quant.h (2631B)
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 uint32_t horizontal_add_uint32x4(const uint32x4_t a) { 25 #if WEBP_AARCH64 26 return vaddvq_u32(a); 27 #else 28 const uint64x2_t b = vpaddlq_u32(a); 29 const uint32x2_t c = vadd_u32(vreinterpret_u32_u64(vget_low_u64(b)), 30 vreinterpret_u32_u64(vget_high_u64(b))); 31 return vget_lane_u32(c, 0); 32 #endif 33 } 34 35 static WEBP_INLINE int IsFlat(const int16_t* levels, int num_blocks, 36 int thresh) { 37 const int16x8_t tst_ones = vdupq_n_s16(-1); 38 uint32x4_t sum = vdupq_n_u32(0); 39 int i; 40 41 for (i = 0; i < num_blocks; ++i) { 42 // Set DC to zero. 43 const int16x8_t a_0 = vsetq_lane_s16(0, vld1q_s16(levels), 0); 44 const int16x8_t a_1 = vld1q_s16(levels + 8); 45 46 const uint16x8_t b_0 = vshrq_n_u16(vtstq_s16(a_0, tst_ones), 15); 47 const uint16x8_t b_1 = vshrq_n_u16(vtstq_s16(a_1, tst_ones), 15); 48 49 sum = vpadalq_u16(sum, b_0); 50 sum = vpadalq_u16(sum, b_1); 51 52 levels += 16; 53 } 54 return thresh >= (int)horizontal_add_uint32x4(sum); 55 } 56 57 #else 58 59 #define IsFlat IsFlat_C 60 61 static WEBP_INLINE int IsFlat(const int16_t* levels, int num_blocks, 62 int thresh) { 63 int score = 0; 64 while (num_blocks-- > 0) { // TODO(skal): refine positional scoring? 65 int i; 66 for (i = 1; i < 16; ++i) { // omit DC, we're only interested in AC 67 score += (levels[i] != 0); 68 if (score > thresh) return 0; 69 } 70 levels += 16; 71 } 72 return 1; 73 } 74 75 #endif // defined(WEBP_USE_NEON) && !defined(WEBP_ANDROID_NEON) && 76 // !defined(WEBP_HAVE_NEON_RTCD) 77 78 static WEBP_INLINE int IsFlatSource16(const uint8_t* src) { 79 const uint32_t v = src[0] * 0x01010101u; 80 int i; 81 for (i = 0; i < 16; ++i) { 82 if (memcmp(src + 0, &v, 4) || memcmp(src + 4, &v, 4) || 83 memcmp(src + 8, &v, 4) || memcmp(src + 12, &v, 4)) { 84 return 0; 85 } 86 src += BPS; 87 } 88 return 1; 89 } 90 91 #endif // WEBP_DSP_QUANT_H_