summaryrefslogtreecommitdiff
path: root/simd/arm/common/jcsample-neon.c
diff options
context:
space:
mode:
Diffstat (limited to 'simd/arm/common/jcsample-neon.c')
-rw-r--r--simd/arm/common/jcsample-neon.c191
1 files changed, 191 insertions, 0 deletions
diff --git a/simd/arm/common/jcsample-neon.c b/simd/arm/common/jcsample-neon.c
new file mode 100644
index 0000000..a5ddf16
--- /dev/null
+++ b/simd/arm/common/jcsample-neon.c
@@ -0,0 +1,191 @@
+/*
+ * jcsample-neon.c - downsampling (Arm NEON)
+ *
+ * Copyright 2020 The Chromium Authors. All Rights Reserved.
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ * claim that you wrote the original software. If you use this software
+ * in a product, an acknowledgment in the product documentation would be
+ * appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ * misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ */
+
+#define JPEG_INTERNALS
+#include "../../../jconfigint.h"
+#include "../../../jinclude.h"
+#include "../../../jpeglib.h"
+#include "../../../jsimd.h"
+#include "../../../jdct.h"
+#include "../../../jsimddct.h"
+#include "../../jsimd.h"
+
+#include <arm_neon.h>
+
+
+ALIGN(16) static const uint8_t jsimd_h2_downsample_consts[] = {
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 0 */
+ 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 1 */
+ 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0E,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 2 */
+ 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0D, 0x0D,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 3 */
+ 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0C, 0x0C, 0x0C,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 4 */
+ 0x08, 0x09, 0x0A, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 5 */
+ 0x08, 0x09, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 6 */
+ 0x08, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 7 */
+ 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 8 */
+ 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x06, /* Pad 9 */
+ 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x05, 0x05, /* Pad 10 */
+ 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x04, 0x04, 0x04, /* Pad 11 */
+ 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
+ 0x00, 0x01, 0x02, 0x03, 0x03, 0x03, 0x03, 0x03, /* Pad 12 */
+ 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
+ 0x00, 0x01, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, /* Pad 13 */
+ 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
+ 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, /* Pad 14 */
+ 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* Pad 15 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+
+/*
+ * Downsample pixel values of a single chroma component i.e. Cb, Cr.
+ * This version handles the common case of 2:1 horizontal and 1:1 vertical,
+ * without smoothing.
+ */
+
+void jsimd_h2v1_downsample_neon(JDIMENSION image_width,
+ int max_v_samp_factor,
+ JDIMENSION v_samp_factor,
+ JDIMENSION width_in_blocks,
+ JSAMPARRAY input_data,
+ JSAMPARRAY output_data)
+{
+ JSAMPROW inptr, outptr;
+ /* Load expansion mask to pad remaining elements of last DCT block. */
+ const int mask_offset = 16 * ((width_in_blocks * 2 * DCTSIZE) - image_width);
+ const uint8x16_t expand_mask = vld1q_u8(
+ &jsimd_h2_downsample_consts[mask_offset]);
+ /* Load bias pattern alternating every pixel. */
+ const uint16x8_t bias = { 0, 1, 0, 1, 0, 1, 0, 1 };
+
+ for (unsigned outrow = 0; outrow < v_samp_factor; outrow++) {
+ outptr = output_data[outrow];
+ inptr = input_data[outrow];
+
+ /* Downsample all but the last DCT block of pixels. */
+ for (unsigned i = 0; i < width_in_blocks - 1; i++) {
+ uint8x16_t pixels = vld1q_u8(inptr + i * 2 * DCTSIZE);
+ /* Add adjacent pixel values, widen to 16-bit and add bias. */
+ uint16x8_t samples_u16 = vpadalq_u8(bias, pixels);
+ /* Divide total by 2 and narrow to 8-bit. */
+ uint8x8_t samples_u8 = vshrn_n_u16(samples_u16, 1);
+ /* Store samples to memory. */
+ vst1_u8(outptr + i * DCTSIZE, samples_u8);
+ }
+
+ /* Load pixels in last DCT block into a table. */
+ uint8x16_t pixels = vld1q_u8(inptr + (width_in_blocks - 1) * 2 * DCTSIZE);
+#if defined(__aarch64__)
+ /* Pad the empty elements with the value of the last pixel. */
+ pixels = vqtbl1q_u8(pixels, expand_mask);
+#else
+ uint8x8x2_t table = { vget_low_u8(pixels), vget_high_u8(pixels) };
+ pixels = vcombine_u8(vtbl2_u8(table, vget_low_u8(expand_mask)),
+ vtbl2_u8(table, vget_high_u8(expand_mask)));
+#endif
+ /* Add adjacent pixel values, widen to 16-bit and add bias. */
+ uint16x8_t samples_u16 = vpadalq_u8(bias, pixels);
+ /* Divide total by 2, narrow to 8-bit and store. */
+ uint8x8_t samples_u8 = vshrn_n_u16(samples_u16, 1);
+ vst1_u8(outptr + (width_in_blocks - 1) * DCTSIZE, samples_u8);
+ }
+}
+
+
+/*
+ * Downsample pixel values of a single chroma component i.e. Cb, Cr.
+ * This version handles the standard case of 2:1 horizontal and 2:1 vertical,
+ * without smoothing.
+ */
+
+void jsimd_h2v2_downsample_neon(JDIMENSION image_width,
+ int max_v_samp_factor,
+ JDIMENSION v_samp_factor,
+ JDIMENSION width_in_blocks,
+ JSAMPARRAY input_data,
+ JSAMPARRAY output_data)
+{
+ JSAMPROW inptr0, inptr1, outptr;
+ /* Load expansion mask to pad remaining elements of last DCT block. */
+ const int mask_offset = 16 * ((width_in_blocks * 2 * DCTSIZE) - image_width);
+ const uint8x16_t expand_mask = vld1q_u8(
+ &jsimd_h2_downsample_consts[mask_offset]);
+ /* Load bias pattern alternating every pixel. */
+ const uint16x8_t bias = { 1, 2, 1, 2, 1, 2, 1, 2 };
+
+ for (unsigned outrow = 0; outrow < v_samp_factor; outrow++) {
+ outptr = output_data[outrow];
+ inptr0 = input_data[outrow];
+ inptr1 = input_data[outrow + 1];
+
+ /* Downsample all but the last DCT block of pixels. */
+ for (unsigned i = 0; i < width_in_blocks - 1; i++) {
+ uint8x16_t pixels_r0 = vld1q_u8(inptr0 + i * 2 * DCTSIZE);
+ uint8x16_t pixels_r1 = vld1q_u8(inptr1 + i * 2 * DCTSIZE);
+ /* Add adjacent pixel values in row 0, widen to 16-bit and add bias. */
+ uint16x8_t samples_u16 = vpadalq_u8(bias, pixels_r0);
+ /* Add adjacent pixel values in row 1, widen to 16-bit and accumulate. */
+ samples_u16 = vpadalq_u8(samples_u16, pixels_r1);
+ /* Divide total by 4 and narrow to 8-bit. */
+ uint8x8_t samples_u8 = vshrn_n_u16(samples_u16, 2);
+ /* Store samples to memory and increment pointers. */
+ vst1_u8(outptr + i * DCTSIZE, samples_u8);
+ }
+
+ /* Load pixels in last DCT block into a table. */
+ uint8x16_t pixels_r0 = vld1q_u8(
+ inptr0 + (width_in_blocks - 1) * 2 * DCTSIZE);
+ uint8x16_t pixels_r1 = vld1q_u8(
+ inptr1 + (width_in_blocks - 1) * 2 * DCTSIZE);
+#if defined(__aarch64__)
+ /* Pad the empty elements with the value of the last pixel. */
+ pixels_r0 = vqtbl1q_u8(pixels_r0, expand_mask);
+ pixels_r1 = vqtbl1q_u8(pixels_r1, expand_mask);
+#else
+ uint8x8x2_t table_r0 = { vget_low_u8(pixels_r0), vget_high_u8(pixels_r0) };
+ uint8x8x2_t table_r1 = { vget_low_u8(pixels_r1), vget_high_u8(pixels_r1) };
+ pixels_r0 = vcombine_u8(vtbl2_u8(table_r0, vget_low_u8(expand_mask)),
+ vtbl2_u8(table_r0, vget_high_u8(expand_mask)));
+ pixels_r1 = vcombine_u8(vtbl2_u8(table_r1, vget_low_u8(expand_mask)),
+ vtbl2_u8(table_r1, vget_high_u8(expand_mask)));
+#endif
+ /* Add adjacent pixel values in row 0, widen to 16-bit and add bias. */
+ uint16x8_t samples_u16 = vpadalq_u8(bias, pixels_r0);
+ /* Add adjacent pixel values in row 1, widen to 16-bit and accumulate. */
+ samples_u16 = vpadalq_u8(samples_u16, pixels_r1);
+ /* Divide total by 4, narrow to 8-bit and store. */
+ uint8x8_t samples_u8 = vshrn_n_u16(samples_u16, 2);
+ vst1_u8(outptr + (width_in_blocks - 1) * DCTSIZE, samples_u8);
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-03 08:15:08 +0000