upsampling_sse2.c revision 1e7bf8805bd030c19924a5306837ecd72c295751
1// Copyright 2011 Google Inc. All Rights Reserved.
2//
3// This code is licensed under the same terms as WebM:
4//  Software License Agreement:  http://www.webmproject.org/license/software/
5//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
6// -----------------------------------------------------------------------------
7//
8// SSE2 version of YUV to RGB upsampling functions.
9//
10// Author: somnath@google.com (Somnath Banerjee)
11
12#include "./dsp.h"
13
14#if defined(__cplusplus) || defined(c_plusplus)
15extern "C" {
16#endif
17
18#if defined(WEBP_USE_SSE2)
19
20#include <assert.h>
21#include <emmintrin.h>
22#include <string.h>
23#include "./yuv.h"
24
25#ifdef FANCY_UPSAMPLING
26
27// We compute (9*a + 3*b + 3*c + d + 8) / 16 as follows
28// u = (9*a + 3*b + 3*c + d + 8) / 16
29//   = (a + (a + 3*b + 3*c + d) / 8 + 1) / 2
30//   = (a + m + 1) / 2
31// where m = (a + 3*b + 3*c + d) / 8
32//         = ((a + b + c + d) / 2 + b + c) / 4
33//
34// Let's say  k = (a + b + c + d) / 4.
35// We can compute k as
36// k = (s + t + 1) / 2 - ((a^d) | (b^c) | (s^t)) & 1
37// where s = (a + d + 1) / 2 and t = (b + c + 1) / 2
38//
39// Then m can be written as
40// m = (k + t + 1) / 2 - (((b^c) & (s^t)) | (k^t)) & 1
41
42// Computes out = (k + in + 1) / 2 - ((ij & (s^t)) | (k^in)) & 1
43#define GET_M(ij, in, out) do {                                                \
44  const __m128i tmp0 = _mm_avg_epu8(k, (in));     /* (k + in + 1) / 2 */       \
45  const __m128i tmp1 = _mm_and_si128((ij), st);   /* (ij) & (s^t) */           \
46  const __m128i tmp2 = _mm_xor_si128(k, (in));    /* (k^in) */                 \
47  const __m128i tmp3 = _mm_or_si128(tmp1, tmp2);  /* ((ij) & (s^t)) | (k^in) */\
48  const __m128i tmp4 = _mm_and_si128(tmp3, one);  /* & 1 -> lsb_correction */  \
49  (out) = _mm_sub_epi8(tmp0, tmp4);    /* (k + in + 1) / 2 - lsb_correction */ \
50} while (0)
51
52// pack and store two alterning pixel rows
53#define PACK_AND_STORE(a, b, da, db, out) do {                                 \
54  const __m128i t_a = _mm_avg_epu8(a, da);  /* (9a + 3b + 3c +  d + 8) / 16 */ \
55  const __m128i t_b = _mm_avg_epu8(b, db);  /* (3a + 9b +  c + 3d + 8) / 16 */ \
56  const __m128i t_1 = _mm_unpacklo_epi8(t_a, t_b);                             \
57  const __m128i t_2 = _mm_unpackhi_epi8(t_a, t_b);                             \
58  _mm_store_si128(((__m128i*)(out)) + 0, t_1);                                 \
59  _mm_store_si128(((__m128i*)(out)) + 1, t_2);                                 \
60} while (0)
61
62// Loads 17 pixels each from rows r1 and r2 and generates 32 pixels.
63#define UPSAMPLE_32PIXELS(r1, r2, out) {                                       \
64  const __m128i one = _mm_set1_epi8(1);                                        \
65  const __m128i a = _mm_loadu_si128((__m128i*)&(r1)[0]);                       \
66  const __m128i b = _mm_loadu_si128((__m128i*)&(r1)[1]);                       \
67  const __m128i c = _mm_loadu_si128((__m128i*)&(r2)[0]);                       \
68  const __m128i d = _mm_loadu_si128((__m128i*)&(r2)[1]);                       \
69                                                                               \
70  const __m128i s = _mm_avg_epu8(a, d);        /* s = (a + d + 1) / 2 */       \
71  const __m128i t = _mm_avg_epu8(b, c);        /* t = (b + c + 1) / 2 */       \
72  const __m128i st = _mm_xor_si128(s, t);      /* st = s^t */                  \
73                                                                               \
74  const __m128i ad = _mm_xor_si128(a, d);      /* ad = a^d */                  \
75  const __m128i bc = _mm_xor_si128(b, c);      /* bc = b^c */                  \
76                                                                               \
77  const __m128i t1 = _mm_or_si128(ad, bc);     /* (a^d) | (b^c) */             \
78  const __m128i t2 = _mm_or_si128(t1, st);     /* (a^d) | (b^c) | (s^t) */     \
79  const __m128i t3 = _mm_and_si128(t2, one);   /* (a^d) | (b^c) | (s^t) & 1 */ \
80  const __m128i t4 = _mm_avg_epu8(s, t);                                       \
81  const __m128i k = _mm_sub_epi8(t4, t3);      /* k = (a + b + c + d) / 4 */   \
82  __m128i diag1, diag2;                                                        \
83                                                                               \
84  GET_M(bc, t, diag1);                  /* diag1 = (a + 3b + 3c + d) / 8 */    \
85  GET_M(ad, s, diag2);                  /* diag2 = (3a + b + c + 3d) / 8 */    \
86                                                                               \
87  /* pack the alternate pixels */                                              \
88  PACK_AND_STORE(a, b, diag1, diag2, &(out)[0 * 32]);                          \
89  PACK_AND_STORE(c, d, diag2, diag1, &(out)[2 * 32]);                          \
90}
91
92// Turn the macro into a function for reducing code-size when non-critical
93static void Upsample32Pixels(const uint8_t r1[], const uint8_t r2[],
94                             uint8_t* const out) {
95  UPSAMPLE_32PIXELS(r1, r2, out);
96}
97
98#define UPSAMPLE_LAST_BLOCK(tb, bb, num_pixels, out) {                         \
99  uint8_t r1[17], r2[17];                                                      \
100  memcpy(r1, (tb), (num_pixels));                                              \
101  memcpy(r2, (bb), (num_pixels));                                              \
102  /* replicate last byte */                                                    \
103  memset(r1 + (num_pixels), r1[(num_pixels) - 1], 17 - (num_pixels));          \
104  memset(r2 + (num_pixels), r2[(num_pixels) - 1], 17 - (num_pixels));          \
105  /* using the shared function instead of the macro saves ~3k code size */     \
106  Upsample32Pixels(r1, r2, out);                                               \
107}
108
109#define CONVERT2RGB(FUNC, XSTEP, top_y, bottom_y, uv,                          \
110                    top_dst, bottom_dst, cur_x, num_pixels) {                  \
111  int n;                                                                       \
112  if (top_y) {                                                                 \
113    for (n = 0; n < (num_pixels); ++n) {                                       \
114      FUNC(top_y[(cur_x) + n], (uv)[n], (uv)[32 + n],                          \
115           top_dst + ((cur_x) + n) * XSTEP);                                   \
116    }                                                                          \
117  }                                                                            \
118  if (bottom_y) {                                                              \
119    for (n = 0; n < (num_pixels); ++n) {                                       \
120      FUNC(bottom_y[(cur_x) + n], (uv)[64 + n], (uv)[64 + 32 + n],             \
121           bottom_dst + ((cur_x) + n) * XSTEP);                                \
122    }                                                                          \
123  }                                                                            \
124}
125
126#define SSE2_UPSAMPLE_FUNC(FUNC_NAME, FUNC, XSTEP)                             \
127static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bottom_y,           \
128                      const uint8_t* top_u, const uint8_t* top_v,              \
129                      const uint8_t* cur_u, const uint8_t* cur_v,              \
130                      uint8_t* top_dst, uint8_t* bottom_dst, int len) {        \
131  int block;                                                                   \
132  /* 16 byte aligned array to cache reconstructed u and v */                   \
133  uint8_t uv_buf[4 * 32 + 15];                                                 \
134  uint8_t* const r_uv = (uint8_t*)((uintptr_t)(uv_buf + 15) & ~15);            \
135  const int uv_len = (len + 1) >> 1;                                           \
136  /* 17 pixels must be read-able for each block */                             \
137  const int num_blocks = (uv_len - 1) >> 4;                                    \
138  const int leftover = uv_len - num_blocks * 16;                               \
139  const int last_pos = 1 + 32 * num_blocks;                                    \
140                                                                               \
141  const int u_diag = ((top_u[0] + cur_u[0]) >> 1) + 1;                         \
142  const int v_diag = ((top_v[0] + cur_v[0]) >> 1) + 1;                         \
143                                                                               \
144  assert(len > 0);                                                             \
145  /* Treat the first pixel in regular way */                                   \
146  if (top_y) {                                                                 \
147    const int u0 = (top_u[0] + u_diag) >> 1;                                   \
148    const int v0 = (top_v[0] + v_diag) >> 1;                                   \
149    FUNC(top_y[0], u0, v0, top_dst);                                           \
150  }                                                                            \
151  if (bottom_y) {                                                              \
152    const int u0 = (cur_u[0] + u_diag) >> 1;                                   \
153    const int v0 = (cur_v[0] + v_diag) >> 1;                                   \
154    FUNC(bottom_y[0], u0, v0, bottom_dst);                                     \
155  }                                                                            \
156                                                                               \
157  for (block = 0; block < num_blocks; ++block) {                               \
158    UPSAMPLE_32PIXELS(top_u, cur_u, r_uv + 0 * 32);                            \
159    UPSAMPLE_32PIXELS(top_v, cur_v, r_uv + 1 * 32);                            \
160    CONVERT2RGB(FUNC, XSTEP, top_y, bottom_y, r_uv, top_dst, bottom_dst,       \
161                32 * block + 1, 32)                                            \
162    top_u += 16;                                                               \
163    cur_u += 16;                                                               \
164    top_v += 16;                                                               \
165    cur_v += 16;                                                               \
166  }                                                                            \
167                                                                               \
168  UPSAMPLE_LAST_BLOCK(top_u, cur_u, leftover, r_uv + 0 * 32);                  \
169  UPSAMPLE_LAST_BLOCK(top_v, cur_v, leftover, r_uv + 1 * 32);                  \
170  CONVERT2RGB(FUNC, XSTEP, top_y, bottom_y, r_uv, top_dst, bottom_dst,         \
171              last_pos, len - last_pos);                                       \
172}
173
174// SSE2 variants of the fancy upsampler.
175SSE2_UPSAMPLE_FUNC(UpsampleRgbLinePairSSE2,  VP8YuvToRgb,  3)
176SSE2_UPSAMPLE_FUNC(UpsampleBgrLinePairSSE2,  VP8YuvToBgr,  3)
177SSE2_UPSAMPLE_FUNC(UpsampleRgbaLinePairSSE2, VP8YuvToRgba, 4)
178SSE2_UPSAMPLE_FUNC(UpsampleBgraLinePairSSE2, VP8YuvToBgra, 4)
179
180#undef GET_M
181#undef PACK_AND_STORE
182#undef UPSAMPLE_32PIXELS
183#undef UPSAMPLE_LAST_BLOCK
184#undef CONVERT2RGB
185#undef SSE2_UPSAMPLE_FUNC
186
187#endif  // FANCY_UPSAMPLING
188
189#endif   // WEBP_USE_SSE2
190
191//------------------------------------------------------------------------------
192
193extern WebPUpsampleLinePairFunc WebPUpsamplers[/* MODE_LAST */];
194
195void WebPInitUpsamplersSSE2(void) {
196#if defined(WEBP_USE_SSE2)
197  WebPUpsamplers[MODE_RGB]  = UpsampleRgbLinePairSSE2;
198  WebPUpsamplers[MODE_RGBA] = UpsampleRgbaLinePairSSE2;
199  WebPUpsamplers[MODE_BGR]  = UpsampleBgrLinePairSSE2;
200  WebPUpsamplers[MODE_BGRA] = UpsampleBgraLinePairSSE2;
201#endif   // WEBP_USE_SSE2
202}
203
204void WebPInitPremultiplySSE2(void) {
205#if defined(WEBP_USE_SSE2)
206  WebPUpsamplers[MODE_rgbA] = UpsampleRgbaLinePairSSE2;
207  WebPUpsamplers[MODE_bgrA] = UpsampleBgraLinePairSSE2;
208#endif   // WEBP_USE_SSE2
209}
210
211#if defined(__cplusplus) || defined(c_plusplus)
212}    // extern "C"
213#endif
214
215
216