ffmpeg/libavfilter/vf_settb.c

142 lines
4.5 KiB
C
Raw Normal View History

/*
* Copyright (C) 2010 Stefano Sabatini
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Set timebase for the output link.
*/
#include "libavutil/avstring.h"
#include "libavutil/eval.h"
#include "libavutil/rational.h"
#include "avfilter.h"
#include "internal.h"
static const char *var_names[] = {
"E",
"PHI",
"PI",
"AVTB", /* default timebase 1/AV_TIME_BASE */
"intb", /* input timebase */
NULL
};
enum var_name {
VAR_E,
VAR_PHI,
VAR_PI,
VAR_AVTB,
VAR_INTB,
VAR_VARS_NB
};
typedef struct {
char tb_expr[256];
double var_values[VAR_VARS_NB];
} SetTBContext;
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
SetTBContext *settb = ctx->priv;
av_strlcpy(settb->tb_expr, "intb", sizeof(settb->tb_expr));
if (args)
sscanf(args, "%255[^:]", settb->tb_expr);
return 0;
}
static int config_output_props(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
SetTBContext *settb = ctx->priv;
AVFilterLink *inlink = ctx->inputs[0];
AVRational time_base;
int ret;
double res;
settb->var_values[VAR_E] = M_E;
settb->var_values[VAR_PHI] = M_PHI;
settb->var_values[VAR_PI] = M_PI;
settb->var_values[VAR_AVTB] = av_q2d(AV_TIME_BASE_Q);
settb->var_values[VAR_INTB] = av_q2d(inlink->time_base);
outlink->w = inlink->w;
outlink->h = inlink->h;
if ((ret = av_expr_parse_and_eval(&res, settb->tb_expr, var_names, settb->var_values,
NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) {
av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", settb->tb_expr);
return ret;
}
time_base = av_d2q(res, INT_MAX);
if (time_base.num <= 0 || time_base.den <= 0) {
av_log(ctx, AV_LOG_ERROR,
"Invalid non-positive values for the timebase num:%d or den:%d.\n",
time_base.num, time_base.den);
return AVERROR(EINVAL);
}
outlink->time_base = time_base;
av_log(outlink->src, AV_LOG_INFO, "tb:%d/%d -> tb:%d/%d\n",
inlink ->time_base.num, inlink ->time_base.den,
outlink->time_base.num, outlink->time_base.den);
return 0;
}
static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
AVFilterBufferRef *picref2 = picref;
if (av_cmp_q(inlink->time_base, outlink->time_base)) {
picref2 = avfilter_ref_buffer(picref, ~0);
picref2->pts = av_rescale_q(picref->pts, inlink->time_base, outlink->time_base);
av_log(ctx, AV_LOG_DEBUG, "tb:%d/%d pts:%"PRId64" -> tb:%d/%d pts:%"PRId64"\n",
inlink ->time_base.num, inlink ->time_base.den, picref ->pts,
outlink->time_base.num, outlink->time_base.den, picref2->pts);
avfilter_unref_buffer(picref);
}
avfilter_start_frame(outlink, picref2);
}
AVFilter avfilter_vf_settb = {
.name = "settb",
.description = NULL_IF_CONFIG_SMALL("Set timebase for the output link."),
.init = init,
.priv_size = sizeof(SetTBContext),
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.get_video_buffer = avfilter_null_get_video_buffer,
.start_frame = start_frame,
.end_frame = avfilter_null_end_frame },
{ .name = NULL }},
.outputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_output_props, },
{ .name = NULL}},
};