> ## Documentation Index
> Fetch the complete documentation index at: https://docs.xbox.com/llms.txt
> Use this file to discover all available pages before exploring further.

# ACP_MESSAGE_TYPE

> ACP_MESSAGE_TYPE

Enumerates the ACP message types.

## Syntax

```cpp theme={null}
enum ACP_MESSAGE_TYPE    
{  
    ACP_MESSAGE_TYPE_AUDIO_FRAME_START = 0x01,  
    ACP_MESSAGE_TYPE_FLOWGRAPH_COMPLETED = 0x02,  
    ACP_MESSAGE_TYPE_SRC_BLOCKED = 0x04,  
    ACP_MESSAGE_TYPE_DMA_BLOCKED = 0x08,  
    ACP_MESSAGE_TYPE_COMMAND_COMPLETED = 0x10,  
    ACP_MESSAGE_TYPE_FLOWGRAPH_TERMINATED = 0x20,  
    ACP_MESSAGE_TYPE_ERROR = 0x40,  
    ACP_MESSAGE_TYPE_DISCONNECTED = 0x80,  
    ACP_MESSAGE_TYPE_MASK = 0xff  
}  
```

## Constants

| Constant | Description |
| - | - |
| ACP\_MESSAGE\_TYPE\_AUDIO\_FRAME\_START | Start of an audio frame. |
| ACP\_MESSAGE\_TYPE\_FLOWGRAPH\_COMPLETED | Current flowgraph has completed. |
| ACP\_MESSAGE\_TYPE\_SRC\_BLOCKED | SRC context is blocked and waiting for the source data. |
| ACP\_MESSAGE\_TYPE\_DMA\_BLOCKED | DMA context is blocked and waiting for the source data. |
| ACP\_MESSAGE\_TYPE\_COMMAND\_COMPLETED | A command has completed. This notification occurs only if the command has a non-zero `commandId`. |
| ACP\_MESSAGE\_TYPE\_FLOWGRAPH\_TERMINATED | The current flowgraph was terminated due to an error. |
| ACP\_MESSAGE\_TYPE\_ERROR | An unspecified error occurred. |
| ACP\_MESSAGE\_TYPE\_DISCONNECTED | Disconnected from the ACP; no data is associated with this message. |
| ACP\_MESSAGE\_TYPE\_MASK | Bit mask of all messages; not an actual message. |

## Remarks

This enumeration is used in the [ACP\_MESSAGE](https://docs.xbox.com/reference/audio/acphal/structs/acp_message.md) structure. It is also used in the [ACP\_COMMAND\_MESSAGE](https://docs.xbox.com/reference/audio/acphal/structs/acp_command_message.md) structure.

For more information on flowgraphs, see the [Flowgraph parsing in Overview of ACP](https://docs.xbox.com/build/console-features/audio/overviews/acp-overview.md#ID4EHF).

## Requirements

**Header:** acphal.h

**Supported platforms:** XBOX One family consoles and XBOX Series consoles

## See also

[ACP\_MESSAGE](https://docs.xbox.com/reference/audio/acphal/structs/acp_message.md)\
[AcpHal](https://docs.xbox.com/reference/audio/acphal/acphal_members.md)


## Related topics

- [ACP_MESSAGE](https://docs.xbox.com/reference/audio/acphal/structs/acp_message.md)
- [ACP_COMMAND_MESSAGE](https://docs.xbox.com/reference/audio/acphal/structs/acp_command_message.md)
- [ACP_MESSAGE_ERROR](https://docs.xbox.com/reference/audio/acphal/structs/acp_message_error.md)
- [ACP_MESSAGE_FLOWGRAPH_COMPLETED](https://docs.xbox.com/reference/audio/acphal/structs/acp_message_flowgraph_completed.md)
- [ACP_MESSAGE_FLOWGRAPH_TERMINATED](https://docs.xbox.com/reference/audio/acphal/structs/acp_message_flowgraph_terminated.md)