1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
// Copyright 2014 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.
// -----------------------------------------------------------------------------
//
// Rescaling functions
//
// Author: Skal (pascal.massimino@gmail.com)
#include <assert.h>
#include "./dsp.h"
#include "../utils/rescaler.h"
//------------------------------------------------------------------------------
// Implementations of critical functions ImportRow / ExportRow
#define ROUNDER (WEBP_RESCALER_ONE >> 1)
#define MULT_FIX(x, y) (((uint64_t)(x) * (y) + ROUNDER) >> WEBP_RESCALER_RFIX)
//------------------------------------------------------------------------------
// Row import
void WebPRescalerImportRowExpandC(WebPRescaler* const wrk, const uint8_t* src) {
const int x_stride = wrk->num_channels;
const int x_out_max = wrk->dst_width * wrk->num_channels;
int channel;
assert(!WebPRescalerInputDone(wrk));
assert(wrk->x_expand);
for (channel = 0; channel < x_stride; ++channel) {
int x_in = channel;
int x_out = channel;
// simple bilinear interpolation
int accum = wrk->x_add;
int left = src[x_in];
int right = (wrk->src_width > 1) ? src[x_in + x_stride] : left;
x_in += x_stride;
while (1) {
wrk->frow[x_out] = right * wrk->x_add + (left - right) * accum;
x_out += x_stride;
if (x_out >= x_out_max) break;
accum -= wrk->x_sub;
if (accum < 0) {
left = right;
x_in += x_stride;
assert(x_in < wrk->src_width * x_stride);
right = src[x_in];
accum += wrk->x_add;
}
}
assert(wrk->x_sub == 0 /* <- special case for src_width=1 */ || accum == 0);
}
}
void WebPRescalerImportRowShrinkC(WebPRescaler* const wrk, const uint8_t* src) {
const int x_stride = wrk->num_channels;
const int x_out_max = wrk->dst_width * wrk->num_channels;
int channel;
assert(!WebPRescalerInputDone(wrk));
assert(!wrk->x_expand);
for (channel = 0; channel < x_stride; ++channel) {
int x_in = channel;
int x_out = channel;
uint32_t sum = 0;
int accum = 0;
while (x_out < x_out_max) {
uint32_t base = 0;
accum += wrk->x_add;
while (accum > 0) {
accum -= wrk->x_sub;
assert(x_in < wrk->src_width * x_stride);
base = src[x_in];
sum += base;
x_in += x_stride;
}
{ // Emit next horizontal pixel.
const rescaler_t frac = base * (-accum);
wrk->frow[x_out] = sum * wrk->x_sub - frac;
// fresh fractional start for next pixel
sum = (int)MULT_FIX(frac, wrk->fx_scale);
}
x_out += x_stride;
}
assert(accum == 0);
}
}
//------------------------------------------------------------------------------
// Row export
void WebPRescalerExportRowExpandC(WebPRescaler* const wrk) {
int x_out;
uint8_t* const dst = wrk->dst;
rescaler_t* const irow = wrk->irow;
const int x_out_max = wrk->dst_width * wrk->num_channels;
const rescaler_t* const frow = wrk->frow;
assert(!WebPRescalerOutputDone(wrk));
assert(wrk->y_accum <= 0);
assert(wrk->y_expand);
assert(wrk->y_sub != 0);
if (wrk->y_accum == 0) {
for (x_out = 0; x_out < x_out_max; ++x_out) {
const uint32_t J = frow[x_out];
const int v = (int)MULT_FIX(J, wrk->fy_scale);
assert(v >= 0 && v <= 255);
dst[x_out] = v;
}
} else {
const uint32_t B = WEBP_RESCALER_FRAC(-wrk->y_accum, wrk->y_sub);
const uint32_t A = (uint32_t)(WEBP_RESCALER_ONE - B);
for (x_out = 0; x_out < x_out_max; ++x_out) {
const uint64_t I = (uint64_t)A * frow[x_out]
+ (uint64_t)B * irow[x_out];
const uint32_t J = (uint32_t)((I + ROUNDER) >> WEBP_RESCALER_RFIX);
const int v = (int)MULT_FIX(J, wrk->fy_scale);
assert(v >= 0 && v <= 255);
dst[x_out] = v;
}
}
}
void WebPRescalerExportRowShrinkC(WebPRescaler* const wrk) {
int x_out;
uint8_t* const dst = wrk->dst;
rescaler_t* const irow = wrk->irow;
const int x_out_max = wrk->dst_width * wrk->num_channels;
const rescaler_t* const frow = wrk->frow;
const uint32_t yscale = wrk->fy_scale * (-wrk->y_accum);
assert(!WebPRescalerOutputDone(wrk));
assert(wrk->y_accum <= 0);
assert(!wrk->y_expand);
if (yscale) {
for (x_out = 0; x_out < x_out_max; ++x_out) {
const uint32_t frac = (uint32_t)MULT_FIX(frow[x_out], yscale);
const int v = (int)MULT_FIX(irow[x_out] - frac, wrk->fxy_scale);
assert(v >= 0 && v <= 255);
dst[x_out] = v;
irow[x_out] = frac; // new fractional start
}
} else {
for (x_out = 0; x_out < x_out_max; ++x_out) {
const int v = (int)MULT_FIX(irow[x_out], wrk->fxy_scale);
assert(v >= 0 && v <= 255);
dst[x_out] = v;
irow[x_out] = 0;
}
}
}
#undef MULT_FIX
#undef ROUNDER
//------------------------------------------------------------------------------
// Main entry calls
void WebPRescalerImportRow(WebPRescaler* const wrk, const uint8_t* src) {
assert(!WebPRescalerInputDone(wrk));
if (!wrk->x_expand) {
WebPRescalerImportRowShrink(wrk, src);
} else {
WebPRescalerImportRowExpand(wrk, src);
}
}
void WebPRescalerExportRow(WebPRescaler* const wrk) {
if (wrk->y_accum <= 0) {
assert(!WebPRescalerOutputDone(wrk));
if (wrk->y_expand) {
WebPRescalerExportRowExpand(wrk);
} else if (wrk->fxy_scale) {
WebPRescalerExportRowShrink(wrk);
} else { // very special case for src = dst = 1x1
int i;
assert(wrk->src_width == 1 && wrk->dst_width <= 2);
assert(wrk->src_height == 1 && wrk->dst_height == 1);
for (i = 0; i < wrk->num_channels * wrk->dst_width; ++i) {
wrk->dst[i] = wrk->irow[i];
wrk->irow[i] = 0;
}
}
wrk->y_accum += wrk->y_add;
wrk->dst += wrk->dst_stride;
++wrk->dst_y;
}
}
//------------------------------------------------------------------------------
WebPRescalerImportRowFunc WebPRescalerImportRowExpand;
WebPRescalerImportRowFunc WebPRescalerImportRowShrink;
WebPRescalerExportRowFunc WebPRescalerExportRowExpand;
WebPRescalerExportRowFunc WebPRescalerExportRowShrink;
extern void WebPRescalerDspInitSSE2(void);
extern void WebPRescalerDspInitMIPS32(void);
extern void WebPRescalerDspInitMIPSdspR2(void);
extern void WebPRescalerDspInitNEON(void);
static volatile VP8CPUInfo rescaler_last_cpuinfo_used =
(VP8CPUInfo)&rescaler_last_cpuinfo_used;
WEBP_TSAN_IGNORE_FUNCTION void WebPRescalerDspInit(void) {
if (rescaler_last_cpuinfo_used == VP8GetCPUInfo) return;
WebPRescalerImportRowExpand = WebPRescalerImportRowExpandC;
WebPRescalerImportRowShrink = WebPRescalerImportRowShrinkC;
WebPRescalerExportRowExpand = WebPRescalerExportRowExpandC;
WebPRescalerExportRowShrink = WebPRescalerExportRowShrinkC;
if (VP8GetCPUInfo != NULL) {
#if defined(WEBP_USE_SSE2)
if (VP8GetCPUInfo(kSSE2)) {
WebPRescalerDspInitSSE2();
}
#endif
#if defined(WEBP_USE_NEON)
if (VP8GetCPUInfo(kNEON)) {
WebPRescalerDspInitNEON();
}
#endif
#if defined(WEBP_USE_MIPS32)
if (VP8GetCPUInfo(kMIPS32)) {
WebPRescalerDspInitMIPS32();
}
#endif
#if defined(WEBP_USE_MIPS_DSP_R2)
if (VP8GetCPUInfo(kMIPSdspR2)) {
WebPRescalerDspInitMIPSdspR2();
}
#endif
}
rescaler_last_cpuinfo_used = VP8GetCPUInfo;
}
|