2 * Copyright (c) 2010 Bobby Bingham
4 * This file is part of FFmpeg.
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.
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.
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
23 * aspect ratio modification video filters
26 #include "config_components.h"
30 #include "libavutil/common.h"
31 #include "libavutil/eval.h"
32 #include "libavutil/mathematics.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/parseutils.h"
35 #include "libavutil/pixdesc.h"
41 static const char *const var_names[] = {
63 typedef struct AspectContext {
71 static int filter_frame(AVFilterLink *link, AVFrame *frame)
73 AspectContext *s = link->dst->priv;
75 frame->sample_aspect_ratio = s->sar;
76 return ff_filter_frame(link->dst->outputs[0], frame);
79 #define OFFSET(x) offsetof(AspectContext, x)
80 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
82 static inline void compute_dar(AVRational *dar, AVRational sar, int w, int h)
84 if (sar.num && sar.den) {
85 av_reduce(&dar->num, &dar->den, sar.num * (int64_t)w, sar.den * (int64_t)h, INT_MAX);
87 av_reduce(&dar->num, &dar->den, w, h, INT_MAX);
91 static int get_aspect_ratio(AVFilterLink *inlink, AVRational *aspect_ratio)
93 AVFilterContext *ctx = inlink->dst;
94 AspectContext *s = inlink->dst->priv;
95 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
96 double var_values[VARS_NB], res;
99 var_values[VAR_W] = inlink->w;
100 var_values[VAR_H] = inlink->h;
101 var_values[VAR_A] = (double) inlink->w / inlink->h;
102 var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
103 (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
104 var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
105 var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
106 var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
108 /* evaluate new aspect ratio*/
109 ret = av_expr_parse_and_eval(&res, s->ratio_expr,
110 var_names, var_values,
111 NULL, NULL, NULL, NULL, NULL, 0, ctx);
113 ret = av_parse_ratio(aspect_ratio, s->ratio_expr, s->max, 0, ctx);
115 *aspect_ratio = av_d2q(res, s->max);
118 av_log(ctx, AV_LOG_ERROR,
119 "Error when evaluating the expression '%s'\n", s->ratio_expr);
122 if (aspect_ratio->num < 0 || aspect_ratio->den <= 0) {
123 av_log(ctx, AV_LOG_ERROR,
124 "Invalid string '%s' for aspect ratio\n", s->ratio_expr);
125 return AVERROR(EINVAL);
130 #if CONFIG_SETDAR_FILTER
132 static int setdar_config_props(AVFilterLink *outlink)
134 AVFilterContext *ctx = outlink->src;
135 AVFilterLink *inlink = ctx->inputs[0];
136 AspectContext *s = ctx->priv;
139 AVRational old_sar = inlink->sample_aspect_ratio;
142 if ((ret = get_aspect_ratio(inlink, &s->dar)))
145 if (s->dar.num && s->dar.den) {
146 av_reduce(&s->sar.num, &s->sar.den,
147 s->dar.num * inlink->h,
148 s->dar.den * inlink->w, INT_MAX);
149 outlink->sample_aspect_ratio = s->sar;
152 outlink->sample_aspect_ratio = (AVRational){ 1, 1 };
153 dar = (AVRational){ inlink->w, inlink->h };
156 compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
157 av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d dar:%d/%d sar:%d/%d -> dar:%d/%d sar:%d/%d\n",
158 inlink->w, inlink->h, old_dar.num, old_dar.den, old_sar.num, old_sar.den,
159 dar.num, dar.den, outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den);
164 static const AVOption setdar_options[] = {
165 { "dar", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
166 { "ratio", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
167 { "r", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
168 { "max", "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
172 AVFILTER_DEFINE_CLASS(setdar);
174 static const AVFilterPad avfilter_vf_setdar_inputs[] = {
177 .type = AVMEDIA_TYPE_VIDEO,
178 .filter_frame = filter_frame,
182 static const AVFilterPad avfilter_vf_setdar_outputs[] = {
185 .type = AVMEDIA_TYPE_VIDEO,
186 .config_props = setdar_config_props,
190 const AVFilter ff_vf_setdar = {
192 .description = NULL_IF_CONFIG_SMALL("Set the frame display aspect ratio."),
193 .priv_size = sizeof(AspectContext),
194 .priv_class = &setdar_class,
195 .flags = AVFILTER_FLAG_METADATA_ONLY,
196 FILTER_INPUTS(avfilter_vf_setdar_inputs),
197 FILTER_OUTPUTS(avfilter_vf_setdar_outputs),
200 #endif /* CONFIG_SETDAR_FILTER */
202 #if CONFIG_SETSAR_FILTER
204 static int setsar_config_props(AVFilterLink *outlink)
206 AVFilterContext *ctx = outlink->src;
207 AVFilterLink *inlink = ctx->inputs[0];
208 AspectContext *s = ctx->priv;
209 AVRational old_sar = inlink->sample_aspect_ratio;
210 AVRational old_dar, dar;
213 if ((ret = get_aspect_ratio(inlink, &s->sar)))
216 outlink->sample_aspect_ratio = s->sar;
218 compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
219 compute_dar(&dar, s->sar, inlink->w, inlink->h);
220 av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d dar:%d/%d -> sar:%d/%d dar:%d/%d\n",
221 inlink->w, inlink->h, old_sar.num, old_sar.den, old_dar.num, old_dar.den,
222 outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den, dar.num, dar.den);
227 static const AVOption setsar_options[] = {
228 { "sar", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
229 { "ratio", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
230 { "r", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
231 { "max", "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
235 AVFILTER_DEFINE_CLASS(setsar);
237 static const AVFilterPad avfilter_vf_setsar_inputs[] = {
240 .type = AVMEDIA_TYPE_VIDEO,
241 .filter_frame = filter_frame,
245 static const AVFilterPad avfilter_vf_setsar_outputs[] = {
248 .type = AVMEDIA_TYPE_VIDEO,
249 .config_props = setsar_config_props,
253 const AVFilter ff_vf_setsar = {
255 .description = NULL_IF_CONFIG_SMALL("Set the pixel sample aspect ratio."),
256 .priv_size = sizeof(AspectContext),
257 .priv_class = &setsar_class,
258 .flags = AVFILTER_FLAG_METADATA_ONLY,
259 FILTER_INPUTS(avfilter_vf_setsar_inputs),
260 FILTER_OUTPUTS(avfilter_vf_setsar_outputs),
263 #endif /* CONFIG_SETSAR_FILTER */