1 | // Copyright 2018 Google Inc. All Rights Reserved. |
2 | // |
3 | // Use of this source code is governed by a BSD-style license |
4 | // that can be found in the COPYING file in the root of the source |
5 | // tree. An additional intellectual property rights grant can be found |
6 | // in the file PATENTS. All contributing project authors may |
7 | // be found in the AUTHORS file in the root of the source tree. |
8 | // ----------------------------------------------------------------------------- |
9 | |
10 | #ifndef WEBP_DSP_QUANT_H_ |
11 | #define WEBP_DSP_QUANT_H_ |
12 | |
13 | #include <string.h> |
14 | |
15 | #include "src/dsp/dsp.h" |
16 | #include "src/webp/types.h" |
17 | |
18 | #if defined(WEBP_USE_NEON) && !defined(WEBP_ANDROID_NEON) && \ |
19 | !defined(WEBP_HAVE_NEON_RTCD) |
20 | #include <arm_neon.h> |
21 | |
22 | #define IsFlat IsFlat_NEON |
23 | |
24 | static uint32x2_t horizontal_add_uint32x4(const uint32x4_t a) { |
25 | const uint64x2_t b = vpaddlq_u32(a); |
26 | return vadd_u32(vreinterpret_u32_u64(vget_low_u64(b)), |
27 | vreinterpret_u32_u64(vget_high_u64(b))); |
28 | } |
29 | |
30 | static WEBP_INLINE int IsFlat(const int16_t* levels, int num_blocks, |
31 | int thresh) { |
32 | const int16x8_t tst_ones = vdupq_n_s16(-1); |
33 | uint32x4_t sum = vdupq_n_u32(0); |
34 | |
35 | for (int i = 0; i < num_blocks; ++i) { |
36 | // Set DC to zero. |
37 | const int16x8_t a_0 = vsetq_lane_s16(0, vld1q_s16(levels), 0); |
38 | const int16x8_t a_1 = vld1q_s16(levels + 8); |
39 | |
40 | const uint16x8_t b_0 = vshrq_n_u16(vtstq_s16(a_0, tst_ones), 15); |
41 | const uint16x8_t b_1 = vshrq_n_u16(vtstq_s16(a_1, tst_ones), 15); |
42 | |
43 | sum = vpadalq_u16(sum, b_0); |
44 | sum = vpadalq_u16(sum, b_1); |
45 | |
46 | levels += 16; |
47 | } |
48 | return thresh >= (int32_t)vget_lane_u32(horizontal_add_uint32x4(sum), 0); |
49 | } |
50 | |
51 | #else |
52 | |
53 | #define IsFlat IsFlat_C |
54 | |
55 | static WEBP_INLINE int IsFlat(const int16_t* levels, int num_blocks, |
56 | int thresh) { |
57 | int score = 0; |
58 | while (num_blocks-- > 0) { // TODO(skal): refine positional scoring? |
59 | int i; |
60 | for (i = 1; i < 16; ++i) { // omit DC, we're only interested in AC |
61 | score += (levels[i] != 0); |
62 | if (score > thresh) return 0; |
63 | } |
64 | levels += 16; |
65 | } |
66 | return 1; |
67 | } |
68 | |
69 | #endif // defined(WEBP_USE_NEON) && !defined(WEBP_ANDROID_NEON) && |
70 | // !defined(WEBP_HAVE_NEON_RTCD) |
71 | |
72 | static WEBP_INLINE int IsFlatSource16(const uint8_t* src) { |
73 | const uint32_t v = src[0] * 0x01010101u; |
74 | int i; |
75 | for (i = 0; i < 16; ++i) { |
76 | if (memcmp(src + 0, &v, 4) || memcmp(src + 4, &v, 4) || |
77 | memcmp(src + 8, &v, 4) || memcmp(src + 12, &v, 4)) { |
78 | return 0; |
79 | } |
80 | src += BPS; |
81 | } |
82 | return 1; |
83 | } |
84 | |
85 | #endif // WEBP_DSP_QUANT_H_ |
86 | |