harmony 鸿蒙AVMuxer

2025-06-12
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AVMuxer

Overview

The AVMuxer module provides the APIs for audio and video multiplexing.

For details about the development guide and sample, see Media Data Multiplexing.

System capability: SystemCapability.Multimedia.Media.Muxer

Since: 10

Summary

Files

Name	Description
native_avmuxer.h	Declares the native APIs used for audio and video multiplexing.

Types

Name	Description
typedef struct OH_AVMuxer OH_AVMuxer	Defines a struct for the native object for the muxer interface.

Functions

Name	Description
OH_AVMuxer * OH_AVMuxer_Create (int32_t fd, OH_AVOutputFormat format)	Creates an OH_AVMuxer instance by using the file descriptor and container format.
OH_AVErrCode OH_AVMuxer_SetRotation (OH_AVMuxer *muxer, int32_t rotation)	Sets the rotation angle (clockwise), which must be 0, 90, 180, or 270, of an output video.
OH_AVErrCode OH_AVMuxer_SetFormat (OH_AVMuxer muxer, OH_AVFormat format)	Sets format data to the muxer.
OH_AVErrCode OH_AVMuxer_AddTrack (OH_AVMuxer muxer, int32_t trackIndex, OH_AVFormat *trackFormat)	Adds an audio or video track to a muxer.
OH_AVErrCode OH_AVMuxer_Start (OH_AVMuxer *muxer)	Starts a muxer.
OH_AVErrCode OH_AVMuxer_WriteSample (OH_AVMuxer muxer, uint32_t trackIndex, OH_AVMemory sample, OH_AVCodecBufferAttr info)	Writes a sample to a muxer. (This function is deprecated from API version 11.)
OH_AVErrCode OH_AVMuxer_WriteSampleBuffer (OH_AVMuxer muxer, uint32_t trackIndex, const OH_AVBuffer sample)	Writes a sample to a muxer.
OH_AVErrCode OH_AVMuxer_Stop (OH_AVMuxer *muxer)	Stops a muxer.
OH_AVErrCode OH_AVMuxer_Destroy (OH_AVMuxer *muxer)	Clears internal resources and destroys an OH_AVMuxer instance.

Type Description

OH_AVMuxer

typedef struct OH_AVMuxer OH_AVMuxer

Description

Defines a struct for the native object for the muxer interface.

Since: 10

Function Description

OH_AVMuxer_AddTrack()

OH_AVErrCode OH_AVMuxer_AddTrack (OH_AVMuxer *muxer, int32_t *trackIndex, OH_AVFormat *trackFormat)

Description

Adds an audio or video track to a muxer.

Each time this function is called, an audio or video track is added to the muxer. This function must be called before OH_AVMuxer_Start.

System capability: SystemCapability.Multimedia.Media.Muxer

Since: 10

Parameters

Name	Description
muxer	Pointer to an OH_AVMuxer instance.
trackIndex	Pointer to the index of the media track. The index will be used in the OH_AVMuxer_WriteSample function. If the audio or video track is added, the index value is greater than or equal to 0; otherwise, the value is less than 0.
trackFormat	Pointer to an OH_AVFormat instance.

Returns

Returns AV_ERR_OK if the operation is successful; returns an error code defined in OH_AVErrCode otherwise.

Returns AV_ERR_INVALID_VAL if the muxer pointer is null, or the track index or track format is invalid.
Returns AV_ERR_OPERATE_NOT_PERMIT if the function is called out of sequence.
Returns AV_ERR_UNSUPPORT if the MIME type is not supported. Returns AV_ERR_NO_MEMORY if memory allocation fails.
Returns AV_ERR_UNKNOWN in the case of an unknown error.

OH_AVMuxer_Create()

OH_AVMuxer* OH_AVMuxer_Create (int32_t fd, OH_AVOutputFormat format)

Description

Creates an OH_AVMuxer instance by using the file descriptor and container format.

System capability: SystemCapability.Multimedia.Media.Muxer

Since: 10

Parameters

Name	Description
fd	File descriptor (FD). You must open the file in read/write mode (O_RDWR) and close the file after using it.
format	Format of the multiplexed output file. For details, see OH_AVOutputFormat.

Returns

Returns the pointer to the OH_AVMuxer instance created. After the multiplexing process is complete, call OH_AVMuxer_Destroy to destroy the instance.

OH_AVMuxer_Destroy()

OH_AVErrCode OH_AVMuxer_Destroy (OH_AVMuxer *muxer)

Description

Clears internal resources and destroys an OH_AVMuxer instance.

Do not repeatedly destroy the instance. Otherwise, the program may crash.

System capability: SystemCapability.Multimedia.Media.Muxer

Since: 10

Parameters

Name	Description
muxer	Pointer to an OH_AVMuxer instance.

Returns

Returns AV_ERR_OK if the operation is successful; returns an error code defined in OH_AVErrCode otherwise. You must set the muxer to null.

Returns AV_ERR_INVALID_VAL if the muxer pointer is null.

OH_AVMuxer_SetRotation()

OH_AVErrCode OH_AVMuxer_SetRotation (OH_AVMuxer *muxer, int32_t rotation)

Description

Sets the rotation angle (clockwise), which must be 0, 90, 180, or 270, of an output video.

This function must be called before OH_AVMuxer_Start.

System capability: SystemCapability.Multimedia.Media.Muxer

Since: 10

Parameters

Name	Description
muxer	Pointer to an OH_AVMuxer instance.
rotation	Angle to set. The value must be 0, 90, 180, or 270.

Returns

Returns AV_ERR_OK if the operation is successful; returns an error code defined in OH_AVErrCode otherwise.

Returns AV_ERR_INVALID_VAL if the muxer pointer is null or the value of rotation is invalid.
Returns AV_ERR_OPERATE_NOT_PERMIT if the function is called out of sequence.

OH_AVMuxer_SetFormat()

OH_AVErrCode OH_AVMuxer_SetFormat(OH_AVMuxer *muxer, OH_AVFormat *format)

Description

Sets format data to the muxer.

Currently, only OH_MD_KEY_CREATION_TIME can be set.

If the setting fails, check whether the value of OH_MD_KEY_CREATION_TIME complies with the ISO 8601 standard and whether the UTC time is used.

System capability: SystemCapability.Multimedia.Media.Muxer

Since: 14

Parameters

Name	Description
muxer	Pointer to an OH_AVMuxer instance.
format	Pointer to an OH_AVFormat instance. It is a file-level metadata set.

Returns

Returns AV_ERR_OK if the format parameter is correctly set.
Returns AV_ERR_INVALID_VAL if the muxer pointer is null or the value of format is invalid.
Returns AV_ERR_OPERATE_NOT_PERMIT if the function is called out of sequence.

OH_AVMuxer_Start()

OH_AVErrCode OH_AVMuxer_Start (OH_AVMuxer *muxer)

Description

Starts a muxer.

This function must be called after OH_AVMuxer_AddTrack and before OH_AVMuxer_WriteSample.

System capability: SystemCapability.Multimedia.Media.Muxer

Since: 10

Parameters

Name	Description
muxer	Pointer to an OH_AVMuxer instance.

Returns

Returns AV_ERR_OK if the operation is successful; returns an error code defined in OH_AVErrCode otherwise.

Returns AV_ERR_INVALID_VAL if the muxer pointer is null.
Returns AV_ERR_OPERATE_NOT_PERMIT if the function is called out of sequence.
Returns AV_ERR_UNKNOWN in the case of an unknown error.

OH_AVMuxer_Stop()

OH_AVErrCode OH_AVMuxer_Stop (OH_AVMuxer *muxer)

Description

Stops a muxer.

Once the muxer is stopped, it cannot be restarted.

System capability: SystemCapability.Multimedia.Media.Muxer

Since: 10

Parameters

Name	Description
muxer	Pointer to an OH_AVMuxer instance.

Returns

Returns AV_ERR_OK if the operation is successful; returns an error code defined in OH_AVErrCode otherwise.

Returns AV_ERR_INVALID_VAL if the muxer pointer is null.
Returns AV_ERR_OPERATE_NOT_PERMIT if the function is called out of sequence.

OH_AVMuxer_WriteSample()

OH_AVErrCode OH_AVMuxer_WriteSample (OH_AVMuxer *muxer, uint32_t trackIndex, OH_AVMemory *sample, OH_AVCodecBufferAttr info)

Description

Writes a sample to a muxer.

This function must be called after OH_AVMuxer_Start and before OH_AVMuxer_Stop. The caller must write the sample to the correct audio or video track based on the timing in info.

System capability: SystemCapability.Multimedia.Media.Muxer

Since: 10

Deprecated from: 11

Substitute API: OH_AVMuxer_WriteSampleBuffer

Parameters

Name	Description
muxer	Pointer to an OH_AVMuxer instance.
trackIndex	Index of the audio or video track corresponding to the data.
sample	Pointer to the data obtained after encoding or demultiplexing.
info	Sample description. For details, see OH_AVCodecBufferAttr.

Returns

Returns AV_ERR_OK if the operation is successful; returns an error code defined in OH_AVErrCode otherwise.

Returns AV_ERR_INVALID_VAL if the muxer pointer is null, or the track index, sample, or info is invalid.
Returns AV_ERR_OPERATE_NOT_PERMIT if the function is called out of sequence.
Returns AV_ERR_NO_MEMORY if memory allocation fails. Returns AV_ERR_UNKNOWN in the case of an unknown error.

OH_AVMuxer_WriteSampleBuffer()

OH_AVErrCode OH_AVMuxer_WriteSampleBuffer (OH_AVMuxer *muxer, uint32_t trackIndex, const OH_AVBuffer *sample)

Description

Writes a sample to a muxer.

This function must be called after OH_AVMuxer_Start and before OH_AVMuxer_Stop. The caller must write the sample to the correct audio or video track based on the timing in sample.

System capability: SystemCapability.Multimedia.Media.Muxer

Since: 11

Parameters

Name	Description
muxer	Pointer to an OH_AVMuxer instance.
trackIndex	Index of the audio or video track corresponding to the data.
sample	Pointer to the data and properties obtained after encoding or demultiplexing.

Returns

Returns AV_ERR_OK if the operation is successful; returns an error code defined in OH_AVErrCode otherwise.

Returns AV_ERR_INVALID_VAL if the muxer pointer is null, or the track index or sample is invalid.
Returns AV_ERR_OPERATE_NOT_PERMIT if the function is called out of sequence.
Returns AV_ERR_NO_MEMORY if memory allocation fails. Returns AV_ERR_UNKNOWN in the case of an unknown error.