aboutsummaryrefslogtreecommitdiffstats
path: root/libavfilter/vf_settb.c
blob: 7b23751fda09cd08b3e8110b7c828679f3fbd709 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
/*
 * Copyright (c) 2010 Stefano Sabatini
 *
 * 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
 * Set timebase for the output link.
 */

#include "libavutil/avstring.h"
#include "libavutil/eval.h"
#include "libavutil/mathematics.h"
#include "libavutil/rational.h"
#include "avfilter.h"
#include "internal.h"
#include "video.h"

static const char *const 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)
{
    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);
    }

    ff_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 = ff_null_get_video_buffer,
                                    .start_frame      = start_frame,
                                    .end_frame        = ff_null_end_frame },
                                  { .name = NULL }},

    .outputs   = (AVFilterPad[]) {{ .name            = "default",
                                    .type            = AVMEDIA_TYPE_VIDEO,
                                    .config_props    = config_output_props, },
                                  { .name = NULL}},
};