aboutsummaryrefslogtreecommitdiffstats
path: root/libavfilter/vf_crop.c
blob: 0dbdedf16970d5429777ba851906b45a1da6879a (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
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
/*
 * 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 libavfilter/vf_crop.c
 * video crop filter
 */

#include "avfilter.h"

typedef struct {
    int  x;             ///< x offset of the non-cropped area with respect to the input area
    int  y;             ///< y offset of the non-cropped area with respect to the input area
    int  w;             ///< width of the cropped area
    int  h;             ///< height of the cropped area

    int bpp;            ///< bits per pixel
    int hsub, vsub;     ///< chroma subsampling
} CropContext;

static int query_formats(AVFilterContext *ctx)
{
    static const enum PixelFormat pix_fmts[] = {
        PIX_FMT_RGB48BE,      PIX_FMT_RGB48LE,
        PIX_FMT_ARGB,         PIX_FMT_RGBA,
        PIX_FMT_ABGR,         PIX_FMT_BGRA,
        PIX_FMT_RGB24,        PIX_FMT_BGR24,
        PIX_FMT_RGB565BE,     PIX_FMT_RGB565LE,
        PIX_FMT_RGB555BE,     PIX_FMT_RGB555LE,
        PIX_FMT_BGR565BE,     PIX_FMT_BGR565LE,
        PIX_FMT_BGR555BE,     PIX_FMT_BGR555LE,
        PIX_FMT_GRAY16BE,     PIX_FMT_GRAY16LE,
        PIX_FMT_YUV420P16LE,  PIX_FMT_YUV420P16BE,
        PIX_FMT_YUV422P16LE,  PIX_FMT_YUV422P16BE,
        PIX_FMT_YUV444P16LE,  PIX_FMT_YUV444P16BE,
        PIX_FMT_YUV444P,      PIX_FMT_YUV422P,
        PIX_FMT_YUV420P,      PIX_FMT_YUV411P,
        PIX_FMT_YUV410P,      PIX_FMT_YUV440P,
        PIX_FMT_YUVJ444P,     PIX_FMT_YUVJ422P,
        PIX_FMT_YUVJ420P,     PIX_FMT_YUVJ440P,
        PIX_FMT_YUVA420P,
        PIX_FMT_RGB8,         PIX_FMT_BGR8,
        PIX_FMT_RGB4_BYTE,    PIX_FMT_BGR4_BYTE,
        PIX_FMT_PAL8,         PIX_FMT_GRAY8,
        PIX_FMT_NONE
    };

    avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));

    return 0;
}

static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
    CropContext *crop = ctx->priv;

    if (args)
        sscanf(args, "%d:%d:%d:%d", &crop->x, &crop->y, &crop->w, &crop->h);

    return 0;
}

static int config_input(AVFilterLink *link)
{
    AVFilterContext *ctx = link->dst;
    CropContext *crop = ctx->priv;

    switch (link->format) {
    case PIX_FMT_RGB48BE:
    case PIX_FMT_RGB48LE:
        crop->bpp = 48;
        break;
    case PIX_FMT_ARGB:
    case PIX_FMT_RGBA:
    case PIX_FMT_ABGR:
    case PIX_FMT_BGRA:
        crop->bpp = 32;
        break;
    case PIX_FMT_RGB24:
    case PIX_FMT_BGR24:
        crop->bpp = 24;
        break;
    case PIX_FMT_RGB565BE:
    case PIX_FMT_RGB565LE:
    case PIX_FMT_RGB555BE:
    case PIX_FMT_RGB555LE:
    case PIX_FMT_BGR565BE:
    case PIX_FMT_BGR565LE:
    case PIX_FMT_BGR555BE:
    case PIX_FMT_BGR555LE:
    case PIX_FMT_GRAY16BE:
    case PIX_FMT_GRAY16LE:
    case PIX_FMT_YUV420P16LE:
    case PIX_FMT_YUV420P16BE:
    case PIX_FMT_YUV422P16LE:
    case PIX_FMT_YUV422P16BE:
    case PIX_FMT_YUV444P16LE:
    case PIX_FMT_YUV444P16BE:
        crop->bpp = 16;
        break;
    default:
        crop->bpp = 8;
    }

    avcodec_get_chroma_sub_sample(link->format, &crop->hsub, &crop->vsub);

    if (crop->w == 0)
        crop->w = link->w - crop->x;
    if (crop->h == 0)
        crop->h = link->h - crop->y;

    crop->x &= ~((1 << crop->hsub) - 1);
    crop->y &= ~((1 << crop->vsub) - 1);

    av_log(link->dst, AV_LOG_INFO, "x:%d y:%d w:%d h:%d\n",
           crop->x, crop->y, crop->w, crop->h);

    if (crop->x <  0 || crop->y <  0                    ||
        crop->w <= 0 || crop->h <= 0                    ||
        (unsigned)crop->x + (unsigned)crop->w > link->w ||
        (unsigned)crop->y + (unsigned)crop->h > link->h) {
        av_log(ctx, AV_LOG_ERROR,
               "Output area %d:%d:%d:%d not within the input area 0:0:%d:%d or zero-sized\n",
               crop->x, crop->y, crop->w, crop->h, link->w, link->h);
        return -1;
    }

    return 0;
}

static int config_output(AVFilterLink *link)
{
    CropContext *crop = link->src->priv;

    link->w = crop->w;
    link->h = crop->h;

    return 0;
}

static AVFilterPicRef *get_video_buffer(AVFilterLink *link, int perms,
                                        int w, int h)
{
    return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);
}

static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
{
    CropContext *crop = link->dst->priv;
    AVFilterPicRef *ref2 = avfilter_ref_pic(picref, ~0);
    int i;

    ref2->w        = crop->w;
    ref2->h        = crop->h;

    ref2->data[0] += crop->y * ref2->linesize[0];
    ref2->data[0] += (crop->x * crop->bpp) >> 3;

    if (link->format != PIX_FMT_PAL8      &&
        link->format != PIX_FMT_BGR4_BYTE &&
        link->format != PIX_FMT_RGB4_BYTE &&
        link->format != PIX_FMT_BGR8      &&
        link->format != PIX_FMT_RGB8) {
        for (i = 1; i < 3; i ++) {
            if (ref2->data[i]) {
                ref2->data[i] += (crop->y >> crop->vsub) * ref2->linesize[i];
                ref2->data[i] += ((crop->x * crop->bpp) >> 3) >> crop->hsub;
            }
        }
    }

    /* alpha plane */
    if (ref2->data[3]) {
        ref2->data[3] += crop->y * ref2->linesize[3];
        ref2->data[3] += (crop->x * crop->bpp) >> 3;
    }

    avfilter_start_frame(link->dst->outputs[0], ref2);
}

static void draw_slice(AVFilterLink *link, int y, int h)
{
    AVFilterContext *ctx = link->dst;
    CropContext *crop = ctx->priv;

    if (y >= crop->y + crop->h || y + h <= crop->y)
        return;

    if (y < crop->y) {
        h -= crop->y - y;
        y  = crop->y;
    }
    if (y + h > crop->y + crop->h)
        h = crop->y + crop->h - y;

    avfilter_draw_slice(ctx->outputs[0], y - crop->y, h);
}

AVFilter avfilter_vf_crop = {
    .name      = "crop",
    .description = NULL_IF_CONFIG_SMALL("Crop the input video to x:y:width:height."),

    .priv_size = sizeof(CropContext),

    .query_formats = query_formats,
    .init          = init,

    .inputs    = (AVFilterPad[]) {{ .name             = "default",
                                    .type             = CODEC_TYPE_VIDEO,
                                    .start_frame      = start_frame,
                                    .draw_slice       = draw_slice,
                                    .get_video_buffer = get_video_buffer,
                                    .config_props     = config_input, },
                                  { .name = NULL}},
    .outputs   = (AVFilterPad[]) {{ .name             = "default",
                                    .type             = CODEC_TYPE_VIDEO,
                                    .config_props     = config_output, },
                                  { .name = NULL}},
};