1# OH_AVDataSource 2 3 4## Overview 5 6The OH_AVDataSource struct describes a user-defined data source. 7 8**System capability**: SystemCapability.Multimedia.Media.CodecBase 9 10**Since**: 12 11 12**Related module**: [CodecBase](_codec_base.md) 13 14**Header file**: [native_avcodec_base.h](native__avcodec__base_8h.md) 15 16 17## Summary 18 19 20### Member Variables 21 22| Name| Description| 23| -------- | -------- | 24| int64_t [size](#size) | Size of the data source. | 25| [OH_AVDataSourceReadAt](_codec_base.md#oh_avdatasourcereadat) [readAt](#readat) | Callback of the data source. | 26 27 28## Member Variable Description 29 30 31### readAt 32 33``` 34OH_AVDataSourceReadAt OH_AVDataSource::readAt 35``` 36 37**Description** 38 39Callback of the data source. 40 41**System capability**: SystemCapability.Multimedia.Media.CodecBase 42 43**Since**: 12 44 45 46### size 47 48``` 49int64_t OH_AVDataSource::size 50``` 51 52**Description** 53 54Size of the data source. 55 56**System capability**: SystemCapability.Multimedia.Media.CodecBase 57 58**Since**: 12 59