FFmpeg  4.2.2
tonemap.c
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1 // Generated from libavfilter/opencl/tonemap.cl
3 "#line 1 \"libavfilter/opencl/tonemap.cl\"\n"
4 "/*\n"
5 " * This file is part of FFmpeg.\n"
6 " *\n"
7 " * FFmpeg is free software; you can redistribute it and/or\n"
8 " * modify it under the terms of the GNU Lesser General Public\n"
9 " * License as published by the Free Software Foundation; either\n"
10 " * version 2.1 of the License, or (at your option) any later version.\n"
11 " *\n"
12 " * FFmpeg is distributed in the hope that it will be useful,\n"
13 " * but WITHOUT ANY WARRANTY; without even the implied warranty of\n"
14 " * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU\n"
15 " * Lesser General Public License for more details.\n"
16 " *\n"
17 " * You should have received a copy of the GNU Lesser General Public\n"
18 " * License along with FFmpeg; if not, write to the Free Software\n"
19 " * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA\n"
20 " */\n"
21 "\n"
22 "#define REFERENCE_WHITE 100.0f\n"
23 "extern float3 lrgb2yuv(float3);\n"
24 "extern float lrgb2y(float3);\n"
25 "extern float3 yuv2lrgb(float3);\n"
26 "extern float3 lrgb2lrgb(float3);\n"
27 "extern float get_luma_src(float3);\n"
28 "extern float get_luma_dst(float3);\n"
29 "extern float3 ootf(float3 c, float peak);\n"
30 "extern float3 inverse_ootf(float3 c, float peak);\n"
31 "extern float3 get_chroma_sample(float3, float3, float3, float3);\n"
32 "\n"
33 "struct detection_result {\n"
34 " float peak;\n"
35 " float average;\n"
36 "};\n"
37 "\n"
38 "float hable_f(float in) {\n"
39 " float a = 0.15f, b = 0.50f, c = 0.10f, d = 0.20f, e = 0.02f, f = 0.30f;\n"
40 " return (in * (in * a + b * c) + d * e) / (in * (in * a + b) + d * f) - e / f;\n"
41 "}\n"
42 "\n"
43 "float direct(float s, float peak) {\n"
44 " return s;\n"
45 "}\n"
46 "\n"
47 "float linear(float s, float peak) {\n"
48 " return s * tone_param / peak;\n"
49 "}\n"
50 "\n"
51 "float gamma(float s, float peak) {\n"
52 " float p = s > 0.05f ? s /peak : 0.05f / peak;\n"
53 " float v = powr(p, 1.0f / tone_param);\n"
54 " return s > 0.05f ? v : (s * v /0.05f);\n"
55 "}\n"
56 "\n"
57 "float clip(float s, float peak) {\n"
58 " return clamp(s * tone_param, 0.0f, 1.0f);\n"
59 "}\n"
60 "\n"
61 "float reinhard(float s, float peak) {\n"
62 " return s / (s + tone_param) * (peak + tone_param) / peak;\n"
63 "}\n"
64 "\n"
65 "float hable(float s, float peak) {\n"
66 " return hable_f(s)/hable_f(peak);\n"
67 "}\n"
68 "\n"
69 "float mobius(float s, float peak) {\n"
70 " float j = tone_param;\n"
71 " float a, b;\n"
72 "\n"
73 " if (s <= j)\n"
74 " return s;\n"
75 "\n"
76 " a = -j * j * (peak - 1.0f) / (j * j - 2.0f * j + peak);\n"
77 " b = (j * j - 2.0f * j * peak + peak) / max(peak - 1.0f, 1e-6f);\n"
78 "\n"
79 " return (b * b + 2.0f * b * j + j * j) / (b - a) * (s + a) / (s + b);\n"
80 "}\n"
81 "\n"
82 "// detect peak/average signal of a frame, the algorithm was ported from:\n"
83 "// libplacebo (https://github.com/haasn/libplacebo)\n"
84 "struct detection_result\n"
85 "detect_peak_avg(global uint *util_buf, __local uint *sum_wg,\n"
86 " float signal, float peak) {\n"
87 "// layout of the util buffer\n"
88 "//\n"
89 "// Name: : Size (units of 4-bytes)\n"
90 "// average buffer : detection_frames + 1\n"
91 "// peak buffer : detection_frames + 1\n"
92 "// workgroup counter : 1\n"
93 "// total of peak : 1\n"
94 "// total of average : 1\n"
95 "// frame index : 1\n"
96 "// frame number : 1\n"
97 " global uint *avg_buf = util_buf;\n"
98 " global uint *peak_buf = avg_buf + DETECTION_FRAMES + 1;\n"
99 " global uint *counter_wg_p = peak_buf + DETECTION_FRAMES + 1;\n"
100 " global uint *max_total_p = counter_wg_p + 1;\n"
101 " global uint *avg_total_p = max_total_p + 1;\n"
102 " global uint *frame_idx_p = avg_total_p + 1;\n"
103 " global uint *scene_frame_num_p = frame_idx_p + 1;\n"
104 "\n"
105 " uint frame_idx = *frame_idx_p;\n"
106 " uint scene_frame_num = *scene_frame_num_p;\n"
107 "\n"
108 " size_t lidx = get_local_id(0);\n"
109 " size_t lidy = get_local_id(1);\n"
110 " size_t lsizex = get_local_size(0);\n"
111 " size_t lsizey = get_local_size(1);\n"
112 " uint num_wg = get_num_groups(0) * get_num_groups(1);\n"
113 " size_t group_idx = get_group_id(0);\n"
114 " size_t group_idy = get_group_id(1);\n"
115 " struct detection_result r = {peak, sdr_avg};\n"
116 " if (lidx == 0 && lidy == 0)\n"
117 " *sum_wg = 0;\n"
118 " barrier(CLK_LOCAL_MEM_FENCE);\n"
119 "\n"
120 " // update workgroup sum\n"
121 " atomic_add(sum_wg, (uint)(signal * REFERENCE_WHITE));\n"
122 " barrier(CLK_LOCAL_MEM_FENCE);\n"
123 "\n"
124 " // update frame peak/avg using work-group-average.\n"
125 " if (lidx == 0 && lidy == 0) {\n"
126 " uint avg_wg = *sum_wg / (lsizex * lsizey);\n"
127 " atomic_max(&peak_buf[frame_idx], avg_wg);\n"
128 " atomic_add(&avg_buf[frame_idx], avg_wg);\n"
129 " }\n"
130 "\n"
131 " if (scene_frame_num > 0) {\n"
132 " float peak = (float)*max_total_p / (REFERENCE_WHITE * scene_frame_num);\n"
133 " float avg = (float)*avg_total_p / (REFERENCE_WHITE * scene_frame_num);\n"
134 " r.peak = max(1.0f, peak);\n"
135 " r.average = max(0.25f, avg);\n"
136 " }\n"
137 "\n"
138 " if (lidx == 0 && lidy == 0 && atomic_add(counter_wg_p, 1) == num_wg - 1) {\n"
139 " *counter_wg_p = 0;\n"
140 " avg_buf[frame_idx] /= num_wg;\n"
141 "\n"
142 " if (scene_threshold > 0.0f) {\n"
143 " uint cur_max = peak_buf[frame_idx];\n"
144 " uint cur_avg = avg_buf[frame_idx];\n"
145 " int diff = (int)(scene_frame_num * cur_avg) - (int)*avg_total_p;\n"
146 "\n"
147 " if (abs(diff) > scene_frame_num * scene_threshold * REFERENCE_WHITE) {\n"
148 " for (uint i = 0; i < DETECTION_FRAMES + 1; i++)\n"
149 " avg_buf[i] = 0;\n"
150 " for (uint i = 0; i < DETECTION_FRAMES + 1; i++)\n"
151 " peak_buf[i] = 0;\n"
152 " *avg_total_p = *max_total_p = 0;\n"
153 " *scene_frame_num_p = 0;\n"
154 " avg_buf[frame_idx] = cur_avg;\n"
155 " peak_buf[frame_idx] = cur_max;\n"
156 " }\n"
157 " }\n"
158 " uint next = (frame_idx + 1) % (DETECTION_FRAMES + 1);\n"
159 " // add current frame, subtract next frame\n"
160 " *max_total_p += peak_buf[frame_idx] - peak_buf[next];\n"
161 " *avg_total_p += avg_buf[frame_idx] - avg_buf[next];\n"
162 " // reset next frame\n"
163 " peak_buf[next] = avg_buf[next] = 0;\n"
164 " *frame_idx_p = next;\n"
165 " *scene_frame_num_p = min(*scene_frame_num_p + 1,\n"
166 " (uint)DETECTION_FRAMES);\n"
167 " }\n"
168 " return r;\n"
169 "}\n"
170 "\n"
171 "float3 map_one_pixel_rgb(float3 rgb, float peak, float average) {\n"
172 " float sig = max(max(rgb.x, max(rgb.y, rgb.z)), 1e-6f);\n"
173 "\n"
174 " // Rescale the variables in order to bring it into a representation where\n"
175 " // 1.0 represents the dst_peak. This is because all of the tone mapping\n"
176 " // algorithms are defined in such a way that they map to the range [0.0, 1.0].\n"
177 " if (target_peak > 1.0f) {\n"
178 " sig *= 1.0f / target_peak;\n"
179 " peak *= 1.0f / target_peak;\n"
180 " }\n"
181 "\n"
182 " float sig_old = sig;\n"
183 "\n"
184 " // Scale the signal to compensate for differences in the average brightness\n"
185 " float slope = min(1.0f, sdr_avg / average);\n"
186 " sig *= slope;\n"
187 " peak *= slope;\n"
188 "\n"
189 " // Desaturate the color using a coefficient dependent on the signal level\n"
190 " if (desat_param > 0.0f) {\n"
191 " float luma = get_luma_dst(rgb);\n"
192 " float coeff = max(sig - 0.18f, 1e-6f) / max(sig, 1e-6f);\n"
193 " coeff = native_powr(coeff, 10.0f / desat_param);\n"
194 " rgb = mix(rgb, (float3)luma, (float3)coeff);\n"
195 " sig = mix(sig, luma * slope, coeff);\n"
196 " }\n"
197 "\n"
198 " sig = TONE_FUNC(sig, peak);\n"
199 "\n"
200 " sig = min(sig, 1.0f);\n"
201 " rgb *= (sig/sig_old);\n"
202 " return rgb;\n"
203 "}\n"
204 "// map from source space YUV to destination space RGB\n"
205 "float3 map_to_dst_space_from_yuv(float3 yuv, float peak) {\n"
206 " float3 c = yuv2lrgb(yuv);\n"
207 " c = ootf(c, peak);\n"
208 " c = lrgb2lrgb(c);\n"
209 " return c;\n"
210 "}\n"
211 "\n"
212 "__kernel void tonemap(__write_only image2d_t dst1,\n"
213 " __read_only image2d_t src1,\n"
214 " __write_only image2d_t dst2,\n"
215 " __read_only image2d_t src2,\n"
216 " global uint *util_buf,\n"
217 " float peak\n"
218 " )\n"
219 "{\n"
220 " __local uint sum_wg;\n"
221 " const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |\n"
222 " CLK_ADDRESS_CLAMP_TO_EDGE |\n"
223 " CLK_FILTER_NEAREST);\n"
224 " int xi = get_global_id(0);\n"
225 " int yi = get_global_id(1);\n"
226 " // each work item process four pixels\n"
227 " int x = 2 * xi;\n"
228 " int y = 2 * yi;\n"
229 "\n"
230 " float y0 = read_imagef(src1, sampler, (int2)(x, y)).x;\n"
231 " float y1 = read_imagef(src1, sampler, (int2)(x + 1, y)).x;\n"
232 " float y2 = read_imagef(src1, sampler, (int2)(x, y + 1)).x;\n"
233 " float y3 = read_imagef(src1, sampler, (int2)(x + 1, y + 1)).x;\n"
234 " float2 uv = read_imagef(src2, sampler, (int2)(xi, yi)).xy;\n"
235 "\n"
236 " float3 c0 = map_to_dst_space_from_yuv((float3)(y0, uv.x, uv.y), peak);\n"
237 " float3 c1 = map_to_dst_space_from_yuv((float3)(y1, uv.x, uv.y), peak);\n"
238 " float3 c2 = map_to_dst_space_from_yuv((float3)(y2, uv.x, uv.y), peak);\n"
239 " float3 c3 = map_to_dst_space_from_yuv((float3)(y3, uv.x, uv.y), peak);\n"
240 "\n"
241 " float sig0 = max(c0.x, max(c0.y, c0.z));\n"
242 " float sig1 = max(c1.x, max(c1.y, c1.z));\n"
243 " float sig2 = max(c2.x, max(c2.y, c2.z));\n"
244 " float sig3 = max(c3.x, max(c3.y, c3.z));\n"
245 " float sig = max(sig0, max(sig1, max(sig2, sig3)));\n"
246 "\n"
247 " struct detection_result r = detect_peak_avg(util_buf, &sum_wg, sig, peak);\n"
248 "\n"
249 " float3 c0_old = c0, c1_old = c1, c2_old = c2;\n"
250 " c0 = map_one_pixel_rgb(c0, r.peak, r.average);\n"
251 " c1 = map_one_pixel_rgb(c1, r.peak, r.average);\n"
252 " c2 = map_one_pixel_rgb(c2, r.peak, r.average);\n"
253 " c3 = map_one_pixel_rgb(c3, r.peak, r.average);\n"
254 "\n"
255 " c0 = inverse_ootf(c0, target_peak);\n"
256 " c1 = inverse_ootf(c1, target_peak);\n"
257 " c2 = inverse_ootf(c2, target_peak);\n"
258 " c3 = inverse_ootf(c3, target_peak);\n"
259 "\n"
260 " y0 = lrgb2y(c0);\n"
261 " y1 = lrgb2y(c1);\n"
262 " y2 = lrgb2y(c2);\n"
263 " y3 = lrgb2y(c3);\n"
264 " float3 chroma_c = get_chroma_sample(c0, c1, c2, c3);\n"
265 " float3 chroma = lrgb2yuv(chroma_c);\n"
266 "\n"
267 " if (xi < get_image_width(dst2) && yi < get_image_height(dst2)) {\n"
268 " write_imagef(dst1, (int2)(x, y), (float4)(y0, 0.0f, 0.0f, 1.0f));\n"
269 " write_imagef(dst1, (int2)(x+1, y), (float4)(y1, 0.0f, 0.0f, 1.0f));\n"
270 " write_imagef(dst1, (int2)(x, y+1), (float4)(y2, 0.0f, 0.0f, 1.0f));\n"
271 " write_imagef(dst1, (int2)(x+1, y+1), (float4)(y3, 0.0f, 0.0f, 1.0f));\n"
272 " write_imagef(dst2, (int2)(xi, yi),\n"
273 " (float4)(chroma.y, chroma.z, 0.0f, 1.0f));\n"
274 " }\n"
275 "}\n"
276 ;
const char * ff_opencl_source_tonemap
Definition: tonemap.c:2