2 * Copyright (C) 2006 Michael Niedermayer <michaelni@gmx.at>
3 * Copyright (C) 2012 Clément Bœsch <ubitux@gmail.com>
5 * This file is part of FFmpeg.
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.
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.
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.
24 * Generic equation change filter
25 * Originally written by Michael Niedermayer for the MPlayer project, and
26 * ported by Clément Bœsch for FFmpeg.
29 #include "libavutil/avstring.h"
30 #include "libavutil/eval.h"
31 #include "libavutil/opt.h"
32 #include "libavutil/pixdesc.h"
37 AVExpr *e[4]; ///< expressions for each plane
38 char *expr_str[4]; ///< expression strings for each plane
39 int framenum; ///< frame counter
40 AVFilterBufferRef *picref; ///< current input buffer
41 int hsub, vsub; ///< chroma subsampling
42 int planes; ///< number of planes
45 #define OFFSET(x) offsetof(GEQContext, x)
46 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
48 static const AVOption geq_options[] = {
49 { "lum_expr", "set luminance expression", OFFSET(expr_str[0]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
50 { "cb_expr", "set chroma blue expression", OFFSET(expr_str[1]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
51 { "cr_expr", "set chroma red expression", OFFSET(expr_str[2]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
52 { "alpha_expr", "set alpha expression", OFFSET(expr_str[3]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
56 AVFILTER_DEFINE_CLASS(geq);
58 static inline double getpix(void *priv, double x, double y, int plane)
61 GEQContext *geq = priv;
62 AVFilterBufferRef *picref = geq->picref;
63 const uint8_t *src = picref->data[plane];
64 const int linesize = picref->linesize[plane];
65 const int w = picref->video->w >> ((plane == 1 || plane == 2) ? geq->hsub : 0);
66 const int h = picref->video->h >> ((plane == 1 || plane == 2) ? geq->vsub : 0);
71 xi = x = av_clipf(x, 0, w - 2);
72 yi = y = av_clipf(y, 0, h - 2);
77 return (1-y)*((1-x)*src[xi + yi * linesize] + x*src[xi + 1 + yi * linesize])
78 + y *((1-x)*src[xi + (yi+1) * linesize] + x*src[xi + 1 + (yi+1) * linesize]);
81 //TODO: cubic interpolate
82 //TODO: keep the last few frames
83 static double lum(void *priv, double x, double y) { return getpix(priv, x, y, 0); }
84 static double cb(void *priv, double x, double y) { return getpix(priv, x, y, 1); }
85 static double cr(void *priv, double x, double y) { return getpix(priv, x, y, 2); }
86 static double alpha(void *priv, double x, double y) { return getpix(priv, x, y, 3); }
88 static const char *const var_names[] = { "X", "Y", "W", "H", "N", "SW", "SH", "T", NULL };
89 enum { VAR_X, VAR_Y, VAR_W, VAR_H, VAR_N, VAR_SW, VAR_SH, VAR_T, VAR_VARS_NB };
91 static av_cold int geq_init(AVFilterContext *ctx, const char *args)
93 GEQContext *geq = ctx->priv;
95 static const char *shorthand[] = { "lum_expr", "cb_expr", "cr_expr", "alpha_expr", NULL };
97 geq->class = &geq_class;
98 av_opt_set_defaults(geq);
100 if ((ret = av_opt_set_from_string(geq, args, shorthand, "=", ":")) < 0)
103 if (!geq->expr_str[0]) {
104 av_log(ctx, AV_LOG_ERROR, "Luminance expression is mandatory\n");
105 ret = AVERROR(EINVAL);
109 if (!geq->expr_str[1] && !geq->expr_str[2]) {
110 /* No chroma at all: fallback on luma */
111 geq->expr_str[1] = av_strdup(geq->expr_str[0]);
112 geq->expr_str[2] = av_strdup(geq->expr_str[0]);
114 /* One chroma unspecified, fallback on the other */
115 if (!geq->expr_str[1]) geq->expr_str[1] = av_strdup(geq->expr_str[2]);
116 if (!geq->expr_str[2]) geq->expr_str[2] = av_strdup(geq->expr_str[1]);
119 if (!geq->expr_str[3])
120 geq->expr_str[3] = av_strdup("255");
122 if (!geq->expr_str[1] || !geq->expr_str[2] || !geq->expr_str[3]) {
123 ret = AVERROR(ENOMEM);
127 for (plane = 0; plane < 4; plane++) {
128 static double (*p[])(void *, double, double) = { lum, cb, cr, alpha };
129 static const char *const func2_names[] = { "lum", "cb", "cr", "alpha", "p", NULL };
130 double (*func2[])(void *, double, double) = { lum, cb, cr, alpha, p[plane], NULL };
132 ret = av_expr_parse(&geq->e[plane], geq->expr_str[plane], var_names,
133 NULL, NULL, func2_names, func2, 0, ctx);
142 static int geq_query_formats(AVFilterContext *ctx)
144 static const enum PixelFormat pix_fmts[] = {
145 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P,
146 AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P,
147 AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
151 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
155 static int geq_config_props(AVFilterLink *inlink)
157 GEQContext *geq = inlink->dst->priv;
158 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
160 geq->hsub = desc->log2_chroma_w;
161 geq->vsub = desc->log2_chroma_h;
162 geq->planes = desc->nb_components;
166 static int geq_filter_frame(AVFilterLink *inlink, AVFilterBufferRef *in)
169 GEQContext *geq = inlink->dst->priv;
170 AVFilterLink *outlink = inlink->dst->outputs[0];
171 AVFilterBufferRef *out;
172 double values[VAR_VARS_NB] = {
173 [VAR_N] = geq->framenum++,
174 [VAR_T] = in->pts == AV_NOPTS_VALUE ? NAN : in->pts * av_q2d(inlink->time_base),
178 out = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
180 avfilter_unref_bufferp(&in);
181 return AVERROR(ENOMEM);
183 avfilter_copy_buffer_ref_props(out, in);
185 for (plane = 0; plane < geq->planes && out->data[plane]; plane++) {
187 uint8_t *dst = out->data[plane];
188 const int linesize = out->linesize[plane];
189 const int w = inlink->w >> ((plane == 1 || plane == 2) ? geq->hsub : 0);
190 const int h = inlink->h >> ((plane == 1 || plane == 2) ? geq->vsub : 0);
194 values[VAR_SW] = w / (double)inlink->w;
195 values[VAR_SH] = h / (double)inlink->h;
197 for (y = 0; y < h; y++) {
199 for (x = 0; x < w; x++) {
201 dst[x] = av_expr_eval(geq->e[plane], values, geq);
207 avfilter_unref_bufferp(&geq->picref);
208 return ff_filter_frame(outlink, out);
211 static av_cold void geq_uninit(AVFilterContext *ctx)
214 GEQContext *geq = ctx->priv;
216 for (i = 0; i < FF_ARRAY_ELEMS(geq->e); i++)
217 av_expr_free(geq->e[i]);
221 static const AVFilterPad geq_inputs[] = {
224 .type = AVMEDIA_TYPE_VIDEO,
225 .config_props = geq_config_props,
226 .filter_frame = geq_filter_frame,
227 .min_perms = AV_PERM_READ,
232 static const AVFilterPad geq_outputs[] = {
235 .type = AVMEDIA_TYPE_VIDEO,
240 AVFilter avfilter_vf_geq = {
242 .description = NULL_IF_CONFIG_SMALL("Apply generic equation to each pixel."),
243 .priv_size = sizeof(GEQContext),
245 .uninit = geq_uninit,
246 .query_formats = geq_query_formats,
247 .inputs = geq_inputs,
248 .outputs = geq_outputs,
249 .priv_class = &geq_class,