# MediaAssetManager


## Overview

Provides APIs for managing media assets.

For details about the development guide and sample, see [Requesting Media Assets Using MediaAssetManager (C/C++)](../../media/medialibrary/using-ndk-mediaassetmanager-for-request-resource.md).

**Since**: 12


## Summary


### Files

| Name| Description| 
| -------- | -------- |
| [media_access_helper_capi.h](media__access__helper__capi_8h.md) | Defines the APIs for album management. | 
| [media_asset_base_capi.h](media__asset__base__capi_8h.md) | Defines the structs and enums of the media asset manager. | 
| [media_asset_capi.h](media__asset__capi_8h.md) | Defines the APIs related to media assets. | 
| [media_asset_change_request_capi.h](media__asset__change__request__capi_8h.md) | Defines the APIs related to media asset change requests. | 
| [media_asset_manager_capi.h](media__asset__manager__capi_8h.md) | Defines the APIs of the media asset manager. | 
| [moving_photo_capi.h](moving__photo__capi_8h.md) | Defines the APIs related to moving photos. | 


### Structs

| Name| Description| 
| -------- | -------- |
| struct  [MediaLibrary_RequestId](_media_library___request_id.md) | Defines a request ID. | 
| struct  [MediaLibrary_RequestOptions](_media_library___request_options.md) | Defines the options related to the media asset quality and delivery mode to set. | 


### Types

| Name| Description| 
| -------- | -------- |
| typedef struct [OH_MediaAssetManager](#oh_mediaassetmanager) [OH_MediaAssetManager](#oh_mediaassetmanager) | Defines a struct for the media asset manager. | 
| typedef struct [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) | Defines a struct for a media asset change request. | 
| typedef struct [OH_MovingPhoto](#oh_movingphoto) [OH_MovingPhoto](#oh_movingphoto) | Defines a struct for a moving photo. | 
| typedef struct [OH_MediaAsset](#oh_mediaasset) [OH_MediaAsset](#oh_mediaasset) | Defines a struct for a media asset. | 
| typedef struct [MediaLibrary_RequestId](_media_library___request_id.md) [MediaLibrary_RequestId](#medialibrary_requestid) | Defines a struct for a request ID. | 
| typedef enum [MediaLibrary_ErrorCode](#medialibrary_errorcode-1) [MediaLibrary_ErrorCode](#medialibrary_errorcode) | Defines an enum for error codes. | 
| typedef enum [MediaLibrary_DeliveryMode](#medialibrary_deliverymode-1) [MediaLibrary_DeliveryMode](#medialibrary_deliverymode) | Defines an enum for delivery modes of the requested media asset. | 
| typedef struct [MediaLibrary_RequestOptions](_media_library___request_options.md) [MediaLibrary_RequestOptions](#medialibrary_requestoptions) | Defines an enum for options related to the media asset quality and delivery mode to set. | 
| typedef enum [MediaLibrary_MediaType](#medialibrary_mediatype-1) [MediaLibrary_MediaType](#medialibrary_mediatype) | Defines an enum for media asset types. | 
| typedef enum [MediaLibrary_MediaSubType](#medialibrary_mediasubtype-1) [MediaLibrary_MediaSubType](#medialibrary_mediasubtype) | Defines an enum for media asset subtypes. | 
| typedef enum [MediaLibrary_ResourceType](#medialibrary_resourcetype-1) [MediaLibrary_ResourceType](#medialibrary_resourcetype) | Defines an enum for media library resource types. | 
| typedef enum [MediaLibrary_ImageFileType](#medialibrary_imagefiletype-1) [MediaLibrary_ImageFileType](#medialibrary_imagefiletype) | Defines an enum for image file types. | 
| typedef enum [MediaLibrary_MediaQuality](#medialibrary_mediaquality-1) [MediaLibrary_MediaQuality](#medialibrary_mediaquality) | Defines an enum for media resource quality. | 
| typedef enum [MediaLibrary_MediaContentType](#medialibrary_mediacontenttype-1) [MediaLibrary_MediaContentType](#medialibrary_mediacontenttype) | Defines an enum for media content types. | 
| typedef void(\* [OH_MediaLibrary_OnDataPrepared](#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](#oh_medialibrary_onimagedataprepared)) ([MediaLibrary_ErrorCode](#medialibrary_errorcode) result, [MediaLibrary_RequestId](_media_library___request_id.md) requestId, [MediaLibrary_MediaQuality](#medialibrary_mediaquality) mediaQuality, [MediaLibrary_MediaContentType](#medialibrary_mediacontenttype) type, OH_ImageSourceNative \*imageSourceNative) | Defines a function pointer to the callback to be invoked when the requested image is ready. | 
| typedef void(\* [OH_MediaLibrary_OnMovingPhotoDataPrepared](#oh_medialibrary_onmovingphotodataprepared)) ([MediaLibrary_ErrorCode](#medialibrary_errorcode) result, [MediaLibrary_RequestId](_media_library___request_id.md) requestId, [MediaLibrary_MediaQuality](#medialibrary_mediaquality) mediaQuality, [MediaLibrary_MediaContentType](#medialibrary_mediacontenttype) type, [OH_MovingPhoto](#oh_movingphoto) \*movingPhoto) | Defines a function pointer to the callback to be invoked when the requested moving photo is ready. | 


### Enums

| Name| Description| 
| -------- | -------- |
| [MediaLibrary_ErrorCode](#medialibrary_errorcode-1) {<br>MEDIA_LIBRARY_OK = 0,<br>MEDIA_LIBRARY_PERMISSION_DENIED = 201,<br>MEDIA_LIBRARY_PARAMETER_ERROR = 401,<br>MEDIA_LIBRARY_NO_SUCH_FILE = 23800101,<br>MEDIA_LIBRARY_INVALID_DISPLAY_NAME = 23800102,<br>MEDIA_LIBRARY_INVALID_ASSET_URI = 23800103,<br>MEDIA_LIBRARY_INVALID_PHOTO_KEY = 23800104,<br>MEDIA_LIBRARY_OPERATION_NOT_SUPPORTED = 23800201,<br>MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR = 23800301<br>} | Enumerates the error codes.| 
| [MediaLibrary_DeliveryMode](#medialibrary_deliverymode-1) {<br>MEDIA_LIBRARY_FAST_MODE = 0,<br>MEDIA_LIBRARY_HIGH_QUALITY_MODE = 1,<br>MEDIA_LIBRARY_BALANCED_MODE = 2 } | Enumerates the delivery modes of the requested media asset.| 
| [MediaLibrary_MediaType](#medialibrary_mediatype-1) {<br>MEDIA_LIBRARY_IMAGE = 1,<br>MEDIA_LIBRARY_VIDEO = 2 } | Enumerates the media asset types.| 
| [MediaLibrary_MediaSubType](#medialibrary_mediasubtype-1) {<br>MEDIA_LIBRARY_DEFAULT = 0,<br>MEDIA_LIBRARY_MOVING_PHOTO = 3,<br>MEDIA_LIBRARY_BURST = 4 } | Enumerates the media asset subtypes.| 
| [MediaLibrary_ResourceType](#medialibrary_resourcetype-1) {<br>MEDIA_LIBRARY_IMAGE_RESOURCE = 1,<br>MEDIA_LIBRARY_VIDEO_RESOURCE = 2 } | Enumerates the media library resource types.| 
| [MediaLibrary_ImageFileType](#medialibrary_imagefiletype-1) {<br>MEDIA_LIBRARY_IMAGE_JPEG = 1 } | Enumerates the image file types.| 
| [MediaLibrary_MediaQuality](#medialibrary_mediaquality-1) {<br>MEDIA_LIBRARY_QUALITY_FAST = 1,<br>MEDIA_LIBRARY_QUALITY_FULL = 2 } | Enumerates the media resource quality.| 
| [MediaLibrary_MediaContentType](#medialibrary_mediacontenttype-1) {<br>MEDIA_LIBRARY_COMPRESSED = 1,<br>MEDIA_LIBRARY_PICTURE_OBJECT = 2 } | Enumerates the media content types.| 


### Functions

| Name| Description| 
| -------- | -------- |
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAccessHelper_ApplyChanges](#oh_mediaaccesshelper_applychanges) ([OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) \*changeRequest) | Applies changes to an asset or album. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetUri](#oh_mediaasset_geturi) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, const char \*\*uri) | Obtains the URI of a media asset. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetMediaType](#oh_mediaasset_getmediatype) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, [MediaLibrary_MediaType](#medialibrary_mediatype) \*mediaType) | Obtains the type of a media asset. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetMediaSubType](#oh_mediaasset_getmediasubtype) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, [MediaLibrary_MediaSubType](#medialibrary_mediasubtype) \*mediaSubType) | Obtains the subtype of a media asset. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetDisplayName](#oh_mediaasset_getdisplayname) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, const char \*\*displayName) | Obtains the displayed name of a media asset. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetSize](#oh_mediaasset_getsize) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, uint32_t \*size) | Obtains the size of a media asset file. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetDateAdded](#oh_mediaasset_getdateadded) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, uint32_t \*dateAdded) | Obtains the date when a media asset was added. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetDateModified](#oh_mediaasset_getdatemodified) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, uint32_t \*dateModified) | Obtains the date when a media asset was last modified. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetDateTaken](#oh_mediaasset_getdatetaken) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, uint32_t \*dateTaken) | Obtains the date when a media asset was taken. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetDateAddedMs](#oh_mediaasset_getdateaddedms) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, uint32_t \*dateAddedMs) | Obtains the date when a media asset was added, in ms. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetDateModifiedMs](#oh_mediaasset_getdatemodifiedms) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, uint32_t \*dateModifiedMs) | Obtains the time when a media asset was last modified, in ms. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetDuration](#oh_mediaasset_getduration) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, uint32_t \*duration) | Obtains the duration of a media asset, in ms. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetWidth](#oh_mediaasset_getwidth) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, uint32_t \*width) | Obtains the image width (in pixels) of a media asset. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetHeight](#oh_mediaasset_getheight) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, uint32_t \*height) | Obtains the image height (in pixels) of a media asset. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetOrientation](#oh_mediaasset_getorientation) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, uint32_t \*orientation) | Obtains the orientation of a media asset, in degrees. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_IsFavorite](#oh_mediaasset_isfavorite) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, uint32_t \*favorite) | Checks whether a media asset is favorited. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_GetTitle](#oh_mediaasset_gettitle) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset, const char \*\*title) | Obtains the title of a media asset. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAsset_Release](#oh_mediaasset_release) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset) | Releases a media asset. | 
| [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) \* [OH_MediaAssetChangeRequest_Create](#oh_mediaassetchangerequest_create) ([OH_MediaAsset](#oh_mediaasset) \*mediaAsset) | Creates an [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) instance. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAssetChangeRequest_AddResourceWithUri](#oh_mediaassetchangerequest_addresourcewithuri) ([OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) \*changeRequest, [MediaLibrary_ResourceType](#medialibrary_resourcetype) resourceType, char \*fileUri) | Adds a resource of the given URI. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAssetChangeRequest_AddResourceWithBuffer](#oh_mediaassetchangerequest_addresourcewithbuffer) ([OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) \*changeRequest, [MediaLibrary_ResourceType](#medialibrary_resourcetype) resourceType, uint8_t \*buffer, uint32_t length) | Adds a resource using **ArrayBuffer** data. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAssetChangeRequest_GetWriteCacheHandler](#oh_mediaassetchangerequest_getwritecachehandler) ([OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) \*changeRequest, int32_t \*fd) | Obtains the handler used for writing a file to cache. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAssetChangeRequest_SaveCameraPhoto](#oh_mediaassetchangerequest_savecameraphoto) ([OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) \*changeRequest, [MediaLibrary_ImageFileType](#medialibrary_imagefiletype) imageFileType) | Saves the photo taken by the camera. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAssetChangeRequest_DiscardCameraPhoto](#oh_mediaassetchangerequest_discardcameraphoto) ([OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) \*changeRequest) | Discards the photo taken by the camera. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAssetChangeRequest_Release](#oh_mediaassetchangerequest_release) ([OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) \*changeRequest) | Releases an [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) instance. | 
| [OH_MediaAssetManager](#oh_mediaassetmanager) \* [OH_MediaAssetManager_Create](#oh_mediaassetmanager_create) (void) | Creates a **MediaAssetManager** instance. | 
| [MediaLibrary_RequestId](_media_library___request_id.md) [OH_MediaAssetManager_RequestImageForPath](#oh_mediaassetmanager_requestimageforpath) ([OH_MediaAssetManager](#oh_mediaassetmanager) \*manager, const char \*uri, [MediaLibrary_RequestOptions](_media_library___request_options.md) requestOptions, const char \*destPath, [OH_MediaLibrary_OnDataPrepared](#oh_medialibrary_ondataprepared) callback) | Requests an image in the specified directory. | 
| [MediaLibrary_RequestId](_media_library___request_id.md) [OH_MediaAssetManager_RequestVideoForPath](#oh_mediaassetmanager_requestvideoforpath) ([OH_MediaAssetManager](#oh_mediaassetmanager) \*manager, const char \*uri, [MediaLibrary_RequestOptions](_media_library___request_options.md) requestOptions, const char \*destPath, [OH_MediaLibrary_OnDataPrepared](#oh_medialibrary_ondataprepared) callback) | Requests a video in the specified directory. | 
| bool [OH_MediaAssetManager_CancelRequest](#oh_mediaassetmanager_cancelrequest) ([OH_MediaAssetManager](#oh_mediaassetmanager) \*manager, const [MediaLibrary_RequestId](_media_library___request_id.md) requestId) | Cancels a request based on the request ID. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAssetManager_RequestMovingPhoto](#oh_mediaassetmanager_requestmovingphoto) ([OH_MediaAssetManager](#oh_mediaassetmanager) \*manager, [OH_MediaAsset](#oh_mediaasset) \*mediaAsset, [MediaLibrary_RequestOptions](_media_library___request_options.md) requestOptions, [MediaLibrary_RequestId](_media_library___request_id.md) \*requestId, [OH_MediaLibrary_OnMovingPhotoDataPrepared](#oh_medialibrary_onmovingphotodataprepared) callback) | Requests moving photo resources based on different policies. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAssetManager_RequestImage](#oh_mediaassetmanager_requestimage) ([OH_MediaAssetManager](#oh_mediaassetmanager) \*manager, [OH_MediaAsset](#oh_mediaasset) \*mediaAsset, [MediaLibrary_RequestOptions](_media_library___request_options.md) requestOptions, [MediaLibrary_RequestId](_media_library___request_id.md) \*requestId, [OH_MediaLibrary_OnImageDataPrepared](#oh_medialibrary_onimagedataprepared) callback) | Requests an image. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MediaAssetManager_Release](#oh_mediaassetmanager_release) ([OH_MediaAssetManager](#oh_mediaassetmanager) \*manager) | Releases an [OH_MediaAssetManager](#oh_mediaassetmanager) instance. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MovingPhoto_GetUri](#oh_movingphoto_geturi) ([OH_MovingPhoto](#oh_movingphoto) \*movingPhoto, const char \*\*uri) | Obtains the URI of a moving photo. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MovingPhoto_RequestContentWithUris](#oh_movingphoto_requestcontentwithuris) ([OH_MovingPhoto](#oh_movingphoto) \*movingPhoto, char \*imageUri, char \*videoUri) | Requests the image data and video data of a moving photo and writes them to the specified URIs, respectively. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MovingPhoto_RequestContentWithUri](#oh_movingphoto_requestcontentwithuri) ([OH_MovingPhoto](#oh_movingphoto) \*movingPhoto, [MediaLibrary_ResourceType](#medialibrary_resourcetype) resourceType, char \*uri) | Requests the moving photo content of the specified resource type and writes it to the specified URI. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MovingPhoto_RequestContentWithBuffer](#oh_movingphoto_requestcontentwithbuffer) ([OH_MovingPhoto](#oh_movingphoto) \*movingPhoto, [MediaLibrary_ResourceType](#medialibrary_resourcetype) resourceType, const uint8_t \*\*buffer, uint32_t \*size) | Requests the moving photo content of the specified resource type and returns it in ArrayBuffer format. | 
| [MediaLibrary_ErrorCode](#medialibrary_errorcode) [OH_MovingPhoto_Release](#oh_movingphoto_release) ([OH_MovingPhoto](#oh_movingphoto) \*movingPhoto) | Releases an [OH_MovingPhoto](#oh_movingphoto) instance. | 


## Type Description


### MediaLibrary_DeliveryMode

```
typedef enum MediaLibrary_DeliveryMode MediaLibrary_DeliveryMode
```
**Description**<br>
Defines an enum for delivery modes of the requested media asset.

The delivery modes include the following:

- **MEDIA_LIBRARY_FAST_MODE**: deliver the media asset available without considering its quality.

- **MEDIA_LIBRARY_HIGH_QUALITY_MODE**: deliver a media asset with high quality. If there is no high-quality asset available, trigger the process for creating a high-quality asset. Then, return the high-quality asset that is successfully created.

- **MEDIA_LIBRARY_BALANCED_MODE**: return the high-quality asset if there is any. Otherwise, return a low-quality asset first and trigger the process for creating a high-quality asset. Then, return the high-quality asset that is successfully created.

**Since**: 12


### MediaLibrary_ErrorCode

```
typedef enum MediaLibrary_ErrorCode MediaLibrary_ErrorCode
```
**Description**<br>
Defines an enum for error codes.

**Since**: 12


### MediaLibrary_ImageFileType

```
typedef enum MediaLibrary_ImageFileType MediaLibrary_ImageFileType
```
**Description**<br>
Defines an enum for image file types.

**Since**: 12


### MediaLibrary_MediaContentType

```
typedef enum MediaLibrary_MediaContentType MediaLibrary_MediaContentType
```
**Description**<br>
Defines an enum for media content types.

**Since**: 12


### MediaLibrary_MediaQuality

```
typedef enum MediaLibrary_MediaQuality MediaLibrary_MediaQuality
```
**Description**<br>
Defines an enum for media resource quality, which varies with the specified delivery mode for the requested media asset.

- **MEDIA_LIBRARY_FAST_MODE**: deliver the media asset available without considering its quality.

- **MEDIA_LIBRARY_HIGH_QUALITY_MODE**: deliver a media asset with high quality. If there is no high-quality asset available, trigger the process for creating a high-quality asset. Then, return the high-quality asset that is successfully created.

- **MEDIA_LIBRARY_BALANCED_MODE**: return the high-quality asset if there is any. Otherwise, return a low-quality asset first and trigger the process for creating a high-quality asset. Then, return the high-quality asset that is successfully created.

**Since**: 12


### MediaLibrary_MediaSubType

```
typedef enum MediaLibrary_MediaSubType MediaLibrary_MediaSubType
```
**Description**<br>
Defines an enum for media asset subtypes.

**Since**: 12


### MediaLibrary_MediaType

```
typedef enum MediaLibrary_MediaType MediaLibrary_MediaType
```
**Description**<br>
Defines an enum for media asset types.

**Since**: 12


### MediaLibrary_RequestId

```
typedef struct MediaLibrary_RequestId MediaLibrary_RequestId
```
**Description**<br>
Defines a request ID.

A value of this type is returned when a media asset is requested. The request ID can be used to cancel a request. If a request fails, an all-zero value, for example, **00000000-0000-0000-0000-000000000000** is returned.

**Since**: 12


### MediaLibrary_RequestOptions

```
typedef struct MediaLibrary_RequestOptions MediaLibrary_RequestOptions
```
**Description**<br>
Defines how media assets are requested and processed.

You can use this struct to set options related to the media asset quality, delivery mode, and more.

**Since**: 12


### MediaLibrary_ResourceType

```
typedef enum MediaLibrary_ResourceType MediaLibrary_ResourceType
```
**Description**<br>
Define an enum for media library resource types.

**Since**: 12


### OH_MediaAsset

```
typedef struct OH_MediaAsset OH_MediaAsset
```
**Description**<br>
Defines a struct for a media asset.

This struct provides the capability of encapsulating media file attributes.

**Since**: 12


### OH_MediaAssetChangeRequest

```
typedef struct OH_MediaAssetChangeRequest OH_MediaAssetChangeRequest
```
**Description**<br>
Defines a struct for a media asset change request.

This struct provides the capability of handling media asset change requests.

**Since**: 12


### OH_MediaAssetManager

```
typedef struct OH_MediaAssetManager OH_MediaAssetManager
```
**Description**<br>
Defines a struct for the media asset manager.

You can use this struct to create a media asset manager instance. If the creation fails, a null pointer is returned.

**Since**: 12


### OH_MediaLibrary_OnDataPrepared

```
typedef void (*OH_MediaLibrary_OnDataPrepared)(int32_t result, MediaLibrary_RequestId requestId)
```
**Description**<br>
Defines a function pointer to the callback to be invoked when the requested media asset is ready.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| result | Processing result of the requested asset. | 
| requestId | Request ID. | 


### OH_MediaLibrary_OnImageDataPrepared

```
typedef void (*OH_MediaLibrary_OnImageDataPrepared)(MediaLibrary_ErrorCode result, MediaLibrary_RequestId requestId, MediaLibrary_MediaQuality mediaQuality, MediaLibrary_MediaContentType type, OH_ImageSourceNative* imageSourceNative)
```
**Description**<br>
Defines a function pointer to the callback to be invoked when the requested image is ready.

This callback is called when the requested image source is ready.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| result | [MediaLibrary_ErrorCode](#medialibrary_errorcode-1).| 
| requestId | [MediaLibrary_RequestId](_media_library___request_id.md).| 
| mediaQuality | [MediaLibrary_MediaQuality](#medialibrary_mediaquality-1).| 
| type | [MediaLibrary_MediaContentType](#medialibrary_mediacontenttype-1).| 
| imageSourceNative | [OH_ImageSourceNative](../apis-image-kit/_image___native_module.md#oh_imagesourcenative) obtained when the requested image source is ready.| 


### OH_MediaLibrary_OnMovingPhotoDataPrepared

```
typedef void (*OH_MediaLibrary_OnMovingPhotoDataPrepared)(MediaLibrary_ErrorCode result, MediaLibrary_RequestId requestId, MediaLibrary_MediaQuality mediaQuality, MediaLibrary_MediaContentType type, OH_MovingPhoto* movingPhoto)
```
**Description**<br>
Defines a function pointer to the callback to be invoked when the requested moving photo is ready.

This callback is invoked when the requested moving photo is ready.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| result | [MediaLibrary_ErrorCode](#medialibrary_errorcode-1). | 
| requestId | [MediaLibrary_RequestId](_media_library___request_id.md). | 
| mediaQuality | [MediaLibrary_MediaQuality](#medialibrary_mediaquality-1). | 
| type | [MediaLibrary_MediaContentType](#medialibrary_mediacontenttype-1). | 
| movingPhoto | Pointer to the [OH_MovingPhoto](#oh_movingphoto) obtained. | 


### OH_MovingPhoto

```
typedef struct OH_MovingPhoto OH_MovingPhoto
```
**Description**<br>
Defines a struct for a moving photo.

This struct provides the capability of obtaining information about a moving photo.

**Since**: 13


## Enum Description


### MediaLibrary_DeliveryMode

```
enum MediaLibrary_DeliveryMode
```
**Description**<br>
Enumerates the delivery modes of the requested media asset.

The delivery modes include the following:

- **MEDIA_LIBRARY_FAST_MODE**: deliver the media asset available without considering its quality.

- **MEDIA_LIBRARY_HIGH_QUALITY_MODE**: deliver a media asset with high quality. If there is no high-quality asset available, trigger the process for creating a high-quality asset. Then, return the high-quality asset that is successfully created.

- **MEDIA_LIBRARY_BALANCED_MODE**: return the high-quality asset if there is any. Otherwise, return a low-quality asset first and trigger the process for creating a high-quality asset. Then, return the high-quality asset that is successfully created.

**Since**: 12

| Value| Description| 
| -------- | -------- |
| MEDIA_LIBRARY_FAST_MODE  | Fast mode.  | 
| MEDIA_LIBRARY_HIGH_QUALITY_MODE  | High-quality mode.  | 
| MEDIA_LIBRARY_BALANCED_MODE  | Balance mode.  | 


### MediaLibrary_ErrorCode

```
enum MediaLibrary_ErrorCode
```
**Description**<br>
Enumerates the error codes.

**Since**: 12

| Value| Description| 
| -------- | -------- |
| MEDIA_LIBRARY_OK | The operation is successful.| 
| MEDIA_LIBRARY_PERMISSION_DENIED | The access is denied due to lack of permission.| 
| MEDIA_LIBRARY_PARAMETER_ERROR | Mandatory parameter is not specified, the parameter type is incorrect, or parameter verification failed.| 
| MEDIA_LIBRARY_NO_SUCH_FILE | The file does not exist.| 
| MEDIA_LIBRARY_INVALID_DISPLAY_NAME | Invalid display name.| 
| MEDIA_LIBRARY_INVALID_ASSET_URI | Invalid asset URI.| 
| MEDIA_LIBRARY_INVALID_PHOTO_KEY | Invalid PhotoKey.| 
| MEDIA_LIBRARY_OPERATION_NOT_SUPPORTED | The operation is not supported.| 
| MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR | Internal system error. Possible causes:<br>1. The database is corrupted.<br>2. The file system is abnormal.<br>3. The IPC request timed out.| 


### MediaLibrary_ImageFileType

```
enum MediaLibrary_ImageFileType
```
**Description**<br>
Enumerates the image file types.

**Since**: 12

| Value| Description| 
| -------- | -------- |
| MEDIA_LIBRARY_IMAGE_JPEG  | JPEG.  | 


### MediaLibrary_MediaContentType

```
enum MediaLibrary_MediaContentType
```
**Description**<br>
Enumerates the media content types.

**Since**: 12

| Value| Description| 
| -------- | -------- |
| MEDIA_LIBRARY_COMPRESSED  | Compressed media content.  | 
| MEDIA_LIBRARY_PICTURE_OBJECT  | Image object.  | 


### MediaLibrary_MediaQuality

```
enum MediaLibrary_MediaQuality
```
**Description**<br>
Enumerates the media resource quality, which varies with the specified delivery mode for the requested media asset.

- **MEDIA_LIBRARY_FAST_MODE**: deliver the media asset available without considering its quality.

- **MEDIA_LIBRARY_HIGH_QUALITY_MODE**: deliver a media asset with high quality. If there is no high-quality asset available, trigger the process for creating a high-quality asset. Then, return the high-quality asset that is successfully created.

- **MEDIA_LIBRARY_BALANCED_MODE**: return the high-quality asset if there is any. Otherwise, return a low-quality asset first and trigger the process for creating a high-quality asset. Then, return the high-quality asset that is successfully created.

**Since**: 12

| Value| Description| 
| -------- | -------- |
| MEDIA_LIBRARY_QUALITY_FAST  | Media asset available without considering its quality.  | 
| MEDIA_LIBRARY_QUALITY_FULL  | High-quality media asset.  | 


### MediaLibrary_MediaSubType

```
enum MediaLibrary_MediaSubType
```
**Description**<br>
Enumerates the media asset subtypes.

**Since**: 12

| Value| Description| 
| -------- | -------- |
| MEDIA_LIBRARY_DEFAULT  | Photo (default type).  | 
| MEDIA_LIBRARY_MOVING_PHOTO  | Moving photo.  | 
| MEDIA_LIBRARY_BURST  | Burst photo.  | 


### MediaLibrary_MediaType

```
enum MediaLibrary_MediaType
```
**Description**<br>
Enumerates the media asset types.

**Since**: 12

| Value| Description| 
| -------- | -------- |
| MEDIA_LIBRARY_IMAGE  | Image.  | 
| MEDIA_LIBRARY_VIDEO  | Video.  | 


### MediaLibrary_ResourceType

```
enum MediaLibrary_ResourceType
```
**Description**<br>
Enumerates the media library resource types.

**Since**: 12

| Value| Description| 
| -------- | -------- |
| MEDIA_LIBRARY_IMAGE_RESOURCE  | Image resource.  | 
| MEDIA_LIBRARY_VIDEO_RESOURCE  | Video resource.  | 


## Function Description


### OH_MediaAccessHelper_ApplyChanges()

```
MediaLibrary_ErrorCode OH_MediaAccessHelper_ApplyChanges(OH_MediaAssetChangeRequest* changeRequest)
```
**Description**<br>
Applies changes to an asset or album.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| changeRequest | Pointer to the [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) instance. | 

**Required permissions**

ohos.permission.WRITE_IMAGEVIDEO

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_PERMISSION_DENIED**: The access is denied due to lack of permission.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetDateAdded()

```
ediaLibrary_ErrorCode OH_MediaAsset_GetDateAdded(OH_MediaAsset* mediaAsset, uint32_t* dateAdded)
```
**Description**<br>
Obtains the date when a media asset was added.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| dateAdded | Pointer to the date obtained. The value is the number of seconds elapsed since the Unix Epoch time (00:00:00 UTC on January 1, 1970). | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.
 
- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetDateAddedMs()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetDateAddedMs(OH_MediaAsset* mediaAsset, uint32_t* dateAddedMs)
```
**Description**<br>
Obtains the date when a media asset was added, in ms.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| dateAddedMs | Pointer to the time obtained, in ms. The value is the number of milliseconds elapsed since the Unix Epoch time. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetDateModified()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetDateModified(OH_MediaAsset* mediaAsset, uint32_t* dateModified)
```
**Description**<br>
Obtains the date when a media asset (content not the media asset name) was last modified.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| dateModified | Pointer to the date obtained. The value is the number of milliseconds elapsed since the Unix Epoch time. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetDateModifiedMs()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetDateModifiedMs(OH_MediaAsset* mediaAsset, uint32_t* dateModifiedMs)
```
**Description**<br>
Obtains the date when a media asset (content not the media asset name) was last modified, in ms.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| dateModifiedMs | Pointer to the date obtained, in ms. The value is the number of milliseconds elapsed since the Unix Epoch time. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetDateTaken()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetDateTaken(OH_MediaAsset* mediaAsset, uint32_t* dateTaken)
```
**Description**<br>
Obtains the date when a media asset was taken.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| dateTaken | Pointer to the media asset taken date obtained. The value is the number of seconds elapsed since the Unix Epoch time. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetDisplayName()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetDisplayName(OH_MediaAsset* mediaAsset, const char** displayName)
```
**Description**<br>
Obtains the displayed name of a media asset.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| displayName | Pointer to the displayed name obtained. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetDuration()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetDuration(OH_MediaAsset* mediaAsset, uint32_t* duration)
```
**Description**<br>
Obtains the duration of a media asset, in ms.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| duration | Pointer to the duration obtained, in ms. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetHeight()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetHeight(OH_MediaAsset* mediaAsset, uint32_t* height)
```
**Description**<br>
Obtains the image height (in pixels) of a media asset.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| height | Pointer to the image height of the media resource, in pixels. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred. 

### OH_MediaAsset_GetMediaSubType()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetMediaSubType(OH_MediaAsset* mediaAsset, MediaLibrary_MediaSubType* mediaSubType)
```
**Description**<br>
Obtains the subtype of a media asset.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| mediaSubType | Pointer to the media asset subtype obtained. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred. 

### OH_MediaAsset_GetMediaType()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetMediaType(OH_MediaAsset* mediaAsset, MediaLibrary_MediaType* mediaType)
```
**Description**<br>
Obtains the type of a media asset.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| mediaType | Pointer to the media asset type obtained. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetOrientation()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetOrientation(OH_MediaAsset* mediaAsset, uint32_t* orientation)
```
**Description**<br>
Obtains the orientation of a media asset, in degrees.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| orientation | Pointer to the orientation of the image obtained, in degrees. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetSize()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetSize(OH_MediaAsset* mediaAsset, uint32_t* size)
```
**Description**<br>
Obtains the size of a media asset file.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| size | Pointer to the file size obtained, in bytes. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetTitle()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetTitle(OH_MediaAsset* mediaAsset, const char** title)
```
**Description**<br>
Obtains the title of a media asset.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| title | Pointer to the media asset title obtained. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetUri()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetUri(OH_MediaAsset* mediaAsset, const char** uri)
```
**Description**<br>
Obtains the URI of a media asset.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| uri | Pointer to the URI obtained. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_GetWidth()

```
MediaLibrary_ErrorCode OH_MediaAsset_GetWidth(OH_MediaAsset* mediaAsset, uint32_t* width)
```
**Description**<br>
Obtains the image width (in pixels) of a media asset.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| width | Pointer to the image width obtained, in pixels. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_IsFavorite()

```
MediaLibrary_ErrorCode OH_MediaAsset_IsFavorite(OH_MediaAsset* mediaAsset, uint32_t* favorite)
```
**Description**<br>
Checks whether a media asset is favorited.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 
| favorite | Pointer to the favorite status obtained. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAsset_Release()

```
MediaLibrary_ErrorCode OH_MediaAsset_Release(OH_MediaAsset* mediaAsset)
```
**Description**<br>
Releases a media asset.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAssetChangeRequest_AddResourceWithBuffer()

```
MediaLibrary_ErrorCode OH_MediaAssetChangeRequest_AddResourceWithBuffer(OH_MediaAssetChangeRequest* changeRequest, MediaLibrary_ResourceType resourceType, uint8_t* buffer, uint32_t length)
```
**Description**<br>
Adds a resource using **ArrayBuffer** data.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| changeRequest | Pointer to the [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) instance. | 
| resourceType | [MediaLibrary_ResourceType](#medialibrary_resourcetype) of the resource to add. | 
| buffer | Pointe to the data buffer. | 
| length | Length of the data buffer. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAssetChangeRequest_AddResourceWithUri()

```
MediaLibrary_ErrorCode OH_MediaAssetChangeRequest_AddResourceWithUri(OH_MediaAssetChangeRequest* changeRequest, MediaLibrary_ResourceType resourceType, char* fileUri)
```
**Description**<br>
Adds a media asset of the given URI.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| changeRequest | Pointer to the [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) instance. | 
| resourceType | [MediaLibrary_ResourceType](#medialibrary_resourcetype) of the resource to add. | 
| fileUri | URI of the file to add. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_NO_SUCH_FILE**: The file does not exist.
  
- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.

- **MEDIA_LIBRARY_OPERATION_NOT_SUPPORTED**: This operation is not supported.


### OH_MediaAssetChangeRequest_Create()

```
OH_MediaAssetChangeRequest* OH_MediaAssetChangeRequest_Create(OH_MediaAsset* mediaAsset)
```
**Description**<br>
Creates an [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) instance.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.
  
- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAssetChangeRequest_DiscardCameraPhoto()

```
MediaLibrary_ErrorCode OH_MediaAssetChangeRequest_DiscardCameraPhoto(OH_MediaAssetChangeRequest* changeRequest)
```
**Description**<br>
Discards the photo taken by the camera.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| changeRequest | Pointer to the [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) instance. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.
 
- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.

- **MEDIA_LIBRARY_OPERATION_NOT_SUPPORTED**: This operation is not supported.


### OH_MediaAssetChangeRequest_GetWriteCacheHandler()

```
MediaLibrary_ErrorCode OH_MediaAssetChangeRequest_GetWriteCacheHandler(OH_MediaAssetChangeRequest* changeRequest, int32_t* fd)
```
**Description**<br>
Obtains the handler used for writing a file to cache.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| changeRequest | Pointer to the [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) instance. | 
| fd | Pointer to the file descriptor (FD) obtained. | 

**Required permissions**

ohos.permission.WRITE_IMAGEVIDEO

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.
 
- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.

- **MEDIA_LIBRARY_PERMISSION_DENIED**: The access is denied due to lack of permission.

- **MEDIA_LIBRARY_OPERATION_NOT_SUPPORTED**: This operation is not supported.


### OH_MediaAssetChangeRequest_Release()

```
MediaLibrary_ErrorCode OH_MediaAssetChangeRequest_Release(OH_MediaAssetChangeRequest* changeRequest)
```
**Description**<br>
Releases an [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) instance.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| changeRequest | Pointer to the [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) instance. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.


### OH_MediaAssetChangeRequest_SaveCameraPhoto()

```
MediaLibrary_ErrorCode OH_MediaAssetChangeRequest_SaveCameraPhoto(OH_MediaAssetChangeRequest* changeRequest, MediaLibrary_ImageFileType imageFileType)
```
**Description**<br>
Saves the photo taken by the camera.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| changeRequest | Pointer to the [OH_MediaAssetChangeRequest](#oh_mediaassetchangerequest) instance. | 
| imageFileType | [MediaLibrary_ImageFileType](#medialibrary_imagefiletype) of the photo to save. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.
 
- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.

- **MEDIA_LIBRARY_OPERATION_NOT_SUPPORTED**: This operation is not supported.


### OH_MediaAssetManager_CancelRequest()

```
bool OH_MediaAssetManager_CancelRequest(OH_MediaAssetManager* manager, const MediaLibrary_RequestId requestId)
```
**Description**<br>
Cancels a request based on the request ID.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| manager | Pointer to the **OH_MediaAssetManager** instance. | 
| requestId | ID of the request to cancel. | 

**Required permissions**

ohos.permission.READ_IMAGEVIDEO

**Returns**

Returns **true** if the request is successfully canceled; returns **false** otherwise.


### OH_MediaAssetManager_Create()

```
OH_MediaAssetManager* OH_MediaAssetManager_Create(void)
```
**Description**<br>
Creates a **MediaAssetManager** instance.

**Since**: 12

**Returns**

Returns the pointer to the **MediaAssetManager** instance created.


### OH_MediaAssetManager_Release()

```
MediaLibrary_ErrorCode OH_MediaAssetManager_Release(OH_MediaAssetManager* manager)
```
**Description**<br>
Releases an [OH_MediaAssetManager](#oh_mediaassetmanager) instance.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| manager | Pointer to the [OH_MediaAssetManager](#oh_mediaassetmanager) instance to release. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.


### OH_MediaAssetManager_RequestImage()

```
MediaLibrary_ErrorCode OH_MediaAssetManager_RequestImage(OH_MediaAssetManager* manager, OH_MediaAsset* mediaAsset, MediaLibrary_RequestOptions requestOptions, MediaLibrary_RequestId* requestId, OH_MediaLibrary_OnImageDataPrepared callback)
```
**Description**<br>
Requests an image.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| manager | Pointer to the [OH_MediaAssetManager](#oh_mediaassetmanager) instance. | 
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance to be requested. | 
| requestOptions | [MediaLibrary_RequestOptions](_media_library___request_options.md). | 
| requestId | Pointer to the [MediaLibrary_RequestId](_media_library___request_id.md) obtained. | 
| callback | Callback [OH_MediaLibrary_OnImageDataPrepared](#oh_medialibrary_onimagedataprepared) to be invoked when the requested image source is ready. | 

**Required permissions**

ohos.permission.READ_IMAGEVIDEO

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.
- **MEDIA_LIBRARY_OPERATION_NOT_SUPPORTED**: This operation is not supported.

- **MEDIA_LIBRARY_PERMISSION_DENIED**: The access is denied due to lack of permission.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAssetManager_RequestImageForPath()

```
MediaLibrary_RequestId OH_MediaAssetManager_RequestImageForPath(OH_MediaAssetManager* manager, const char* uri, MediaLibrary_RequestOptions requestOptions, const char* destPath, OH_MediaLibrary_OnDataPrepared callback)
```
**Description**<br>
Requests an image in the specified directory.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| manager | Pointer to the **OH_MediaAssetManager** instance. | 
| uri | Pointer to the URI of the requested image asset. | 
| requestOptions | Options related to the image asset quality and delivery mode. | 
| destPath | Pointer to the destination directory of the requested image asset. | 
| callback | Callback to be invoked when the requested image asset is ready. | 

**Required permissions**

ohos.permission.READ_IMAGEVIDEO

**Returns**

Returns the request ID.


### OH_MediaAssetManager_RequestMovingPhoto()

```
MediaLibrary_ErrorCode OH_MediaAssetManager_RequestMovingPhoto(OH_MediaAssetManager* manager, OH_MediaAsset* mediaAsset, MediaLibrary_RequestOptions requestOptions, MediaLibrary_RequestId* requestId, OH_MediaLibrary_OnMovingPhotoDataPrepared callback)
```
**Description**<br>
Requests moving photo resources based on different policies.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| manager | Pointer to the [OH_MediaAssetManager](#oh_mediaassetmanager) instance. | 
| mediaAsset | Pointer to the [OH_MediaAsset](#oh_mediaasset) instance to be requested. | 
| requestOptions | [MediaLibrary_RequestOptions](_media_library___request_options.md). | 
| requestId | Pointer to the [MediaLibrary_RequestId](_media_library___request_id.md) obtained. | 
| callback | [OH_MediaLibrary_OnMovingPhotoDataPrepared](#oh_medialibrary_onmovingphotodataprepared) to be called when the requested moving photo is ready. | 

**Required permissions**

ohos.permission.READ_IMAGEVIDEO

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.
- **MEDIA_LIBRARY_OPERATION_NOT_SUPPORTED**: This operation is not supported.

- **MEDIA_LIBRARY_PERMISSION_DENIED**: The access is denied due to lack of permission.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MediaAssetManager_RequestVideoForPath()

```
MediaLibrary_RequestId OH_MediaAssetManager_RequestVideoForPath(OH_MediaAssetManager* manager, const char* uri, MediaLibrary_RequestOptions requestOptions, const char* destPath, OH_MediaLibrary_OnDataPrepared callback)
```
**Description**<br>
Requests a video asset in the specified directory.

**Since**: 12

**Parameters**

| Name| Description| 
| -------- | -------- |
| manager | Pointer to the **OH_MediaAssetManager** instance. | 
| uri | Pointer to the URI of the requested video asset. | 
| requestOptions | Options related to the image asset quality and delivery mode. | 
| destPath | Pointer to the destination directory of the requested image asset. | 
| callback | Callback to be invoked when the requested image asset is ready. | 

**Required permissions**

ohos.permission.READ_IMAGEVIDEO

**Returns**

Returns the request ID.


### OH_MovingPhoto_GetUri()

```
MediaLibrary_ErrorCode OH_MovingPhoto_GetUri(OH_MovingPhoto* movingPhoto, const char** uri)
```
**Description**<br>
Obtains the URI of a moving photo.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| movingPhoto | Pointer to the [OH_MovingPhoto](#oh_movingphoto) instance. | 
| uri | Double pointer to the URI of the moving photo obtained. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MovingPhoto_Release()

```
MediaLibrary_ErrorCode OH_MovingPhoto_Release(OH_MovingPhoto* movingPhoto)
```
**Description**<br>
Releases an [OH_MovingPhoto](#oh_movingphoto) instance.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| movingPhoto | Pointer to the [OH_MovingPhoto](#oh_movingphoto) instance to release. | 

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.


### OH_MovingPhoto_RequestContentWithBuffer()

```
MediaLibrary_ErrorCode OH_MovingPhoto_RequestContentWithBuffer(OH_MovingPhoto* movingPhoto, MediaLibrary_ResourceType resourceType, const uint8_t** buffer, uint32_t* size)
```
**Description**<br>
Requests the moving photo content of the specified resource type and returns it in ArrayBuffer format.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| movingPhoto | Pointer to the [OH_MovingPhoto](#oh_movingphoto) instance. | 
| resourceType | [MediaLibrary_ResourceType](#medialibrary_resourcetype) of the moving photo. | 
| buffer | Double pointer to the buffer for storing the target file data. | 
| size | Pointer to the buffer size. | 

**Required permissions**

ohos.permission.READ_IMAGEVIDEO

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_PERMISSION_DENIED**: The access is denied due to lack of permission.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MovingPhoto_RequestContentWithUri()

```
MediaLibrary_ErrorCode OH_MovingPhoto_RequestContentWithUri(OH_MovingPhoto* movingPhoto, MediaLibrary_ResourceType resourceType, char* uri)
```
**Description**<br>
Requests the moving photo content of the specified resource type and writes it to the specified URI.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| movingPhoto | Pointer to the [OH_MovingPhoto](#oh_movingphoto) instance. | 
| resourceType | [MediaLibrary_ResourceType](#medialibrary_resourcetype) of the moving photo. | 
| uri | Pointer to the URI of the file, to which the data is written. | 

**Required permissions**

ohos.permission.READ_IMAGEVIDEO

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_PERMISSION_DENIED**: The access is denied due to lack of permission.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.


### OH_MovingPhoto_RequestContentWithUris()

```
MediaLibrary_ErrorCode OH_MovingPhoto_RequestContentWithUris(OH_MovingPhoto* movingPhoto, char* imageUri, char* videoUri)
```
**Description**<br>
Requests the image data and video data of a moving photo and writes them to the specified URIs, respectively.

**Since**: 13

**Parameters**

| Name| Description| 
| -------- | -------- |
| movingPhoto | Pointer to the [OH_MovingPhoto](#oh_movingphoto) instance. | 
| imageUri | Pointer to the URI of the file, to which the image data is written. | 
| videoUri | Pointer to the URI of the file, to which the video data is written. | 

**Required permissions**

ohos.permission.READ_IMAGEVIDEO

**Returns**

[MediaLibrary_ErrorCode](#medialibrary_errorcode-1):

- **MEDIA_LIBRARY_OK**: The operation is successful.

- **MEDIA_LIBRARY_PARAMETER_ERROR**: Incorrect parameters.
  Possible causes:
  1. There is mandatory parameter that is not specified.
  2. The parameter type is incorrect.
  3. The parameter verification failed.

- **MEDIA_LIBRARY_PERMISSION_DENIED**: The access is denied due to lack of permission.

- **MEDIA_LIBRARY_INTERNAL_SYSTEM_ERROR**: An internal system error occurred.