2 * Copyright (c) 2010 Stefano Sabatini
4 * This file is part of Libav.
6 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * Set timebase for the output link.
29 #include "libavutil/avstring.h"
30 #include "libavutil/eval.h"
31 #include "libavutil/internal.h"
32 #include "libavutil/mathematics.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/rational.h"
39 static const char *const var_names[] = {
43 "AVTB", /* default timebase 1/AV_TIME_BASE */
44 "intb", /* input timebase */
60 double var_values[VAR_VARS_NB];
63 static int config_output_props(AVFilterLink *outlink)
65 AVFilterContext *ctx = outlink->src;
66 SetTBContext *settb = ctx->priv;
67 AVFilterLink *inlink = ctx->inputs[0];
72 settb->var_values[VAR_E] = M_E;
73 settb->var_values[VAR_PHI] = M_PHI;
74 settb->var_values[VAR_PI] = M_PI;
75 settb->var_values[VAR_AVTB] = av_q2d(AV_TIME_BASE_Q);
76 settb->var_values[VAR_INTB] = av_q2d(inlink->time_base);
78 outlink->w = inlink->w;
79 outlink->h = inlink->h;
81 if ((ret = av_expr_parse_and_eval(&res, settb->tb_expr, var_names, settb->var_values,
82 NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) {
83 av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", settb->tb_expr);
86 time_base = av_d2q(res, INT_MAX);
87 if (time_base.num <= 0 || time_base.den <= 0) {
88 av_log(ctx, AV_LOG_ERROR,
89 "Invalid non-positive values for the timebase num:%d or den:%d.\n",
90 time_base.num, time_base.den);
91 return AVERROR(EINVAL);
94 outlink->time_base = time_base;
95 av_log(outlink->src, AV_LOG_VERBOSE, "tb:%d/%d -> tb:%d/%d\n",
96 inlink ->time_base.num, inlink ->time_base.den,
97 outlink->time_base.num, outlink->time_base.den);
102 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
104 AVFilterContext *ctx = inlink->dst;
105 AVFilterLink *outlink = ctx->outputs[0];
107 if (av_cmp_q(inlink->time_base, outlink->time_base)) {
108 int64_t orig_pts = frame->pts;
109 frame->pts = av_rescale_q(frame->pts, inlink->time_base, outlink->time_base);
110 av_log(ctx, AV_LOG_DEBUG, "tb:%d/%d pts:%"PRId64" -> tb:%d/%d pts:%"PRId64"\n",
111 inlink ->time_base.num, inlink ->time_base.den, orig_pts,
112 outlink->time_base.num, outlink->time_base.den, frame->pts);
115 return ff_filter_frame(outlink, frame);
118 #define OFFSET(x) offsetof(SetTBContext, x)
119 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM
120 static const AVOption options[] = {
121 { "expr", "Expression determining the output timebase", OFFSET(tb_expr), AV_OPT_TYPE_STRING, { .str = "intb" }, .flags = FLAGS },
125 static const AVClass settb_class = {
126 .class_name = "settb",
127 .item_name = av_default_item_name,
129 .version = LIBAVUTIL_VERSION_INT,
132 static const AVFilterPad avfilter_vf_settb_inputs[] = {
135 .type = AVMEDIA_TYPE_VIDEO,
136 .get_video_buffer = ff_null_get_video_buffer,
137 .filter_frame = filter_frame,
142 static const AVFilterPad avfilter_vf_settb_outputs[] = {
145 .type = AVMEDIA_TYPE_VIDEO,
146 .config_props = config_output_props,
151 AVFilter ff_vf_settb = {
153 .description = NULL_IF_CONFIG_SMALL("Set timebase for the output link."),
155 .priv_size = sizeof(SetTBContext),
156 .priv_class = &settb_class,
158 .inputs = avfilter_vf_settb_inputs,
160 .outputs = avfilter_vf_settb_outputs,