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1 /*
2  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #include "webrtc/modules/video_processing/content_analysis.h"
12 
13 #include <emmintrin.h>
14 #include <math.h>
15 
16 namespace webrtc {
17 
TemporalDiffMetric_SSE2()18 int32_t VPMContentAnalysis::TemporalDiffMetric_SSE2() {
19   uint32_t num_pixels = 0;  // counter for # of pixels
20   const uint8_t* imgBufO = orig_frame_ + border_ * width_ + border_;
21   const uint8_t* imgBufP = prev_frame_ + border_ * width_ + border_;
22 
23   const int32_t width_end = ((width_ - 2 * border_) & -16) + border_;
24 
25   __m128i sad_64 = _mm_setzero_si128();
26   __m128i sum_64 = _mm_setzero_si128();
27   __m128i sqsum_64 = _mm_setzero_si128();
28   const __m128i z = _mm_setzero_si128();
29 
30   for (uint16_t i = 0; i < (height_ - 2 * border_); i += skip_num_) {
31     __m128i sqsum_32 = _mm_setzero_si128();
32 
33     const uint8_t* lineO = imgBufO;
34     const uint8_t* lineP = imgBufP;
35 
36     // Work on 16 pixels at a time.  For HD content with a width of 1920
37     // this loop will run ~67 times (depending on border).  Maximum for
38     // abs(o-p) and sum(o) will be 255. _mm_sad_epu8 produces 2 64 bit
39     // results which are then accumulated.  There is no chance of
40     // rollover for these two accumulators.
41     // o*o will have a maximum of 255*255 = 65025.  This will roll over
42     // a 16 bit accumulator as 67*65025 > 65535, but will fit in a
43     // 32 bit accumulator.
44     for (uint16_t j = 0; j < width_end - border_; j += 16) {
45       const __m128i o = _mm_loadu_si128((__m128i*)(lineO));
46       const __m128i p = _mm_loadu_si128((__m128i*)(lineP));
47 
48       lineO += 16;
49       lineP += 16;
50 
51       // Abs pixel difference between frames.
52       sad_64 = _mm_add_epi64(sad_64, _mm_sad_epu8(o, p));
53 
54       // sum of all pixels in frame
55       sum_64 = _mm_add_epi64(sum_64, _mm_sad_epu8(o, z));
56 
57       // Squared sum of all pixels in frame.
58       const __m128i olo = _mm_unpacklo_epi8(o, z);
59       const __m128i ohi = _mm_unpackhi_epi8(o, z);
60 
61       const __m128i sqsum_32_lo = _mm_madd_epi16(olo, olo);
62       const __m128i sqsum_32_hi = _mm_madd_epi16(ohi, ohi);
63 
64       sqsum_32 = _mm_add_epi32(sqsum_32, sqsum_32_lo);
65       sqsum_32 = _mm_add_epi32(sqsum_32, sqsum_32_hi);
66     }
67 
68     // Add to 64 bit running sum as to not roll over.
69     sqsum_64 =
70         _mm_add_epi64(sqsum_64, _mm_add_epi64(_mm_unpackhi_epi32(sqsum_32, z),
71                                               _mm_unpacklo_epi32(sqsum_32, z)));
72 
73     imgBufO += width_ * skip_num_;
74     imgBufP += width_ * skip_num_;
75     num_pixels += (width_end - border_);
76   }
77 
78   __m128i sad_final_128;
79   __m128i sum_final_128;
80   __m128i sqsum_final_128;
81 
82   // Bring sums out of vector registers and into integer register
83   // domain, summing them along the way.
84   _mm_store_si128(&sad_final_128, sad_64);
85   _mm_store_si128(&sum_final_128, sum_64);
86   _mm_store_si128(&sqsum_final_128, sqsum_64);
87 
88   uint64_t* sad_final_64 = reinterpret_cast<uint64_t*>(&sad_final_128);
89   uint64_t* sum_final_64 = reinterpret_cast<uint64_t*>(&sum_final_128);
90   uint64_t* sqsum_final_64 = reinterpret_cast<uint64_t*>(&sqsum_final_128);
91 
92   const uint32_t pixelSum = sum_final_64[0] + sum_final_64[1];
93   const uint64_t pixelSqSum = sqsum_final_64[0] + sqsum_final_64[1];
94   const uint32_t tempDiffSum = sad_final_64[0] + sad_final_64[1];
95 
96   // Default.
97   motion_magnitude_ = 0.0f;
98 
99   if (tempDiffSum == 0)
100     return VPM_OK;
101 
102   // Normalize over all pixels.
103   const float tempDiffAvg =
104       static_cast<float>(tempDiffSum) / static_cast<float>(num_pixels);
105   const float pixelSumAvg =
106       static_cast<float>(pixelSum) / static_cast<float>(num_pixels);
107   const float pixelSqSumAvg =
108       static_cast<float>(pixelSqSum) / static_cast<float>(num_pixels);
109   float contrast = pixelSqSumAvg - (pixelSumAvg * pixelSumAvg);
110 
111   if (contrast > 0.0) {
112     contrast = sqrt(contrast);
113     motion_magnitude_ = tempDiffAvg / contrast;
114   }
115 
116   return VPM_OK;
117 }
118 
ComputeSpatialMetrics_SSE2()119 int32_t VPMContentAnalysis::ComputeSpatialMetrics_SSE2() {
120   const uint8_t* imgBuf = orig_frame_ + border_ * width_;
121   const int32_t width_end = ((width_ - 2 * border_) & -16) + border_;
122 
123   __m128i se_32 = _mm_setzero_si128();
124   __m128i sev_32 = _mm_setzero_si128();
125   __m128i seh_32 = _mm_setzero_si128();
126   __m128i msa_32 = _mm_setzero_si128();
127   const __m128i z = _mm_setzero_si128();
128 
129   // Error is accumulated as a 32 bit value.  Looking at HD content with a
130   // height of 1080 lines, or about 67 macro blocks.  If the 16 bit row
131   // value is maxed out at 65529 for every row, 65529*1080 = 70777800, which
132   // will not roll over a 32 bit accumulator.
133   // skip_num_ is also used to reduce the number of rows
134   for (int32_t i = 0; i < (height_ - 2 * border_); i += skip_num_) {
135     __m128i se_16 = _mm_setzero_si128();
136     __m128i sev_16 = _mm_setzero_si128();
137     __m128i seh_16 = _mm_setzero_si128();
138     __m128i msa_16 = _mm_setzero_si128();
139 
140     // Row error is accumulated as a 16 bit value.  There are 8
141     // accumulators.  Max value of a 16 bit number is 65529.  Looking
142     // at HD content, 1080p, has a width of 1920, 120 macro blocks.
143     // A mb at a time is processed at a time.  Absolute max error at
144     // a point would be abs(0-255+255+255+255) which equals 1020.
145     // 120*1020 = 122400.  The probability of hitting this is quite low
146     // on well behaved content.  A specially crafted image could roll over.
147     // border_ could also be adjusted to concentrate on just the center of
148     // the images for an HD capture in order to reduce the possiblity of
149     // rollover.
150     const uint8_t* lineTop = imgBuf - width_ + border_;
151     const uint8_t* lineCen = imgBuf + border_;
152     const uint8_t* lineBot = imgBuf + width_ + border_;
153 
154     for (int32_t j = 0; j < width_end - border_; j += 16) {
155       const __m128i t = _mm_loadu_si128((__m128i*)(lineTop));
156       const __m128i l = _mm_loadu_si128((__m128i*)(lineCen - 1));
157       const __m128i c = _mm_loadu_si128((__m128i*)(lineCen));
158       const __m128i r = _mm_loadu_si128((__m128i*)(lineCen + 1));
159       const __m128i b = _mm_loadu_si128((__m128i*)(lineBot));
160 
161       lineTop += 16;
162       lineCen += 16;
163       lineBot += 16;
164 
165       // center pixel unpacked
166       __m128i clo = _mm_unpacklo_epi8(c, z);
167       __m128i chi = _mm_unpackhi_epi8(c, z);
168 
169       // left right pixels unpacked and added together
170       const __m128i lrlo =
171           _mm_add_epi16(_mm_unpacklo_epi8(l, z), _mm_unpacklo_epi8(r, z));
172       const __m128i lrhi =
173           _mm_add_epi16(_mm_unpackhi_epi8(l, z), _mm_unpackhi_epi8(r, z));
174 
175       // top & bottom pixels unpacked and added together
176       const __m128i tblo =
177           _mm_add_epi16(_mm_unpacklo_epi8(t, z), _mm_unpacklo_epi8(b, z));
178       const __m128i tbhi =
179           _mm_add_epi16(_mm_unpackhi_epi8(t, z), _mm_unpackhi_epi8(b, z));
180 
181       // running sum of all pixels
182       msa_16 = _mm_add_epi16(msa_16, _mm_add_epi16(chi, clo));
183 
184       clo = _mm_slli_epi16(clo, 1);
185       chi = _mm_slli_epi16(chi, 1);
186       const __m128i sevtlo = _mm_subs_epi16(clo, tblo);
187       const __m128i sevthi = _mm_subs_epi16(chi, tbhi);
188       const __m128i sehtlo = _mm_subs_epi16(clo, lrlo);
189       const __m128i sehthi = _mm_subs_epi16(chi, lrhi);
190 
191       clo = _mm_slli_epi16(clo, 1);
192       chi = _mm_slli_epi16(chi, 1);
193       const __m128i setlo = _mm_subs_epi16(clo, _mm_add_epi16(lrlo, tblo));
194       const __m128i sethi = _mm_subs_epi16(chi, _mm_add_epi16(lrhi, tbhi));
195 
196       // Add to 16 bit running sum
197       se_16 =
198           _mm_add_epi16(se_16, _mm_max_epi16(setlo, _mm_subs_epi16(z, setlo)));
199       se_16 =
200           _mm_add_epi16(se_16, _mm_max_epi16(sethi, _mm_subs_epi16(z, sethi)));
201       sev_16 = _mm_add_epi16(sev_16,
202                              _mm_max_epi16(sevtlo, _mm_subs_epi16(z, sevtlo)));
203       sev_16 = _mm_add_epi16(sev_16,
204                              _mm_max_epi16(sevthi, _mm_subs_epi16(z, sevthi)));
205       seh_16 = _mm_add_epi16(seh_16,
206                              _mm_max_epi16(sehtlo, _mm_subs_epi16(z, sehtlo)));
207       seh_16 = _mm_add_epi16(seh_16,
208                              _mm_max_epi16(sehthi, _mm_subs_epi16(z, sehthi)));
209     }
210 
211     // Add to 32 bit running sum as to not roll over.
212     se_32 = _mm_add_epi32(se_32, _mm_add_epi32(_mm_unpackhi_epi16(se_16, z),
213                                                _mm_unpacklo_epi16(se_16, z)));
214     sev_32 =
215         _mm_add_epi32(sev_32, _mm_add_epi32(_mm_unpackhi_epi16(sev_16, z),
216                                             _mm_unpacklo_epi16(sev_16, z)));
217     seh_32 =
218         _mm_add_epi32(seh_32, _mm_add_epi32(_mm_unpackhi_epi16(seh_16, z),
219                                             _mm_unpacklo_epi16(seh_16, z)));
220     msa_32 =
221         _mm_add_epi32(msa_32, _mm_add_epi32(_mm_unpackhi_epi16(msa_16, z),
222                                             _mm_unpacklo_epi16(msa_16, z)));
223 
224     imgBuf += width_ * skip_num_;
225   }
226 
227   __m128i se_128;
228   __m128i sev_128;
229   __m128i seh_128;
230   __m128i msa_128;
231 
232   // Bring sums out of vector registers and into integer register
233   // domain, summing them along the way.
234   _mm_store_si128(&se_128, _mm_add_epi64(_mm_unpackhi_epi32(se_32, z),
235                                          _mm_unpacklo_epi32(se_32, z)));
236   _mm_store_si128(&sev_128, _mm_add_epi64(_mm_unpackhi_epi32(sev_32, z),
237                                           _mm_unpacklo_epi32(sev_32, z)));
238   _mm_store_si128(&seh_128, _mm_add_epi64(_mm_unpackhi_epi32(seh_32, z),
239                                           _mm_unpacklo_epi32(seh_32, z)));
240   _mm_store_si128(&msa_128, _mm_add_epi64(_mm_unpackhi_epi32(msa_32, z),
241                                           _mm_unpacklo_epi32(msa_32, z)));
242 
243   uint64_t* se_64 = reinterpret_cast<uint64_t*>(&se_128);
244   uint64_t* sev_64 = reinterpret_cast<uint64_t*>(&sev_128);
245   uint64_t* seh_64 = reinterpret_cast<uint64_t*>(&seh_128);
246   uint64_t* msa_64 = reinterpret_cast<uint64_t*>(&msa_128);
247 
248   const uint32_t spatialErrSum = se_64[0] + se_64[1];
249   const uint32_t spatialErrVSum = sev_64[0] + sev_64[1];
250   const uint32_t spatialErrHSum = seh_64[0] + seh_64[1];
251   const uint32_t pixelMSA = msa_64[0] + msa_64[1];
252 
253   // Normalize over all pixels.
254   const float spatialErr = static_cast<float>(spatialErrSum >> 2);
255   const float spatialErrH = static_cast<float>(spatialErrHSum >> 1);
256   const float spatialErrV = static_cast<float>(spatialErrVSum >> 1);
257   const float norm = static_cast<float>(pixelMSA);
258 
259   // 2X2:
260   spatial_pred_err_ = spatialErr / norm;
261 
262   // 1X2:
263   spatial_pred_err_h_ = spatialErrH / norm;
264 
265   // 2X1:
266   spatial_pred_err_v_ = spatialErrV / norm;
267 
268   return VPM_OK;
269 }
270 
271 }  // namespace webrtc
272