avimage_generator.h

Overview

The avimage_generator.h file declares the AVImageGenerator APIs. You can use the APIs to extract video frames at given time points from videos.

Library: libavimage_generator.so

System capability: SystemCapability.Multimedia.Media.AVImageGenerator

Since: 18

Related module: AVImageGenerator

Summary

Structs

Name	typedef Keyword	Description
OH_AVImageGenerator	OH_AVImageGenerator	Defines the type used for generating video frames at given time points.

Functions

Name	Description
OH_AVImageGenerator* OH_AVImageGenerator_Create(void)	Creates an OH_AVImageGenerator instance, which is used to generate video frames at given time points.
OH_AVErrCode OH_AVImageGenerator_SetFDSource(OH_AVImageGenerator* generator,int32_t fd, int64_t offset, int64_t size)	Sets a data source based on the media file descriptor.
OH_AVErrCode OH_AVImageGenerator_FetchFrameByTime(OH_AVImageGenerator* generator,int64_t timeUs, OH_AVImageGenerator_QueryOptions options, OH_PixelmapNative** pixelMap)	Extracts a video frame at a given time from a video. This function must be called after OH_AVImageGenerator_SetFDSource.
OH_AVErrCode OH_AVImageGenerator_Release(OH_AVImageGenerator* generator)	Releases the resources used by the OH_AVImageGenerator instance and destroys the instance.

Function Description

OH_AVImageGenerator_Create()

OH_AVImageGenerator* OH_AVImageGenerator_Create(void)

Description

Creates an OH_AVImageGenerator instance, which is used to generate video frames at given time points.

System capability: SystemCapability.Multimedia.Media.AVImageGenerator

Since: 18

Return value

Type	Description
OH_AVImageGenerator*	Pointer to the OH_AVImageGenerator instance created if the operation is successful; a null pointer otherwise. Possible cause of failures: HstEngineFactory fails to create an AVMetadataHelperEngine.

OH_AVImageGenerator_SetFDSource()

OH_AVErrCode OH_AVImageGenerator_SetFDSource(OH_AVImageGenerator* generator,int32_t fd, int64_t offset, int64_t size)

Description

Sets a data source based on the media file descriptor.

System capability: SystemCapability.Multimedia.Media.AVImageGenerator

Since: 18

Parameters

Parameter	Description
OH_AVImageGenerator* generator	Pointer to the OH_AVImageGenerator instance.
int32_t fd	File descriptor of the media source.
int64_t offset	Offset of the media source in the file descriptor.
int64_t size	Size of the media source.

Return value

Type	Description
OH_AVErrCode	AV_ERR_OK: The operation is successful. AV_ERR_INVALID_VAL: The input parameter generator is a null pointer or a parameter is invalid. AV_ERR_OPERATE_NOT_PERMIT: The operation is forbidden. AV_ERR_NO_MEMORY: Internal memory allocation failed.

OH_AVImageGenerator_FetchFrameByTime()

OH_AVErrCode OH_AVImageGenerator_FetchFrameByTime(OH_AVImageGenerator* generator,int64_t timeUs, OH_AVImageGenerator_QueryOptions options, OH_PixelmapNative** pixelMap)

Description

Extracts a video frame at a given time from a video.

This function must be called after OH_AVImageGenerator_SetFDSource.

System capability: SystemCapability.Multimedia.Media.AVImageGenerator

Since: 18

Parameters

Parameter	Description
OH_AVImageGenerator* generator	Pointer to the OH_AVImageGenerator instance.
int64_t timeUs	Time point of the video frame to be extracted in the video, in μs.
OH_AVImageGenerator_QueryOptions options	Mappings between the given time points and video frames.
OH_PixelmapNative** pixelMap	Double pointer to the video frame object obtained.

Return value

Type	Description
OH_AVErrCode	AV_ERR_OK: The operation is successful. AV_ERR_INVALID_VAL: The input parameter generator is a null pointer or a parameter is invalid. AV_ERR_OPERATE_NOT_PERMIT: The operation is forbidden. AV_ERR_UNSUPPORTED_FORMAT: The format is not supported. AV_ERR_NO_MEMORY: Internal memory allocation failed.

OH_AVImageGenerator_Release()

OH_AVErrCode OH_AVImageGenerator_Release(OH_AVImageGenerator* generator)

Description

Releases the resources used by the OH_AVImageGenerator instance and destroys the instance.

System capability: SystemCapability.Multimedia.Media.AVImageGenerator

Since: 18

Parameters

Parameter	Description
OH_AVImageGenerator* generator	Pointer to the OH_AVImageGenerator instance.

Return value

Type	Description
OH_AVErrCode	AV_ERR_OK: The operation is successful. AV_ERR_INVALID_VAL: The input parameter generator is a null pointer or a parameter is invalid.