aboutsummaryrefslogtreecommitdiffstats
path: root/libavfilter/vf_vflip.c
blob: 1de3dc5dac721836f4005ecfeb1ab8f18522deb5 (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
/*
 * Copyright (c) 2007 Bobby Bingham
 *
 * 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
 * video vertical flip filter
 */

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

typedef struct FlipContext {
    const AVClass *class;
    int vsub;   ///< vertical chroma subsampling
    int bayer;
} FlipContext;

static const AVOption vflip_options[] = {
    { NULL }
};

AVFILTER_DEFINE_CLASS(vflip);

static int config_input(AVFilterLink *link)
{
    FlipContext *flip = link->dst->priv;
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);

    flip->vsub = desc->log2_chroma_h;
    flip->bayer = !!(desc->flags & AV_PIX_FMT_FLAG_BAYER);

    return 0;
}

static AVFrame *get_video_buffer(AVFilterLink *link, int w, int h)
{
    FlipContext *flip = link->dst->priv;
    AVFrame *frame;
    int i;

    frame = ff_get_video_buffer(link->dst->outputs[0], w, h);
    if (!frame)
        return NULL;

    for (i = 0; i < 4; i ++) {
        int vsub = i == 1 || i == 2 ? flip->vsub : 0;
        int height = AV_CEIL_RSHIFT(h, vsub);

        if (frame->data[i]) {
            frame->data[i] += (height - 1) * frame->linesize[i];
            frame->linesize[i] = -frame->linesize[i];
        }
    }

    return frame;
}

static int flip_bayer(AVFilterLink *link, AVFrame *in)
{
    AVFilterContext *ctx  = link->dst;
    AVFilterLink *outlink = ctx->outputs[0];
    AVFrame *out;
    uint8_t *inrow = in->data[0], *outrow;
    int i, width = outlink->w << (av_pix_fmt_desc_get(link->format)->comp[0].step > 1);
    if (outlink->h & 1) {
        av_log(ctx, AV_LOG_ERROR, "Bayer vertical flip needs even height\n");
        return AVERROR_INVALIDDATA;
    }

    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
    if (!out) {
        av_frame_free(&in);
        return AVERROR(ENOMEM);
    }
    av_frame_copy_props(out, in);
    outrow = out->data[0] + out->linesize[0] * (outlink->h - 2);
    for (i = 0; i < outlink->h >> 1; i++) {
        memcpy(outrow, inrow, width);
        memcpy(outrow + out->linesize[0], inrow + in->linesize[0], width);
        inrow  += 2 *  in->linesize[0];
        outrow -= 2 * out->linesize[0];
    }
    av_frame_free(&in);
    return ff_filter_frame(outlink, out);
}

static int filter_frame(AVFilterLink *link, AVFrame *frame)
{
    FlipContext *flip = link->dst->priv;
    int i;

    if (flip->bayer)
        return flip_bayer(link, frame);

    for (i = 0; i < 4; i ++) {
        int vsub = i == 1 || i == 2 ? flip->vsub : 0;
        int height = AV_CEIL_RSHIFT(link->h, vsub);

        if (frame->data[i]) {
            frame->data[i] += (height - 1) * frame->linesize[i];
            frame->linesize[i] = -frame->linesize[i];
        }
    }

    return ff_filter_frame(link->dst->outputs[0], frame);
}
static const AVFilterPad avfilter_vf_vflip_inputs[] = {
    {
        .name             = "default",
        .type             = AVMEDIA_TYPE_VIDEO,
        .get_video_buffer = get_video_buffer,
        .filter_frame     = filter_frame,
        .config_props     = config_input,
    },
    { NULL }
};

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

AVFilter ff_vf_vflip = {
    .name        = "vflip",
    .description = NULL_IF_CONFIG_SMALL("Flip the input video vertically."),
    .priv_size   = sizeof(FlipContext),
    .priv_class  = &vflip_class,
    .inputs      = avfilter_vf_vflip_inputs,
    .outputs     = avfilter_vf_vflip_outputs,
    .flags       = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
};