1/*
2 * Copyright (c) 2010 Stefano Sabatini
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21/**
22 * @file
23 * Set timebase for the output link.
24 */
25
26#include <inttypes.h>
27#include <stdio.h>
28
29#include "libavutil/avstring.h"
30#include "libavutil/eval.h"
31#include "libavutil/internal.h"
32#include "libavutil/mathematics.h"
33#include "libavutil/opt.h"
34#include "libavutil/rational.h"
35#include "audio.h"
36#include "avfilter.h"
37#include "internal.h"
38#include "video.h"
39
40static const char *const var_names[] = {
41    "AVTB",   /* default timebase 1/AV_TIME_BASE */
42    "intb",   /* input timebase */
43    "sr",     /* sample rate */
44    NULL
45};
46
47enum var_name {
48    VAR_AVTB,
49    VAR_INTB,
50    VAR_SR,
51    VAR_VARS_NB
52};
53
54typedef struct SetTBContext {
55    const AVClass *class;
56    char *tb_expr;
57    double var_values[VAR_VARS_NB];
58} SetTBContext;
59
60#define OFFSET(x) offsetof(SetTBContext, x)
61#define DEFINE_OPTIONS(filt_name, filt_type)                                               \
62static const AVOption filt_name##_options[] = {                                            \
63    { "expr", "set expression determining the output timebase", OFFSET(tb_expr), AV_OPT_TYPE_STRING, {.str="intb"}, \
64           .flags=AV_OPT_FLAG_##filt_type##_PARAM|AV_OPT_FLAG_FILTERING_PARAM },           \
65    { "tb",   "set expression determining the output timebase", OFFSET(tb_expr), AV_OPT_TYPE_STRING, {.str="intb"}, \
66           .flags=AV_OPT_FLAG_##filt_type##_PARAM|AV_OPT_FLAG_FILTERING_PARAM },           \
67    { NULL }                                                                               \
68}
69
70static int config_output_props(AVFilterLink *outlink)
71{
72    AVFilterContext *ctx = outlink->src;
73    SetTBContext *settb = ctx->priv;
74    AVFilterLink *inlink = ctx->inputs[0];
75    AVRational time_base;
76    int ret;
77    double res;
78
79    settb->var_values[VAR_AVTB] = av_q2d(AV_TIME_BASE_Q);
80    settb->var_values[VAR_INTB] = av_q2d(inlink->time_base);
81    settb->var_values[VAR_SR]   = inlink->sample_rate;
82
83    outlink->w = inlink->w;
84    outlink->h = inlink->h;
85
86    if ((ret = av_expr_parse_and_eval(&res, settb->tb_expr, var_names, settb->var_values,
87                                      NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) {
88        av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", settb->tb_expr);
89        return ret;
90    }
91    time_base = av_d2q(res, INT_MAX);
92    if (time_base.num <= 0 || time_base.den <= 0) {
93        av_log(ctx, AV_LOG_ERROR,
94               "Invalid non-positive values for the timebase num:%d or den:%d.\n",
95               time_base.num, time_base.den);
96        return AVERROR(EINVAL);
97    }
98
99    outlink->time_base = time_base;
100    av_log(outlink->src, AV_LOG_VERBOSE, "tb:%d/%d -> tb:%d/%d\n",
101           inlink ->time_base.num, inlink ->time_base.den,
102           outlink->time_base.num, outlink->time_base.den);
103
104    return 0;
105}
106
107static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
108{
109    AVFilterContext *ctx = inlink->dst;
110    AVFilterLink *outlink = ctx->outputs[0];
111
112    if (av_cmp_q(inlink->time_base, outlink->time_base)) {
113        int64_t orig_pts = frame->pts;
114        frame->pts = av_rescale_q(frame->pts, inlink->time_base, outlink->time_base);
115        av_log(ctx, AV_LOG_DEBUG, "tb:%d/%d pts:%"PRId64" -> tb:%d/%d pts:%"PRId64"\n",
116               inlink ->time_base.num, inlink ->time_base.den, orig_pts,
117               outlink->time_base.num, outlink->time_base.den, frame->pts);
118    }
119
120    return ff_filter_frame(outlink, frame);
121}
122
123#if CONFIG_SETTB_FILTER
124
125DEFINE_OPTIONS(settb, VIDEO);
126AVFILTER_DEFINE_CLASS(settb);
127
128static const AVFilterPad avfilter_vf_settb_inputs[] = {
129    {
130        .name         = "default",
131        .type         = AVMEDIA_TYPE_VIDEO,
132        .filter_frame = filter_frame,
133    },
134    { NULL }
135};
136
137static const AVFilterPad avfilter_vf_settb_outputs[] = {
138    {
139        .name         = "default",
140        .type         = AVMEDIA_TYPE_VIDEO,
141        .config_props = config_output_props,
142    },
143    { NULL }
144};
145
146AVFilter ff_vf_settb = {
147    .name        = "settb",
148    .description = NULL_IF_CONFIG_SMALL("Set timebase for the video output link."),
149    .priv_size   = sizeof(SetTBContext),
150    .priv_class  = &settb_class,
151    .inputs      = avfilter_vf_settb_inputs,
152    .outputs     = avfilter_vf_settb_outputs,
153};
154#endif /* CONFIG_SETTB_FILTER */
155
156#if CONFIG_ASETTB_FILTER
157
158DEFINE_OPTIONS(asettb, AUDIO);
159AVFILTER_DEFINE_CLASS(asettb);
160
161static const AVFilterPad avfilter_af_asettb_inputs[] = {
162    {
163        .name         = "default",
164        .type         = AVMEDIA_TYPE_AUDIO,
165        .filter_frame = filter_frame,
166    },
167    { NULL }
168};
169
170static const AVFilterPad avfilter_af_asettb_outputs[] = {
171    {
172        .name         = "default",
173        .type         = AVMEDIA_TYPE_AUDIO,
174        .config_props = config_output_props,
175    },
176    { NULL }
177};
178
179AVFilter ff_af_asettb = {
180    .name        = "asettb",
181    .description = NULL_IF_CONFIG_SMALL("Set timebase for the audio output link."),
182    .priv_size   = sizeof(SetTBContext),
183    .inputs      = avfilter_af_asettb_inputs,
184    .outputs     = avfilter_af_asettb_outputs,
185    .priv_class  = &asettb_class,
186};
187#endif /* CONFIG_ASETTB_FILTER */
188