2 * Copyright (c) 2010 Stefano Sabatini
3 * Copyright (c) 2008 Victor Paesa
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (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 GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * video presentation timestamp (PTS) modification filter
29 #include "libavutil/eval.h"
30 #include "libavutil/mathematics.h"
33 static const char *const var_names[] = {
34 "INTERLACED", ///< tell if the current frame is interlaced
35 "N", ///< frame number (starting at zero)
36 "POS", ///< original position in the file of the frame
37 "PREV_INPTS", ///< previous input PTS
38 "PREV_OUTPTS", ///< previous output PTS
39 "PTS", ///< original pts in the file of the frame
40 "STARTPTS", ///< PTS at start of movie
59 double var_values[VAR_VARS_NB];
62 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
64 SetPTSContext *setpts = ctx->priv;
67 if ((ret = av_expr_parse(&setpts->expr, args ? args : "PTS",
68 var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) {
69 av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n", args);
73 setpts->var_values[VAR_N ] = 0.0;
74 setpts->var_values[VAR_PREV_INPTS ] = NAN;
75 setpts->var_values[VAR_PREV_OUTPTS] = NAN;
76 setpts->var_values[VAR_STARTPTS ] = NAN;
80 static int config_input(AVFilterLink *inlink)
82 SetPTSContext *setpts = inlink->dst->priv;
84 setpts->var_values[VAR_TB] = av_q2d(inlink->time_base);
86 av_log(inlink->src, AV_LOG_INFO, "TB:%f\n", setpts->var_values[VAR_TB]);
90 #define D2TS(d) (isnan(d) ? AV_NOPTS_VALUE : (int64_t)(d))
91 #define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts))
93 static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
95 SetPTSContext *setpts = inlink->dst->priv;
97 AVFilterBufferRef *outpicref = avfilter_ref_buffer(inpicref, ~0);
99 if (isnan(setpts->var_values[VAR_STARTPTS]))
100 setpts->var_values[VAR_STARTPTS] = TS2D(inpicref->pts);
102 setpts->var_values[VAR_INTERLACED] = inpicref->video->interlaced;
103 setpts->var_values[VAR_PTS ] = TS2D(inpicref->pts);
104 setpts->var_values[VAR_POS ] = inpicref->pos == -1 ? NAN : inpicref->pos;
106 d = av_expr_eval(setpts->expr, setpts->var_values, NULL);
107 outpicref->pts = D2TS(d);
110 av_log(inlink->dst, AV_LOG_DEBUG,
111 "n:%"PRId64" interlaced:%d pos:%"PRId64" pts:%"PRId64" t:%f -> pts:%"PRId64" t:%f\n",
112 (int64_t)setpts->var_values[VAR_N],
113 (int)setpts->var_values[VAR_INTERLACED],
115 inpicref ->pts, inpicref ->pts * av_q2d(inlink->time_base),
116 outpicref->pts, outpicref->pts * av_q2d(inlink->time_base));
119 setpts->var_values[VAR_N] += 1.0;
120 setpts->var_values[VAR_PREV_INPTS ] = TS2D(inpicref ->pts);
121 setpts->var_values[VAR_PREV_OUTPTS] = TS2D(outpicref->pts);
122 avfilter_start_frame(inlink->dst->outputs[0], outpicref);
125 static av_cold void uninit(AVFilterContext *ctx)
127 SetPTSContext *setpts = ctx->priv;
128 av_expr_free(setpts->expr);
132 AVFilter avfilter_vf_setpts = {
134 .description = NULL_IF_CONFIG_SMALL("Set PTS for the output video frame."),
138 .priv_size = sizeof(SetPTSContext),
140 .inputs = (const AVFilterPad[]) {{ .name = "default",
141 .type = AVMEDIA_TYPE_VIDEO,
142 .get_video_buffer = avfilter_null_get_video_buffer,
143 .config_props = config_input,
144 .start_frame = start_frame, },
146 .outputs = (const AVFilterPad[]) {{ .name = "default",
147 .type = AVMEDIA_TYPE_VIDEO, },