1# OH_AVCodecCallback 2 3 4## Overview 5 6The **OH_AVCodecCallback** struct defines all the asynchronous callback function pointers of an **OH_AVCodec** instance. To ensure the normal running of **OH_AVCodec**, you must register the instance of this struct with the **OH_AVCodec** instance and process the information reported by the callback function. 7 8**System capability**: SystemCapability.Multimedia.Media.CodecBase 9 10**Since**: 11 11 12**Related module**: [CodecBase](_codec_base.md) 13 14 15## Summary 16 17 18### Member Variables 19 20| Name| Description| 21| -------- | -------- | 22| [OH_AVCodecOnError](_codec_base.md#oh_avcodeconerror) [onError](#onerror) | Defines the callback used to report a codec operation error.| 23| [OH_AVCodecOnStreamChanged](_codec_base.md#oh_avcodeconstreamchanged) [onStreamChanged](#onstreamchanged) | Defines the callback used to report a codec stream change.| 24| [OH_AVCodecOnNeedInputBuffer](_codec_base.md#oh_avcodeconneedinputbuffer) [onNeedInputBuffer](#onneedinputbuffer) | Defines the callback used to report input data required.| 25| [OH_AVCodecOnNewOutputBuffer](_codec_base.md#oh_avcodeconnewoutputbuffer) [onNewOutputBuffer](#onnewoutputbuffer) | Defines the callback used to report output data generated.| 26 27 28## Member Variable Description 29 30 31### onError 32 33**Description** 34 35Defines the callback used to report a codec operation error. 36 37**Since**: 11 38 39 40### onNeedInputBuffer 41 42**Description** 43 44Defines the callback used to report input data required. 45 46**Since**: 11 47 48 49### onNewOutputBuffer 50 51**Description** 52 53Defines the callback used to report output data generated. 54 55**Since**: 11 56 57 58### onStreamChanged 59 60**Description** 61 62Defines the callback used to report a codec stream change. 63 64**Since**: 11 65