> ## 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. # SHAPE_XMA_CONTEXT > SHAPE_XMA_CONTEXT The XBOX Media Audio (XMA) context. ## Syntax ```cpp theme={null} typedef struct SHAPE_XMA_CONTEXT { UINT32 sizeRead0 : 12; UINT32 numLoops : 8; UINT32 validBuffer : 2; UINT32 sizeWrite : 5; UINT32 offsetWrite : 5; UINT32 sizeRead1 : 12; UINT32 loopSubframeEnd : 2; UINT32 reserved0 : 3; UINT32 loopSubframeSkip : 3; UINT32 numSubframesToDecode : 4; UINT32 numSubframesToSkip : 3; UINT32 sampleRate : 2; UINT32 numChannels : 1; UINT32 reserved1 : 1; UINT32 validWrite : 1; UINT32 offsetRead : 26; UINT32 errorStatus : 5; UINT32 errorSet : 1; UINT32 loopStartOffset : 26; UINT32 parserErrorStatus : 5; UINT32 parserErrorSet : 1; UINT32 loopEndOffset : 26; UINT32 packetMetaData : 5; UINT32 currentBuffer : 1; UINT32 ptrRead0; UINT32 ptrRead1; UINT32 ptrWrite; UINT32 ptrOverlapAdd; UINT32 writeBufferOffsetRead : 5; UINT32 reserved2 : 25; UINT32 stopWhenDone : 1; UINT32 interruptWhenDone : 1; UINT32 reserved[6]; } SHAPE_XMA_CONTEXT ``` ### Members *sizeRead0*\ Type: UINT32 Write: Size, in 2-KB blocks, of the left input buffer. *numLoops*\ Type: UINT32 Read/Write: Number of loops. 255 specifies infinite (continuous) looping. *validBuffer*\ Type: UINT32 Read/Write: Validity flags for the input buffers. | Value | Description | | - | - | | 00 | Neither buffer is valid. | | 01 | Only buffer 0 (left) is valid. | | 10 | Only buffer 1 (right) is valid. | | 11 | Both buffers are valid. | *sizeWrite*\ Type: UINT32 Write: Size, in 256-byte blocks, of the output buffer. *offsetWrite*\ Type: UINT32 Read: Offset, in 256-byte blocks, into the output buffer where the hardware will write. *sizeRead1*\ Type: UINT32 Write: Size, in 2-KB blocks, of the right input buffer. *loopSubframeEnd*\ Type: UINT32 Write: Subframe number of the loop endpoint, inclusive. *reserved0*\ Type: UINT32 Reserved. *loopSubframeSkip*\ Type: UINT32 Write: Number of subframes to skip at the beginning of the loop. Valid values are 0, 1, 2, 3, and 4. *numSubframesToDecode*\ Type: UINT32 Write: Number of subframes to decode per pass. Valid values are 1, 2, 4, and 8. *numSubframesToSkip*\ Type: UINT32 Write: Number of subframes to skip. Valid values are 0, 1, 2, 3, and 4. *sampleRate*\ Type: UINT32 Write: Sample rate of the stream. Valid values are in the [SHAPE\_XMA\_SAMPLE\_RATE](https://docs.xbox.com/reference/audio/shapexmacontext/enums/shape_xma_sample_rate.md) enumeration. *numChannels*\ Type: UINT32 Write: Number of channels in the stream. 0 specifies mono (one channel); 1 specifies stereo (two channels). *reserved1*\ Type: UINT32 Reserved. *validWrite*\ Type: UINT32 Read/Write: Validity flag for the write buffer. 1 indicates that the hardware can write; 0 indicates that the hardware cannot write. *offsetRead*\ Type: UINT32 Read/Write: Offset, in bits, from the beginning of the input buffer. *errorStatus*\ Type: UINT32 Read: One or more error values. | Error | Value | | - | - | | SHAPE\_XMA\_ERROR\_STATUS\_NO\_ERROR\_OCCURRED\_ERRORSET\_IS\_0 | 0 | | SHAPE\_XMA\_ERROR\_STATUS\_WRITE\_BUFFER\_INVALID\_VALIDWR\_IS\_0 | 1 | | SHAPE\_XMA\_ERROR\_STATUS\_INSUFFICIENT\_WRITE\_BUFFER\_SPACE\_VALIDWR\_IS\_1 | 2 | | SHAPE\_XMA\_ERROR\_STATUS\_READ\_BUFFER\_INVALID\_VALIDBUFFER\_CURRBUF\_IS\_0 | 4 | | SHAPE\_XMA\_ERROR\_STATUS\_FRAME\_CROSSES\_BOUNDARY\_INTO\_INVALID\_READ\_BUFFER\_VALIDBUFFER\_CURRBUF\_IS\_0 | 8 | | SHAPE\_XMA\_ERROR\_STATUS\_FRAME\_CROSSES\_BOTH\_READ\_BUFFER\_BOUNDARIES | 16 | *errorSet*\ Type: UINT32 Read: Error flag. 0 if no error has occurred; 1 if an error has occurred. Use [GetShapeXmaErrorStatus](https://docs.xbox.com/reference/audio/shapexmacontext/functions/getshapexmaerrorstatus.md) to retrieve error values. *loopStartOffset*\ Type: UINT32 Write: Offset, in bits, from the read-buffer pointer where the hardware will start decoding. *parserErrorStatus*\ Type: UINT32 Read: Parser error value. | Error | Value | | - | - | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_UNKNOWN\_STATE | 1 | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_OUT\_OF\_RANGE | 2 | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_FRAME\_SIZE\_EXCEEDED | 3 | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_BITSTREAM\_CORRUPTION | 4 | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_BARKVLC\_ERROR | 5 | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_BARKRLC\_ERROR | 6 | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_VLC4D\_ERROR | 7 | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_VLC2D\_ERROR | 8 | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_VLC1D\_ERROR | 9 | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_RLC0\_ERROR | 10 | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_RLC1\_ERROR | 11 | | SHAPE\_XMA\_PARSER\_ERROR\_STATUS\_LARGEVAL24\_ERROR | 15 | *parserErrorSet*\ Type: UINT32 Read: Parser error flag. 0 if no error has occurred; 1 if an error has occurred. Use [GetShapeXmaParserErrorStatus](https://docs.xbox.com/reference/audio/shapexmacontext/functions/getshapexmaparsererrorstatus.md) to retrieve error value. *loopEndOffset*\ Type: UINT32 Write: Offset, in bits, from the read-buffer pointer where the hardware will end decoding. *packetMetaData*\ Type: UINT32 Reserved for internal use. *currentBuffer*\ Type: UINT32 Read/Write: Current input buffer. 0 specifies the left buffer, and 1 specifies the right buffer. *ptrRead0*\ Type: UINT32 Write: Pointer to the left input buffer. Aligned on 2-KB boundaries; lower 11 bits are ignored. *ptrRead1*\ Type: UINT32 Write: Pointer to the right input buffer. Aligned on 2-KB boundaries; lower 11 bits are ignored. *ptrWrite*\ Type: UINT32 Write: Pointer to the output buffer. Aligned on 64-byte boundaries. *ptrOverlapAdd*\ Type: UINT32 Write: Pointer to the working buffer. Aligned on 128-byte boundaries. *writeBufferOffsetRead*\ Type: UINT32 Write: Offset, in 256-byte blocks, of the read pointer in the output buffer. *reserved2*\ Type: UINT32 Reserved. *stopWhenDone*\ Type: UINT32 Reserved for internal use. *interruptWhenDone*\ Type: UINT32 Reserved for internal use. *reserved*\ Type: UINT32\[6] Reserved. ## Remarks This structure contains the context for the XMA decoder block. The maximum size of an input buffer is 8 MB. To determine the status of an input buffer's consumption, examine the *offsetRead*, *currentBuffer*, and *validBuffer* members. Members that are marked as **Read** are written by the Audio Control Processor (ACP) library and should only be read by your application. Members that marked as **Write** are set by your application and are not changed by the ACP library. Members that are marked as **Read/Write** are set by your application but can be changed by the ACP library. For more information, see the [XMA](https://docs.xbox.com/build/console-features/audio/overviews/shape-overview.md#ID4EYD) section of [Overview of SHAPE](https://docs.xbox.com/build/console-features/audio/overviews/shape-overview.md). ## Requirements **Header:** shapexmacontext.h **Supported platforms:** XBOX One family consoles and XBOX Series consoles ## Conceptual documentation * [ACP overview](https://docs.xbox.com/build/console-features/audio/overviews/acp-overview.md) ## See also [ShapeXmaContext](https://docs.xbox.com/reference/audio/shapexmacontext/shapexmacontext_members.md) ## Related topics - [ShapeXmaContext](https://docs.xbox.com/reference/audio/shapexmacontext/shapexmacontext_members.md) - [SetShapeXmaSampleRate(SHAPE_XMA_CONTEXT*, SHAPE_XMA_SAMPLE_RATE)](https://docs.xbox.com/reference/audio/shapexmacontext/functions/setshapexmasamplerate.md) - [SetShapeXmaOutputBuffer(SHAPE_XMA_CONTEXT*, void*)](https://docs.xbox.com/reference/audio/shapexmacontext/functions/setshapexmaoutputbuffer.md) - [SetShapeXmaOverlapAddBuffer(SHAPE_XMA_CONTEXT*, void*)](https://docs.xbox.com/reference/audio/shapexmacontext/functions/setshapexmaoverlapaddbuffer.md) - [SetShapeXmaSampleRate(SHAPE_XMA_CONTEXT*, UINT32)](https://docs.xbox.com/reference/audio/shapexmacontext/functions/setshapexmasamplerate_2.md)