# native_avsession.h
## Overview
The **native_avsession.h** file declares the AVSession definition, which can be used to set metadata, playback state, and other information.
**Library**: libohavsession.so
**File to include**: <multimedia/av_session/native_avsession.h>
**System capability**: SystemCapability.Multimedia.AVSession.Core
**Since**: 13
**Related module**: [OHAVSession](_o_h_a_v_session.md)
## Summary
### Structs
| Name| Description|
| -------- | -------- |
| struct [AVSession_PlaybackPosition](_a_v_session___playback_position.md) | Describes the information related to the playback position.|
### Types
| Name| Description|
| -------- | -------- |
| typedef struct [AVSession_PlaybackPosition](_a_v_session___playback_position.md) [AVSession_PlaybackPosition](_o_h_a_v_session.md#avsession_playbackposition) | Defines a struct for the information related to the playback position.|
| typedef enum [AVSession_ControlCommand](_o_h_a_v_session.md#avsession_controlcommand) [AVSession_ControlCommand](_o_h_a_v_session.md#avsession_controlcommand) | Defines an enum for the playback control commands.|
| typedef [AVSessionCallback_Result](_o_h_a_v_session.md#avsessioncallback_result)(\* [OH_AVSessionCallback_OnCommand](_o_h_a_v_session.md#oh_avsessioncallback_oncommand)) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*session, [AVSession_ControlCommand](_o_h_a_v_session.md#avsession_controlcommand) command, void \*userData) | Defines a callback for a common playback control command.|
| typedef [AVSessionCallback_Result](_o_h_a_v_session.md#avsessioncallback_result)(\* [OH_AVSessionCallback_OnFastForward](_o_h_a_v_session.md#oh_avsessioncallback_onfastforward)) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*session, uint32_t seekTime, void \*userData) | Defines a callback for the fast-forward operation.|
| typedef [AVSessionCallback_Result](_o_h_a_v_session.md#avsessioncallback_result)(\* [OH_AVSessionCallback_OnRewind](_o_h_a_v_session.md#oh_avsessioncallback_onrewind)) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*session, uint32_t seekTime, void \*userData) | Defines a callback for the rewind operation.|
| typedef [AVSessionCallback_Result](_o_h_a_v_session.md#avsessioncallback_result)(\* [OH_AVSessionCallback_OnSeek](_o_h_a_v_session.md#oh_avsessioncallback_onseek)) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*session, uint64_t seekTime, void \*userData) | Defines a callback for the seek operation.|
| typedef [AVSessionCallback_Result](_o_h_a_v_session.md#avsessioncallback_result)(\* [OH_AVSessionCallback_OnSetLoopMode](_o_h_a_v_session.md#oh_avsessioncallback_onsetloopmode)) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*session, [AVSession_LoopMode](_o_h_a_v_session.md#avsession_loopmode) curLoopMode, void \*userData) | Defines a callback for the operation of setting the loop mode.|
| typedef [AVSessionCallback_Result](_o_h_a_v_session.md#avsessioncallback_result)(\* [OH_AVSessionCallback_OnToggleFavorite](_o_h_a_v_session.md#oh_avsessioncallback_ontogglefavorite)) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*session, const char \*assetId, void \*userData) | Defines a callback for the operation of favoriting a media asset.|
| typedef struct [OH_AVSession](_o_h_a_v_session.md#oh_avsession) [OH_AVSession](_o_h_a_v_session.md#oh_avsession) | Defines a struct for the playback control session object.|
### Enums
| Name| Description|
| -------- | -------- |
| [AVSession_Type](_o_h_a_v_session.md#avsession_type) {
SESSION_TYPE_AUDIO = 0,
SESSION_TYPE_VIDEO = 1,
SESSION_TYPE_VOICE_CALL = 2,
SESSION_TYPE_VIDEO_CALL = 3 } | Enumerates the session types.|
| [AVSession_PlaybackState](_o_h_a_v_session.md#avsession_playbackstate) {
PLAYBACK_STATE_INITIAL = 0,
PLAYBACK_STATE_PREPARING = 1,
PLAYBACK_STATE_PLAYING = 2,
PLAYBACK_STATE_PAUSED = 3,
PLAYBACK_STATE_FAST_FORWARDING = 4,
PLAYBACK_STATE_REWINDED = 5,
PLAYBACK_STATE_STOPPED = 6,
PLAYBACK_STATE_COMPLETED = 7,
PLAYBACK_STATE_RELEASED = 8,
PLAYBACK_STATE_ERROR = 9,
PLAYBACK_STATE_IDLE = 10,
PLAYBACK_STATE_BUFFERING = 11,
PLAYBACK_STATE_MAX = 12
} | Enumerates the media playback states.|
| [AVSession_LoopMode](_o_h_a_v_session.md#avsession_loopmode) {
LOOP_MODE_SEQUENCE = 0,
LOOP_MODE_SINGLE = 1,
LOOP_MODE_LIST = 2,
LOOP_MODE_SHUFFLE = 3,
LOOP_MODE_CUSTOM = 4
} | Enumerates the loop modes of media playback.|
| [AVSession_ControlCommand](_o_h_a_v_session.md#avsession_controlcommand) {
CONTROL_CMD_INVALID = -1,
CONTROL_CMD_PLAY = 0,
CONTROL_CMD_PAUSE = 1,
CONTROL_CMD_STOP = 2,
CONTROL_CMD_PLAY_NEXT = 3,
CONTROL_CMD_PLAY_PREVIOUS = 4
} | Enumerates the playback control commands.|
| [AVSessionCallback_Result](_o_h_a_v_session.md#avsessioncallback_result) {
AVSESSION_CALLBACK_RESULT_SUCCESS = 0,
AVSESSION_CALLBACK_RESULT_FAILURE = -1 } | Enumerates the callback execution results.|
### Functions
| Name| Description|
| -------- | -------- |
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_Create](_o_h_a_v_session.md#oh_avsession_create) ([AVSession_Type](_o_h_a_v_session.md#avsession_type) sessionType, const char \*sessionTag, const char \*bundleName, const char \*abilityName, [OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*\*avsession) | Creates a session object.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_Destroy](_o_h_a_v_session.md#oh_avsession_destroy) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession) | Destroys a session object.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_Activate](_o_h_a_v_session.md#oh_avsession_activate) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession) | Activates a session.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_Deactivate](_o_h_a_v_session.md#oh_avsession_deactivate) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession) | Deactivates a session.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_GetSessionType](_o_h_a_v_session.md#oh_avsession_getsessiontype) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [AVSession_Type](_o_h_a_v_session.md#avsession_type) \*sessionType) | Obtains the session type.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_GetSessionId](_o_h_a_v_session.md#oh_avsession_getsessionid) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, const char \*\*sessionId) | Obtains the session ID.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_SetAVMetadata](_o_h_a_v_session.md#oh_avsession_setavmetadata) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [OH_AVMetadata](_o_h_a_v_session.md#oh_avmetadata) \*avmetadata) | Sets media metadata.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_SetPlaybackState](_o_h_a_v_session.md#oh_avsession_setplaybackstate) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [AVSession_PlaybackState](_o_h_a_v_session.md#avsession_playbackstate) playbackState) | Sets the playback state.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_SetPlaybackPosition](_o_h_a_v_session.md#oh_avsession_setplaybackposition) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [AVSession_PlaybackPosition](_a_v_session___playback_position.md) \*playbackPosition) | Sets the playback position.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_SetFavorite](_o_h_a_v_session.md#oh_avsession_setfavorite) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, bool favorite) | Favorites or unfavorites the media asset.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_SetLoopMode](_o_h_a_v_session.md#oh_avsession_setloopmode) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [AVSession_LoopMode](_o_h_a_v_session.md#avsession_loopmode) loopMode) | Sets the loop mode.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_RegisterCommandCallback](_o_h_a_v_session.md#oh_avsession_registercommandcallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [AVSession_ControlCommand](_o_h_a_v_session.md#avsession_controlcommand) command, [OH_AVSessionCallback_OnCommand](_o_h_a_v_session.md#oh_avsessioncallback_oncommand) callback, void \*userData) | Registers a callback for a common playback control command.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_UnregisterCommandCallback](_o_h_a_v_session.md#oh_avsession_unregistercommandcallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [AVSession_ControlCommand](_o_h_a_v_session.md#avsession_controlcommand) command, [OH_AVSessionCallback_OnCommand](_o_h_a_v_session.md#oh_avsessioncallback_oncommand) callback) | Unregisters the callback for a common playback control command.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_RegisterForwardCallback](_o_h_a_v_session.md#oh_avsession_registerforwardcallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [OH_AVSessionCallback_OnFastForward](_o_h_a_v_session.md#oh_avsessioncallback_onfastforward) callback, void \*userData) | Registers a callback for the fast-forward operation.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_UnregisterForwardCallback](_o_h_a_v_session.md#oh_avsession_unregisterforwardcallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [OH_AVSessionCallback_OnFastForward](_o_h_a_v_session.md#oh_avsessioncallback_onfastforward) callback) | Unregisters the callback for the fast-forward operation.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_RegisterRewindCallback](_o_h_a_v_session.md#oh_avsession_registerrewindcallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [OH_AVSessionCallback_OnRewind](_o_h_a_v_session.md#oh_avsessioncallback_onrewind) callback, void \*userData) | Registers a callback for the rewind operation.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_UnregisterRewindCallback](_o_h_a_v_session.md#oh_avsession_unregisterrewindcallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [OH_AVSessionCallback_OnRewind](_o_h_a_v_session.md#oh_avsessioncallback_onrewind) callback) | Unregisters the callback for the rewind operation.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_RegisterSeekCallback](_o_h_a_v_session.md#oh_avsession_registerseekcallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [OH_AVSessionCallback_OnSeek](_o_h_a_v_session.md#oh_avsessioncallback_onseek) callback, void \*userData) | Registers a callback for the seek operation.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_UnregisterSeekCallback](_o_h_a_v_session.md#oh_avsession_unregisterseekcallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [OH_AVSessionCallback_OnSeek](_o_h_a_v_session.md#oh_avsessioncallback_onseek) callback) | Unregisters the callback for the seek operation.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_RegisterSetLoopModeCallback](_o_h_a_v_session.md#oh_avsession_registersetloopmodecallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [OH_AVSessionCallback_OnSetLoopMode](_o_h_a_v_session.md#oh_avsessioncallback_onsetloopmode) callback, void \*userData) | Registers a callback for the operation of setting the loop mode.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_UnregisterSetLoopModeCallback](_o_h_a_v_session.md#oh_avsession_unregistersetloopmodecallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [OH_AVSessionCallback_OnSetLoopMode](_o_h_a_v_session.md#oh_avsessioncallback_onsetloopmode) callback) | Unregisters the callback for the operation of setting the loop mode.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_RegisterToggleFavoriteCallback](_o_h_a_v_session.md#oh_avsession_registertogglefavoritecallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [OH_AVSessionCallback_OnToggleFavorite](_o_h_a_v_session.md#oh_avsessioncallback_ontogglefavorite) callback, void \*userData) | Registers a callback for the operation of favoriting a media asset.|
| [AVSession_ErrCode](_o_h_a_v_session.md#avsession_errcode) [OH_AVSession_UnregisterToggleFavoriteCallback](_o_h_a_v_session.md#oh_avsession_unregistertogglefavoritecallback) ([OH_AVSession](_o_h_a_v_session.md#oh_avsession) \*avsession, [OH_AVSessionCallback_OnToggleFavorite](_o_h_a_v_session.md#oh_avsessioncallback_ontogglefavorite) callback) | Unregisters the callback for the operation of favoriting a media asset.|