diff options
Diffstat (limited to 'hid-dials/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_dct4_f32.c')
| -rw-r--r-- | hid-dials/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_dct4_f32.c | 449 |
1 files changed, 0 insertions, 449 deletions
diff --git a/hid-dials/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_dct4_f32.c b/hid-dials/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_dct4_f32.c deleted file mode 100644 index ccb3c52..0000000 --- a/hid-dials/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_dct4_f32.c +++ /dev/null @@ -1,449 +0,0 @@ -/* ----------------------------------------------------------------------
- * Project: CMSIS DSP Library
- * Title: arm_dct4_f32.c
- * Description: Processing function of DCT4 & IDCT4 F32
- *
- * $Date: 27. January 2017
- * $Revision: V.1.5.1
- *
- * Target Processor: Cortex-M cores
- * -------------------------------------------------------------------- */
-/*
- * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Licensed under the Apache License, Version 2.0 (the License); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an AS IS BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "arm_math.h"
-
-/**
- * @ingroup groupTransforms
- */
-
-/**
- * @defgroup DCT4_IDCT4 DCT Type IV Functions
- * Representation of signals by minimum number of values is important for storage and transmission.
- * The possibility of large discontinuity between the beginning and end of a period of a signal
- * in DFT can be avoided by extending the signal so that it is even-symmetric.
- * Discrete Cosine Transform (DCT) is constructed such that its energy is heavily concentrated in the lower part of the
- * spectrum and is very widely used in signal and image coding applications.
- * The family of DCTs (DCT type- 1,2,3,4) is the outcome of different combinations of homogeneous boundary conditions.
- * DCT has an excellent energy-packing capability, hence has many applications and in data compression in particular.
- *
- * DCT is essentially the Discrete Fourier Transform(DFT) of an even-extended real signal.
- * Reordering of the input data makes the computation of DCT just a problem of
- * computing the DFT of a real signal with a few additional operations.
- * This approach provides regular, simple, and very efficient DCT algorithms for practical hardware and software implementations.
- *
- * DCT type-II can be implemented using Fast fourier transform (FFT) internally, as the transform is applied on real values, Real FFT can be used.
- * DCT4 is implemented using DCT2 as their implementations are similar except with some added pre-processing and post-processing.
- * DCT2 implementation can be described in the following steps:
- * - Re-ordering input
- * - Calculating Real FFT
- * - Multiplication of weights and Real FFT output and getting real part from the product.
- *
- * This process is explained by the block diagram below:
- * \image html DCT4.gif "Discrete Cosine Transform - type-IV"
- *
- * \par Algorithm:
- * The N-point type-IV DCT is defined as a real, linear transformation by the formula:
- * \image html DCT4Equation.gif
- * where <code>k = 0,1,2,.....N-1</code>
- *\par
- * Its inverse is defined as follows:
- * \image html IDCT4Equation.gif
- * where <code>n = 0,1,2,.....N-1</code>
- *\par
- * The DCT4 matrices become involutory (i.e. they are self-inverse) by multiplying with an overall scale factor of sqrt(2/N).
- * The symmetry of the transform matrix indicates that the fast algorithms for the forward
- * and inverse transform computation are identical.
- * Note that the implementation of Inverse DCT4 and DCT4 is same, hence same process function can be used for both.
- *
- * \par Lengths supported by the transform:
- * As DCT4 internally uses Real FFT, it supports all the lengths 128, 512, 2048 and 8192.
- * The library provides separate functions for Q15, Q31, and floating-point data types.
- * \par Instance Structure
- * The instances for Real FFT and FFT, cosine values table and twiddle factor table are stored in an instance data structure.
- * A separate instance structure must be defined for each transform.
- * There are separate instance structure declarations for each of the 3 supported data types.
- *
- * \par Initialization Functions
- * There is also an associated initialization function for each data type.
- * The initialization function performs the following operations:
- * - Sets the values of the internal structure fields.
- * - Initializes Real FFT as its process function is used internally in DCT4, by calling arm_rfft_init_f32().
- * \par
- * Use of the initialization function is optional.
- * However, if the initialization function is used, then the instance structure cannot be placed into a const data section.
- * To place an instance structure into a const data section, the instance structure must be manually initialized.
- * Manually initialize the instance structure as follows:
- * <pre>
- *arm_dct4_instance_f32 S = {N, Nby2, normalize, pTwiddle, pCosFactor, pRfft, pCfft};
- *arm_dct4_instance_q31 S = {N, Nby2, normalize, pTwiddle, pCosFactor, pRfft, pCfft};
- *arm_dct4_instance_q15 S = {N, Nby2, normalize, pTwiddle, pCosFactor, pRfft, pCfft};
- * </pre>
- * where \c N is the length of the DCT4; \c Nby2 is half of the length of the DCT4;
- * \c normalize is normalizing factor used and is equal to <code>sqrt(2/N)</code>;
- * \c pTwiddle points to the twiddle factor table;
- * \c pCosFactor points to the cosFactor table;
- * \c pRfft points to the real FFT instance;
- * \c pCfft points to the complex FFT instance;
- * The CFFT and RFFT structures also needs to be initialized, refer to arm_cfft_radix4_f32()
- * and arm_rfft_f32() respectively for details regarding static initialization.
- *
- * \par Fixed-Point Behavior
- * Care must be taken when using the fixed-point versions of the DCT4 transform functions.
- * In particular, the overflow and saturation behavior of the accumulator used in each function must be considered.
- * Refer to the function specific documentation below for usage guidelines.
- */
-
- /**
- * @addtogroup DCT4_IDCT4
- * @{
- */
-
-/**
- * @brief Processing function for the floating-point DCT4/IDCT4.
- * @param[in] *S points to an instance of the floating-point DCT4/IDCT4 structure.
- * @param[in] *pState points to state buffer.
- * @param[in,out] *pInlineBuffer points to the in-place input and output buffer.
- * @return none.
- */
-
-void arm_dct4_f32(
- const arm_dct4_instance_f32 * S,
- float32_t * pState,
- float32_t * pInlineBuffer)
-{
- uint32_t i; /* Loop counter */
- float32_t *weights = S->pTwiddle; /* Pointer to the Weights table */
- float32_t *cosFact = S->pCosFactor; /* Pointer to the cos factors table */
- float32_t *pS1, *pS2, *pbuff; /* Temporary pointers for input buffer and pState buffer */
- float32_t in; /* Temporary variable */
-
-
- /* DCT4 computation involves DCT2 (which is calculated using RFFT)
- * along with some pre-processing and post-processing.
- * Computational procedure is explained as follows:
- * (a) Pre-processing involves multiplying input with cos factor,
- * r(n) = 2 * u(n) * cos(pi*(2*n+1)/(4*n))
- * where,
- * r(n) -- output of preprocessing
- * u(n) -- input to preprocessing(actual Source buffer)
- * (b) Calculation of DCT2 using FFT is divided into three steps:
- * Step1: Re-ordering of even and odd elements of input.
- * Step2: Calculating FFT of the re-ordered input.
- * Step3: Taking the real part of the product of FFT output and weights.
- * (c) Post-processing - DCT4 can be obtained from DCT2 output using the following equation:
- * Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
- * where,
- * Y4 -- DCT4 output, Y2 -- DCT2 output
- * (d) Multiplying the output with the normalizing factor sqrt(2/N).
- */
-
- /*-------- Pre-processing ------------*/
- /* Multiplying input with cos factor i.e. r(n) = 2 * x(n) * cos(pi*(2*n+1)/(4*n)) */
- arm_scale_f32(pInlineBuffer, 2.0f, pInlineBuffer, S->N);
- arm_mult_f32(pInlineBuffer, cosFact, pInlineBuffer, S->N);
-
- /* ----------------------------------------------------------------
- * Step1: Re-ordering of even and odd elements as,
- * pState[i] = pInlineBuffer[2*i] and
- * pState[N-i-1] = pInlineBuffer[2*i+1] where i = 0 to N/2
- ---------------------------------------------------------------------*/
-
- /* pS1 initialized to pState */
- pS1 = pState;
-
- /* pS2 initialized to pState+N-1, so that it points to the end of the state buffer */
- pS2 = pState + (S->N - 1U);
-
- /* pbuff initialized to input buffer */
- pbuff = pInlineBuffer;
-
-#if defined (ARM_MATH_DSP)
-
- /* Run the below code for Cortex-M4 and Cortex-M3 */
-
- /* Initializing the loop counter to N/2 >> 2 for loop unrolling by 4 */
- i = (uint32_t) S->Nby2 >> 2U;
-
- /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
- ** a second loop below computes the remaining 1 to 3 samples. */
- do
- {
- /* Re-ordering of even and odd elements */
- /* pState[i] = pInlineBuffer[2*i] */
- *pS1++ = *pbuff++;
- /* pState[N-i-1] = pInlineBuffer[2*i+1] */
- *pS2-- = *pbuff++;
-
- *pS1++ = *pbuff++;
- *pS2-- = *pbuff++;
-
- *pS1++ = *pbuff++;
- *pS2-- = *pbuff++;
-
- *pS1++ = *pbuff++;
- *pS2-- = *pbuff++;
-
- /* Decrement the loop counter */
- i--;
- } while (i > 0U);
-
- /* pbuff initialized to input buffer */
- pbuff = pInlineBuffer;
-
- /* pS1 initialized to pState */
- pS1 = pState;
-
- /* Initializing the loop counter to N/4 instead of N for loop unrolling */
- i = (uint32_t) S->N >> 2U;
-
- /* Processing with loop unrolling 4 times as N is always multiple of 4.
- * Compute 4 outputs at a time */
- do
- {
- /* Writing the re-ordered output back to inplace input buffer */
- *pbuff++ = *pS1++;
- *pbuff++ = *pS1++;
- *pbuff++ = *pS1++;
- *pbuff++ = *pS1++;
-
- /* Decrement the loop counter */
- i--;
- } while (i > 0U);
-
-
- /* ---------------------------------------------------------
- * Step2: Calculate RFFT for N-point input
- * ---------------------------------------------------------- */
- /* pInlineBuffer is real input of length N , pState is the complex output of length 2N */
- arm_rfft_f32(S->pRfft, pInlineBuffer, pState);
-
- /*----------------------------------------------------------------------
- * Step3: Multiply the FFT output with the weights.
- *----------------------------------------------------------------------*/
- arm_cmplx_mult_cmplx_f32(pState, weights, pState, S->N);
-
- /* ----------- Post-processing ---------- */
- /* DCT-IV can be obtained from DCT-II by the equation,
- * Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
- * Hence, Y4(0) = Y2(0)/2 */
- /* Getting only real part from the output and Converting to DCT-IV */
-
- /* Initializing the loop counter to N >> 2 for loop unrolling by 4 */
- i = ((uint32_t) S->N - 1U) >> 2U;
-
- /* pbuff initialized to input buffer. */
- pbuff = pInlineBuffer;
-
- /* pS1 initialized to pState */
- pS1 = pState;
-
- /* Calculating Y4(0) from Y2(0) using Y4(0) = Y2(0)/2 */
- in = *pS1++ * (float32_t) 0.5;
- /* input buffer acts as inplace, so output values are stored in the input itself. */
- *pbuff++ = in;
-
- /* pState pointer is incremented twice as the real values are located alternatively in the array */
- pS1++;
-
- /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
- ** a second loop below computes the remaining 1 to 3 samples. */
- do
- {
- /* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
- /* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
- in = *pS1++ - in;
- *pbuff++ = in;
- /* points to the next real value */
- pS1++;
-
- in = *pS1++ - in;
- *pbuff++ = in;
- pS1++;
-
- in = *pS1++ - in;
- *pbuff++ = in;
- pS1++;
-
- in = *pS1++ - in;
- *pbuff++ = in;
- pS1++;
-
- /* Decrement the loop counter */
- i--;
- } while (i > 0U);
-
- /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
- ** No loop unrolling is used. */
- i = ((uint32_t) S->N - 1U) % 0x4U;
-
- while (i > 0U)
- {
- /* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
- /* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
- in = *pS1++ - in;
- *pbuff++ = in;
- /* points to the next real value */
- pS1++;
-
- /* Decrement the loop counter */
- i--;
- }
-
-
- /*------------ Normalizing the output by multiplying with the normalizing factor ----------*/
-
- /* Initializing the loop counter to N/4 instead of N for loop unrolling */
- i = (uint32_t) S->N >> 2U;
-
- /* pbuff initialized to the pInlineBuffer(now contains the output values) */
- pbuff = pInlineBuffer;
-
- /* Processing with loop unrolling 4 times as N is always multiple of 4. Compute 4 outputs at a time */
- do
- {
- /* Multiplying pInlineBuffer with the normalizing factor sqrt(2/N) */
- in = *pbuff;
- *pbuff++ = in * S->normalize;
-
- in = *pbuff;
- *pbuff++ = in * S->normalize;
-
- in = *pbuff;
- *pbuff++ = in * S->normalize;
-
- in = *pbuff;
- *pbuff++ = in * S->normalize;
-
- /* Decrement the loop counter */
- i--;
- } while (i > 0U);
-
-
-#else
-
- /* Run the below code for Cortex-M0 */
-
- /* Initializing the loop counter to N/2 */
- i = (uint32_t) S->Nby2;
-
- do
- {
- /* Re-ordering of even and odd elements */
- /* pState[i] = pInlineBuffer[2*i] */
- *pS1++ = *pbuff++;
- /* pState[N-i-1] = pInlineBuffer[2*i+1] */
- *pS2-- = *pbuff++;
-
- /* Decrement the loop counter */
- i--;
- } while (i > 0U);
-
- /* pbuff initialized to input buffer */
- pbuff = pInlineBuffer;
-
- /* pS1 initialized to pState */
- pS1 = pState;
-
- /* Initializing the loop counter */
- i = (uint32_t) S->N;
-
- do
- {
- /* Writing the re-ordered output back to inplace input buffer */
- *pbuff++ = *pS1++;
-
- /* Decrement the loop counter */
- i--;
- } while (i > 0U);
-
-
- /* ---------------------------------------------------------
- * Step2: Calculate RFFT for N-point input
- * ---------------------------------------------------------- */
- /* pInlineBuffer is real input of length N , pState is the complex output of length 2N */
- arm_rfft_f32(S->pRfft, pInlineBuffer, pState);
-
- /*----------------------------------------------------------------------
- * Step3: Multiply the FFT output with the weights.
- *----------------------------------------------------------------------*/
- arm_cmplx_mult_cmplx_f32(pState, weights, pState, S->N);
-
- /* ----------- Post-processing ---------- */
- /* DCT-IV can be obtained from DCT-II by the equation,
- * Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
- * Hence, Y4(0) = Y2(0)/2 */
- /* Getting only real part from the output and Converting to DCT-IV */
-
- /* pbuff initialized to input buffer. */
- pbuff = pInlineBuffer;
-
- /* pS1 initialized to pState */
- pS1 = pState;
-
- /* Calculating Y4(0) from Y2(0) using Y4(0) = Y2(0)/2 */
- in = *pS1++ * (float32_t) 0.5;
- /* input buffer acts as inplace, so output values are stored in the input itself. */
- *pbuff++ = in;
-
- /* pState pointer is incremented twice as the real values are located alternatively in the array */
- pS1++;
-
- /* Initializing the loop counter */
- i = ((uint32_t) S->N - 1U);
-
- do
- {
- /* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
- /* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
- in = *pS1++ - in;
- *pbuff++ = in;
- /* points to the next real value */
- pS1++;
-
-
- /* Decrement the loop counter */
- i--;
- } while (i > 0U);
-
-
- /*------------ Normalizing the output by multiplying with the normalizing factor ----------*/
-
- /* Initializing the loop counter */
- i = (uint32_t) S->N;
-
- /* pbuff initialized to the pInlineBuffer(now contains the output values) */
- pbuff = pInlineBuffer;
-
- do
- {
- /* Multiplying pInlineBuffer with the normalizing factor sqrt(2/N) */
- in = *pbuff;
- *pbuff++ = in * S->normalize;
-
- /* Decrement the loop counter */
- i--;
- } while (i > 0U);
-
-#endif /* #if defined (ARM_MATH_DSP) */
-
-}
-
-/**
- * @} end of DCT4_IDCT4 group
- */
|