Tizen Native API

The Player API provides functions for media playback and controlling media playback attributes.

Required Header

#include <player.h>

Overview

The Player API provides a way to play multimedia content. Content can be played from a file, from the network, or from memory. It gives the ability to start/stop/pause/mute, set the playback position (that is, seek), perform various status queries, and control the display.

Additional functions allow registering notifications via callback functions for various state change events.

This API also enables collaboration with the GUI service to present a video.

State Diagram

Playback of multimedia content is controlled by a state machine. The following diagram shows the life cycle and states of the Player.

capi_media_player_state_diagram.png

State Transitions

FUNCTION PRE-STATE POST-STATE SYNC TYPE
player_create() NONE IDLE SYNC
player_destroy() IDLE NONE SYNC
player_prepare() IDLE READY SYNC
player_prepare_async() IDLE READY ASYNC
player_unprepare() READY, PLAYING or PAUSED IDLE SYNC
player_start() READY or PAUSED PLAYING SYNC
player_stop() PLAYING READY SYNC
player_pause() PLAYING PAUSED SYNC

State Dependent Function Calls

The following table shows state-dependent function calls. It is forbidden to call the functions listed below in wrong states. Violation of this rule may result in unpredictable behavior.

FUNCTION VALID STATES DESCRIPTION
player_create() ANY -
player_destroy() ANY -
player_prepare() IDLE This function must be called after player_create()
player_unprepare() READY/PAUSED/PLAYING This function must be called after player_stop() or player_start() or player_pause()
player_start() READY/ PAUSED This function must be called after player_prepare()
player_stop() PLAYING/ PAUSED This function must be called after player_start() or player_pause()
player_pause() PLAYING This function must be called after player_start()
player_set_completed_cb()
player_set_interrupted_cb()
player_set_error_cb()
player_set_buffering_cb()
player_set_subtitle_updated_cb()
IDLE/ READY/ PLAYING/ PAUSED This function must be called after player_create()
player_unset_completed_cb()
player_unset_interrupted_cb()
player_unset_error_cb()
player_unset_buffering_cb()
player_unset_subtitle_updated_cb()
IDLE/ READY/ PLAYING/ PAUSED This function must be called after register callback functions such as player_set_completed_cb()
player_get_state() ANY -
player_set_uri() IDLE This function must be called before player_prepare()
player_set_memory_buffer() IDLE This function must be called before player_prepare()
player_set_subtitle_path() IDLE This function must be called before player_prepare()
player_set_volume() IDLE/ READY/ PLAYING/ PAUSED This function must be called after player_create()
player_get_volume() IDLE/ READY/ PLAYING/ PAUSED This function must be called after player_create()
player_set_sound_type() IDLE This function must be called after player_create()
player_set_mute() IDLE/ READY/ PLAYING/ PAUSED This function must be called after player_create()
player_is_muted() IDLE/ READY/ PLAYING/ PAUSED This function must be called after player_create()
player_set_looping() IDLE/ READY/ PLAYING/ PAUSED This function must be called after player_create()
player_is_looping() IDLE/ READY/ PLAYING/ PAUSED This function must be called after player_create()
player_get_duration() PLAYING/ PAUSED This function must be called after player_start()
player_set_display() IDLE This function must be called before player_prepare()
player_set_display_mode()
player_set_display_visible()
IDLE/ READY/ PLAYING/ PAUSED This function must be called after player_create()
player_get_display_rotation()
player_is_display_visible()
IDLE/ READY/ PLAYING/ PAUSED This function must be called after player_create()
player_get_video_size() READY/ PLAYING/ PAUSED This function must be called after player_prepare()

Asynchronous Operations

All functions that change the player state are synchronous except player_prepare_async(), player_set_play_position(), and player_capture_video(). Thus the result is passed to the application via the callback mechanism.

Callback(Event) Operations

REGISTER UNREGISTER CALLBACK DESCRIPTION
player_set_completed_cb() player_unset_completed_cb() player_completed_cb() called when playback is completed
player_set_interrupted_cb() player_unset_interrupted_cb() player_interrupted_cb() called when playback is interrupted by player_interrupted_code_e
player_set_error_cb() player_unset_error_cb() player_error_cb() called when an error has occurred
player_set_buffering_cb() player_unset_buffering_cb() player_buffering_cb() called during content buffering
player_set_progressive_download_message_cb() player_unset_progressive_download_message_cb() player_pd_message_cb() called when a progressive download starts or completes
player_set_subtitle_updated_cb() player_unset_subtitle_updated_cb() player_subtitle_updated_cb() called when a subtitle updates
player_set_media_packet_video_frame_decoded_cb() player_unset_media_packet_video_frame_decoded_cb() player_media_packet_video_decoded_cb()

called when a video frame is decoded

Functions

int player_create (player_h *player)
 Creates a player handle for playing multimedia content.
int player_destroy (player_h player)
 Destroys the media player handle and releases all its resources.
int player_prepare (player_h player)
 Prepares the media player for playback.
int player_prepare_async (player_h player, player_prepared_cb callback, void *user_data)
 Prepares the media player for playback, asynchronously.
int player_unprepare (player_h player)
 Resets the media player.
int player_set_uri (player_h player, const char *uri)
 Sets the data source (file-path or HTTP URI) to use.
int player_set_memory_buffer (player_h player, const void *data, int size)
 Sets memory as the data source.
int player_get_state (player_h player, player_state_e *state)
 Gets the player's current state.
int player_set_volume (player_h player, float left, float right)
 Sets the player's volume.
int player_get_volume (player_h player, float *left, float *right)
 Gets the player's current volume factor.
int player_set_sound_type (player_h player, sound_type_e type)
 Sets the player's volume type.
int player_set_audio_latency_mode (player_h player, audio_latency_mode_e latency_mode)
 Sets the audio latency mode.
int player_get_audio_latency_mode (player_h player, audio_latency_mode_e *latency_mode)
 Gets the current audio latency mode.
int player_start (player_h player)
 Starts or resumes playback.
int player_stop (player_h player)
 Stops playing media content.
int player_pause (player_h player)
 Pauses the player.
int player_set_play_position (player_h player, int millisecond, bool accurate, player_seek_completed_cb callback, void *user_data)
 Sets the seek position for playback, asynchronously.
int player_get_play_position (player_h player, int *millisecond)
 Gets the current position in milliseconds.
int player_set_mute (player_h player, bool muted)
 Sets the player's mute status.
int player_is_muted (player_h player, bool *muted)
 Gets the player's mute status.
int player_set_looping (player_h player, bool looping)
 Sets the player's looping status.
int player_is_looping (player_h player, bool *looping)
 Gets the player's looping status.
int player_set_display (player_h player, player_display_type_e type, player_display_h display)
 Sets the video display.
int player_set_media_packet_video_frame_decoded_cb (player_h player, player_media_packet_video_decoded_cb callback, void *user_data)
 Registers a media packet video callback function to be called once per frame.
int player_unset_media_packet_video_frame_decoded_cb (player_h player)
 Unregisters the callback function.
int player_capture_video (player_h player, player_video_captured_cb callback, void *user_data)
 Captures the video frame, asynchronously.
int player_set_streaming_cookie (player_h player, const char *cookie, int size)
 Sets the cookie for streaming playback.
int player_set_streaming_user_agent (player_h player, const char *user_agent, int size)
 Sets the streaming user agent for playback.
int player_get_streaming_download_progress (player_h player, int *start, int *current)
 Gets the download progress for streaming playback.
int player_set_completed_cb (player_h player, player_completed_cb callback, void *user_data)
 Registers a callback function to be invoked when the playback is finished.
int player_unset_completed_cb (player_h player)
 Unregisters the callback function.
int player_set_interrupted_cb (player_h player, player_interrupted_cb callback, void *user_data)
 Registers a callback function to be invoked when the playback is interrupted or the interrupt is completed.
int player_unset_interrupted_cb (player_h player)
 Unregisters the callback function.
int player_set_error_cb (player_h player, player_error_cb callback, void *user_data)
 Registers a callback function to be invoked when an error occurs.
int player_unset_error_cb (player_h player)
 Unregisters the callback function.
int player_set_buffering_cb (player_h player, player_buffering_cb callback, void *user_data)
 Registers a callback function to be invoked when there is a change in the buffering status of a media stream.
int player_unset_buffering_cb (player_h player)
 Unregisters the callback function.
int player_set_progressive_download_path (player_h player, const char *path)
 Sets a path to download, progressively.
int player_get_progressive_download_status (player_h player, unsigned long *current, unsigned long *total_size)
 Gets the status of progressive download.
int player_set_progressive_download_message_cb (player_h player, player_pd_message_cb callback, void *user_data)
 Registers a callback function to be invoked when progressive download is started or completed.
int player_unset_progressive_download_message_cb (player_h player)
 Unregisters the callback function.
int player_set_playback_rate (player_h player, float rate)
 Sets the playback rate.

Typedefs

typedef struct player_s * player_h
 The media player's type handle.
typedef void * player_display_h
 The player display handle.
typedef void(* player_prepared_cb )(void *user_data)
 Called when the media player is prepared.
typedef void(* player_completed_cb )(void *user_data)
 Called when the media player is completed.
typedef void(* player_seek_completed_cb )(void *user_data)
 Called when the seek operation is completed.
typedef void(* player_interrupted_cb )(player_interrupted_code_e code, void *user_data)
 Called when the media player is interrupted.
typedef void(* player_error_cb )(int error_code, void *user_data)
 Called when an error occurs in the media player.
typedef void(* player_buffering_cb )(int percent, void *user_data)
 Called when the buffering percentage of the media playback is updated.
typedef void(* player_pd_message_cb )(player_pd_message_type_e type, void *user_data)
 Called when progressive download is started or completed.
typedef void(* player_video_captured_cb )(unsigned char *data, int width, int height, unsigned int size, void *user_data)
 Called when the video is captured.
typedef void(* player_media_packet_video_decoded_cb )(media_packet_h pkt, void *user_data)
 Called to register for notifications about delivering media packet when every video frame is decoded.

Defines

#define GET_DISPLAY(x)   (void*)(x)
 Definition for a display handle from evas object.

Define Documentation

#define GET_DISPLAY (   x)    (void*)(x)

Definition for a display handle from evas object.

Since :
2.3.1

Typedef Documentation

typedef void(* player_buffering_cb)(int percent, void *user_data)

Called when the buffering percentage of the media playback is updated.

Since :
2.3.1

If the buffer is full, it will return 100%.

Parameters:
[in]percentThe percentage of buffering completed (0~100)
[in]user_dataThe user data passed from the callback registration function
See also:
player_set_buffering_cb()
player_unset_buffering_cb()
typedef void(* player_completed_cb)(void *user_data)

Called when the media player is completed.

Since :
2.3.1

It will be invoked when player has reached the end of the stream.

Parameters:
[in]user_dataThe user data passed from the callback registration function
Precondition:
It will be invoked when the playback is completed if you register this callback using player_set_completed_cb().
See also:
player_set_completed_cb()
player_unset_completed_cb()
typedef void* player_display_h

The player display handle.

Since :
2.3.1
typedef void(* player_error_cb)(int error_code, void *user_data)

Called when an error occurs in the media player.

Since :
2.3.1
Parameters:
[in]error_codeThe error code
[in]user_dataThe user data passed from the callback registration function
See also:
player_set_error_cb()
player_unset_error_cb()
player_error_e
typedef struct player_s* player_h

The media player's type handle.

Since :
2.3.1
typedef void(* player_interrupted_cb)(player_interrupted_code_e code, void *user_data)

Called when the media player is interrupted.

Since :
2.3.1
Parameters:
[in]error_codeThe interrupted error code
[in]user_dataThe user data passed from the callback registration function
See also:
player_set_interrupted_cb()
player_unset_interrupted_cb()
typedef void(* player_media_packet_video_decoded_cb)(media_packet_h pkt, void *user_data)

Called to register for notifications about delivering media packet when every video frame is decoded.

Since :
2.3.1
Remarks:
This function is issued in the context of gstreamer so the UI update code should not be directly invoked.
the packet should be released by media_packet_destroy() after use.
Otherwises, decoder can't work more because it can't have enough buffer to fill decoded frame.
Parameters:
[in]pktReference pointer to the media packet
[in]user_dataThe user data passed from the callback registration function
typedef void(* player_pd_message_cb)(player_pd_message_type_e type, void *user_data)

Called when progressive download is started or completed.

Since :
2.3.1
Parameters:
[in]typeThe message type for progressive download
[in]user_dataThe user data passed from the callback registration function
See also:
player_set_progressive_download_path()
typedef void(* player_prepared_cb)(void *user_data)

Called when the media player is prepared.

Since :
2.3.1

It will be invoked when player has reached the begin of stream.

Parameters:
[in]user_dataThe user data passed from the callback registration function
Precondition:
player_prepare_async() will cause this callback.
Postcondition:
The player state will be PLAYER_STATE_READY.
See also:
player_prepare_async()
typedef void(* player_seek_completed_cb)(void *user_data)

Called when the seek operation is completed.

Since :
2.3.1
Parameters:
[in]user_dataThe user data passed from the callback registration function
See also:
player_set_play_position()
typedef void(* player_video_captured_cb)(unsigned char *data, int width, int height, unsigned int size, void *user_data)

Called when the video is captured.

Since :
2.3.1
Remarks:
The color space format of the captured image is IMAGE_UTIL_COLORSPACE_RGB888.
Parameters:
[in]dataThe captured image buffer
[in]widthThe width of the captured image
[in]heightThe height of the captured image
[in]sizeThe size of the captured image
[in]user_dataThe user data passed from the callback registration function
See also:
player_capture_video()

Enumeration Type Documentation

Enumeration for audio latency mode.

Since :
2.3.1
Enumerator:
AUDIO_LATENCY_MODE_LOW 

Low audio latency mode

AUDIO_LATENCY_MODE_MID 

Middle audio latency mode

AUDIO_LATENCY_MODE_HIGH 

High audio latency mode

Enumeration for display type.

Since :
2.3.1
Enumerator:
PLAYER_DISPLAY_TYPE_OVERLAY 

Overlay surface display

PLAYER_DISPLAY_TYPE_NONE 

This disposes off buffers

Enumeration for media player's error codes.

Since :
2.3.1
Enumerator:
PLAYER_ERROR_NONE 

Successful

PLAYER_ERROR_OUT_OF_MEMORY 

Out of memory

PLAYER_ERROR_INVALID_PARAMETER 

Invalid parameter

PLAYER_ERROR_NO_SUCH_FILE 

No such file or directory

PLAYER_ERROR_INVALID_OPERATION 

Invalid operation

PLAYER_ERROR_FILE_NO_SPACE_ON_DEVICE 

No space left on the device

PLAYER_ERROR_FEATURE_NOT_SUPPORTED_ON_DEVICE 

Not supported

PLAYER_ERROR_SEEK_FAILED 

Seek operation failure

PLAYER_ERROR_INVALID_STATE 

Invalid state

PLAYER_ERROR_NOT_SUPPORTED_FILE 

File format not supported

PLAYER_ERROR_INVALID_URI 

Invalid URI

PLAYER_ERROR_SOUND_POLICY 

Sound policy error

PLAYER_ERROR_CONNECTION_FAILED 

Streaming connection failed

PLAYER_ERROR_VIDEO_CAPTURE_FAILED 

Video capture failed

PLAYER_ERROR_DRM_EXPIRED 

Expired license

PLAYER_ERROR_DRM_NO_LICENSE 

No license

PLAYER_ERROR_DRM_FUTURE_USE 

License for future use

PLAYER_ERROR_DRM_NOT_PERMITTED 

Format not permitted

PLAYER_ERROR_RESOURCE_LIMIT 

Resource limit

PLAYER_ERROR_PERMISSION_DENIED 

Permission denied

Enumeration for media player's interruption type.

Since :
2.3.1
Enumerator:
PLAYER_INTERRUPTED_COMPLETED 

Interrupt completed

PLAYER_INTERRUPTED_BY_MEDIA 

Interrupted by a non-resumable media application

PLAYER_INTERRUPTED_BY_CALL 

Interrupted by an incoming call

PLAYER_INTERRUPTED_BY_EARJACK_UNPLUG 

Interrupted by unplugging headphones

PLAYER_INTERRUPTED_BY_RESOURCE_CONFLICT 

Interrupted by a resource conflict

PLAYER_INTERRUPTED_BY_ALARM 

Interrupted by an alarm

PLAYER_INTERRUPTED_BY_EMERGENCY 

Interrupted by an emergency

PLAYER_INTERRUPTED_BY_NOTIFICATION 

Interrupted by a notification

Enumeration for progressive download message type.

Since :
2.3.1
Enumerator:
PLAYER_PD_STARTED 

Progressive download is started

PLAYER_PD_COMPLETED 

Progressive download is completed

Enumeration for media player state.

Since :
2.3.1
Enumerator:
PLAYER_STATE_NONE 

Player is not created

PLAYER_STATE_IDLE 

Player is created, but not prepared

PLAYER_STATE_READY 

Player is ready to play media

PLAYER_STATE_PLAYING 

Player is playing media

PLAYER_STATE_PAUSED 

Player is paused while playing media


Function Documentation

int player_capture_video ( player_h  player,
player_video_captured_cb  callback,
void *  user_data 
)

Captures the video frame, asynchronously.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[in]callbackThe callback function to register
[in]user_dataThe user data to be passed to the callback function
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation Video type should be set using player_set_display() otherwises, audio stream is only processed even though video file is set.
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The player state must be set to PLAYER_STATE_PLAYING by calling player_start() or set to PLAYER_STATE_PAUSED by calling player_pause().
Postcondition:
It invokes player_video_captured_cb() when capture completes, if you set a callback.
See also:
player_video_captured_cb()
int player_create ( player_h player)

Creates a player handle for playing multimedia content.

Since :
2.3.1
Remarks:
You must release player by using player_destroy().
Although you can create multiple player handles at the same time, the player cannot guarantee proper operation because of limited resources, such as audio or display device.
Parameters:
[out]playerA new handle to the media player
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_OUT_OF_MEMORYOut of memory
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
Postcondition:
The player state will be PLAYER_STATE_IDLE.
See also:
player_destroy()
int player_destroy ( player_h  player)

Destroys the media player handle and releases all its resources.

Since :
2.3.1
Remarks:
To completely shutdown player operation, call this function with a valid player handle from any player state.
Parameters:
[in]playerThe handle to the media player to be destroyed
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
Precondition:
The player state must be set to PLAYER_STATE_IDLE.
Postcondition:
The player state will be PLAYER_STATE_NONE.
See also:
player_create()
int player_get_audio_latency_mode ( player_h  player,
audio_latency_mode_e latency_mode 
)

Gets the current audio latency mode.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[out]latency_modeThe latency mode to get from the audio
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
See also:
audio_latency_mode_e
player_set_audio_latency_mode()
int player_get_play_position ( player_h  player,
int *  millisecond 
)

Gets the current position in milliseconds.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[out]millisecondThe current position in milliseconds
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_SEEK_FAILEDSeek operation failure
Precondition:
The player state must be one of these: PLAYER_STATE_IDLE, PLAYER_STATE_READY, PLAYER_STATE_PLAYING, or PLAYER_STATE_PAUSED.
See also:
player_set_play_position()
int player_get_progressive_download_status ( player_h  player,
unsigned long *  current,
unsigned long *  total_size 
)

Gets the status of progressive download.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[out]currentThe current download position (bytes)
[out]total_sizeThe total size of the file (bytes)
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The progressive download path must be set by calling player_set_progressive_download_path().
The player state must be set to PLAYER_STATE_PLAYING by calling player_start() or set to PLAYER_STATE_PAUSED by calling player_pause().
int player_get_state ( player_h  player,
player_state_e state 
)

Gets the player's current state.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[out]stateThe current state of the player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
See also:
player_state_e
int player_get_streaming_download_progress ( player_h  player,
int *  start,
int *  current 
)

Gets the download progress for streaming playback.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[out]startThe starting position in percentage [0, 100]
[out]currentThe current position in percentage [0, 100]
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The player state must be set to PLAYER_STATE_PLAYING by calling player_start() or set to PLAYER_STATE_PAUSED by calling player_pause().
int player_get_volume ( player_h  player,
float *  left,
float *  right 
)

Gets the player's current volume factor.

Since :
2.3.1

The range of left and right is from 0 to 1.0, inclusive (1.0 = 100%). This function gets the player volume, not the system volume. To get the system volume, use the Sound Manager API.

Parameters:
[in]playerThe handle to the media player
[out]leftThe current left volume scalar
[out]rightThe current right volume scalar
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
See also:
player_set_volume()
int player_is_looping ( player_h  player,
bool *  looping 
)

Gets the player's looping status.

Since :
2.3.1

If the looping status is true, playback automatically restarts upon finishing. If it is false, it won't.

Parameters:
[in]playerThe handle to the media player
[out]loopingThe looping status: (true = looping, false = non-looping )
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The player state must be one of these: PLAYER_STATE_IDLE, PLAYER_STATE_READY, PLAYER_STATE_PLAYING, or PLAYER_STATE_PAUSED.
See also:
player_set_looping()
int player_is_muted ( player_h  player,
bool *  muted 
)

Gets the player's mute status.

Since :
2.3.1

If the mute status is true, no sounds are played. If it is false, sounds are played at the previously set volume level.

Parameters:
[in]playerThe handle to the media player
[out]mutedThe current mute status: (true = mute, false = not muted)
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
Precondition:
The player state must be one of these: PLAYER_STATE_IDLE, PLAYER_STATE_READY, PLAYER_STATE_PLAYING, or PLAYER_STATE_PAUSED.
See also:
player_set_mute()
int player_pause ( player_h  player)

Pauses the player.

Since :
2.3.1
Remarks:
You can resume playback using player_start().
Parameters:
[in]playerThe handle to the media player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid state
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
PLAYER_ERROR_SOUND_POLICYSound policy error
Precondition:
The player state must be set to PLAYER_STATE_PLAYING.
Postcondition:
The player state will be PLAYER_STATE_READY.
See also:
player_start()
int player_prepare ( player_h  player)

Prepares the media player for playback.

Since :
2.3.1
Remarks:
The mediastorage privilege(http://tizen.org/privilege/mediastorage) should be added if any video/audio files are used to play located in the internal storage.
The externalstorage privilege(http://tizen.org/privilege/externalstorage) should be added if any video/audio files are used to play located in the external storage.
The internet privilege(http://tizen.org/privilege/internet) should be added if any URLs are used to play from network.
Parameters:
[in]playerThe handle to the media player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_URIInvalid URI
PLAYER_ERROR_NO_SUCH_FILEFile not found
PLAYER_ERROR_NOT_SUPPORTED_FILEFile not supported
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
PLAYER_ERROR_PERMISSION_DENIEDPermission denied
Precondition:
The player state must be set to PLAYER_STATE_IDLE by calling player_create() or player_unprepare(). After that, call player_set_uri() to load the media content you want to play.
Postcondition:
The player state will be PLAYER_STATE_READY.
See also:
player_prepare_async()
player_unprepare()
player_set_uri()
int player_prepare_async ( player_h  player,
player_prepared_cb  callback,
void *  user_data 
)

Prepares the media player for playback, asynchronously.

Since :
2.3.1
Remarks:
The mediastorage privilege(http://tizen.org/privilege/mediastorage) should be added if any video/audio files are used to play located in the internal storage.
The externalstorage privilege(http://tizen.org/privilege/externalstorage) should be added if any video/audio files are used to play located in the external storage.
The internet privilege(http://tizen.org/privilege/internet) should be added if any URLs are used to play from network.
Parameters:
[in]playerThe handle to the media player
[in]callbackThe callback function to register
[in]user_dataThe user data to be passed to the callback function
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_URIInvalid URI
PLAYER_ERROR_NO_SUCH_FILEFile not found
PLAYER_ERROR_NOT_SUPPORTED_FILEFile not supported
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
PLAYER_ERROR_PERMISSION_DENIEDPermission denied
Precondition:
The player state must be set to PLAYER_STATE_IDLE by calling player_create() or player_unprepare(). After that, call player_set_uri() to load the media content you want to play.
Postcondition:
It invokes player_prepared_cb() when playback is prepared.
See also:
player_prepare()
player_prepared_cb()
player_unprepare()
player_set_uri()
int player_set_audio_latency_mode ( player_h  player,
audio_latency_mode_e  latency_mode 
)

Sets the audio latency mode.

Since :
2.3.1
Remarks:
The default audio latency mode of the player is AUDIO_LATENCY_MODE_MID. To get the current audio latency mode, use player_get_audio_latency_mode(). If it's high mode, audio output interval can be increased so, it can keep more audio data to play. But, state transition like pause or resume can be more slower than default(mid) mode.
Parameters:
[in]playerThe handle to the media player
[in]latency_modeThe latency mode to be applied to the audio
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
See also:
audio_latency_mode_e
player_get_audio_latency_mode()
int player_set_buffering_cb ( player_h  player,
player_buffering_cb  callback,
void *  user_data 
)

Registers a callback function to be invoked when there is a change in the buffering status of a media stream.

Since :
2.3.1
Remarks:
The media resource should be streamed over the network.
Parameters:
[in]playerThe handle to the media player
[in]callbackThe callback function to register
[in]user_dataThe user data to be passed to the callback function
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_FEATURE_NOT_SUPPORTED_ON_DEVICEUnsupported feature
Postcondition:
player_buffering_cb() will be invoked.
See also:
player_unset_buffering_cb()
player_set_uri()
player_buffering_cb()
int player_set_completed_cb ( player_h  player,
player_completed_cb  callback,
void *  user_data 
)

Registers a callback function to be invoked when the playback is finished.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[in]callbackThe callback function to register
[in]user_dataThe user data to be passed to the callback function
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
Postcondition:
player_completed_cb() will be invoked.
See also:
player_unset_completed_cb()
player_completed_cb()
player_start()
int player_set_display ( player_h  player,
player_display_type_e  type,
player_display_h  display 
)

Sets the video display.

Since :
2.3.1
Remarks:
To get display to set, use GET_DISPLAY().
To use the multiple surface display mode, use player_set_display() again with a different display type.
Parameters:
[in]playerThe handle to the media player
[in]typeThe display type
[in]displayThe handle to display
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The player state must be one of these: PLAYER_STATE_IDLE, PLAYER_STATE_READY, PLAYER_STATE_PLAYING, or PLAYER_STATE_PAUSED.
See also:
player_set_display_rotation
int player_set_error_cb ( player_h  player,
player_error_cb  callback,
void *  user_data 
)

Registers a callback function to be invoked when an error occurs.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[in]callbackThe callback function to register
[in]user_dataThe user data to be passed to the callback function
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
Postcondition:
player_error_cb() will be invoked.
See also:
player_unset_error_cb()
player_error_cb()
int player_set_interrupted_cb ( player_h  player,
player_interrupted_cb  callback,
void *  user_data 
)

Registers a callback function to be invoked when the playback is interrupted or the interrupt is completed.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[in]callbackThe callback function to register
[in]user_dataThe user data to be passed to the callback function
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
Postcondition:
player_interrupted_cb() will be invoked.
See also:
player_unset_interrupted_cb()
player_interrupted_code_e
player_interrupted_cb()
int player_set_looping ( player_h  player,
bool  looping 
)

Sets the player's looping status.

Since :
2.3.1

If the looping status is true, playback automatically restarts upon finishing. If it is false, it won't. The default value is false.

Parameters:
[in]playerThe handle to the media player
[in]loopingThe new looping status: (true = looping, false = non-looping )
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The player state must be one of these: PLAYER_STATE_IDLE, PLAYER_STATE_READY, PLAYER_STATE_PLAYING, or PLAYER_STATE_PAUSED.
See also:
player_is_looping()

Registers a media packet video callback function to be called once per frame.

Since :
2.3.1
Remarks:
This function should be called before preparing.
A registered callback is called on the internal thread of the player.
A video frame can be retrieved using a registered callback as a media packet.
The callback function holds the same buffer that will be drawn on the display device.
So if you change the media packet in a registerd callback, it will be displayed on the device
and the media packet is available until it's destroyed by media_packet_destroy().
Parameters:
[in]playerThe handle to the media player
[in]callbackThe callback function to be registered
[in]user_dataThe user data to be passed to the callback function
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_STATEInvalid state
Precondition:
The player's state should be PLAYER_STATE_IDLE. And, PLAYER_DISPLAY_TYPE_NONE should be set by calling player_set_display.
See also:
player_unset_media_packet_video_frame_decoded_cb
int player_set_memory_buffer ( player_h  player,
const void *  data,
int  size 
)

Sets memory as the data source.

Associates media content, cached in memory, with the player. Unlike the case of player_set_uri(), the media resides in memory. If the function call is successful, subsequent calls to player_prepare() and player_start() will start playing the media.

Since :
2.3.1
Remarks:
If you provide an invalid data, you won't receive an error message until you call player_start().
Parameters:
[in]playerThe handle to the media player
[in]dataThe memory pointer of media data
[in]sizeThe size of media data
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The player state must be set to PLAYER_STATE_IDLE by calling player_create() or player_unprepare().
See also:
player_set_uri()
int player_set_mute ( player_h  player,
bool  muted 
)

Sets the player's mute status.

Since :
2.3.1

If the mute status is true, no sounds are played. If it is false, sounds are played at the previously set volume level. Until this function is called, by default the player is not muted.

Parameters:
[in]playerThe handle to the media player
[in]mutedThe new mute status: (true = mute, false = not muted)
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
Precondition:
The player state must be one of these: PLAYER_STATE_IDLE, PLAYER_STATE_READY, PLAYER_STATE_PLAYING, or PLAYER_STATE_PAUSED.
See also:
player_is_muted()
int player_set_play_position ( player_h  player,
int  millisecond,
bool  accurate,
player_seek_completed_cb  callback,
void *  user_data 
)

Sets the seek position for playback, asynchronously.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[in]millisecondThe position in milliseconds from the start to the seek point
[in]accurateIf true the selected position is returned, but this might be considerably slow, otherwise false
[in]callbackThe callback function to register
[in]user_dataThe user data to be passed to the callback function
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_SEEK_FAILEDSeek operation failure
Precondition:
The player state must be one of these: PLAYER_STATE_READY, PLAYER_STATE_PLAYING, or PLAYER_STATE_PAUSED.
Postcondition:
It invokes player_seek_completed_cb() when seek operation completes, if you set a callback.
See also:
player_get_play_position()
int player_set_playback_rate ( player_h  player,
float  rate 
)

Sets the playback rate.

Since :
2.3.1

The default value is 1.0.

Remarks:
PLAYER_ERROR_INVALID_OPERATION occurs when streaming playback.
No operation is performed, if rate is 0.
The sound is muted, when playback rate is under 0.0 and over 2.0.
Parameters:
[in]playerThe handle to the media player
[in]rateThe playback rate (-5.0x ~ 5.0x)
Return values:
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The player state must be set to PLAYER_STATE_PLAYING by calling player_start().
The player state must be set to PLAYER_STATE_READY by calling player_prepare() or set to PLAYER_STATE_PLAYING by calling player_start() or set to PLAYER_STATE_PAUSED by calling player_pause().
int player_set_progressive_download_message_cb ( player_h  player,
player_pd_message_cb  callback,
void *  user_data 
)

Registers a callback function to be invoked when progressive download is started or completed.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[in]callbackThe callback function to register
[in]user_dataThe user data to be passed to the callback function
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_FEATURE_NOT_SUPPORTED_ON_DEVICEUnsupported feature
Precondition:
The path to download must be set by calling player_set_progressive_download_path().
Postcondition:
player_pd_message_cb() will be invoked.
See also:
player_unset_progressive_download_message_cb()
player_set_progressive_download_path()
int player_set_progressive_download_path ( player_h  player,
const char *  path 
)

Sets a path to download, progressively.

Since :
2.3.1
Remarks:
Progressive download will be started when you invoke player_start().
Parameters:
[in]playerThe handle to the media player
[in]pathThe absolute path to download
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
PLAYER_ERROR_FEATURE_NOT_SUPPORTED_ON_DEVICEUnsupported feature
Precondition:
The player state must be set to PLAYER_STATE_IDLE by calling player_create() or player_unprepare().
See also:
player_set_progressive_download_message_cb()
player_unset_progressive_download_message_cb()
int player_set_sound_type ( player_h  player,
sound_type_e  type 
)

Sets the player's volume type.

Since :
2.3.1
Remarks:
The default sound type of the player is SOUND_TYPE_MEDIA. To get the current sound type, use sound_manager_get_current_sound_type().
Parameters:
[in]playerThe handle to the media player
[in]typeThe sound type
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
Precondition:
The player state must be set to PLAYER_STATE_IDLE by calling player_create().
See also:
sound_manager_get_current_sound_type()
int player_set_streaming_cookie ( player_h  player,
const char *  cookie,
int  size 
)

Sets the cookie for streaming playback.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[in]cookieThe cookie to set
[in]sizeThe size of the cookie
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The player state must be set to PLAYER_STATE_IDLE by calling player_create() or player_unprepare().
See also:
player_set_streaming_user_agent()
int player_set_streaming_user_agent ( player_h  player,
const char *  user_agent,
int  size 
)

Sets the streaming user agent for playback.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
[in]user_agentThe user agent to set
[in]sizeThe size of the user agent
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The player state must be set to PLAYER_STATE_IDLE by calling player_create() or player_unprepare().
See also:
player_set_streaming_cookie()
int player_set_uri ( player_h  player,
const char *  uri 
)

Sets the data source (file-path or HTTP URI) to use.

Associates media contents, referred to by the URI, with the player. If the function call is successful, subsequent calls to player_prepare() and player_start() will start playing the media.

Since :
2.3.1
Remarks:
If you use HTTP, URI should start with "http://". The default protocol is "file://". If you provide an invalid URI, you won't receive an error message until you call player_start().
Parameters:
[in]playerThe handle to the media player
[in]uriThe content location, such as the file path or HTTP URI
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The player state must be set to PLAYER_STATE_IDLE by calling player_create() or player_unprepare().
See also:
player_set_memory_buffer()
int player_set_volume ( player_h  player,
float  left,
float  right 
)

Sets the player's volume.

Since :
2.3.1

Setting this volume adjusts the player's instance volume, not the system volume. The valid range is from 0 to 1.0, inclusive (1.0 = 100%). Default value is 1.0. To change system volume, use the Sound Manager API. Finally, it does not support to set other value into each channel currently.

Parameters:
[in]playerThe handle to the media player
[in]leftThe left volume scalar
[in]rightThe right volume scalar
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
See also:
player_get_volume()
int player_start ( player_h  player)

Starts or resumes playback.

Since :
2.3.1

Plays current media content, or resumes play if paused.

Parameters:
[in]playerThe handle to the media player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
PLAYER_ERROR_CONNECTION_FAILEDNetwork connection failed
PLAYER_ERROR_SOUND_POLICYSound policy error
Precondition:
player_prepare() must be called before calling this function.
The player state must be set to PLAYER_STATE_READY by calling player_prepare() or set to PLAYER_STATE_PAUSED by calling player_pause().
Postcondition:
The player state will be PLAYER_STATE_PLAYING.
It invokes player_completed_cb() when playback completes, if you set a callback with player_set_completed_cb().
It invokes player_pd_message_cb() when progressive download starts or completes, if you set a download path with player_set_progressive_download_path() and a callback with player_set_progressive_download_message_cb().
See also:
player_prepare()
player_prepare_async()
player_stop()
player_pause()
player_set_completed_cb()
player_completed_cb()
player_set_progressive_download_path()
player_set_progressive_download_message_cb()
player_pd_message_cb()
int player_stop ( player_h  player)

Stops playing media content.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid state
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
PLAYER_ERROR_SOUND_POLICYSound policy error
Precondition:
The player state must be set to PLAYER_STATE_PLAYING by calling player_start() or set to PLAYER_STATE_PAUSED by calling player_pause().
Postcondition:
The player state will be PLAYER_STATE_READY.
The downloading will be aborted if you use progressive download.
See also:
player_start()
player_pause()
int player_unprepare ( player_h  player)

Resets the media player.

The most recently used media is reset and no longer associated with the player. Playback is no longer possible. If you want to use the player again, you will have to set the data URI and call player_prepare() again.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
PLAYER_ERROR_INVALID_STATEInvalid player state
Precondition:
The player state should be higher than PLAYER_STATE_IDLE.
Postcondition:
The player state will be PLAYER_STATE_IDLE.
See also:
player_prepare()

Unregisters the callback function.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
See also:
player_set_buffering_cb()

Unregisters the callback function.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
See also:
player_set_completed_cb()

Unregisters the callback function.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
See also:
player_set_error_cb()

Unregisters the callback function.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
See also:
player_set_interrupted_cb()

Unregisters the callback function.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
Precondition:
The player's state should be PLAYER_STATE_READY or PLAYER_STATE_IDLE
See also:
player_set_media_packet_video_frame_decoded_cb()

Unregisters the callback function.

Since :
2.3.1
Parameters:
[in]playerThe handle to the media player
Returns:
0 on success, otherwise a negative error value
Return values:
PLAYER_ERROR_NONESuccessful
PLAYER_ERROR_INVALID_PARAMETERInvalid parameter
PLAYER_ERROR_INVALID_OPERATIONInvalid operation
See also:
player_set_progressive_download_message_cb()