ref: 8ad9338e2e4297cebc234350c5ae0368c38f3a38
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). */ uint8_t temp[64 * 72]; // Account for the vertical phase needing 3 lines prior and 4 lines post const 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, w, 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 + w * 3, w, 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) { uint8_t temp[64 * 72]; const 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, w, filter_x, x_step_q4, filter_y, y_step_q4, w, intermediate_height); vpx_convolve8_avg_vert_neon(temp + w * 3, w, dst, dst_stride, filter_x, x_step_q4, filter_y, y_step_q4, w, h); }