# media_asset_base_capi.h
## Overview
Defines the following structs and enums of the media asset manager:
- [OH_MediaAssetManager](_media_asset_manager.md#oh_mediaassetmanager): provides the capability of requesting assets from the media library.
- [MediaLibrary_RequestId](_media_library___request_id.md): defines a request ID returned when a media asset is requested. The request ID can be used to cancel a request.
- [MediaLibrary_DeliveryMode](_media_asset_manager.md#medialibrary_deliverymode-1): enumerates the deliver modes of the requested media asset.
- [OH_MediaLibrary_OnDataPrepared](_media_asset_manager.md#oh_medialibrary_ondataprepared): defines a function pointer to the callback to be invoked when the requested media asset is ready.
- [MediaLibrary_RequestOptions](_media_library___request_options.md): defines the options related to the media asset quality and delivery mode to set.
**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core
**Library**: libmedia_asset_manager.so
**File to include**: <multimedia/media_library/media_asset_base_capi.h>
**Since**: 12
**Related module**: [MediaAssetManager](_media_asset_manager.md)
## Summary
### Structs
| Name| Description|
| -------- | -------- |
| struct [MediaLibrary_RequestId](_media_library___request_id.md) | Defines a request ID. |
| struct [MediaLibrary_RequestOptions](_media_library___request_options.md) | Defines how media assets are requested and processed. |
### Types
| Name| Description|
| -------- | -------- |
| typedef struct [OH_MediaAssetManager](_media_asset_manager.md#oh_mediaassetmanager) [OH_MediaAssetManager](_media_asset_manager.md#oh_mediaassetmanager) | Defines a struct for the media asset manager. |
| typedef struct [OH_MediaAssetChangeRequest](_media_asset_manager.md#oh_mediaassetchangerequest) [OH_MediaAssetChangeRequest](_media_asset_manager.md#oh_mediaassetchangerequest) | Defines a struct for a media asset change request. |
| typedef struct [OH_MovingPhoto](_media_asset_manager.md#oh_movingphoto) [OH_MovingPhoto](_media_asset_manager.md#oh_movingphoto) | Defines a struct for a moving photo. |
| typedef struct [OH_MediaAsset](_media_asset_manager.md#oh_mediaasset) [OH_MediaAsset](_media_asset_manager.md#oh_mediaasset) | Defines a struct for a media asset. |
| typedef struct [MediaLibrary_RequestId](_media_library___request_id.md) [MediaLibrary_RequestId](_media_asset_manager.md#medialibrary_requestid) | Defines a struct for a request ID. |
| typedef enum [MediaLibrary_ErrorCode](_media_asset_manager.md#medialibrary_errorcode-1) [MediaLibrary_ErrorCode](_media_asset_manager.md#medialibrary_errorcode) | Defines an enum for error codes. |
| typedef enum [MediaLibrary_DeliveryMode](_media_asset_manager.md#medialibrary_deliverymode-1) [MediaLibrary_DeliveryMode](_media_asset_manager.md#medialibrary_deliverymode) | Defines an enum for delivery modes of the requested media asset. |
| typedef struct [MediaLibrary_RequestOptions](_media_library___request_options.md) [MediaLibrary_RequestOptions](_media_asset_manager.md#medialibrary_requestoptions) | Defines a struct for the options related to the media asset quality and delivery mode to set. |
| typedef enum [MediaLibrary_MediaType](_media_asset_manager.md#medialibrary_mediatype-1) [MediaLibrary_MediaType](_media_asset_manager.md#medialibrary_mediatype) | Defines an enum for media types. |
| typedef enum [MediaLibrary_MediaSubType](_media_asset_manager.md#medialibrary_mediasubtype-1) [MediaLibrary_MediaSubType](_media_asset_manager.md#medialibrary_mediasubtype) | Defines an enum for media subtypes. |
| typedef enum [MediaLibrary_ResourceType](_media_asset_manager.md#medialibrary_resourcetype-1) [MediaLibrary_ResourceType](_media_asset_manager.md#medialibrary_resourcetype) | Defines an enum for media library resource types. |
| typedef enum [MediaLibrary_ImageFileType](_media_asset_manager.md#medialibrary_imagefiletype-1) [MediaLibrary_ImageFileType](_media_asset_manager.md#medialibrary_imagefiletype) | Defines an enum for image file types. |
| typedef enum [MediaLibrary_MediaQuality](_media_asset_manager.md#medialibrary_mediaquality-1) [MediaLibrary_MediaQuality](_media_asset_manager.md#medialibrary_mediaquality) | Defines an enum for media resource quality. |
| typedef enum [MediaLibrary_MediaContentType](_media_asset_manager.md#medialibrary_mediacontenttype-1) [MediaLibrary_MediaContentType](_media_asset_manager.md#medialibrary_mediacontenttype) | Defines an enum for media content types. |
| typedef void(\* [OH_MediaLibrary_OnDataPrepared](_media_asset_manager.md#oh_medialibrary_ondataprepared)) (int32_t result, [MediaLibrary_RequestId](_media_library___request_id.md) requestId) | Defines a function pointer to the callback to be invoked when the requested media asset is ready. |
| typedef void(\* [OH_MediaLibrary_OnImageDataPrepared](_media_asset_manager.md#oh_medialibrary_onimagedataprepared)) ([MediaLibrary_ErrorCode](_media_asset_manager.md#medialibrary_errorcode) result, [MediaLibrary_RequestId](_media_library___request_id.md) requestId, [MediaLibrary_MediaQuality](_media_asset_manager.md#medialibrary_mediaquality) mediaQuality, [MediaLibrary_MediaContentType](_media_asset_manager.md#medialibrary_mediacontenttype) type, OH_ImageSourceNative \*imageSourceNative) | Defines a function pointer to the callback to be invoked when the requested image source is ready. |
| typedef void(\* [OH_MediaLibrary_OnMovingPhotoDataPrepared](_media_asset_manager.md#oh_medialibrary_onmovingphotodataprepared)) ([MediaLibrary_ErrorCode](_media_asset_manager.md#medialibrary_errorcode) result, [MediaLibrary_RequestId](_media_library___request_id.md) requestId, [MediaLibrary_MediaQuality](_media_asset_manager.md#medialibrary_mediaquality) mediaQuality, [MediaLibrary_MediaContentType](_media_asset_manager.md#medialibrary_mediacontenttype) type, [OH_MovingPhoto](_media_asset_manager.md#oh_movingphoto) \*movingPhoto) | Called when the requested moving photo is ready. |
### Enums
| Name| Description|
| -------- | -------- |
| [MediaLibrary_ErrorCode](_media_asset_manager.md#medialibrary_errorcode) {
MEDIA_LIBRARY_OK = 0,
MEDIA_LIBRARY_PERMISSION_DENIED = 201,
MEDIA_LIBRARY_PARAMETER_ERROR = 401,
MEDIA_LIBRARY_NO_SUCH_FILE = 23800101,
MEDIA_LIBRARY_INVALID_DISPLAY_NAME = 23800102,
MEDIA_LIBRARY_INVALID_ASSET_URI = 23800103,
MEDIA_LIBRARY_INVALID_PHOTO_KEY = 23800104,
MEDIA_LIBRARY_OPERATION_NOT_SUPPORTED = 23800201,
MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR = 23800301
} | Enumerates the error codes.|
| [MediaLibrary_DeliveryMode](_media_asset_manager.md#medialibrary_deliverymode) {
MEDIA_LIBRARY_FAST_MODE = 0,
MEDIA_LIBRARY_HIGH_QUALITY_MODE = 1,
MEDIA_LIBRARY_BALANCED_MODE = 2 } | Enumerates the delivery modes of the requested media asset.|
| [MediaLibrary_MediaType](_media_asset_manager.md#medialibrary_mediatype) {
MEDIA_LIBRARY_IMAGE = 1,
MEDIA_LIBRARY_VIDEO = 2 } | Enumerates the media types.|
| [MediaLibrary_MediaSubType](_media_asset_manager.md#medialibrary_mediasubtype) {
MEDIA_LIBRARY_DEFAULT = 0,
MEDIA_LIBRARY_MOVING_PHOTO = 3,
MEDIA_LIBRARY_BURST = 4 } | Enumerates the media subtypes.|
| [MediaLibrary_ResourceType](_media_asset_manager.md#medialibrary_resourcetype) {
MEDIA_LIBRARY_IMAGE_RESOURCE = 1,
MEDIA_LIBRARY_VIDEO_RESOURCE = 2 } | Enumerates the media library resource types.|
| [MediaLibrary_ImageFileType](_media_asset_manager.md#medialibrary_imagefiletype) {
MEDIA_LIBRARY_IMAGE_JPEG = 1 } | Enumerates the image file types.|
| [MediaLibrary_MediaQuality](_media_asset_manager.md#medialibrary_mediaquality) {
MEDIA_LIBRARY_QUALITY_FAST = 1,
MEDIA_LIBRARY_QUALITY_FULL = 2 } | Enumerates the media resource quality.|
| [MediaLibrary_MediaContentType](_media_asset_manager.md#medialibrary_mediacontenttype) {
MEDIA_LIBRARY_COMPRESSED = 1,
MEDIA_LIBRARY_PICTURE_OBJECT = 2 } | Enumerates the media content types.|