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"
37 #define FF_INTERNAL_FIELDS 1
38 #include "framequeue.h"
43 typedef struct FPSContext {
46 AVFifoBuffer *fifo; ///< store frames until we get two successive timestamps
48 /* timestamps in input timebase */
49 int64_t first_pts; ///< pts of the first frame that arrived on this filter
51 double start_time; ///< pts, in seconds, of the expected first frame
53 AVRational framerate; ///< target framerate
54 int rounding; ///< AVRounding method for timestamps
57 int frames_in; ///< number of frames on input
58 int frames_out; ///< number of frames on output
59 int dup; ///< number of frames duplicated
60 int drop; ///< number of framed dropped
63 #define OFFSET(x) offsetof(FPSContext, x)
64 #define V AV_OPT_FLAG_VIDEO_PARAM
65 #define F AV_OPT_FLAG_FILTERING_PARAM
66 static const AVOption fps_options[] = {
67 { "fps", "A string describing desired output framerate", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, { .str = "25" }, 0, INT_MAX, V|F },
68 { "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 },
69 { "round", "set rounding method for timestamps", OFFSET(rounding), AV_OPT_TYPE_INT, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" },
70 { "zero", "round towards 0", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_ZERO }, 0, 5, V|F, "round" },
71 { "inf", "round away from 0", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_INF }, 0, 5, V|F, "round" },
72 { "down", "round towards -infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_DOWN }, 0, 5, V|F, "round" },
73 { "up", "round towards +infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_UP }, 0, 5, V|F, "round" },
74 { "near", "round to nearest", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" },
78 AVFILTER_DEFINE_CLASS(fps);
80 static av_cold int init(AVFilterContext *ctx)
82 FPSContext *s = ctx->priv;
84 if (!(s->fifo = av_fifo_alloc_array(2, sizeof(AVFrame*))))
85 return AVERROR(ENOMEM);
87 s->first_pts = AV_NOPTS_VALUE;
89 av_log(ctx, AV_LOG_VERBOSE, "fps=%d/%d\n", s->framerate.num, s->framerate.den);
93 static void flush_fifo(AVFifoBuffer *fifo)
95 while (av_fifo_size(fifo)) {
97 av_fifo_generic_read(fifo, &tmp, sizeof(tmp), NULL);
102 static av_cold void uninit(AVFilterContext *ctx)
104 FPSContext *s = ctx->priv;
106 s->drop += av_fifo_size(s->fifo) / sizeof(AVFrame*);
108 av_fifo_freep(&s->fifo);
111 av_log(ctx, AV_LOG_VERBOSE, "%d frames in, %d frames out; %d frames dropped, "
112 "%d frames duplicated.\n", s->frames_in, s->frames_out, s->drop, s->dup);
115 static int config_props(AVFilterLink* link)
117 FPSContext *s = link->src->priv;
119 link->time_base = av_inv_q(s->framerate);
120 link->frame_rate= s->framerate;
121 link->w = link->src->inputs[0]->w;
122 link->h = link->src->inputs[0]->h;
127 static int request_frame(AVFilterLink *outlink)
129 AVFilterContext *ctx = outlink->src;
130 FPSContext *s = ctx->priv;
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 if (av_fifo_size(s->fifo)) {
143 buf->pts = av_rescale_q(s->first_pts, ctx->inputs[0]->time_base,
144 outlink->time_base) + s->frames_out;
146 if ((ret = ff_filter_frame(outlink, buf)) < 0)
151 /* This is the last frame, we may have to duplicate it to match
152 * the last frame duration */
154 int delta = av_rescale_q_rnd(ctx->inputs[0]->current_pts - s->first_pts,
155 ctx->inputs[0]->time_base,
156 outlink->time_base, s->rounding) - s->frames_out ;
157 /* if the delta is equal to 1, it means we just need to output
158 * the last frame. Greater than 1 means we will need duplicate
161 for (j = 0; j < delta; j++) {
162 AVFrame *dup = av_frame_clone(buf);
164 av_log(ctx, AV_LOG_DEBUG, "Duplicating frame.\n");
165 dup->pts = av_rescale_q(s->first_pts, ctx->inputs[0]->time_base,
166 outlink->time_base) + s->frames_out;
168 if ((ret = ff_filter_frame(outlink, dup)) < 0)
175 /* for delta less or equal to 0, we should drop the frame,
176 * otherwise, we will have one or more extra frames */
188 static int write_to_fifo(AVFifoBuffer *fifo, AVFrame *buf)
192 if (!av_fifo_space(fifo) &&
193 (ret = av_fifo_realloc2(fifo, 2*av_fifo_size(fifo)))) {
198 av_fifo_generic_write(fifo, &buf, sizeof(buf), NULL);
202 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
204 AVFilterContext *ctx = inlink->dst;
205 FPSContext *s = ctx->priv;
206 AVFilterLink *outlink = ctx->outputs[0];
211 /* discard frames until we get the first timestamp */
212 if (s->first_pts == AV_NOPTS_VALUE) {
213 if (buf->pts != AV_NOPTS_VALUE) {
214 ret = write_to_fifo(s->fifo, buf);
218 if (s->start_time != DBL_MAX && s->start_time != AV_NOPTS_VALUE) {
219 double first_pts = s->start_time * AV_TIME_BASE;
220 first_pts = FFMIN(FFMAX(first_pts, INT64_MIN), INT64_MAX);
221 s->first_pts = av_rescale_q(first_pts, AV_TIME_BASE_Q,
223 av_log(ctx, AV_LOG_VERBOSE, "Set first pts to (in:%"PRId64" out:%"PRId64")\n",
224 s->first_pts, av_rescale_q(first_pts, AV_TIME_BASE_Q,
225 outlink->time_base));
227 s->first_pts = buf->pts;
230 av_log(ctx, AV_LOG_WARNING, "Discarding initial frame(s) with no "
238 /* now wait for the next timestamp */
239 if (buf->pts == AV_NOPTS_VALUE || av_fifo_size(s->fifo) <= 0) {
240 return write_to_fifo(s->fifo, buf);
243 /* number of output frames */
244 delta = av_rescale_q_rnd(buf->pts - s->first_pts, inlink->time_base,
245 outlink->time_base, s->rounding) - s->frames_out ;
248 /* drop everything buffered except the last */
249 int drop = av_fifo_size(s->fifo)/sizeof(AVFrame*);
251 av_log(ctx, AV_LOG_DEBUG, "Dropping %d frame(s).\n", drop);
255 ret = write_to_fifo(s->fifo, buf);
260 /* can output >= 1 frames */
261 for (i = 0; i < delta; i++) {
263 av_fifo_generic_read(s->fifo, &buf_out, sizeof(buf_out), NULL);
265 /* duplicate the frame if needed */
266 if (!av_fifo_size(s->fifo) && i < delta - 1) {
267 AVFrame *dup = av_frame_clone(buf_out);
269 av_log(ctx, AV_LOG_DEBUG, "Duplicating frame.\n");
271 ret = write_to_fifo(s->fifo, dup);
273 ret = AVERROR(ENOMEM);
276 av_frame_free(&buf_out);
284 buf_out->pts = av_rescale_q(s->first_pts, inlink->time_base,
285 outlink->time_base) + s->frames_out;
287 if ((ret = ff_filter_frame(outlink, buf_out)) < 0) {
296 ret = write_to_fifo(s->fifo, buf);
301 static const AVFilterPad avfilter_vf_fps_inputs[] = {
304 .type = AVMEDIA_TYPE_VIDEO,
305 .filter_frame = filter_frame,
310 static const AVFilterPad avfilter_vf_fps_outputs[] = {
313 .type = AVMEDIA_TYPE_VIDEO,
314 .request_frame = request_frame,
315 .config_props = config_props
320 AVFilter ff_vf_fps = {
322 .description = NULL_IF_CONFIG_SMALL("Force constant framerate."),
325 .priv_size = sizeof(FPSContext),
326 .priv_class = &fps_class,
327 .inputs = avfilter_vf_fps_inputs,
328 .outputs = avfilter_vf_fps_outputs,