ref: 5de049b0677eb4f2f0e9d4c4b4f0bd82d6ed17cd
dir: /vpx_dsp/arm/vpx_convolve_neon.c/
/*
* Copyright (c) 2013 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include <assert.h>
#include "./vpx_dsp_rtcd.h"
#include "vpx_dsp/vpx_dsp_common.h"
#include "vpx_ports/mem.h"
void vpx_convolve8_neon(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const int16_t *filter_x, int x_step_q4,
const int16_t *filter_y, int y_step_q4,
int w, int h) {
/* Given our constraints: w <= 64, h <= 64, taps == 8 we can reduce the
* maximum buffer size to 64 * 64 + 7 (+ 1 to make it divisible by 4).
*/
DECLARE_ALIGNED(8, uint8_t, temp[64 * 72]);
// Account for the vertical phase needing 3 lines prior and 4 lines post
int intermediate_height = h + 7;
assert(y_step_q4 == 16);
assert(x_step_q4 == 16);
/* Filter starting 3 lines back. The neon implementation will ignore the
* given height and filter a multiple of 4 lines. Since this goes in to
* the temp buffer which has lots of extra room and is subsequently discarded
* this is safe if somewhat less than ideal.
*/
vpx_convolve8_horiz_neon(src - src_stride * 3, src_stride,
temp, 64,
filter_x, x_step_q4, filter_y, y_step_q4,
w, intermediate_height);
/* Step into the temp buffer 3 lines to get the actual frame data */
vpx_convolve8_vert_neon(temp + 64 * 3, 64,
dst, dst_stride,
filter_x, x_step_q4, filter_y, y_step_q4,
w, h);
}
void vpx_convolve8_avg_neon(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const int16_t *filter_x, int x_step_q4,
const int16_t *filter_y, int y_step_q4,
int w, int h) {
DECLARE_ALIGNED(8, uint8_t, temp[64 * 72]);
int intermediate_height = h + 7;
assert(y_step_q4 == 16);
assert(x_step_q4 == 16);
/* This implementation has the same issues as above. In addition, we only want
* to average the values after both passes.
*/
vpx_convolve8_horiz_neon(src - src_stride * 3, src_stride,
temp, 64,
filter_x, x_step_q4, filter_y, y_step_q4,
w, intermediate_height);
vpx_convolve8_avg_vert_neon(temp + 64 * 3,
64, dst, dst_stride,
filter_x, x_step_q4, filter_y, y_step_q4,
w, h);
}