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1 /*
2  *  Copyright (c) 2010 The WebM 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 <assert.h>
12 #include <limits.h>
13 #include <stdlib.h>
14 #include <string.h>
15 
16 #include "vpx/vpx_image.h"
17 #include "vpx/vpx_integer.h"
18 #include "vpx_mem/vpx_mem.h"
19 
img_alloc_helper(vpx_image_t * img,vpx_img_fmt_t fmt,unsigned int d_w,unsigned int d_h,unsigned int buf_align,unsigned int stride_align,unsigned char * img_data)20 static vpx_image_t *img_alloc_helper(vpx_image_t *img, vpx_img_fmt_t fmt,
21                                      unsigned int d_w, unsigned int d_h,
22                                      unsigned int buf_align,
23                                      unsigned int stride_align,
24                                      unsigned char *img_data) {
25   unsigned int h, w, xcs, ycs, bps;
26   uint64_t s;
27   int stride_in_bytes;
28   unsigned int align;
29 
30   if (img != NULL) memset(img, 0, sizeof(vpx_image_t));
31 
32   if (fmt == VPX_IMG_FMT_NONE) goto fail;
33 
34   /* Impose maximum values on input parameters so that this function can
35    * perform arithmetic operations without worrying about overflows.
36    */
37   if (d_w > 0x08000000 || d_h > 0x08000000 || buf_align > 65536 ||
38       stride_align > 65536) {
39     goto fail;
40   }
41 
42   /* Treat align==0 like align==1 */
43   if (!buf_align) buf_align = 1;
44 
45   /* Validate alignment (must be power of 2) */
46   if (buf_align & (buf_align - 1)) goto fail;
47 
48   /* Treat align==0 like align==1 */
49   if (!stride_align) stride_align = 1;
50 
51   /* Validate alignment (must be power of 2) */
52   if (stride_align & (stride_align - 1)) goto fail;
53 
54   /* Get sample size for this format */
55   switch (fmt) {
56     case VPX_IMG_FMT_I420:
57     case VPX_IMG_FMT_YV12:
58     case VPX_IMG_FMT_NV12: bps = 12; break;
59     case VPX_IMG_FMT_I422:
60     case VPX_IMG_FMT_I440: bps = 16; break;
61     case VPX_IMG_FMT_I444: bps = 24; break;
62     case VPX_IMG_FMT_I42016: bps = 24; break;
63     case VPX_IMG_FMT_I42216:
64     case VPX_IMG_FMT_I44016: bps = 32; break;
65     case VPX_IMG_FMT_I44416: bps = 48; break;
66     default: bps = 16; break;
67   }
68 
69   /* Get chroma shift values for this format */
70   // For VPX_IMG_FMT_NV12, xcs needs to be 0 such that UV data is all read at
71   // one time.
72   switch (fmt) {
73     case VPX_IMG_FMT_I420:
74     case VPX_IMG_FMT_YV12:
75     case VPX_IMG_FMT_I422:
76     case VPX_IMG_FMT_I42016:
77     case VPX_IMG_FMT_I42216: xcs = 1; break;
78     default: xcs = 0; break;
79   }
80 
81   switch (fmt) {
82     case VPX_IMG_FMT_I420:
83     case VPX_IMG_FMT_NV12:
84     case VPX_IMG_FMT_I440:
85     case VPX_IMG_FMT_YV12:
86     case VPX_IMG_FMT_I42016:
87     case VPX_IMG_FMT_I44016: ycs = 1; break;
88     default: ycs = 0; break;
89   }
90 
91   /* Calculate storage sizes. */
92   if (img_data) {
93     /* If the buffer was allocated externally, the width and height shouldn't
94      * be adjusted. */
95     w = d_w;
96     h = d_h;
97   } else {
98     /* Calculate storage sizes given the chroma subsampling */
99     align = (1 << xcs) - 1;
100     w = (d_w + align) & ~align;
101     assert(d_w <= w);
102     align = (1 << ycs) - 1;
103     h = (d_h + align) & ~align;
104     assert(d_h <= h);
105   }
106 
107   s = (fmt & VPX_IMG_FMT_PLANAR) ? w : (uint64_t)bps * w / 8;
108   s = (fmt & VPX_IMG_FMT_HIGHBITDEPTH) ? s * 2 : s;
109   s = (s + stride_align - 1) & ~((uint64_t)stride_align - 1);
110   if (s > INT_MAX) goto fail;
111   stride_in_bytes = (int)s;
112   s = (fmt & VPX_IMG_FMT_HIGHBITDEPTH) ? s / 2 : s;
113 
114   /* Allocate the new image */
115   if (!img) {
116     img = (vpx_image_t *)calloc(1, sizeof(vpx_image_t));
117 
118     if (!img) goto fail;
119 
120     img->self_allocd = 1;
121   }
122 
123   img->img_data = img_data;
124 
125   if (!img_data) {
126     uint64_t alloc_size;
127     alloc_size = (fmt & VPX_IMG_FMT_PLANAR) ? (uint64_t)h * s * bps / 8
128                                             : (uint64_t)h * s;
129 
130     if (alloc_size != (size_t)alloc_size) goto fail;
131 
132     img->img_data = (uint8_t *)vpx_memalign(buf_align, (size_t)alloc_size);
133     img->img_data_owner = 1;
134   }
135 
136   if (!img->img_data) goto fail;
137 
138   img->fmt = fmt;
139   img->bit_depth = (fmt & VPX_IMG_FMT_HIGHBITDEPTH) ? 16 : 8;
140   img->w = w;
141   img->h = h;
142   img->x_chroma_shift = xcs;
143   img->y_chroma_shift = ycs;
144   img->bps = bps;
145 
146   /* Calculate strides */
147   img->stride[VPX_PLANE_Y] = img->stride[VPX_PLANE_ALPHA] = stride_in_bytes;
148   img->stride[VPX_PLANE_U] = img->stride[VPX_PLANE_V] = stride_in_bytes >> xcs;
149 
150   /* Default viewport to entire image */
151   if (!vpx_img_set_rect(img, 0, 0, d_w, d_h)) return img;
152 
153 fail:
154   vpx_img_free(img);
155   return NULL;
156 }
157 
vpx_img_alloc(vpx_image_t * img,vpx_img_fmt_t fmt,unsigned int d_w,unsigned int d_h,unsigned int align)158 vpx_image_t *vpx_img_alloc(vpx_image_t *img, vpx_img_fmt_t fmt,
159                            unsigned int d_w, unsigned int d_h,
160                            unsigned int align) {
161   return img_alloc_helper(img, fmt, d_w, d_h, align, align, NULL);
162 }
163 
vpx_img_wrap(vpx_image_t * img,vpx_img_fmt_t fmt,unsigned int d_w,unsigned int d_h,unsigned int stride_align,unsigned char * img_data)164 vpx_image_t *vpx_img_wrap(vpx_image_t *img, vpx_img_fmt_t fmt, unsigned int d_w,
165                           unsigned int d_h, unsigned int stride_align,
166                           unsigned char *img_data) {
167   /* By setting buf_align = 1, we don't change buffer alignment in this
168    * function. */
169   return img_alloc_helper(img, fmt, d_w, d_h, 1, stride_align, img_data);
170 }
171 
vpx_img_set_rect(vpx_image_t * img,unsigned int x,unsigned int y,unsigned int w,unsigned int h)172 int vpx_img_set_rect(vpx_image_t *img, unsigned int x, unsigned int y,
173                      unsigned int w, unsigned int h) {
174   if (x <= UINT_MAX - w && x + w <= img->w && y <= UINT_MAX - h &&
175       y + h <= img->h) {
176     img->d_w = w;
177     img->d_h = h;
178 
179     /* Calculate plane pointers */
180     if (!(img->fmt & VPX_IMG_FMT_PLANAR)) {
181       img->planes[VPX_PLANE_PACKED] =
182           img->img_data + x * img->bps / 8 + y * img->stride[VPX_PLANE_PACKED];
183     } else {
184       const int bytes_per_sample =
185           (img->fmt & VPX_IMG_FMT_HIGHBITDEPTH) ? 2 : 1;
186       unsigned char *data = img->img_data;
187 
188       if (img->fmt & VPX_IMG_FMT_HAS_ALPHA) {
189         img->planes[VPX_PLANE_ALPHA] =
190             data + x * bytes_per_sample + y * img->stride[VPX_PLANE_ALPHA];
191         data += (size_t)img->h * img->stride[VPX_PLANE_ALPHA];
192       }
193 
194       img->planes[VPX_PLANE_Y] =
195           data + x * bytes_per_sample + y * img->stride[VPX_PLANE_Y];
196       data += (size_t)img->h * img->stride[VPX_PLANE_Y];
197 
198       if (img->fmt == VPX_IMG_FMT_NV12) {
199         img->planes[VPX_PLANE_U] =
200             data + (x >> img->x_chroma_shift) +
201             (y >> img->y_chroma_shift) * img->stride[VPX_PLANE_U];
202         img->planes[VPX_PLANE_V] = img->planes[VPX_PLANE_U] + 1;
203       } else if (!(img->fmt & VPX_IMG_FMT_UV_FLIP)) {
204         img->planes[VPX_PLANE_U] =
205             data + (x >> img->x_chroma_shift) * bytes_per_sample +
206             (y >> img->y_chroma_shift) * img->stride[VPX_PLANE_U];
207         data +=
208             (size_t)(img->h >> img->y_chroma_shift) * img->stride[VPX_PLANE_U];
209         img->planes[VPX_PLANE_V] =
210             data + (x >> img->x_chroma_shift) * bytes_per_sample +
211             (y >> img->y_chroma_shift) * img->stride[VPX_PLANE_V];
212       } else {
213         img->planes[VPX_PLANE_V] =
214             data + (x >> img->x_chroma_shift) * bytes_per_sample +
215             (y >> img->y_chroma_shift) * img->stride[VPX_PLANE_V];
216         data +=
217             (size_t)(img->h >> img->y_chroma_shift) * img->stride[VPX_PLANE_V];
218         img->planes[VPX_PLANE_U] =
219             data + (x >> img->x_chroma_shift) * bytes_per_sample +
220             (y >> img->y_chroma_shift) * img->stride[VPX_PLANE_U];
221       }
222     }
223     return 0;
224   }
225   return -1;
226 }
227 
vpx_img_flip(vpx_image_t * img)228 void vpx_img_flip(vpx_image_t *img) {
229   /* Note: In the calculation pointer adjustment calculation, we want the
230    * rhs to be promoted to a signed type. Section 6.3.1.8 of the ISO C99
231    * standard indicates that if the adjustment parameter is unsigned, the
232    * stride parameter will be promoted to unsigned, causing errors when
233    * the lhs is a larger type than the rhs.
234    */
235   img->planes[VPX_PLANE_Y] += (signed)(img->d_h - 1) * img->stride[VPX_PLANE_Y];
236   img->stride[VPX_PLANE_Y] = -img->stride[VPX_PLANE_Y];
237 
238   img->planes[VPX_PLANE_U] += (signed)((img->d_h >> img->y_chroma_shift) - 1) *
239                               img->stride[VPX_PLANE_U];
240   img->stride[VPX_PLANE_U] = -img->stride[VPX_PLANE_U];
241 
242   img->planes[VPX_PLANE_V] += (signed)((img->d_h >> img->y_chroma_shift) - 1) *
243                               img->stride[VPX_PLANE_V];
244   img->stride[VPX_PLANE_V] = -img->stride[VPX_PLANE_V];
245 
246   img->planes[VPX_PLANE_ALPHA] +=
247       (signed)(img->d_h - 1) * img->stride[VPX_PLANE_ALPHA];
248   img->stride[VPX_PLANE_ALPHA] = -img->stride[VPX_PLANE_ALPHA];
249 }
250 
vpx_img_free(vpx_image_t * img)251 void vpx_img_free(vpx_image_t *img) {
252   if (img) {
253     if (img->img_data && img->img_data_owner) vpx_free(img->img_data);
254 
255     if (img->self_allocd) free(img);
256   }
257 }
258