2 * Copyright 2007 Bobby Bingham
3 * Copyright 2012 Robert Nagy <ronag89 gmail com>
4 * Copyright 2012 Anton Khirnov <anton khirnov net>
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 * a filter enforcing given constant framerate
31 #include "libavutil/common.h"
32 #include "libavutil/fifo.h"
33 #include "libavutil/mathematics.h"
34 #include "libavutil/opt.h"
35 #include "libavutil/parseutils.h"
41 typedef struct FPSContext {
44 AVFifoBuffer *fifo; ///< store frames until we get two successive timestamps
46 /* timestamps in input timebase */
47 int64_t first_pts; ///< pts of the first frame that arrived on this filter
49 double start_time; ///< pts, in seconds, of the expected first frame
51 AVRational framerate; ///< target framerate
52 int rounding; ///< AVRounding method for timestamps
55 int frames_in; ///< number of frames on input
56 int frames_out; ///< number of frames on output
57 int dup; ///< number of frames duplicated
58 int drop; ///< number of framed dropped
61 #define OFFSET(x) offsetof(FPSContext, x)
62 #define V AV_OPT_FLAG_VIDEO_PARAM
63 #define F AV_OPT_FLAG_FILTERING_PARAM
64 static const AVOption fps_options[] = {
65 { "fps", "A string describing desired output framerate", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, { .str = "25" }, .flags = V|F },
66 { "start_time", "Assume the first PTS should be this value.", OFFSET(start_time), AV_OPT_TYPE_DOUBLE, { .dbl = DBL_MAX}, -DBL_MAX, DBL_MAX, V },
67 { "round", "set rounding method for timestamps", OFFSET(rounding), AV_OPT_TYPE_INT, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" },
68 { "zero", "round towards 0", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_ZERO }, 0, 5, V|F, "round" },
69 { "inf", "round away from 0", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_INF }, 0, 5, V|F, "round" },
70 { "down", "round towards -infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_DOWN }, 0, 5, V|F, "round" },
71 { "up", "round towards +infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_UP }, 0, 5, V|F, "round" },
72 { "near", "round to nearest", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" },
76 AVFILTER_DEFINE_CLASS(fps);
78 static av_cold int init(AVFilterContext *ctx)
80 FPSContext *s = ctx->priv;
82 if (!(s->fifo = av_fifo_alloc_array(2, sizeof(AVFrame*))))
83 return AVERROR(ENOMEM);
85 s->first_pts = AV_NOPTS_VALUE;
87 av_log(ctx, AV_LOG_VERBOSE, "fps=%d/%d\n", s->framerate.num, s->framerate.den);
91 static void flush_fifo(AVFifoBuffer *fifo)
93 while (av_fifo_size(fifo)) {
95 av_fifo_generic_read(fifo, &tmp, sizeof(tmp), NULL);
100 static av_cold void uninit(AVFilterContext *ctx)
102 FPSContext *s = ctx->priv;
104 s->drop += av_fifo_size(s->fifo) / sizeof(AVFrame*);
106 av_fifo_freep(&s->fifo);
109 av_log(ctx, AV_LOG_VERBOSE, "%d frames in, %d frames out; %d frames dropped, "
110 "%d frames duplicated.\n", s->frames_in, s->frames_out, s->drop, s->dup);
113 static int config_props(AVFilterLink* link)
115 FPSContext *s = link->src->priv;
117 link->time_base = av_inv_q(s->framerate);
118 link->frame_rate= s->framerate;
119 link->w = link->src->inputs[0]->w;
120 link->h = link->src->inputs[0]->h;
125 static int request_frame(AVFilterLink *outlink)
127 AVFilterContext *ctx = outlink->src;
128 FPSContext *s = ctx->priv;
129 int frames_out = s->frames_out;
132 while (ret >= 0 && s->frames_out == frames_out)
133 ret = ff_request_frame(ctx->inputs[0]);
136 if (ret == AVERROR_EOF && av_fifo_size(s->fifo)) {
138 for (i = 0; av_fifo_size(s->fifo); i++) {
141 av_fifo_generic_read(s->fifo, &buf, sizeof(buf), NULL);
142 buf->pts = av_rescale_q(s->first_pts, ctx->inputs[0]->time_base,
143 outlink->time_base) + s->frames_out;
145 if ((ret = ff_filter_frame(outlink, buf)) < 0)
156 static int write_to_fifo(AVFifoBuffer *fifo, AVFrame *buf)
160 if (!av_fifo_space(fifo) &&
161 (ret = av_fifo_realloc2(fifo, 2*av_fifo_size(fifo)))) {
166 av_fifo_generic_write(fifo, &buf, sizeof(buf), NULL);
170 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
172 AVFilterContext *ctx = inlink->dst;
173 FPSContext *s = ctx->priv;
174 AVFilterLink *outlink = ctx->outputs[0];
179 /* discard frames until we get the first timestamp */
180 if (s->first_pts == AV_NOPTS_VALUE) {
181 if (buf->pts != AV_NOPTS_VALUE) {
182 ret = write_to_fifo(s->fifo, buf);
186 if (s->start_time != DBL_MAX && s->start_time != AV_NOPTS_VALUE) {
187 double first_pts = s->start_time * AV_TIME_BASE;
188 first_pts = FFMIN(FFMAX(first_pts, INT64_MIN), INT64_MAX);
189 s->first_pts = av_rescale_q(first_pts, AV_TIME_BASE_Q,
191 av_log(ctx, AV_LOG_VERBOSE, "Set first pts to (in:%"PRId64" out:%"PRId64")\n",
192 s->first_pts, av_rescale_q(first_pts, AV_TIME_BASE_Q,
193 outlink->time_base));
195 s->first_pts = buf->pts;
198 av_log(ctx, AV_LOG_WARNING, "Discarding initial frame(s) with no "
206 /* now wait for the next timestamp */
207 if (buf->pts == AV_NOPTS_VALUE || av_fifo_size(s->fifo) <= 0) {
208 return write_to_fifo(s->fifo, buf);
211 /* number of output frames */
212 delta = av_rescale_q_rnd(buf->pts - s->first_pts, inlink->time_base,
213 outlink->time_base, s->rounding) - s->frames_out ;
216 /* drop everything buffered except the last */
217 int drop = av_fifo_size(s->fifo)/sizeof(AVFrame*);
219 av_log(ctx, AV_LOG_DEBUG, "Dropping %d frame(s).\n", drop);
223 ret = write_to_fifo(s->fifo, buf);
228 /* can output >= 1 frames */
229 for (i = 0; i < delta; i++) {
231 av_fifo_generic_read(s->fifo, &buf_out, sizeof(buf_out), NULL);
233 /* duplicate the frame if needed */
234 if (!av_fifo_size(s->fifo) && i < delta - 1) {
235 AVFrame *dup = av_frame_clone(buf_out);
237 av_log(ctx, AV_LOG_DEBUG, "Duplicating frame.\n");
239 ret = write_to_fifo(s->fifo, dup);
241 ret = AVERROR(ENOMEM);
244 av_frame_free(&buf_out);
252 buf_out->pts = av_rescale_q(s->first_pts, inlink->time_base,
253 outlink->time_base) + s->frames_out;
255 if ((ret = ff_filter_frame(outlink, buf_out)) < 0) {
264 ret = write_to_fifo(s->fifo, buf);
269 static const AVFilterPad avfilter_vf_fps_inputs[] = {
272 .type = AVMEDIA_TYPE_VIDEO,
273 .filter_frame = filter_frame,
278 static const AVFilterPad avfilter_vf_fps_outputs[] = {
281 .type = AVMEDIA_TYPE_VIDEO,
282 .request_frame = request_frame,
283 .config_props = config_props
288 AVFilter ff_vf_fps = {
290 .description = NULL_IF_CONFIG_SMALL("Force constant framerate."),
293 .priv_size = sizeof(FPSContext),
294 .priv_class = &fps_class,
295 .inputs = avfilter_vf_fps_inputs,
296 .outputs = avfilter_vf_fps_outputs,