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-rw-r--r--media/libwebp/dsp/quant.h70
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diff --git a/media/libwebp/dsp/quant.h b/media/libwebp/dsp/quant.h
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+++ b/media/libwebp/dsp/quant.h
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+// Copyright 2018 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING 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.
+// -----------------------------------------------------------------------------
+
+#ifndef WEBP_DSP_QUANT_H_
+#define WEBP_DSP_QUANT_H_
+
+#include "../dsp/dsp.h"
+#include "../webp/types.h"
+
+#if defined(WEBP_USE_NEON) && !defined(WEBP_ANDROID_NEON) && \
+ !defined(WEBP_HAVE_NEON_RTCD)
+#include <arm_neon.h>
+
+#define IsFlat IsFlat_NEON
+
+static uint32x2_t horizontal_add_uint32x4(const uint32x4_t a) {
+ const uint64x2_t b = vpaddlq_u32(a);
+ return vadd_u32(vreinterpret_u32_u64(vget_low_u64(b)),
+ vreinterpret_u32_u64(vget_high_u64(b)));
+}
+
+static WEBP_INLINE int IsFlat(const int16_t* levels, int num_blocks,
+ int thresh) {
+ const int16x8_t tst_ones = vdupq_n_s16(-1);
+ uint32x4_t sum = vdupq_n_u32(0);
+
+ for (int i = 0; i < num_blocks; ++i) {
+ // Set DC to zero.
+ const int16x8_t a_0 = vsetq_lane_s16(0, vld1q_s16(levels), 0);
+ const int16x8_t a_1 = vld1q_s16(levels + 8);
+
+ const uint16x8_t b_0 = vshrq_n_u16(vtstq_s16(a_0, tst_ones), 15);
+ const uint16x8_t b_1 = vshrq_n_u16(vtstq_s16(a_1, tst_ones), 15);
+
+ sum = vpadalq_u16(sum, b_0);
+ sum = vpadalq_u16(sum, b_1);
+
+ levels += 16;
+ }
+ return thresh >= (int32_t)vget_lane_u32(horizontal_add_uint32x4(sum), 0);
+}
+
+#else
+
+#define IsFlat IsFlat_C
+
+static WEBP_INLINE int IsFlat(const int16_t* levels, int num_blocks,
+ int thresh) {
+ int score = 0;
+ while (num_blocks-- > 0) { // TODO(skal): refine positional scoring?
+ int i;
+ for (i = 1; i < 16; ++i) { // omit DC, we're only interested in AC
+ score += (levels[i] != 0);
+ if (score > thresh) return 0;
+ }
+ levels += 16;
+ }
+ return 1;
+}
+
+#endif // defined(WEBP_USE_NEON) && !defined(WEBP_ANDROID_NEON) &&
+ // !defined(WEBP_HAVE_NEON_RTCD)
+
+#endif // WEBP_DSP_QUANT_H_