Commit 54c5dd89 authored by Anton Khirnov's avatar Anton Khirnov

lavfi: Add fps filter.

Partially based on a patch by Robert Nagy <ronag89@gmail.com>
parent 7b3b24a8
......@@ -18,6 +18,7 @@ version <next>:
- drop support for avconv without libavfilter
- add libavresample audio conversion library
- audio filters support in libavfilter and avconv
- add fps filter
version 0.8:
......
......@@ -814,6 +814,19 @@ format=yuv420p
format=yuv420p:yuv444p:yuv410p
@end example
@section fps
Convert the video to specified constant framerate by duplicating or dropping
frames as necessary.
This filter accepts the following named parameters:
@table @option
@item fps
Desired output framerate.
@end table
@anchor{frei0r}
@section frei0r
......
......@@ -46,6 +46,7 @@ OBJS-$(CONFIG_FADE_FILTER) += vf_fade.o
OBJS-$(CONFIG_FIELDORDER_FILTER) += vf_fieldorder.o
OBJS-$(CONFIG_FIFO_FILTER) += vf_fifo.o
OBJS-$(CONFIG_FORMAT_FILTER) += vf_format.o
OBJS-$(CONFIG_FPS_FILTER) += vf_fps.o
OBJS-$(CONFIG_FREI0R_FILTER) += vf_frei0r.o
OBJS-$(CONFIG_GRADFUN_FILTER) += vf_gradfun.o
OBJS-$(CONFIG_HFLIP_FILTER) += vf_hflip.o
......
......@@ -55,6 +55,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (FIELDORDER, fieldorder, vf);
REGISTER_FILTER (FIFO, fifo, vf);
REGISTER_FILTER (FORMAT, format, vf);
REGISTER_FILTER (FPS, fps, vf);
REGISTER_FILTER (FREI0R, frei0r, vf);
REGISTER_FILTER (GRADFUN, gradfun, vf);
REGISTER_FILTER (HFLIP, hflip, vf);
......
......@@ -29,7 +29,7 @@
#include "libavutil/avutil.h"
#define LIBAVFILTER_VERSION_MAJOR 2
#define LIBAVFILTER_VERSION_MINOR 17
#define LIBAVFILTER_VERSION_MINOR 18
#define LIBAVFILTER_VERSION_MICRO 0
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
......
/*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* a filter enforcing given constant framerate
*/
#include "libavutil/fifo.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "avfilter.h"
typedef struct FPSContext {
const AVClass *class;
AVFifoBuffer *fifo; ///< store frames until we get two successive timestamps
/* timestamps in input timebase */
int64_t first_pts; ///< pts of the first frame that arrived on this filter
int64_t pts; ///< pts of the first frame currently in the fifo
AVRational framerate; ///< target framerate
char *fps; ///< a string describing target framerate
/* statistics */
int frames_in; ///< number of frames on input
int frames_out; ///< number of frames on output
int dup; ///< number of frames duplicated
int drop; ///< number of framed dropped
} FPSContext;
#define OFFSET(x) offsetof(FPSContext, x)
#define V AV_OPT_FLAG_VIDEO_PARAM
static const AVOption options[] = {
{ "fps", "A string describing desired output framerate", OFFSET(fps), AV_OPT_TYPE_STRING, { .str = "25" }, .flags = V },
{ NULL },
};
static const AVClass class = {
.class_name = "FPS filter",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
FPSContext *s = ctx->priv;
int ret;
s->class = &class;
av_opt_set_defaults(s);
if ((ret = av_set_options_string(s, args, "=", ":")) < 0) {
av_log(ctx, AV_LOG_ERROR, "Error parsing the options string %s.\n",
args);
return ret;
}
if ((ret = av_parse_video_rate(&s->framerate, s->fps)) < 0) {
av_log(ctx, AV_LOG_ERROR, "Error parsing framerate %s.\n", s->fps);
return ret;
}
av_opt_free(s);
if (!(s->fifo = av_fifo_alloc(2*sizeof(AVFilterBufferRef*))))
return AVERROR(ENOMEM);
av_log(ctx, AV_LOG_VERBOSE, "fps=%d/%d\n", s->framerate.num, s->framerate.den);
return 0;
}
static void flush_fifo(AVFifoBuffer *fifo)
{
while (av_fifo_size(fifo)) {
AVFilterBufferRef *tmp;
av_fifo_generic_read(fifo, &tmp, sizeof(tmp), NULL);
avfilter_unref_buffer(tmp);
}
}
static av_cold void uninit(AVFilterContext *ctx)
{
FPSContext *s = ctx->priv;
if (s->fifo) {
flush_fifo(s->fifo);
av_fifo_free(s->fifo);
}
av_log(ctx, AV_LOG_VERBOSE, "%d frames in, %d frames out; %d frames dropped, "
"%d frames duplicated.\n", s->frames_in, s->frames_out, s->drop, s->dup);
}
static int config_props(AVFilterLink* link)
{
FPSContext *s = link->src->priv;
link->time_base = (AVRational){ s->framerate.den, s->framerate.num };
link->w = link->src->inputs[0]->w;
link->h = link->src->inputs[0]->h;
s->pts = AV_NOPTS_VALUE;
return 0;
}
static int request_frame(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
FPSContext *s = ctx->priv;
int frames_out = s->frames_out;
int ret = 0;
while (ret >= 0 && s->frames_out == frames_out)
ret = avfilter_request_frame(ctx->inputs[0]);
/* flush the fifo */
if (ret == AVERROR_EOF && av_fifo_size(s->fifo)) {
int i;
for (i = 0; av_fifo_size(s->fifo); i++) {
AVFilterBufferRef *buf;
av_fifo_generic_read(s->fifo, &buf, sizeof(buf), NULL);
buf->pts = av_rescale_q(s->first_pts, ctx->inputs[0]->time_base,
outlink->time_base) + s->frames_out;
avfilter_start_frame(outlink, buf);
avfilter_draw_slice(outlink, 0, outlink->h, 1);
avfilter_end_frame(outlink);
s->frames_out++;
}
return 0;
}
return ret;
}
static int write_to_fifo(AVFifoBuffer *fifo, AVFilterBufferRef *buf)
{
int ret;
if (!av_fifo_space(fifo) &&
(ret = av_fifo_realloc2(fifo, 2*av_fifo_size(fifo))))
return ret;
av_fifo_generic_write(fifo, &buf, sizeof(buf), NULL);
return 0;
}
static void end_frame(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
FPSContext *s = ctx->priv;
AVFilterLink *outlink = ctx->outputs[0];
AVFilterBufferRef *buf = inlink->cur_buf;
int64_t delta;
int i;
s->frames_in++;
/* discard frames until we get the first timestamp */
if (s->pts == AV_NOPTS_VALUE) {
if (buf->pts != AV_NOPTS_VALUE) {
write_to_fifo(s->fifo, buf);
s->first_pts = s->pts = buf->pts;
} else {
av_log(ctx, AV_LOG_WARNING, "Discarding initial frame(s) with no "
"timestamp.\n");
avfilter_unref_buffer(buf);
s->drop++;
}
return;
}
/* now wait for the next timestamp */
if (buf->pts == AV_NOPTS_VALUE) {
write_to_fifo(s->fifo, buf);
return;
}
/* number of output frames */
delta = av_rescale_q(buf->pts - s->pts, inlink->time_base,
outlink->time_base);
if (delta < 1) {
/* drop the frame and everything buffered except the first */
AVFilterBufferRef *tmp;
int drop = av_fifo_size(s->fifo)/sizeof(AVFilterBufferRef*);
av_log(ctx, AV_LOG_DEBUG, "Dropping %d frame(s).\n", drop);
s->drop += drop;
av_fifo_generic_read(s->fifo, &tmp, sizeof(tmp), NULL);
flush_fifo(s->fifo);
write_to_fifo(s->fifo, tmp);
avfilter_unref_buffer(buf);
return;
}
/* can output >= 1 frames */
for (i = 0; i < delta; i++) {
AVFilterBufferRef *buf_out;
av_fifo_generic_read(s->fifo, &buf_out, sizeof(buf_out), NULL);
/* duplicate the frame if needed */
if (!av_fifo_size(s->fifo) && i < delta - 1) {
av_log(ctx, AV_LOG_DEBUG, "Duplicating frame.\n");
write_to_fifo(s->fifo, avfilter_ref_buffer(buf_out, AV_PERM_READ));
s->dup++;
}
buf_out->pts = av_rescale_q(s->first_pts, inlink->time_base,
outlink->time_base) + s->frames_out;
avfilter_start_frame(outlink, buf_out);
avfilter_draw_slice(outlink, 0, outlink->h, 1);
avfilter_end_frame(outlink);
s->frames_out++;
}
flush_fifo(s->fifo);
write_to_fifo(s->fifo, buf);
s->pts = s->first_pts + av_rescale_q(s->frames_out, outlink->time_base, inlink->time_base);
}
static void null_start_frame(AVFilterLink *link, AVFilterBufferRef *buf)
{
}
static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
{
}
AVFilter avfilter_vf_fps = {
.name = "fps",
.description = NULL_IF_CONFIG_SMALL("Force constant framerate"),
.init = init,
.uninit = uninit,
.priv_size = sizeof(FPSContext),
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.start_frame = null_start_frame,
.draw_slice = null_draw_slice,
.end_frame = end_frame, },
{ .name = NULL}},
.outputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.request_frame = request_frame,
.config_props = config_props},
{ .name = NULL}},
};
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