IXAPO::Process Method

Runs the XAPO’s digital signal processing (DSP) code on the given input and output buffers.

Syntax

public:
void Process(
         UINT32 InputProcessParameterCount,
         const XAPO_PROCESS_BUFFER_PARAMETERS *pInputProcessParameters,
         UINT32 OutputProcessParameterCount,
         (OutputProcessParameterCount)XAPO_PROCESS_BUFFER_PARAMETERS *pOutputProcessParameters,
         BOOL IsEnabled
)

Parameters

InputProcessParameterCount
Type: UINT32

Number of elements in pInputProcessParameters.

Note

XAudio2 currently supports only one input stream and one output stream.

pInputProcessParameters
Type: XAPO_PROCESS_BUFFER_PARAMETERS *

[in, optional] Input array of XAPO_PROCESS_BUFFER_PARAMETERS structures.

OutputProcessParameterCount
Type: UINT32

Number of elements in pOutputProcessParameters.

Note

XAudio2 currently supports only one input stream and one output stream.

*pOutputProcessParameters
Type: (OutputProcessParameterCount)XAPO_PROCESS_BUFFER_PARAMETERS

[in, out, optional] Output array of XAPO_PROCESS_BUFFER_PARAMETERS structures. On input, the value of XAPO_PROCESS_BUFFER_PARAMETERS. ValidFrameCount indicates the number of frames that the XAPO should write to the output buffer. On output, the value of XAPO_PROCESS_BUFFER_PARAMETERS. ValidFrameCount indicates the actual number of frames written.

IsEnabled
Type: BOOL

TRUE to process normally; FALSE to process thru. See Remarks for additional information.

Return value

None.

Remarks

Implementations of this function should not block, as the function is called from the realtime audio processing thread.

All code that could cause a delay, such as format validation and memory allocation, should be put in the IXAPO::LockForProcess method, which is not called from the realtime audio processing thread.

For in-place processing, the pInputProcessParameters parameter will not necessarily be the same as pOutputProcessParameters. Rather, their pBuffer members will point to the same memory.

Multiple input and output buffers may be used with in-place XAPOs, though the input buffer count must equal the output buffer count. For in-place processing when multiple input and output buffers are used, the XAPO may assume the number of input buffers equals the number of output buffers.

In addition to writing to the output buffer, as appropriate, an XAPO is responsible for setting the output stream’s buffer flags and valid frame count.

When IsEnabled is FALSE, the XAPO should not apply its normal processing to the given input/output buffers during. It should instead pass data from input to output with as little modification possible. Effects that perform format conversion should continue to do so. Effects must ensure transitions between normal and thru processing do not introduce discontinuities into the signal.

When writing a Process method, it is important to note XAudio2 audio data is interleaved, which means data from each channel is adjacent for a particular sample number. For example, if there was a 4-channel wave playing into an XAudio2 source voice, the audio data would be a sample of channel 0, a sample of channel 1, a sample of channel 2, a sample of channel 3, and then the next sample of channels 0, 1, 2, 3, and so on.

Requirements

Header: Declared in xapo.h.