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- /*-----------------------------------------------------------------------------
- * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
- *
- * $Date: 17. January 2013
- * $Revision: V1.4.1
- *
- * Project: CMSIS DSP Library
- * Title: arm_fir_decimate_init_f32.c
- *
- * Description: Floating-point FIR Decimator initialization function.
- *
- * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * - Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- * - Neither the name of ARM LIMITED nor the names of its contributors
- * may be used to endorse or promote products derived from this
- * software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- * ---------------------------------------------------------------------------*/
-
- #include "arm_math.h"
-
- /**
- * @ingroup groupFilters
- */
-
- /**
- * @addtogroup FIR_decimate
- * @{
- */
-
- /**
- * @brief Initialization function for the floating-point FIR decimator.
- * @param[in,out] *S points to an instance of the floating-point FIR decimator structure.
- * @param[in] numTaps number of coefficients in the filter.
- * @param[in] M decimation factor.
- * @param[in] *pCoeffs points to the filter coefficients.
- * @param[in] *pState points to the state buffer.
- * @param[in] blockSize number of input samples to process per call.
- * @return The function returns ARM_MATH_SUCCESS if initialization was successful or ARM_MATH_LENGTH_ERROR if
- * <code>blockSize</code> is not a multiple of <code>M</code>.
- *
- * <b>Description:</b>
- * \par
- * <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order:
- * <pre>
- * {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}
- * </pre>
- * \par
- * <code>pState</code> points to the array of state variables.
- * <code>pState</code> is of length <code>numTaps+blockSize-1</code> words where <code>blockSize</code> is the number of input samples passed to <code>arm_fir_decimate_f32()</code>.
- * <code>M</code> is the decimation factor.
- */
-
- arm_status arm_fir_decimate_init_f32(
- arm_fir_decimate_instance_f32 * S,
- uint16_t numTaps,
- uint8_t M,
- float32_t * pCoeffs,
- float32_t * pState,
- uint32_t blockSize)
- {
- arm_status status;
-
- /* The size of the input block must be a multiple of the decimation factor */
- if((blockSize % M) != 0u)
- {
- /* Set status as ARM_MATH_LENGTH_ERROR */
- status = ARM_MATH_LENGTH_ERROR;
- }
- else
- {
- /* Assign filter taps */
- S->numTaps = numTaps;
-
- /* Assign coefficient pointer */
- S->pCoeffs = pCoeffs;
-
- /* Clear state buffer and size is always (blockSize + numTaps - 1) */
- memset(pState, 0, (numTaps + (blockSize - 1u)) * sizeof(float32_t));
-
- /* Assign state pointer */
- S->pState = pState;
-
- /* Assign Decimation Factor */
- S->M = M;
-
- status = ARM_MATH_SUCCESS;
- }
-
- return (status);
-
- }
-
- /**
- * @} end of FIR_decimate group
- */
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