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