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vf_geq.c
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1 /*
2  * Copyright (C) 2006 Michael Niedermayer <michaelni@gmx.at>
3  * Copyright (C) 2012 Clément Bœsch <u pkh me>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License along
18  * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20  */
21 
22 /**
23  * @file
24  * Generic equation change filter
25  * Originally written by Michael Niedermayer for the MPlayer project, and
26  * ported by Clément Bœsch for FFmpeg.
27  */
28 
29 #include "libavutil/avstring.h"
30 #include "libavutil/eval.h"
31 #include "libavutil/opt.h"
32 #include "libavutil/pixdesc.h"
33 #include "internal.h"
34 
35 typedef struct {
36  const AVClass *class;
37  AVExpr *e[4]; ///< expressions for each plane
38  char *expr_str[4+3]; ///< expression strings for each plane
39  AVFrame *picref; ///< current input buffer
40  int hsub, vsub; ///< chroma subsampling
41  int planes; ///< number of planes
42  int is_rgb;
43 } GEQContext;
44 
45 enum { Y = 0, U, V, A, G, B, R };
46 
47 #define OFFSET(x) offsetof(GEQContext, x)
48 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
49 
50 static const AVOption geq_options[] = {
51  { "lum_expr", "set luminance expression", OFFSET(expr_str[Y]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
52  { "lum", "set luminance expression", OFFSET(expr_str[Y]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
53  { "cb_expr", "set chroma blue expression", OFFSET(expr_str[U]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
54  { "cb", "set chroma blue expression", OFFSET(expr_str[U]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
55  { "cr_expr", "set chroma red expression", OFFSET(expr_str[V]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
56  { "cr", "set chroma red expression", OFFSET(expr_str[V]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
57  { "alpha_expr", "set alpha expression", OFFSET(expr_str[A]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
58  { "a", "set alpha expression", OFFSET(expr_str[A]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
59  { "red_expr", "set red expression", OFFSET(expr_str[R]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
60  { "r", "set red expression", OFFSET(expr_str[R]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
61  { "green_expr", "set green expression", OFFSET(expr_str[G]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
62  { "g", "set green expression", OFFSET(expr_str[G]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
63  { "blue_expr", "set blue expression", OFFSET(expr_str[B]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
64  { "b", "set blue expression", OFFSET(expr_str[B]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
65  {NULL},
66 };
67 
68 AVFILTER_DEFINE_CLASS(geq);
69 
70 static inline double getpix(void *priv, double x, double y, int plane)
71 {
72  int xi, yi;
73  GEQContext *geq = priv;
74  AVFrame *picref = geq->picref;
75  const uint8_t *src = picref->data[plane];
76  const int linesize = picref->linesize[plane];
77  const int w = (plane == 1 || plane == 2) ? FF_CEIL_RSHIFT(picref->width, geq->hsub) : picref->width;
78  const int h = (plane == 1 || plane == 2) ? FF_CEIL_RSHIFT(picref->height, geq->vsub) : picref->height;
79 
80  if (!src)
81  return 0;
82 
83  xi = x = av_clipf(x, 0, w - 2);
84  yi = y = av_clipf(y, 0, h - 2);
85 
86  x -= xi;
87  y -= yi;
88 
89  return (1-y)*((1-x)*src[xi + yi * linesize] + x*src[xi + 1 + yi * linesize])
90  + y *((1-x)*src[xi + (yi+1) * linesize] + x*src[xi + 1 + (yi+1) * linesize]);
91 }
92 
93 //TODO: cubic interpolate
94 //TODO: keep the last few frames
95 static double lum(void *priv, double x, double y) { return getpix(priv, x, y, 0); }
96 static double cb(void *priv, double x, double y) { return getpix(priv, x, y, 1); }
97 static double cr(void *priv, double x, double y) { return getpix(priv, x, y, 2); }
98 static double alpha(void *priv, double x, double y) { return getpix(priv, x, y, 3); }
99 
100 static const char *const var_names[] = { "X", "Y", "W", "H", "N", "SW", "SH", "T", NULL };
101 enum { VAR_X, VAR_Y, VAR_W, VAR_H, VAR_N, VAR_SW, VAR_SH, VAR_T, VAR_VARS_NB };
102 
103 static av_cold int geq_init(AVFilterContext *ctx)
104 {
105  GEQContext *geq = ctx->priv;
106  int plane, ret = 0;
107 
108  if (!geq->expr_str[Y] && !geq->expr_str[G] && !geq->expr_str[B] && !geq->expr_str[R]) {
109  av_log(ctx, AV_LOG_ERROR, "A luminance or RGB expression is mandatory\n");
110  ret = AVERROR(EINVAL);
111  goto end;
112  }
113  geq->is_rgb = !geq->expr_str[Y];
114 
115  if ((geq->expr_str[Y] || geq->expr_str[U] || geq->expr_str[V]) && (geq->expr_str[G] || geq->expr_str[B] || geq->expr_str[R])) {
116  av_log(ctx, AV_LOG_ERROR, "Either YCbCr or RGB but not both must be specified\n");
117  ret = AVERROR(EINVAL);
118  goto end;
119  }
120 
121  if (!geq->expr_str[U] && !geq->expr_str[V]) {
122  /* No chroma at all: fallback on luma */
123  geq->expr_str[U] = av_strdup(geq->expr_str[Y]);
124  geq->expr_str[V] = av_strdup(geq->expr_str[Y]);
125  } else {
126  /* One chroma unspecified, fallback on the other */
127  if (!geq->expr_str[U]) geq->expr_str[U] = av_strdup(geq->expr_str[V]);
128  if (!geq->expr_str[V]) geq->expr_str[V] = av_strdup(geq->expr_str[U]);
129  }
130 
131  if (!geq->expr_str[A])
132  geq->expr_str[A] = av_strdup("255");
133  if (!geq->expr_str[G])
134  geq->expr_str[G] = av_strdup("g(X,Y)");
135  if (!geq->expr_str[B])
136  geq->expr_str[B] = av_strdup("b(X,Y)");
137  if (!geq->expr_str[R])
138  geq->expr_str[R] = av_strdup("r(X,Y)");
139 
140  if (geq->is_rgb ?
141  (!geq->expr_str[G] || !geq->expr_str[B] || !geq->expr_str[R])
142  :
143  (!geq->expr_str[U] || !geq->expr_str[V] || !geq->expr_str[A])) {
144  ret = AVERROR(ENOMEM);
145  goto end;
146  }
147 
148  for (plane = 0; plane < 4; plane++) {
149  static double (*p[])(void *, double, double) = { lum, cb, cr, alpha };
150  static const char *const func2_yuv_names[] = { "lum", "cb", "cr", "alpha", "p", NULL };
151  static const char *const func2_rgb_names[] = { "g", "b", "r", "alpha", "p", NULL };
152  const char *const *func2_names = geq->is_rgb ? func2_rgb_names : func2_yuv_names;
153  double (*func2[])(void *, double, double) = { lum, cb, cr, alpha, p[plane], NULL };
154 
155  ret = av_expr_parse(&geq->e[plane], geq->expr_str[plane < 3 && geq->is_rgb ? plane+4 : plane], var_names,
156  NULL, NULL, func2_names, func2, 0, ctx);
157  if (ret < 0)
158  break;
159  }
160 
161 end:
162  return ret;
163 }
164 
165 static int geq_query_formats(AVFilterContext *ctx)
166 {
167  GEQContext *geq = ctx->priv;
168  static const enum PixelFormat yuv_pix_fmts[] = {
169  AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P,
170  AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P,
171  AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
172  AV_PIX_FMT_GRAY8,
173  AV_PIX_FMT_NONE
174  };
175  static const enum PixelFormat rgb_pix_fmts[] = {
176  AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP,
177  AV_PIX_FMT_NONE
178  };
179  if (geq->is_rgb) {
180  ff_set_common_formats(ctx, ff_make_format_list(rgb_pix_fmts));
181  } else
182  ff_set_common_formats(ctx, ff_make_format_list(yuv_pix_fmts));
183  return 0;
184 }
185 
186 static int geq_config_props(AVFilterLink *inlink)
187 {
188  GEQContext *geq = inlink->dst->priv;
189  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
190 
191  geq->hsub = desc->log2_chroma_w;
192  geq->vsub = desc->log2_chroma_h;
193  geq->planes = desc->nb_components;
194  return 0;
195 }
196 
197 static int geq_filter_frame(AVFilterLink *inlink, AVFrame *in)
198 {
199  int plane;
200  GEQContext *geq = inlink->dst->priv;
201  AVFilterLink *outlink = inlink->dst->outputs[0];
202  AVFrame *out;
203  double values[VAR_VARS_NB] = {
204  [VAR_N] = inlink->frame_count,
205  [VAR_T] = in->pts == AV_NOPTS_VALUE ? NAN : in->pts * av_q2d(inlink->time_base),
206  };
207 
208  geq->picref = in;
209  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
210  if (!out) {
211  av_frame_free(&in);
212  return AVERROR(ENOMEM);
213  }
214  av_frame_copy_props(out, in);
215 
216  for (plane = 0; plane < geq->planes && out->data[plane]; plane++) {
217  int x, y;
218  uint8_t *dst = out->data[plane];
219  const int linesize = out->linesize[plane];
220  const int w = (plane == 1 || plane == 2) ? FF_CEIL_RSHIFT(inlink->w, geq->hsub) : inlink->w;
221  const int h = (plane == 1 || plane == 2) ? FF_CEIL_RSHIFT(inlink->h, geq->vsub) : inlink->h;
222 
223  values[VAR_W] = w;
224  values[VAR_H] = h;
225  values[VAR_SW] = w / (double)inlink->w;
226  values[VAR_SH] = h / (double)inlink->h;
227 
228  for (y = 0; y < h; y++) {
229  values[VAR_Y] = y;
230  for (x = 0; x < w; x++) {
231  values[VAR_X] = x;
232  dst[x] = av_expr_eval(geq->e[plane], values, geq);
233  }
234  dst += linesize;
235  }
236  }
237 
238  av_frame_free(&geq->picref);
239  return ff_filter_frame(outlink, out);
240 }
241 
242 static av_cold void geq_uninit(AVFilterContext *ctx)
243 {
244  int i;
245  GEQContext *geq = ctx->priv;
246 
247  for (i = 0; i < FF_ARRAY_ELEMS(geq->e); i++)
248  av_expr_free(geq->e[i]);
249 }
250 
251 static const AVFilterPad geq_inputs[] = {
252  {
253  .name = "default",
254  .type = AVMEDIA_TYPE_VIDEO,
255  .config_props = geq_config_props,
256  .filter_frame = geq_filter_frame,
257  },
258  { NULL }
259 };
260 
261 static const AVFilterPad geq_outputs[] = {
262  {
263  .name = "default",
264  .type = AVMEDIA_TYPE_VIDEO,
265  },
266  { NULL }
267 };
268 
269 AVFilter ff_vf_geq = {
270  .name = "geq",
271  .description = NULL_IF_CONFIG_SMALL("Apply generic equation to each pixel."),
272  .priv_size = sizeof(GEQContext),
273  .init = geq_init,
274  .uninit = geq_uninit,
275  .query_formats = geq_query_formats,
276  .inputs = geq_inputs,
277  .outputs = geq_outputs,
278  .priv_class = &geq_class,
279  .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
280 };
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