1/*
2 * copyright (c) 2007 Bobby Bingham
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 * video crop filter
24 */
25
26#include "avfilter.h"
27#include "libavutil/pixdesc.h"
28
29typedef struct {
30    int  x;             ///< x offset of the non-cropped area with respect to the input area
31    int  y;             ///< y offset of the non-cropped area with respect to the input area
32    int  w;             ///< width of the cropped area
33    int  h;             ///< height of the cropped area
34
35    int bpp;            ///< bits per pixel
36    int hsub, vsub;     ///< chroma subsampling
37} CropContext;
38
39static int query_formats(AVFilterContext *ctx)
40{
41    static const enum PixelFormat pix_fmts[] = {
42        PIX_FMT_RGB48BE,      PIX_FMT_RGB48LE,
43        PIX_FMT_ARGB,         PIX_FMT_RGBA,
44        PIX_FMT_ABGR,         PIX_FMT_BGRA,
45        PIX_FMT_RGB24,        PIX_FMT_BGR24,
46        PIX_FMT_RGB565BE,     PIX_FMT_RGB565LE,
47        PIX_FMT_RGB555BE,     PIX_FMT_RGB555LE,
48        PIX_FMT_BGR565BE,     PIX_FMT_BGR565LE,
49        PIX_FMT_BGR555BE,     PIX_FMT_BGR555LE,
50        PIX_FMT_GRAY16BE,     PIX_FMT_GRAY16LE,
51        PIX_FMT_YUV420P16LE,  PIX_FMT_YUV420P16BE,
52        PIX_FMT_YUV422P16LE,  PIX_FMT_YUV422P16BE,
53        PIX_FMT_YUV444P16LE,  PIX_FMT_YUV444P16BE,
54        PIX_FMT_YUV444P,      PIX_FMT_YUV422P,
55        PIX_FMT_YUV420P,      PIX_FMT_YUV411P,
56        PIX_FMT_YUV410P,      PIX_FMT_YUV440P,
57        PIX_FMT_YUVJ444P,     PIX_FMT_YUVJ422P,
58        PIX_FMT_YUVJ420P,     PIX_FMT_YUVJ440P,
59        PIX_FMT_YUVA420P,
60        PIX_FMT_RGB8,         PIX_FMT_BGR8,
61        PIX_FMT_RGB4_BYTE,    PIX_FMT_BGR4_BYTE,
62        PIX_FMT_PAL8,         PIX_FMT_GRAY8,
63        PIX_FMT_NONE
64    };
65
66    avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
67
68    return 0;
69}
70
71static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
72{
73    CropContext *crop = ctx->priv;
74
75    if (args)
76        sscanf(args, "%d:%d:%d:%d", &crop->x, &crop->y, &crop->w, &crop->h);
77
78    return 0;
79}
80
81static int config_input(AVFilterLink *link)
82{
83    AVFilterContext *ctx = link->dst;
84    CropContext *crop = ctx->priv;
85
86    switch (link->format) {
87    case PIX_FMT_RGB48BE:
88    case PIX_FMT_RGB48LE:
89        crop->bpp = 48;
90        break;
91    case PIX_FMT_ARGB:
92    case PIX_FMT_RGBA:
93    case PIX_FMT_ABGR:
94    case PIX_FMT_BGRA:
95        crop->bpp = 32;
96        break;
97    case PIX_FMT_RGB24:
98    case PIX_FMT_BGR24:
99        crop->bpp = 24;
100        break;
101    case PIX_FMT_RGB565BE:
102    case PIX_FMT_RGB565LE:
103    case PIX_FMT_RGB555BE:
104    case PIX_FMT_RGB555LE:
105    case PIX_FMT_BGR565BE:
106    case PIX_FMT_BGR565LE:
107    case PIX_FMT_BGR555BE:
108    case PIX_FMT_BGR555LE:
109    case PIX_FMT_GRAY16BE:
110    case PIX_FMT_GRAY16LE:
111    case PIX_FMT_YUV420P16LE:
112    case PIX_FMT_YUV420P16BE:
113    case PIX_FMT_YUV422P16LE:
114    case PIX_FMT_YUV422P16BE:
115    case PIX_FMT_YUV444P16LE:
116    case PIX_FMT_YUV444P16BE:
117        crop->bpp = 16;
118        break;
119    default:
120        crop->bpp = 8;
121    }
122
123    avcodec_get_chroma_sub_sample(link->format, &crop->hsub, &crop->vsub);
124
125    if (crop->w == 0)
126        crop->w = link->w - crop->x;
127    if (crop->h == 0)
128        crop->h = link->h - crop->y;
129
130    crop->x &= ~((1 << crop->hsub) - 1);
131    crop->y &= ~((1 << crop->vsub) - 1);
132
133    av_log(link->dst, AV_LOG_INFO, "x:%d y:%d w:%d h:%d\n",
134           crop->x, crop->y, crop->w, crop->h);
135
136    if (crop->x <  0 || crop->y <  0                    ||
137        crop->w <= 0 || crop->h <= 0                    ||
138        (unsigned)crop->x + (unsigned)crop->w > link->w ||
139        (unsigned)crop->y + (unsigned)crop->h > link->h) {
140        av_log(ctx, AV_LOG_ERROR,
141               "Output area %d:%d:%d:%d not within the input area 0:0:%d:%d or zero-sized\n",
142               crop->x, crop->y, crop->w, crop->h, link->w, link->h);
143        return -1;
144    }
145
146    return 0;
147}
148
149static int config_output(AVFilterLink *link)
150{
151    CropContext *crop = link->src->priv;
152
153    link->w = crop->w;
154    link->h = crop->h;
155
156    return 0;
157}
158
159static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
160{
161    CropContext *crop = link->dst->priv;
162    AVFilterPicRef *ref2 = avfilter_ref_pic(picref, ~0);
163    int i;
164
165    ref2->w        = crop->w;
166    ref2->h        = crop->h;
167
168    ref2->data[0] += crop->y * ref2->linesize[0];
169    ref2->data[0] += (crop->x * crop->bpp) >> 3;
170
171    if (!(av_pix_fmt_descriptors[link->format].flags & PIX_FMT_PAL)) {
172        for (i = 1; i < 3; i ++) {
173            if (ref2->data[i]) {
174                ref2->data[i] += (crop->y >> crop->vsub) * ref2->linesize[i];
175                ref2->data[i] += ((crop->x * crop->bpp) >> 3) >> crop->hsub;
176            }
177        }
178    }
179
180    /* alpha plane */
181    if (ref2->data[3]) {
182        ref2->data[3] += crop->y * ref2->linesize[3];
183        ref2->data[3] += (crop->x * crop->bpp) >> 3;
184    }
185
186    avfilter_start_frame(link->dst->outputs[0], ref2);
187}
188
189static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
190{
191    AVFilterContext *ctx = link->dst;
192    CropContext *crop = ctx->priv;
193
194    if (y >= crop->y + crop->h || y + h <= crop->y)
195        return;
196
197    if (y < crop->y) {
198        h -= crop->y - y;
199        y  = crop->y;
200    }
201    if (y + h > crop->y + crop->h)
202        h = crop->y + crop->h - y;
203
204    avfilter_draw_slice(ctx->outputs[0], y - crop->y, h, slice_dir);
205}
206
207AVFilter avfilter_vf_crop = {
208    .name      = "crop",
209    .description = NULL_IF_CONFIG_SMALL("Crop the input video to x:y:width:height."),
210
211    .priv_size = sizeof(CropContext),
212
213    .query_formats = query_formats,
214    .init          = init,
215
216    .inputs    = (AVFilterPad[]) {{ .name             = "default",
217                                    .type             = AVMEDIA_TYPE_VIDEO,
218                                    .start_frame      = start_frame,
219                                    .draw_slice       = draw_slice,
220                                    .get_video_buffer = avfilter_null_get_video_buffer,
221                                    .config_props     = config_input, },
222                                  { .name = NULL}},
223    .outputs   = (AVFilterPad[]) {{ .name             = "default",
224                                    .type             = AVMEDIA_TYPE_VIDEO,
225                                    .config_props     = config_output, },
226                                  { .name = NULL}},
227};
228