aboutsummaryrefslogtreecommitdiffstats
path: root/libavfilter/vf_fade.c
blob: 9f3a60206a6557502263568ae298be86b5a9e599 (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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
/*
 * Copyright (c) 2010 Brandon Mintern
 * Copyright (c) 2007 Bobby Bingham
 *
 * 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
 * video fade filter
 * based heavily on vf_negate.c by Bobby Bingham
 */

#include "libavutil/common.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"

#define FADE_IN  0
#define FADE_OUT 1

typedef struct {
    const AVClass *class;
    int type;
    int factor, fade_per_frame;
    int start_frame, nb_frames;
    unsigned int frame_index, stop_frame;
    int hsub, vsub, bpp;
} FadeContext;

static av_cold int init(AVFilterContext *ctx)
{
    FadeContext *s = ctx->priv;

    s->fade_per_frame = (1 << 16) / s->nb_frames;
    if (s->type == FADE_IN) {
        s->factor = 0;
    } else if (s->type == FADE_OUT) {
        s->fade_per_frame = -s->fade_per_frame;
        s->factor = (1 << 16);
    }
    s->stop_frame = s->start_frame + s->nb_frames;

    av_log(ctx, AV_LOG_VERBOSE,
           "type:%s start_frame:%d nb_frames:%d\n",
           s->type == FADE_IN ? "in" : "out", s->start_frame,
           s->nb_frames);
    return 0;
}

static int query_formats(AVFilterContext *ctx)
{
    static const enum AVPixelFormat pix_fmts[] = {
        AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV422P,  AV_PIX_FMT_YUV420P,
        AV_PIX_FMT_YUV411P,  AV_PIX_FMT_YUV410P,
        AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
        AV_PIX_FMT_YUV440P,  AV_PIX_FMT_YUVJ440P,
        AV_PIX_FMT_RGB24,    AV_PIX_FMT_BGR24,
        AV_PIX_FMT_NONE
    };

    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
    return 0;
}

static int config_props(AVFilterLink *inlink)
{
    FadeContext *s = inlink->dst->priv;
    const AVPixFmtDescriptor *pixdesc = av_pix_fmt_desc_get(inlink->format);

    s->hsub = pixdesc->log2_chroma_w;
    s->vsub = pixdesc->log2_chroma_h;

    s->bpp = av_get_bits_per_pixel(pixdesc) >> 3;
    return 0;
}

static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
{
    FadeContext *s = inlink->dst->priv;
    uint8_t *p;
    int i, j, plane;

    if (s->factor < UINT16_MAX) {
        /* luma or rgb plane */
        for (i = 0; i < frame->height; i++) {
            p = frame->data[0] + i * frame->linesize[0];
            for (j = 0; j < inlink->w * s->bpp; j++) {
                /* s->factor is using 16 lower-order bits for decimal
                 * places. 32768 = 1 << 15, it is an integer representation
                 * of 0.5 and is for rounding. */
                *p = (*p * s->factor + 32768) >> 16;
                p++;
            }
        }

        if (frame->data[1] && frame->data[2]) {
            /* chroma planes */
            for (plane = 1; plane < 3; plane++) {
                for (i = 0; i < frame->height; i++) {
                    p = frame->data[plane] + (i >> s->vsub) * frame->linesize[plane];
                    for (j = 0; j < inlink->w >> s->hsub; j++) {
                        /* 8421367 = ((128 << 1) + 1) << 15. It is an integer
                         * representation of 128.5. The .5 is for rounding
                         * purposes. */
                        *p = ((*p - 128) * s->factor + 8421367) >> 16;
                        p++;
                    }
                }
            }
        }
    }

    if (s->frame_index >= s->start_frame &&
        s->frame_index <= s->stop_frame)
        s->factor += s->fade_per_frame;
    s->factor = av_clip_uint16(s->factor);
    s->frame_index++;

    return ff_filter_frame(inlink->dst->outputs[0], frame);
}

#define OFFSET(x) offsetof(FadeContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM
static const AVOption options[] = {
    { "type", "'in' or 'out' for fade-in/fade-out", OFFSET(type), AV_OPT_TYPE_INT, { .i64 = FADE_IN }, FADE_IN, FADE_OUT, FLAGS, "type" },
        { "in",  "fade-in",  0, AV_OPT_TYPE_CONST, { .i64 = FADE_IN },  .unit = "type" },
        { "out", "fade-out", 0, AV_OPT_TYPE_CONST, { .i64 = FADE_OUT }, .unit = "type" },
    { "start_frame", "Number of the first frame to which to apply the effect.",
                                                    OFFSET(start_frame), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
    { "nb_frames",   "Number of frames to which the effect should be applied.",
                                                    OFFSET(nb_frames),   AV_OPT_TYPE_INT, { .i64 = 1 }, 0, INT_MAX, FLAGS },
    { NULL },
};

static const AVClass fade_class = {
    .class_name = "fade",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
};

static const AVFilterPad avfilter_vf_fade_inputs[] = {
    {
        .name             = "default",
        .type             = AVMEDIA_TYPE_VIDEO,
        .config_props     = config_props,
        .get_video_buffer = ff_null_get_video_buffer,
        .filter_frame     = filter_frame,
        .needs_writable   = 1,
    },
    { NULL }
};

static const AVFilterPad avfilter_vf_fade_outputs[] = {
    {
        .name = "default",
        .type = AVMEDIA_TYPE_VIDEO,
    },
    { NULL }
};

AVFilter avfilter_vf_fade = {
    .name          = "fade",
    .description   = NULL_IF_CONFIG_SMALL("Fade in/out input video"),
    .init          = init,
    .priv_size     = sizeof(FadeContext),
    .priv_class    = &fade_class,
    .query_formats = query_formats,

    .inputs    = avfilter_vf_fade_inputs,
    .outputs   = avfilter_vf_fade_outputs,
};