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

# ACP_MESSAGE_TYPE

> 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](/reference/audio/acphal/structs/acp_message) structure. It is also used in the [ACP\_COMMAND\_MESSAGE](/reference/audio/acphal/structs/acp_command_message) structure.

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

## Requirements

**Header:** acphal.h

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

## See also

[ACP\_MESSAGE](/reference/audio/acphal/structs/acp_message)\
[AcpHal](/reference/audio/acphal/acphal_members)


## Related topics

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