# CodecCallback - [Overview](#section1117951861165631) - [Summary](#section1269918023165631) - [Data Fields](#pub-attribs) - [Details](#section1278003397165631) - [Field](#section1513699407165631) - [InputBufferAvailable](#a97ba05617547d79b459bfed6172b4d75) - [OnEvent](#a039d0a4af8c4e3d10f49426d46f0b0f3) - [OutputBufferAvailable](#ad99eedd9953bdf22e426a181b08b8d0d) ## **Overview** **Related Modules:** [Codec](Codec.md) **Description:** Defines callbacks and their parameters. ## **Summary** ## Data Fields

Variable Name	Description
OnEvent )(UINTPTR comp, UINTPTR appData, EventType event, uint32_t data1, uint32_t data2, UINTPTR eventData)	int(* Reports an event.
InputBufferAvailable )(UINTPTR comp, UINTPTR appData, InputInfo *inBuf)	int(* Reports that the input data has been used.
OutputBufferAvailable )(UINTPTR comp, UINTPTR appData, OutputInfo *outBuf)	int(* Reports that the output is complete.

Variable Name

Description

OnEvent )(UINTPTR comp, UINTPTR appData, EventType event, uint32_t data1, uint32_t data2, UINTPTR eventData)

int(*

Reports an event.

InputBufferAvailable )(UINTPTR comp, UINTPTR appData, InputInfo *inBuf)

int(*

Reports that the input data has been used.

OutputBufferAvailable )(UINTPTR comp, UINTPTR appData, OutputInfo *outBuf)

int(*

Reports that the output is complete.

## **Details** ## **Field ** ## InputBufferAvailable ``` int(* CodecCallback::InputBufferAvailable) ([UINTPTR](Codec.md#ga58d2f4a8d12daa1dcf4eb297f3ebaabc) comp, [UINTPTR](Codec.md#ga58d2f4a8d12daa1dcf4eb297f3ebaabc) appData, [InputInfo](InputInfo.md) *inBuf) ``` **Description:** Reports that the input data has been used. This callback is invoked in asynchronous mode. **Parameters:**

Name	Description
hComponent	Indicates the handle of the codec component.
pAppData	Indicates upper-layer data, which is generally an upper-layer instance passed when this callback is set.
pBuffer	Indicates the pointer to the input data that has been used.

**Returns:** Returns **0** if the operation is successful; returns a non-zero value otherwise. ## OnEvent ``` int(* CodecCallback::OnEvent) ([UINTPTR](Codec.md#ga58d2f4a8d12daa1dcf4eb297f3ebaabc) comp, [UINTPTR](Codec.md#ga58d2f4a8d12daa1dcf4eb297f3ebaabc) appData, [EventType](Codec.md#ga2628ea8d12e8b2563c32f05dc7fff6fa) event, uint32_t data1, uint32_t data2, [UINTPTR](Codec.md#ga58d2f4a8d12daa1dcf4eb297f3ebaabc) eventData) ``` **Description:** Reports an event. Reports event errors and output format changes. **Parameters:**

Name	Description
hComponent	Indicates the handle of the codec component.
pAppData	Indicates upper-layer data, which is generally an upper-layer instance passed when this callback is set.
EVENTTYPE	Indicates the event type.
nData1	Indicates the first value contained in the reported event. This parameter is optional.
nData2	Indicates the second value contained in the reported event. This parameter is optional.
pEventData	Indicates the pointer to data contained in the reported event. This parameter is optional.

**Returns:** Returns **0** if the operation is successful; returns a non-zero value otherwise. ## OutputBufferAvailable ``` int(* CodecCallback::OutputBufferAvailable) ([UINTPTR](Codec.md#ga58d2f4a8d12daa1dcf4eb297f3ebaabc) comp, [UINTPTR](Codec.md#ga58d2f4a8d12daa1dcf4eb297f3ebaabc) appData, [OutputInfo](OutputInfo.md) *outBuf) ``` **Description:** Reports that the output is complete. This callback is invoked in asynchronous mode. **Parameters:**

Name	Description
hComponent	Indicates the handle of the codec component.
pAppData	Indicates upper-layer data, which is generally an upper-layer instance passed when this callback is registered.
pBuffer	Indicates the pointer to the output data that has been generated.

**Returns:** Returns **0** if the operation is successful; returns a non-zero value otherwise.