1// Copyright 2014 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// WebPPicture tools: copy, crop, rescaling and view.
11//
12// Author: Skal (pascal.massimino@gmail.com)
13
14#include "src/webp/encode.h"
15
16#include <assert.h>
17#include <stdlib.h>
18
19#include "src/enc/vp8i_enc.h"
20
21#if !defined(WEBP_REDUCE_SIZE)
22#include "src/utils/rescaler_utils.h"
23#include "src/utils/utils.h"
24#endif // !defined(WEBP_REDUCE_SIZE)
25
26#define HALVE(x) (((x) + 1) >> 1)
27
28// Grab the 'specs' (writer, *opaque, width, height...) from 'src' and copy them
29// into 'dst'. Mark 'dst' as not owning any memory.
30static void PictureGrabSpecs(const WebPPicture* const src,
31 WebPPicture* const dst) {
32 assert(src != NULL && dst != NULL);
33 *dst = *src;
34 WebPPictureResetBuffers(dst);
35}
36
37//------------------------------------------------------------------------------
38
39// Adjust top-left corner to chroma sample position.
40static void SnapTopLeftPosition(const WebPPicture* const pic,
41 int* const left, int* const top) {
42 if (!pic->use_argb) {
43 *left &= ~1;
44 *top &= ~1;
45 }
46}
47
48// Adjust top-left corner and verify that the sub-rectangle is valid.
49static int AdjustAndCheckRectangle(const WebPPicture* const pic,
50 int* const left, int* const top,
51 int width, int height) {
52 SnapTopLeftPosition(pic, left, top);
53 if ((*left) < 0 || (*top) < 0) return 0;
54 if (width <= 0 || height <= 0) return 0;
55 if ((*left) + width > pic->width) return 0;
56 if ((*top) + height > pic->height) return 0;
57 return 1;
58}
59
60#if !defined(WEBP_REDUCE_SIZE)
61int WebPPictureCopy(const WebPPicture* src, WebPPicture* dst) {
62 if (src == NULL || dst == NULL) return 0;
63 if (src == dst) return 1;
64
65 PictureGrabSpecs(src, dst);
66 if (!WebPPictureAlloc(dst)) return 0;
67
68 if (!src->use_argb) {
69 WebPCopyPlane(src->y, src->y_stride,
70 dst->y, dst->y_stride, dst->width, dst->height);
71 WebPCopyPlane(src->u, src->uv_stride, dst->u, dst->uv_stride,
72 HALVE(dst->width), HALVE(dst->height));
73 WebPCopyPlane(src->v, src->uv_stride, dst->v, dst->uv_stride,
74 HALVE(dst->width), HALVE(dst->height));
75 if (dst->a != NULL) {
76 WebPCopyPlane(src->a, src->a_stride,
77 dst->a, dst->a_stride, dst->width, dst->height);
78 }
79 } else {
80 WebPCopyPlane((const uint8_t*)src->argb, 4 * src->argb_stride,
81 (uint8_t*)dst->argb, 4 * dst->argb_stride,
82 4 * dst->width, dst->height);
83 }
84 return 1;
85}
86#endif // !defined(WEBP_REDUCE_SIZE)
87
88int WebPPictureIsView(const WebPPicture* picture) {
89 if (picture == NULL) return 0;
90 if (picture->use_argb) {
91 return (picture->memory_argb_ == NULL);
92 }
93 return (picture->memory_ == NULL);
94}
95
96int WebPPictureView(const WebPPicture* src,
97 int left, int top, int width, int height,
98 WebPPicture* dst) {
99 if (src == NULL || dst == NULL) return 0;
100
101 // verify rectangle position.
102 if (!AdjustAndCheckRectangle(src, &left, &top, width, height)) return 0;
103
104 if (src != dst) { // beware of aliasing! We don't want to leak 'memory_'.
105 PictureGrabSpecs(src, dst);
106 }
107 dst->width = width;
108 dst->height = height;
109 if (!src->use_argb) {
110 dst->y = src->y + top * src->y_stride + left;
111 dst->u = src->u + (top >> 1) * src->uv_stride + (left >> 1);
112 dst->v = src->v + (top >> 1) * src->uv_stride + (left >> 1);
113 dst->y_stride = src->y_stride;
114 dst->uv_stride = src->uv_stride;
115 if (src->a != NULL) {
116 dst->a = src->a + top * src->a_stride + left;
117 dst->a_stride = src->a_stride;
118 }
119 } else {
120 dst->argb = src->argb + top * src->argb_stride + left;
121 dst->argb_stride = src->argb_stride;
122 }
123 return 1;
124}
125
126#if !defined(WEBP_REDUCE_SIZE)
127//------------------------------------------------------------------------------
128// Picture cropping
129
130int WebPPictureCrop(WebPPicture* pic,
131 int left, int top, int width, int height) {
132 WebPPicture tmp;
133
134 if (pic == NULL) return 0;
135 if (!AdjustAndCheckRectangle(pic, &left, &top, width, height)) return 0;
136
137 PictureGrabSpecs(pic, &tmp);
138 tmp.width = width;
139 tmp.height = height;
140 if (!WebPPictureAlloc(&tmp)) {
141 return WebPEncodingSetError(pic, tmp.error_code);
142 }
143
144 if (!pic->use_argb) {
145 const int y_offset = top * pic->y_stride + left;
146 const int uv_offset = (top / 2) * pic->uv_stride + left / 2;
147 WebPCopyPlane(pic->y + y_offset, pic->y_stride,
148 tmp.y, tmp.y_stride, width, height);
149 WebPCopyPlane(pic->u + uv_offset, pic->uv_stride,
150 tmp.u, tmp.uv_stride, HALVE(width), HALVE(height));
151 WebPCopyPlane(pic->v + uv_offset, pic->uv_stride,
152 tmp.v, tmp.uv_stride, HALVE(width), HALVE(height));
153
154 if (tmp.a != NULL) {
155 const int a_offset = top * pic->a_stride + left;
156 WebPCopyPlane(pic->a + a_offset, pic->a_stride,
157 tmp.a, tmp.a_stride, width, height);
158 }
159 } else {
160 const uint8_t* const src =
161 (const uint8_t*)(pic->argb + top * pic->argb_stride + left);
162 WebPCopyPlane(src, pic->argb_stride * 4, (uint8_t*)tmp.argb,
163 tmp.argb_stride * 4, width * 4, height);
164 }
165 WebPPictureFree(pic);
166 *pic = tmp;
167 return 1;
168}
169
170//------------------------------------------------------------------------------
171// Simple picture rescaler
172
173static int RescalePlane(const uint8_t* src,
174 int src_width, int src_height, int src_stride,
175 uint8_t* dst,
176 int dst_width, int dst_height, int dst_stride,
177 rescaler_t* const work,
178 int num_channels) {
179 WebPRescaler rescaler;
180 int y = 0;
181 if (!WebPRescalerInit(&rescaler, src_width, src_height,
182 dst, dst_width, dst_height, dst_stride,
183 num_channels, work)) {
184 return 0;
185 }
186 while (y < src_height) {
187 y += WebPRescalerImport(&rescaler, src_height - y,
188 src + y * src_stride, src_stride);
189 WebPRescalerExport(&rescaler);
190 }
191 return 1;
192}
193
194static void AlphaMultiplyARGB(WebPPicture* const pic, int inverse) {
195 assert(pic->argb != NULL);
196 WebPMultARGBRows((uint8_t*)pic->argb, pic->argb_stride * sizeof(*pic->argb),
197 pic->width, pic->height, inverse);
198}
199
200static void AlphaMultiplyY(WebPPicture* const pic, int inverse) {
201 if (pic->a != NULL) {
202 WebPMultRows(pic->y, pic->y_stride, pic->a, pic->a_stride,
203 pic->width, pic->height, inverse);
204 }
205}
206
207int WebPPictureRescale(WebPPicture* picture, int width, int height) {
208 WebPPicture tmp;
209 int prev_width, prev_height;
210 rescaler_t* work;
211
212 if (picture == NULL) return 0;
213 prev_width = picture->width;
214 prev_height = picture->height;
215 if (!WebPRescalerGetScaledDimensions(
216 prev_width, prev_height, &width, &height)) {
217 return WebPEncodingSetError(picture, VP8_ENC_ERROR_BAD_DIMENSION);
218 }
219
220 PictureGrabSpecs(picture, &tmp);
221 tmp.width = width;
222 tmp.height = height;
223 if (!WebPPictureAlloc(&tmp)) {
224 return WebPEncodingSetError(picture, tmp.error_code);
225 }
226
227 if (!picture->use_argb) {
228 work = (rescaler_t*)WebPSafeMalloc(2ULL * width, sizeof(*work));
229 if (work == NULL) {
230 WebPPictureFree(&tmp);
231 return WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
232 }
233 // If present, we need to rescale alpha first (for AlphaMultiplyY).
234 if (picture->a != NULL) {
235 WebPInitAlphaProcessing();
236 if (!RescalePlane(picture->a, prev_width, prev_height, picture->a_stride,
237 tmp.a, width, height, tmp.a_stride, work, 1)) {
238 return WebPEncodingSetError(picture, VP8_ENC_ERROR_BAD_DIMENSION);
239 }
240 }
241
242 // We take transparency into account on the luma plane only. That's not
243 // totally exact blending, but still is a good approximation.
244 AlphaMultiplyY(picture, 0);
245 if (!RescalePlane(picture->y, prev_width, prev_height, picture->y_stride,
246 tmp.y, width, height, tmp.y_stride, work, 1) ||
247 !RescalePlane(picture->u, HALVE(prev_width), HALVE(prev_height),
248 picture->uv_stride, tmp.u, HALVE(width), HALVE(height),
249 tmp.uv_stride, work, 1) ||
250 !RescalePlane(picture->v, HALVE(prev_width), HALVE(prev_height),
251 picture->uv_stride, tmp.v, HALVE(width), HALVE(height),
252 tmp.uv_stride, work, 1)) {
253 return WebPEncodingSetError(picture, VP8_ENC_ERROR_BAD_DIMENSION);
254 }
255 AlphaMultiplyY(&tmp, 1);
256 } else {
257 work = (rescaler_t*)WebPSafeMalloc(2ULL * width * 4, sizeof(*work));
258 if (work == NULL) {
259 WebPPictureFree(&tmp);
260 return WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
261 }
262 // In order to correctly interpolate colors, we need to apply the alpha
263 // weighting first (black-matting), scale the RGB values, and remove
264 // the premultiplication afterward (while preserving the alpha channel).
265 WebPInitAlphaProcessing();
266 AlphaMultiplyARGB(picture, 0);
267 if (!RescalePlane((const uint8_t*)picture->argb, prev_width, prev_height,
268 picture->argb_stride * 4, (uint8_t*)tmp.argb, width,
269 height, tmp.argb_stride * 4, work, 4)) {
270 return WebPEncodingSetError(picture, VP8_ENC_ERROR_BAD_DIMENSION);
271 }
272 AlphaMultiplyARGB(&tmp, 1);
273 }
274 WebPPictureFree(picture);
275 WebPSafeFree(work);
276 *picture = tmp;
277 return 1;
278}
279
280#else // defined(WEBP_REDUCE_SIZE)
281
282int WebPPictureCopy(const WebPPicture* src, WebPPicture* dst) {
283 (void)src;
284 (void)dst;
285 return 0;
286}
287
288int WebPPictureCrop(WebPPicture* pic,
289 int left, int top, int width, int height) {
290 (void)pic;
291 (void)left;
292 (void)top;
293 (void)width;
294 (void)height;
295 return 0;
296}
297
298int WebPPictureRescale(WebPPicture* pic, int width, int height) {
299 (void)pic;
300 (void)width;
301 (void)height;
302 return 0;
303}
304#endif // !defined(WEBP_REDUCE_SIZE)
305