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.|

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