mirror of
https://github.com/google/pebble.git
synced 2025-07-10 00:20:27 -04:00
Import of the watch repository from Pebble
This commit is contained in:
Matthieu Jeanson
Katharine Berry
commit
3b92768480
10334 changed files with 2564465 additions and 0 deletions
394
third_party/ARM/Source/TransformFunctions/arm_dct4_q15.c
vendored
Normal file
394
third_party/ARM/Source/TransformFunctions/arm_dct4_q15.c
vendored
Normal file
|
|
@ -0,0 +1,394 @@
|
|||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 19. March 2015
|
||||
* $Revision: V.1.4.5
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_dct4_q15.c
|
||||
*
|
||||
* Description: Processing function of DCT4 & IDCT4 Q15.
|
||||
*
|
||||
* 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"
|
||||
|
||||
/**
|
||||
* @addtogroup DCT4_IDCT4
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Processing function for the Q15 DCT4/IDCT4.
|
||||
* @param[in] *S points to an instance of the Q15 DCT4 structure.
|
||||
* @param[in] *pState points to state buffer.
|
||||
* @param[in,out] *pInlineBuffer points to the in-place input and output buffer.
|
||||
* @return none.
|
||||
*
|
||||
* \par Input an output formats:
|
||||
* Internally inputs are downscaled in the RFFT process function to avoid overflows.
|
||||
* Number of bits downscaled, depends on the size of the transform.
|
||||
* The input and output formats for different DCT sizes and number of bits to upscale are mentioned in the table below:
|
||||
*
|
||||
* \image html dct4FormatsQ15Table.gif
|
||||
*/
|
||||
|
||||
void arm_dct4_q15(
|
||||
const arm_dct4_instance_q15 * S,
|
||||
q15_t * pState,
|
||||
q15_t * pInlineBuffer)
|
||||
{
|
||||
uint32_t i; /* Loop counter */
|
||||
q15_t *weights = S->pTwiddle; /* Pointer to the Weights table */
|
||||
q15_t *cosFact = S->pCosFactor; /* Pointer to the cos factors table */
|
||||
q15_t *pS1, *pS2, *pbuff; /* Temporary pointers for input buffer and pState buffer */
|
||||
q15_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_mult_q15(pInlineBuffer, cosFact, pInlineBuffer, S->N);
|
||||
arm_shift_q15(pInlineBuffer, 1, 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;
|
||||
|
||||
|
||||
#ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
/* 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_q15(S->pRfft, pInlineBuffer, pState);
|
||||
|
||||
/*----------------------------------------------------------------------
|
||||
* Step3: Multiply the FFT output with the weights.
|
||||
*----------------------------------------------------------------------*/
|
||||
arm_cmplx_mult_cmplx_q15(pState, weights, pState, S->N);
|
||||
|
||||
/* The output of complex multiplication is in 3.13 format.
|
||||
* Hence changing the format of N (i.e. 2*N elements) complex numbers to 1.15 format by shifting left by 2 bits. */
|
||||
arm_shift_q15(pState, 2, pState, S->N * 2);
|
||||
|
||||
/* ----------- 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++ >> 1u;
|
||||
/* 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++ = ((q15_t) (((q31_t) in * S->normalize) >> 15));
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q15_t) (((q31_t) in * S->normalize) >> 15));
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q15_t) (((q31_t) in * S->normalize) >> 15));
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q15_t) (((q31_t) in * S->normalize) >> 15));
|
||||
|
||||
/* 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_q15(S->pRfft, pInlineBuffer, pState);
|
||||
|
||||
/*----------------------------------------------------------------------
|
||||
* Step3: Multiply the FFT output with the weights.
|
||||
*----------------------------------------------------------------------*/
|
||||
arm_cmplx_mult_cmplx_q15(pState, weights, pState, S->N);
|
||||
|
||||
/* The output of complex multiplication is in 3.13 format.
|
||||
* Hence changing the format of N (i.e. 2*N elements) complex numbers to 1.15 format by shifting left by 2 bits. */
|
||||
arm_shift_q15(pState, 2, pState, S->N * 2);
|
||||
|
||||
/* ----------- 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 */
|
||||
i = ((uint32_t) S->N - 1u);
|
||||
|
||||
/* 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++ >> 1u;
|
||||
/* 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++;
|
||||
|
||||
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++ = ((q15_t) (((q31_t) in * S->normalize) >> 15));
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
#endif /* #ifndef ARM_MATH_CM0_FAMILY */
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of DCT4_IDCT4 group
|
||||
*/
|
||||
Loading…
Add table
Add a link
Reference in a new issue