FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavfilter/vf_tonemap.c
Date: 2025-04-25 22:50:00
Exec Total Coverage
Lines: 0 138 0.0%
Functions: 0 6 0.0%
Branches: 0 85 0.0%

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1 /*
2 * Copyright (c) 2017 Vittorio Giovara <vittorio.giovara@gmail.com>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 /**
22 * @file
23 * tonemap algorithms
24 */
25
26 #include <float.h>
27 #include <stdio.h>
28
29 #include "libavutil/csp.h"
30 #include "libavutil/imgutils.h"
31 #include "libavutil/internal.h"
32 #include "libavutil/intfloat.h"
33 #include "libavutil/intreadwrite.h"
34 #include "libavutil/opt.h"
35 #include "libavutil/pixdesc.h"
36
37 #include "avfilter.h"
38 #include "colorspace.h"
39 #include "filters.h"
40 #include "video.h"
41
42 enum TonemapAlgorithm {
43 TONEMAP_NONE,
44 TONEMAP_LINEAR,
45 TONEMAP_GAMMA,
46 TONEMAP_CLIP,
47 TONEMAP_REINHARD,
48 TONEMAP_HABLE,
49 TONEMAP_MOBIUS,
50 TONEMAP_MAX,
51 };
52
53 typedef struct TonemapContext {
54 const AVClass *class;
55
56 enum TonemapAlgorithm tonemap;
57 double param;
58 double desat;
59 double peak;
60
61 const AVLumaCoefficients *coeffs;
62 } TonemapContext;
63
64 static av_cold int init(AVFilterContext *ctx)
65 {
66 TonemapContext *s = ctx->priv;
67
68 switch(s->tonemap) {
69 case TONEMAP_GAMMA:
70 if (isnan(s->param))
71 s->param = 1.8f;
72 break;
73 case TONEMAP_REINHARD:
74 if (!isnan(s->param))
75 s->param = (1.0f - s->param) / s->param;
76 break;
77 case TONEMAP_MOBIUS:
78 if (isnan(s->param))
79 s->param = 0.3f;
80 break;
81 }
82
83 if (isnan(s->param))
84 s->param = 1.0f;
85
86 return 0;
87 }
88
89 static float hable(float in)
90 {
91 float a = 0.15f, b = 0.50f, c = 0.10f, d = 0.20f, e = 0.02f, f = 0.30f;
92 return (in * (in * a + b * c) + d * e) / (in * (in * a + b) + d * f) - e / f;
93 }
94
95 static float mobius(float in, float j, double peak)
96 {
97 float a, b;
98
99 if (in <= j)
100 return in;
101
102 a = -j * j * (peak - 1.0f) / (j * j - 2.0f * j + peak);
103 b = (j * j - 2.0f * j * peak + peak) / FFMAX(peak - 1.0f, 1e-6);
104
105 return (b * b + 2.0f * b * j + j * j) / (b - a) * (in + a) / (in + b);
106 }
107
108 #define MIX(x,y,a) (x) * (1 - (a)) + (y) * (a)
109 static void tonemap(TonemapContext *s, AVFrame *out, const AVFrame *in,
110 const AVPixFmtDescriptor *desc, int x, int y, double peak)
111 {
112 int map[3] = { desc->comp[0].plane, desc->comp[1].plane, desc->comp[2].plane };
113 const float *r_in = (const float *)(in->data[map[0]] + x * desc->comp[map[0]].step + y * in->linesize[map[0]]);
114 const float *g_in = (const float *)(in->data[map[1]] + x * desc->comp[map[1]].step + y * in->linesize[map[1]]);
115 const float *b_in = (const float *)(in->data[map[2]] + x * desc->comp[map[2]].step + y * in->linesize[map[2]]);
116 float *r_out = (float *)(out->data[map[0]] + x * desc->comp[map[0]].step + y * out->linesize[map[0]]);
117 float *g_out = (float *)(out->data[map[1]] + x * desc->comp[map[1]].step + y * out->linesize[map[1]]);
118 float *b_out = (float *)(out->data[map[2]] + x * desc->comp[map[2]].step + y * out->linesize[map[2]]);
119 float sig, sig_orig;
120
121 /* load values */
122 *r_out = *r_in;
123 *g_out = *g_in;
124 *b_out = *b_in;
125
126 /* desaturate to prevent unnatural colors */
127 if (s->desat > 0) {
128 float luma = av_q2d(s->coeffs->cr) * *r_in + av_q2d(s->coeffs->cg) * *g_in + av_q2d(s->coeffs->cb) * *b_in;
129 float overbright = FFMAX(luma - s->desat, 1e-6) / FFMAX(luma, 1e-6);
130 *r_out = MIX(*r_in, luma, overbright);
131 *g_out = MIX(*g_in, luma, overbright);
132 *b_out = MIX(*b_in, luma, overbright);
133 }
134
135 /* pick the brightest component, reducing the value range as necessary
136 * to keep the entire signal in range and preventing discoloration due to
137 * out-of-bounds clipping */
138 sig = FFMAX(FFMAX3(*r_out, *g_out, *b_out), 1e-6);
139 sig_orig = sig;
140
141 switch(s->tonemap) {
142 default:
143 case TONEMAP_NONE:
144 // do nothing
145 break;
146 case TONEMAP_LINEAR:
147 sig = sig * s->param / peak;
148 break;
149 case TONEMAP_GAMMA:
150 sig = sig > 0.05f ? pow(sig / peak, 1.0f / s->param)
151 : sig * pow(0.05f / peak, 1.0f / s->param) / 0.05f;
152 break;
153 case TONEMAP_CLIP:
154 sig = av_clipf(sig * s->param, 0, 1.0f);
155 break;
156 case TONEMAP_HABLE:
157 sig = hable(sig) / hable(peak);
158 break;
159 case TONEMAP_REINHARD:
160 sig = sig / (sig + s->param) * (peak + s->param) / peak;
161 break;
162 case TONEMAP_MOBIUS:
163 sig = mobius(sig, s->param, peak);
164 break;
165 }
166
167 /* apply the computed scale factor to the color,
168 * linearly to prevent discoloration */
169 *r_out *= sig / sig_orig;
170 *g_out *= sig / sig_orig;
171 *b_out *= sig / sig_orig;
172 }
173
174 typedef struct ThreadData {
175 AVFrame *in, *out;
176 const AVPixFmtDescriptor *desc;
177 double peak;
178 } ThreadData;
179
180 static int tonemap_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
181 {
182 TonemapContext *s = ctx->priv;
183 ThreadData *td = arg;
184 AVFrame *in = td->in;
185 AVFrame *out = td->out;
186 const AVPixFmtDescriptor *desc = td->desc;
187 const int slice_start = (in->height * jobnr) / nb_jobs;
188 const int slice_end = (in->height * (jobnr+1)) / nb_jobs;
189 double peak = td->peak;
190
191 for (int y = slice_start; y < slice_end; y++)
192 for (int x = 0; x < out->width; x++)
193 tonemap(s, out, in, desc, x, y, peak);
194
195 return 0;
196 }
197
198 static int filter_frame(AVFilterLink *link, AVFrame *in)
199 {
200 AVFilterContext *ctx = link->dst;
201 TonemapContext *s = ctx->priv;
202 AVFilterLink *outlink = ctx->outputs[0];
203 ThreadData td;
204 AVFrame *out;
205 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
206 const AVPixFmtDescriptor *odesc = av_pix_fmt_desc_get(outlink->format);
207 int ret, x, y;
208 double peak = s->peak;
209
210 if (!desc || !odesc) {
211 av_frame_free(&in);
212 return AVERROR_BUG;
213 }
214
215 out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
216 if (!out) {
217 av_frame_free(&in);
218 return AVERROR(ENOMEM);
219 }
220
221 ret = av_frame_copy_props(out, in);
222 if (ret < 0) {
223 av_frame_free(&in);
224 av_frame_free(&out);
225 return ret;
226 }
227
228 /* input and output transfer will be linear */
229 if (in->color_trc == AVCOL_TRC_UNSPECIFIED) {
230 av_log(s, AV_LOG_WARNING, "Untagged transfer, assuming linear light\n");
231 out->color_trc = AVCOL_TRC_LINEAR;
232 } else if (in->color_trc != AVCOL_TRC_LINEAR)
233 av_log(s, AV_LOG_WARNING, "Tonemapping works on linear light only\n");
234
235 /* read peak from side data if not passed in */
236 if (!peak) {
237 peak = ff_determine_signal_peak(in);
238 av_log(s, AV_LOG_DEBUG, "Computed signal peak: %f\n", peak);
239 }
240
241 /* load original color space even if pixel format is RGB to compute overbrights */
242 s->coeffs = av_csp_luma_coeffs_from_avcsp(in->colorspace);
243 if (s->desat > 0 && (in->colorspace == AVCOL_SPC_UNSPECIFIED || !s->coeffs)) {
244 if (in->colorspace == AVCOL_SPC_UNSPECIFIED)
245 av_log(s, AV_LOG_WARNING, "Missing color space information, ");
246 else if (!s->coeffs)
247 av_log(s, AV_LOG_WARNING, "Unsupported color space '%s', ",
248 av_color_space_name(in->colorspace));
249 av_log(s, AV_LOG_WARNING, "desaturation is disabled\n");
250 s->desat = 0;
251 }
252
253 /* do the tone map */
254 td.out = out;
255 td.in = in;
256 td.desc = desc;
257 td.peak = peak;
258 ff_filter_execute(ctx, tonemap_slice, &td, NULL,
259 FFMIN(in->height, ff_filter_get_nb_threads(ctx)));
260
261 /* copy/generate alpha if needed */
262 if (desc->flags & AV_PIX_FMT_FLAG_ALPHA && odesc->flags & AV_PIX_FMT_FLAG_ALPHA) {
263 av_image_copy_plane(out->data[3], out->linesize[3],
264 in->data[3], in->linesize[3],
265 out->linesize[3], outlink->h);
266 } else if (odesc->flags & AV_PIX_FMT_FLAG_ALPHA) {
267 for (y = 0; y < out->height; y++) {
268 for (x = 0; x < out->width; x++) {
269 AV_WN32(out->data[3] + x * odesc->comp[3].step + y * out->linesize[3],
270 av_float2int(1.0f));
271 }
272 }
273 }
274
275 av_frame_free(&in);
276
277 ff_update_hdr_metadata(out, peak);
278
279 return ff_filter_frame(outlink, out);
280 }
281
282 #define OFFSET(x) offsetof(TonemapContext, x)
283 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
284 static const AVOption tonemap_options[] = {
285 { "tonemap", "tonemap algorithm selection", OFFSET(tonemap), AV_OPT_TYPE_INT, {.i64 = TONEMAP_NONE}, TONEMAP_NONE, TONEMAP_MAX - 1, FLAGS, .unit = "tonemap" },
286 { "none", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_NONE}, 0, 0, FLAGS, .unit = "tonemap" },
287 { "linear", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_LINEAR}, 0, 0, FLAGS, .unit = "tonemap" },
288 { "gamma", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_GAMMA}, 0, 0, FLAGS, .unit = "tonemap" },
289 { "clip", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_CLIP}, 0, 0, FLAGS, .unit = "tonemap" },
290 { "reinhard", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_REINHARD}, 0, 0, FLAGS, .unit = "tonemap" },
291 { "hable", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_HABLE}, 0, 0, FLAGS, .unit = "tonemap" },
292 { "mobius", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_MOBIUS}, 0, 0, FLAGS, .unit = "tonemap" },
293 { "param", "tonemap parameter", OFFSET(param), AV_OPT_TYPE_DOUBLE, {.dbl = NAN}, DBL_MIN, DBL_MAX, FLAGS },
294 { "desat", "desaturation strength", OFFSET(desat), AV_OPT_TYPE_DOUBLE, {.dbl = 2}, 0, DBL_MAX, FLAGS },
295 { "peak", "signal peak override", OFFSET(peak), AV_OPT_TYPE_DOUBLE, {.dbl = 0}, 0, DBL_MAX, FLAGS },
296 { NULL }
297 };
298
299 AVFILTER_DEFINE_CLASS(tonemap);
300
301 static const AVFilterPad tonemap_inputs[] = {
302 {
303 .name = "default",
304 .type = AVMEDIA_TYPE_VIDEO,
305 .filter_frame = filter_frame,
306 },
307 };
308
309 const FFFilter ff_vf_tonemap = {
310 .p.name = "tonemap",
311 .p.description = NULL_IF_CONFIG_SMALL("Conversion to/from different dynamic ranges."),
312 .p.priv_class = &tonemap_class,
313 .p.flags = AVFILTER_FLAG_SLICE_THREADS,
314 .init = init,
315 .priv_size = sizeof(TonemapContext),
316 FILTER_INPUTS(tonemap_inputs),
317 FILTER_OUTPUTS(ff_video_default_filterpad),
318 FILTER_PIXFMTS(AV_PIX_FMT_GBRPF32, AV_PIX_FMT_GBRAPF32),
319 };
320