| /* palette_neon_intrinsics.c - NEON optimised palette expansion functions |
| * |
| * Copyright (c) 2017 The Chromium Authors. All rights reserved. |
| * Written by Richard Townsend <Richard.Townsend@arm.com>, February 2017. |
| * |
| * This code is released under the libpng license. |
| * For conditions of distribution and use, see the disclaimer |
| * and license in png.h |
| */ |
| |
| #include "../pngpriv.h" |
| |
| #if PNG_ARM_NEON_IMPLEMENTATION == 1 |
| |
| #include <arm_neon.h> |
| |
| /* Build an RGBA palette from the RGB and separate alpha palettes. */ |
| void |
| png_riffle_palette_rgba(png_structrp png_ptr, png_row_infop row_info) |
| { |
| png_const_colorp palette = png_ptr->palette; |
| png_bytep riffled_palette = png_ptr->riffled_palette; |
| png_const_bytep trans_alpha = png_ptr->trans_alpha; |
| int num_trans = png_ptr->num_trans; |
| |
| if (row_info->bit_depth != 8) { |
| png_error(png_ptr, "bit_depth must be 8 for png_riffle_palette_rgba"); |
| return; |
| } |
| |
| /* Initially black, opaque. */ |
| uint8x16x4_t w = {{ |
| vdupq_n_u8(0x00), |
| vdupq_n_u8(0x00), |
| vdupq_n_u8(0x00), |
| vdupq_n_u8(0xff), |
| }}; |
| |
| int i; |
| /* First, riffle the RGB colours into a RGBA palette, the A value is |
| * set to opaque for now. */ |
| for (i = 0; i < (1 << row_info->bit_depth); i += 16) { |
| uint8x16x3_t v = vld3q_u8((png_const_bytep)(palette + i)); |
| w.val[0] = v.val[0]; |
| w.val[1] = v.val[1]; |
| w.val[2] = v.val[2]; |
| vst4q_u8(riffled_palette + (i << 2), w); |
| } |
| |
| /* Fix up the missing transparency values. */ |
| for (i = 0; i < num_trans; i++) { |
| riffled_palette[(i << 2) + 3] = trans_alpha[i]; |
| } |
| } |
| |
| |
| /* Expands a palettized row into RGBA. */ |
| int |
| png_do_expand_palette_neon_rgba(png_structrp png_ptr, png_row_infop row_info, |
| png_const_bytep row, const png_bytepp ssp, const png_bytepp ddp) |
| { |
| |
| png_uint_32 row_width = row_info->width; |
| const png_uint_32 *riffled_palette = (const png_uint_32*)png_ptr->riffled_palette; |
| const png_int_32 pixels_per_chunk = 4; |
| |
| if (row_width < pixels_per_chunk) { |
| return 0; |
| } |
| |
| /* This function originally gets the last byte of the output row. |
| The NEON part writes forward from a given position, so we have |
| to seek this back by 4 pixels x 4 bytes. */ |
| *ddp = *ddp - ((pixels_per_chunk * sizeof(png_uint_32)) - 1); |
| |
| int i; |
| for (i = 0; i < row_width; i += pixels_per_chunk) { |
| uint32x4_t cur; |
| png_bytep sp = *ssp - i, dp = *ddp - (i << 2); |
| cur = vld1q_dup_u32 (riffled_palette + *(sp - 3)); |
| cur = vld1q_lane_u32(riffled_palette + *(sp - 2), cur, 1); |
| cur = vld1q_lane_u32(riffled_palette + *(sp - 1), cur, 2); |
| cur = vld1q_lane_u32(riffled_palette + *(sp - 0), cur, 3); |
| vst1q_u32((void *)dp, cur); |
| } |
| if (i != row_width) { |
| i -= pixels_per_chunk; /* Remove the amount that wasn't processed. */ |
| } |
| |
| /* Decrement output pointers. */ |
| *ssp = *ssp - i; |
| *ddp = *ddp - (i << 2); |
| return i; |
| } |
| |
| /* Expands a palettized row into RGB format. */ |
| int |
| png_do_expand_palette_neon_rgb(png_structrp png_ptr, png_row_infop row_info, |
| png_const_bytep row, const png_bytepp ssp, const png_bytepp ddp) |
| { |
| png_uint_32 row_width = row_info->width; |
| png_const_bytep palette = (png_const_bytep)png_ptr->palette; |
| const png_uint_32 pixels_per_chunk = 8; |
| |
| if (row_width <= pixels_per_chunk) { |
| return 0; |
| } |
| |
| /* Seeking this back by 8 pixels x 3 bytes. */ |
| *ddp = *ddp - ((pixels_per_chunk * sizeof(png_color)) - 1); |
| |
| int i; |
| for (i = 0; i < row_width; i += pixels_per_chunk) { |
| uint8x8x3_t cur; |
| png_bytep sp = *ssp - i, dp = *ddp - ((i << 1) + i); |
| cur = vld3_dup_u8(palette + sizeof(png_color) * (*(sp - 7))); |
| cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 6)), cur, 1); |
| cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 5)), cur, 2); |
| cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 4)), cur, 3); |
| cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 3)), cur, 4); |
| cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 2)), cur, 5); |
| cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 1)), cur, 6); |
| cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 0)), cur, 7); |
| vst3_u8((void *)dp, cur); |
| } |
| |
| if (i != row_width) { |
| i -= pixels_per_chunk; /* Remove the amount that wasn't processed. */ |
| } |
| |
| /* Decrement output pointers. */ |
| *ssp = *ssp - i; |
| *ddp = *ddp - ((i << 1) + i); |
| return i; |
| } |
| |
| #endif /* PNG_ARM_NEON_IMPLEMENTATION */ |