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1 // Copyright 2018 Google Inc.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //      http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 //
15 ////////////////////////////////////////////////////////////////////////////////
16 
17 #include <stdint.h>
18 #include <stdlib.h>
19 
20 #include "dsp/dsp.h"
21 #include "img_alpha.h"
22 #include "img_grid.h"
23 #include "img_peak.h"
24 #include "webp/encode.h"
25 
26 //------------------------------------------------------------------------------
27 // Arbitrary limits to prevent OOM, timeout, or slow execution.
28 //
29 // The decoded image size, and for animations additionally the canvas size.
30 static const size_t kFuzzPxLimit = 1024 * 1024;
31 // Demuxed or decoded animation frames.
32 static const int kFuzzFrameLimit = 3;
33 
34 // Reads and sums (up to) 128 spread-out bytes.
FuzzHash(const uint8_t * const data,size_t size)35 uint8_t FuzzHash(const uint8_t* const data, size_t size) {
36   uint8_t value = 0;
37   size_t incr = size / 128;
38   if (!incr) incr = 1;
39   for (size_t i = 0; i < size; i += incr) value += data[i];
40   return value;
41 }
42 
43 //------------------------------------------------------------------------------
44 // Extract an integer in [0, max_value].
45 
Extract(uint32_t max_value,const uint8_t data[],size_t size,uint32_t * const bit_pos)46 static uint32_t Extract(uint32_t max_value, const uint8_t data[], size_t size,
47                         uint32_t* const bit_pos) {
48   uint32_t v = 0;
49   int range = 1;
50   while (*bit_pos < 8 * size && range <= max_value) {
51     const uint8_t mask = 1u << (*bit_pos & 7);
52     v = (v << 1) | !!(data[*bit_pos >> 3] & mask);
53     range <<= 1;
54     ++*bit_pos;
55   }
56   return v % (max_value + 1);
57 }
58 
59 //------------------------------------------------------------------------------
60 // Some functions to override VP8GetCPUInfo and disable some optimizations.
61 
62 static VP8CPUInfo GetCPUInfo;
63 
GetCPUInfoNoSSE41(CPUFeature feature)64 static int GetCPUInfoNoSSE41(CPUFeature feature) {
65   if (feature == kSSE4_1 || feature == kAVX) return 0;
66   return GetCPUInfo(feature);
67 }
68 
GetCPUInfoNoAVX(CPUFeature feature)69 static int GetCPUInfoNoAVX(CPUFeature feature) {
70   if (feature == kAVX) return 0;
71   return GetCPUInfo(feature);
72 }
73 
GetCPUInfoForceSlowSSSE3(CPUFeature feature)74 static int GetCPUInfoForceSlowSSSE3(CPUFeature feature) {
75   if (feature == kSlowSSSE3 && GetCPUInfo(kSSE3)) {
76     return 1;  // we have SSE3 -> force SlowSSSE3
77   }
78   return GetCPUInfo(feature);
79 }
80 
GetCPUInfoOnlyC(CPUFeature feature)81 static int GetCPUInfoOnlyC(CPUFeature feature) { return 0; }
82 
ExtractAndDisableOptimizations(VP8CPUInfo default_VP8GetCPUInfo,const uint8_t data[],size_t size,uint32_t * const bit_pos)83 static void ExtractAndDisableOptimizations(VP8CPUInfo default_VP8GetCPUInfo,
84                                            const uint8_t data[], size_t size,
85                                            uint32_t* const bit_pos) {
86   GetCPUInfo = default_VP8GetCPUInfo;
87   const VP8CPUInfo kVP8CPUInfos[5] = {GetCPUInfoOnlyC, GetCPUInfoForceSlowSSSE3,
88                                       GetCPUInfoNoSSE41, GetCPUInfoNoAVX,
89                                       GetCPUInfo};
90   int VP8GetCPUInfo_index = Extract(4, data, size, bit_pos);
91   VP8GetCPUInfo = kVP8CPUInfos[VP8GetCPUInfo_index];
92 }
93 
94 //------------------------------------------------------------------------------
95 
ExtractWebPConfig(WebPConfig * const config,const uint8_t data[],size_t size,uint32_t * const bit_pos)96 static int ExtractWebPConfig(WebPConfig* const config, const uint8_t data[],
97                              size_t size, uint32_t* const bit_pos) {
98   if (config == NULL || !WebPConfigInit(config)) return 0;
99   config->lossless = Extract(1, data, size, bit_pos);
100   config->quality = Extract(100, data, size, bit_pos);
101   config->method = Extract(6, data, size, bit_pos);
102   config->image_hint =
103       (WebPImageHint)Extract(WEBP_HINT_LAST - 1, data, size, bit_pos);
104   config->segments = 1 + Extract(3, data, size, bit_pos);
105   config->sns_strength = Extract(100, data, size, bit_pos);
106   config->filter_strength = Extract(100, data, size, bit_pos);
107   config->filter_sharpness = Extract(7, data, size, bit_pos);
108   config->filter_type = Extract(1, data, size, bit_pos);
109   config->autofilter = Extract(1, data, size, bit_pos);
110   config->alpha_compression = Extract(1, data, size, bit_pos);
111   config->alpha_filtering = Extract(2, data, size, bit_pos);
112   config->alpha_quality = Extract(100, data, size, bit_pos);
113   config->pass = 1 + Extract(9, data, size, bit_pos);
114   config->show_compressed = 1;
115   config->preprocessing = Extract(2, data, size, bit_pos);
116   config->partitions = Extract(3, data, size, bit_pos);
117   config->partition_limit = 10 * Extract(10, data, size, bit_pos);
118   config->emulate_jpeg_size = Extract(1, data, size, bit_pos);
119   config->thread_level = Extract(1, data, size, bit_pos);
120   config->low_memory = Extract(1, data, size, bit_pos);
121   config->near_lossless = 20 * Extract(5, data, size, bit_pos);
122   config->exact = Extract(1, data, size, bit_pos);
123   config->use_delta_palette = Extract(1, data, size, bit_pos);
124   config->use_sharp_yuv = Extract(1, data, size, bit_pos);
125   return WebPValidateConfig(config);
126 }
127 
128 //------------------------------------------------------------------------------
129 
ExtractSourcePicture(WebPPicture * const pic,const uint8_t data[],size_t size,uint32_t * const bit_pos)130 static int ExtractSourcePicture(WebPPicture* const pic,
131                                 const uint8_t data[], size_t size,
132                                 uint32_t* const bit_pos) {
133   if (pic == NULL) return 0;
134 
135   // Pick a source picture.
136   const uint8_t* kImagesData[] = {
137       kImgAlphaData,
138       kImgGridData,
139       kImgPeakData
140   };
141   const int kImagesWidth[] = {
142       kImgAlphaWidth,
143       kImgGridWidth,
144       kImgPeakWidth
145   };
146   const int kImagesHeight[] = {
147       kImgAlphaHeight,
148       kImgGridHeight,
149       kImgPeakHeight
150   };
151   const size_t kNbImages = sizeof(kImagesData) / sizeof(kImagesData[0]);
152   const size_t image_index = Extract(kNbImages - 1, data, size, bit_pos);
153   const uint8_t* const image_data = kImagesData[image_index];
154   pic->width = kImagesWidth[image_index];
155   pic->height = kImagesHeight[image_index];
156   pic->argb_stride = pic->width * 4 * sizeof(uint8_t);
157 
158   // Read the bytes.
159   return WebPPictureImportRGBA(pic, image_data, pic->argb_stride);
160 }
161 
162 //------------------------------------------------------------------------------
163 
max(int a,int b)164 static int max(int a, int b) { return ((a < b) ? b : a); }
165 
ExtractAndCropOrScale(WebPPicture * const pic,const uint8_t data[],size_t size,uint32_t * const bit_pos)166 static int ExtractAndCropOrScale(WebPPicture* const pic, const uint8_t data[],
167                                  size_t size, uint32_t* const bit_pos) {
168   if (pic == NULL) return 0;
169   const int alter_input = Extract(1, data, size, bit_pos);
170   const int crop_or_scale = Extract(1, data, size, bit_pos);
171   const int width_ratio = 1 + Extract(7, data, size, bit_pos);
172   const int height_ratio = 1 + Extract(7, data, size, bit_pos);
173   if (alter_input) {
174     if (crop_or_scale) {
175       const uint32_t left_ratio = 1 + Extract(7, data, size, bit_pos);
176       const uint32_t top_ratio = 1 + Extract(7, data, size, bit_pos);
177       const int cropped_width = max(1, pic->width / width_ratio);
178       const int cropped_height = max(1, pic->height / height_ratio);
179       const int cropped_left = (pic->width - cropped_width) / left_ratio;
180       const int cropped_top = (pic->height - cropped_height) / top_ratio;
181       return WebPPictureCrop(pic, cropped_left, cropped_top, cropped_width,
182                              cropped_height);
183     } else {
184       const int scaled_width = 1 + (pic->width * width_ratio) / 8;
185       const int scaled_height = 1 + (pic->height * height_ratio) / 8;
186       return WebPPictureRescale(pic, scaled_width, scaled_height);
187     }
188   }
189   return 1;
190 }
191