio metadata.
int	audio_meta_get_duration (audio_meta_h audio, int *duration)
	Gets the track duration of the given audio metadata.
Typedefs
typedef struct audio_meta_s *	audio_meta_h
	The structure type for the Audio metadata handle.

Typedef Documentation

typedef struct audio_meta_s* audio_meta_h

The structure type for the Audio metadata handle.

Since :: 2.3

Function Documentation

int audio_meta_clone	(	audio_meta_h *	dst,
		audio_meta_h	src
	)

Clones the audio metadata.

This function copies the audio metadata handle from a source to destination.

Since :: 2.3

Remarks:: The dst should be released using audio_meta_destroy().

Parameters:

[out]	dst	The destination handle to the audio metadata
[in]	src	The source handle to the audio metadata

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter
MEDIA_CONTENT_ERROR_OUT_OF_MEMORY	Out of memory

See also:: audio_meta_destroy()

int audio_meta_destroy ( audio_meta_h audio )

Destroys the audio metadata.

This function frees all resources related to the audio metadata handle. This handle no longer can be used to perform any operations. A new handle has to be created before the next use.

Since :: 2.3

Parameters:

[in] audio The handle to the audio metadata

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter

Precondition:: Get a copy of audio metadata handle handle by calling audio_meta_clone().

See also:: audio_meta_clone()

int audio_meta_get_album	(	audio_meta_h	audio,
		char **	album
	)

Gets the album of the given audio metadata.

If the value is an empty string, the method returns "Unknown".
Since 3.0, if the media content has no album info, the method returns empty string.

Since :: 2.3

Remarks:: The album should be released using free().

Parameters:

[in]	audio	The handle to the audio metadata
[out]	album	The album of the audio metadata

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter
MEDIA_CONTENT_ERROR_OUT_OF_MEMORY	Out of memory

int audio_meta_get_album_artist	(	audio_meta_h	audio,
		char **	album_artist
	)

Gets the album artist of the given audio metadata.

If the value is an empty string, the method returns "Unknown".
Since 3.0, if the media content has no album artist info, the method returns empty string.

Since :: 2.3

Remarks:: The album_artist should be released using free().

Parameters:

[in]	audio	The handle to the audio metadata
[out]	album_artist	The album artist of the audio metadata

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter
MEDIA_CONTENT_ERROR_OUT_OF_MEMORY	Out of memory

int audio_meta_get_artist	(	audio_meta_h	audio,
		char **	artist
	)

Gets the artist of the given audio metadata.

If the value is an empty string, the method returns "Unknown".
Since 3.0, if the media content has no artist info, the method returns empty string.

Since :: 2.3

Remarks:: The artist should be released using free().

Parameters:

[in]	audio	The handle to the audio metadata
[out]	artist	The artist of the audio metadata

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter
MEDIA_CONTENT_ERROR_OUT_OF_MEMORY	Out of memory

int audio_meta_get_bit_rate	(	audio_meta_h	audio,
		int *	bit_rate
	)

Gets the bitrate of the given audio metadata in bitrate per second.

Since :: 2.3

Parameters:

[in]	audio	The handle to the audio metadata
[out]	bit_rate	The audio bitrate in bit per second [bps]

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter

int audio_meta_get_bitpersample	(	audio_meta_h	audio,
		int *	bitpersample
	)

Gets bit per sample of the given audio metadata.

Since :: 2.3

Parameters:

[in]	audio	The handle to the audio metadata
[out]	bitpersample	The audio bit per sample

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter

int audio_meta_get_channel	(	audio_meta_h	audio,
		int *	channel
	)

Gets the channel of the given audio metadata.

Since :: 2.3

Parameters:

[in]	audio	The handle to the audio metadata
[out]	channel	The channel of the audio

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter

int audio_meta_get_composer	(	audio_meta_h	audio,
		char **	composer
	)

Gets the composer of the given audio metadata.

If the value is an empty string, the method returns "Unknown".
Since 3.0, if the media content has no composer info, the method returns empty string.

Since :: 2.3

Remarks:: The composer should be released using free().

Parameters:

[in]	audio	The handle to the audio metadata
[out]	composer	The composer of the audio metadata

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter
MEDIA_CONTENT_ERROR_OUT_OF_MEMORY	Out of memory

int audio_meta_get_copyright	(	audio_meta_h	audio,
		char **	copyright
	)

Gets the copyright notice of the given audio metadata.

If the media content has no copyright info, the method returns empty string.

Since :: 2.3

Remarks:: The copyright should be released using free().

Parameters:

[in]	audio	The handle to the audio metadata
[out]	copyright	The copyright of the audio metadata

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter
MEDIA_CONTENT_ERROR_OUT_OF_MEMORY	Out of memory

int audio_meta_get_duration	(	audio_meta_h	audio,
		int *	duration
	)

Gets the track duration of the given audio metadata.

Since :: 2.3

Parameters:

[in]	audio	The handle to the audio metadata
[out]	duration	The audio file duration

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter

int audio_meta_get_genre	(	audio_meta_h	audio,
		char **	genre
	)

Gets the genre of the given audio metadata.

If the value is an empty string, the method returns "Unknown".
Since 3.0, if the media content has no genre info, the method returns empty string.

Since :: 2.3

Remarks:: The genre should be released using free().

Parameters:

[in]	audio	The handle to the audio metadata
[out]	genre	The genre of the audio metadata

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter
MEDIA_CONTENT_ERROR_OUT_OF_MEMORY	Out of memory

int audio_meta_get_media_id	(	audio_meta_h	audio,
		char **	media_id
	)

Gets the ID of the media of the given audio metadata.

Since :: 2.3

Remarks:: The media_id should be released using free().

Parameters:

[in]	audio	The handle to the audio metadata
[out]	media_id	The media ID

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter
MEDIA_CONTENT_ERROR_OUT_OF_MEMORY	Out of memory

int audio_meta_get_recorded_date	(	audio_meta_h	audio,
		char **	recorded_date
	)

Gets the recorded date of the given audio metadata.

The format of the recorded date may vary depending on the file format.
For more details on the recorded date format, refer to the file format specification.

Since :: 2.3

Remarks:: The recorded_date should be released using free().

Parameters:

[in]	audio	The handle to the audio metadata
[out]	recorded_date	The recorded date of the audio metadata

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter
MEDIA_CONTENT_ERROR_OUT_OF_MEMORY	Out of memory

int audio_meta_get_sample_rate	(	audio_meta_h	audio,
		int *	sample_rate
	)

Gets the sample rate of the given audio metadata.

Since :: 2.3

Parameters:

[in]	audio	The handle to the audio metadata
[out]	sample_rate	The audio sample rate[hz]

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter

int audio_meta_get_track_num	(	audio_meta_h	audio,
		char **	track_num
	)

Gets the track number of the given audio metadata.

If the value is an empty string, the method returns "Unknown".
Since 3.0, if the media content has no track info, the method returns empty string.

Since :: 2.3

Remarks:: The track_num should be released using free().

Parameters:

[in]	audio	The handle to the audio metadata
[out]	track_num	The audio track number of the audio metadata

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter
MEDIA_CONTENT_ERROR_OUT_OF_MEMORY	Out of memory

int audio_meta_get_year	(	audio_meta_h	audio,
		char **	year
	)

Gets the year of the given audio metadata.

If the value is an empty string, the method returns "Unknown".
Since 3.0, if the media content has no year info, the method returns empty string.

Since :: 2.3

Remarks:: The year should be released using free().

Parameters:

[in]	audio	The handle to the audio metadata
[out]	year	The year of the audio metadata

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

Return values:

MEDIA_CONTENT_ERROR_NONE	Successful
MEDIA_CONTENT_ERROR_INVALID_PARAMETER	Invalid parameter
MEDIA_CONTENT_ERROR_OUT_OF_MEMORY	Out of memory

Required Header

Overview

Functions

Typedefs

Typedef Documentation

Function Documentation