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# ACP_COMMAND_UPDATE_PCM_CONTEXT

> ACP_COMMAND_UPDATE_PCM_CONTEXT

# ACP\_COMMAND\_UPDATE\_PCM\_CONTEXT

Command for updating a PCM context.

## Syntax

```cpp theme={null}
typedef struct ACP_COMMAND_UPDATE_PCM_CONTEXT {  
    UINT32 contextIndex;  
    UINT32 updateMask;  
    APU_ADDRESS contextData;  
} ACP_COMMAND_UPDATE_PCM_CONTEXT  
```

### Members

*contextIndex*\
Type: UINT32

Index of a context to be updated.

*updateMask*\
Type: UINT32

One or more update flags.

| Flag                                            | Value      |
| ----------------------------------------------- | ---------- |
| SHAPE\_PCM\_UPDATE\_BUFFER\_START               | 0x00000001 |
| SHAPE\_PCM\_UPDATE\_BUFFER\_LENGTH              | 0x00000002 |
| SHAPE\_PCM\_UPDATE\_FORMAT                      | 0x00000004 |
| SHAPE\_PCM\_UPDATE\_MODE                        | 0x00000008 |
| SHAPE\_PCM\_UPDATE\_READ\_POINTER               | 0x00000010 |
| SHAPE\_PCM\_UPDATE\_LOOP\_START\_WRITE\_POINTER | 0x00000020 |
| SHAPE\_PCM\_UPDATE\_LOOP\_END                   | 0x00000040 |
| SHAPE\_PCM\_UPDATE\_LOOP\_COUNT                 | 0x00000080 |
| SHAPE\_PCM\_UPDATE\_FULL                        | 0x00000100 |
| SHAPE\_PCM\_UPDATE\_MASK                        | 0x000001ff |

*contextData*\
Type: APU\_ADDRESS

Physical address of the context data to be updated. Refer to the [SHAPE\_PCM\_CONTEXT](/reference/audio/shapepcmcontext/structs/shape_pcm_context) structure.

## Remarks

This structure is used by the `ACP_COMMAND_TYPE_UPDATE_PCM_CONTEXT` command. Use the command to update only a small number of contexts per audio frame; updating a large number of contexts is not efficient. See the [Rendering audio section of Overview of ACP](/build/console-features/audio/overviews/acp-overview#ID4E6C) for more detail.

## Requirements

**Header:** acphal.h

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

## Conceptual documentation

* [ACP overview](/build/console-features/audio/overviews/acp-overview)

## See also

[SHAPE\_PCM\_CONTEXT](/reference/audio/shapepcmcontext/structs/shape_pcm_context)\
[ACP\_COMMAND\_TYPE](/reference/audio/acphal/enums/acp_command_type)\
[SubmitCommand](/reference/audio/acphal/interfaces/IAcpHal/methods/iacphal_submitcommand)\
[AcpHal](/reference/audio/acphal/acphal_members)


## Related topics

- [ACP overview](/build/console-features/audio/overviews/acp-overview.md)
- [ACP_COMMAND_TYPE](/reference/audio/acphal/enums/acp_command_type.md)
- [ACP_COMMAND_LOAD_SHAPE_FLOWGRAPH](/reference/audio/acphal/structs/acp_command_load_shape_flowgraph.md)
- [AcpHal](/reference/audio/acphal/acphal_members.md)
- [ACP_COMMAND_UPDATE_PCM_CONTEXT_ENTRY](/reference/audio/acphal/structs/acp_command_update_pcm_context_entry.md)