| [native_avcodec_base.h](native__avcodec__base_8h.md) | Declares the common structs, character constants, and enums for running **OH_AVCodec** instances. <br>File to Include: <multimedia/player_framework/native_avcodec_base.h> |
### Structs
| Name | Description |
| -------- | -------- |
| [OH_AVCodecBufferAttr](_o_h___a_v_codec_buffer_attr.md) | Defines the buffer attributes of an **OH_AVCodec** instance. |
| [OH_AVCodecAsyncCallback](_o_h___a_v_codec_async_callback.md) | Defines a collection of asynchronous callback functions for an **OH_AVCodec** instance. You must register this struct instance for an **OH_AVCodec** instance and process the information reported through these callbacks to ensure the normal running of the instance. |
### Types
| Name | Description |
| -------- | -------- |
| [OH_AVCodecBufferFlags](#oh_avcodecbufferflags) | Enumerates the buffer flags of an **OH_AVCodec** instance. |
| [OH_AVCodecBufferAttr](#oh_avcodecbufferattr) | Defines the buffer attributes of an **OH_AVCodec** instance. |
| [OH_AVCodecOnError](#oh_avcodeconerror)) (OH_AVCodec \*codec, int32_t errorCode, void \*userData) | Defines the function pointer that is called to report error information when an error occurs during the running of an **OH_AVCodec** instance. |
| [OH_AVCodecOnStreamChanged](#oh_avcodeconstreamchanged)) (OH_AVCodec \*codec, OH_AVFormat \*format, void \*userData) | Defines the function pointer that is called to report the attributes of the new stream when the output stream changes. Note that the lifecycle of the pointer to the **OH_AVFormat** instance is valid only when the function pointer is being called. Do not access the pointer to the instance after the function pointer is called. |
| [OH_AVCodecOnNeedInputData](#oh_avcodeconneedinputdata)) (OH_AVCodec \*codec, uint32_t index, OH_AVMemory \*data, void \*userData) | Defines the function pointer that is called, with a new buffer to fill in new input data, when new input data is required during the running of an **OH_AVCodec** instance. |
| [OH_AVCodecOnNewOutputData](#oh_avcodeconnewoutputdata)) (OH_AVCodec \*codec, uint32_t index, OH_AVMemory \*data, [OH_AVCodecBufferAttr](_o_h___a_v_codec_buffer_attr.md)\*attr, void \*userData) | Defines the function pointer that is called, with a buffer containing new output data, when the new output data is generated during the running of an **OH_AVCodec** instance. Note that the lifecycle of the pointer to the **[OH_AVCodecBufferAttr](_o_h___a_v_codec_buffer_attr.md)** instance is valid only when the function pointer is being called. Do not access the pointer to the instance after the function pointer is called. |
| [OH_AVCodecAsyncCallback](#oh_avcodecasynccallback) | Defines a collection of asynchronous callback functions for an **OH_AVCodec** instance. You must register this struct instance for an **OH_AVCodec** instance and process the information reported through these callbacks to ensure the normal running of the instance. |
| [OH_MediaType](#oh_mediatype) | Enumerates the media types. |
| [OH_AVCProfile](#oh_avcprofile) | Enumerates the AVC profiles. |
| [OH_AACProfile](#oh_aacprofile) | Enumerates the AAC profiles. |
| [OH_AVCodecBufferAttr::pts](#pts) | Presentation timestamp of the buffer, in microseconds. |
| [OH_AVCodecBufferAttr::size](#size) | Size of the data contained in the buffer, in bytes. |
| [OH_AVCodecBufferAttr::offset](#offset) | Start offset of valid data in the buffer. |
| [OH_AVCodecBufferAttr::flags](#flags) | Buffer flag, which is a combination of multiple [OH_AVCodecBufferFlags](#oh_avcodecbufferflags). |
| [OH_AVCODEC_MIMETYPE_VIDEO_AVC](#oh_avcodec_mimetype_video_avc) | Defines the Multipurpose Internet Mail Extension (MIME) type for Advanced Video Coding (AVC). |
| [OH_AVCODEC_MIMETYPE_AUDIO_AAC](#oh_avcodec_mimetype_audio_aac) | Defines the MIME type for Advanced Audio Coding (AAC). |
| [OH_ED_KEY_TIME_STAMP](#oh_ed_key_time_stamp) | Provides unified character descriptors for the auxiliary data of the surface buffer. |
| [OH_ED_KEY_EOS](#oh_ed_key_eos) | Character descriptor of the end-of-stream in the surface auxiliary data. The value type is bool. |
| [OH_MD_KEY_TRACK_TYPE](#oh_md_key_track_type) | Provides unified character descriptors for the media playback framework. |
| [OH_MD_KEY_CODEC_MIME](#oh_md_key_codec_mime) | Character descriptor of the MIME type. The value type is string. |
| [OH_MD_KEY_DURATION](#oh_md_key_duration) | Character descriptor of duration. The value type is int64_t. |
| [OH_MD_KEY_BITRATE](#oh_md_key_bitrate) | Character descriptor of the bit rate. The value type is uint32_t. |
| [OH_MD_KEY_MAX_INPUT_SIZE](#oh_md_key_max_input_size) | Character descriptor of the maximum input size. The value type is uint32_t. |
| [OH_MD_KEY_WIDTH](#oh_md_key_width) | Character descriptor of the video width. The value type is uint32_t. |
| [OH_MD_KEY_HEIGHT](#oh_md_key_height) | Character descriptor of the video height. The value type is uint32_t. |
| [OH_MD_KEY_PIXEL_FORMAT](#oh_md_key_pixel_format) | Character descriptor of the video pixel format. The value type is int32_t. For details, see [OH_AVPixelFormat](_core.md#oh_avpixelformat). |
| [OH_MD_KEY_AUDIO_SAMPLE_FORMAT](#oh_md_key_audio_sample_format) | Character descriptor of the audio sample format. The value type is uint32_t. |
| [OH_MD_KEY_FRAME_RATE](#oh_md_key_frame_rate) | Character descriptor of the video frame rate. The value type is double. |
| [OH_MD_KEY_VIDEO_ENCODE_BITRATE_MODE](#oh_md_key_video_encode_bitrate_mode) | Character descriptor of the video encoding bit rate mode. The value type is int32_t. For details, see [OH_VideoEncodeBitrateMode](_video_encoder.md#oh_videoencodebitratemode). |
| [OH_MD_KEY_PROFILE](#oh_md_key_profile) | Character descriptor of the audio/video encoding capability. The value type is int32_t. For details, see [OH_AVCProfile](#oh_avcprofile) or [OH_AACProfile](#oh_aacprofile). |
| [OH_MD_KEY_AUD_CHANNEL_COUNT](#oh_md_key_aud_channel_count) | Character descriptor of the number of audio channels. The value type is uint32_t. |
| [OH_MD_KEY_AUD_SAMPLE_RATE](#oh_md_key_aud_sample_rate) | Character descriptor of the audio sampling rate. The value type is uint32_t. |
| [OH_MD_KEY_I_FRAME_INTERVAL](#oh_md_key_i_frame_interval) | Character descriptor of the I-frame interval. The value type is int32_t, and the unit is ms. |
| [OH_MD_KEY_ROTATION](#oh_md_key_rotation) | Character descriptor of the surface rotation angle. The value type is int32_t. The value range is {0, 90, 180, 270}. The default value is 0. |
Defines a collection of asynchronous callback functions for an **OH_AVCodec** instance. You must register this struct instance for an **OH_AVCodec** instance and process the information reported through these callbacks to ensure the normal running of the instance.
| onError | Indicates the callback used to report errors occurred during the running of the instance. For details, see [OH_AVCodecOnError](#oh_avcodeconerror). |
| onStreamChanged | Indicates the callback used to report stream information. For details, see [OH_AVCodecOnStreamChanged](#oh_avcodeconstreamchanged). |
| onNeedInputData | Indicates the callback used to report input data needed. For details, see [OH_AVCodecOnNeedInputData](#oh_avcodeconneedinputdata). |
| onNeedInputData | Indicates the callback used to report output data needed. For details, see [OH_AVCodecOnNewOutputData](#oh_avcodeconnewoutputdata). |
Defines the function pointer that is called, with a new buffer to fill in new input data, when new input data is required during the running of an **OH_AVCodec** instance.
Defines the function pointer that is called, with a buffer containing new output data, when the new output data is generated during the running of an **OH_AVCodec** instance. Note that the lifecycle of the pointer to the **[OH_AVCodecBufferAttr](_o_h___a_v_codec_buffer_attr.md)** instance is valid only when the function pointer is being called. Do not access the pointer to the instance after the function pointer is called.
Defines the function pointer that is called to report the attributes of the new stream when the output stream changes. Note that the lifecycle of the pointer to the **OH_AVFormat** instance is valid only when the function pointer is being called. Do not access the pointer to the instance after the function pointer is called.
Character descriptor of the number of audio channels. The value type is uint32_t.
### OH_MD_KEY_AUD_SAMPLE_RATE
```
const char* OH_MD_KEY_AUD_SAMPLE_RATE
```
**Description**<br>
Character descriptor of the audio sampling rate. The value type is uint32_t.
### OH_MD_KEY_AUDIO_SAMPLE_FORMAT
```
const char* OH_MD_KEY_AUDIO_SAMPLE_FORMAT
```
**Description**<br>
Character descriptor of the audio sample format. The value type is uint32_t.
### OH_MD_KEY_BITRATE
```
const char* OH_MD_KEY_BITRATE
```
**Description**<br>
Character descriptor of the bit rate. The value type is uint32_t.
### OH_MD_KEY_CODEC_MIME
```
const char* OH_MD_KEY_CODEC_MIME
```
**Description**<br>
Character descriptor of the MIME type. The value type is string.
### OH_MD_KEY_DURATION
```
const char* OH_MD_KEY_DURATION
```
**Description**<br>
Character descriptor of duration. The value type is int64_t.
### OH_MD_KEY_FRAME_RATE
```
const char* OH_MD_KEY_FRAME_RATE
```
**Description**<br>
Character descriptor of the video frame rate. The value type is double.
### OH_MD_KEY_HEIGHT
```
const char* OH_MD_KEY_HEIGHT
```
**Description**<br>
Character descriptor of the video height. The value type is uint32_t.
### OH_MD_KEY_I_FRAME_INTERVAL
```
const char* OH_MD_KEY_I_FRAME_INTERVAL
```
**Description**<br>
Character descriptor of the I-frame interval. The value type is int32_t, and the unit is ms.
### OH_MD_KEY_MAX_INPUT_SIZE
```
const char* OH_MD_KEY_MAX_INPUT_SIZE
```
**Description**<br>
Character descriptor of the maximum input size. The value type is uint32_t.
### OH_MD_KEY_PIXEL_FORMAT
```
const char* OH_MD_KEY_PIXEL_FORMAT
```
**Description**<br>
Character descriptor of the video pixel format. The value type is int32_t. For details, see [OH_AVPixelFormat](_core.md#oh_avpixelformat).
### OH_MD_KEY_PROFILE
```
const char* OH_MD_KEY_PROFILE
```
**Description**<br>
Character descriptor of the audio/video encoding capability. The value type is int32_t. For details, see [OH_AVCProfile](#oh_avcprofile) or [OH_AACProfile](#oh_aacprofile).
### OH_MD_KEY_ROTATION
```
const char* OH_MD_KEY_ROTATION
```
**Description**<br>
Character descriptor of the surface rotation angle. The value type is int32_t. The value range is {0, 90, 180, 270}. The default value is 0.
### OH_MD_KEY_TRACK_TYPE
```
const char* OH_MD_KEY_TRACK_TYPE
```
**Description**<br>
Provides unified character descriptors for the media playback framework.
Character descriptor of the video encoding bit rate mode. The value type is int32_t. For details, see [OH_VideoEncodeBitrateMode](_video_encoder.md#oh_videoencodebitratemode).
### OH_MD_KEY_WIDTH
```
const char* OH_MD_KEY_WIDTH
```
**Description**<br>
Character descriptor of the video width. The value type is uint32_t.
### pts
```
int64_t OH_AVCodecBufferAttr::pts
```
**Description**<br>
Presentation timestamp of the buffer, in microseconds.
### size
```
int32_t OH_AVCodecBufferAttr::size
```
**Description**<br>
Size of the data contained in the buffer, in bytes.
