Compute the max pixel step for each plane, and use it in place of
[libav.git] / libavfilter / vf_crop.c
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
29 typedef 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 max_step[4]; ///< max pixel step for each plane, expressed as a number of bytes
36 int hsub, vsub; ///< chroma subsampling
37 } CropContext;
38
39 static 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
71 static 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
81 static int config_input(AVFilterLink *link)
82 {
83 AVFilterContext *ctx = link->dst;
84 CropContext *crop = ctx->priv;
85 const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[link->format];
86 int i;
87
88 memset(crop->max_step, 0, sizeof(crop->max_step));
89 for (i = 0; i < 4; i++) {
90 const AVComponentDescriptor *comp = &(pix_desc->comp[i]);
91 if ((comp->step_minus1+1) > crop->max_step[comp->plane])
92 crop->max_step[comp->plane] = comp->step_minus1+1;
93 }
94
95 crop->hsub = av_pix_fmt_descriptors[link->format].log2_chroma_w;
96 crop->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
97
98 if (crop->w == 0)
99 crop->w = link->w - crop->x;
100 if (crop->h == 0)
101 crop->h = link->h - crop->y;
102
103 crop->x &= ~((1 << crop->hsub) - 1);
104 crop->y &= ~((1 << crop->vsub) - 1);
105
106 av_log(link->dst, AV_LOG_INFO, "x:%d y:%d w:%d h:%d\n",
107 crop->x, crop->y, crop->w, crop->h);
108
109 if (crop->x < 0 || crop->y < 0 ||
110 crop->w <= 0 || crop->h <= 0 ||
111 (unsigned)crop->x + (unsigned)crop->w > link->w ||
112 (unsigned)crop->y + (unsigned)crop->h > link->h) {
113 av_log(ctx, AV_LOG_ERROR,
114 "Output area %d:%d:%d:%d not within the input area 0:0:%d:%d or zero-sized\n",
115 crop->x, crop->y, crop->w, crop->h, link->w, link->h);
116 return -1;
117 }
118
119 return 0;
120 }
121
122 static int config_output(AVFilterLink *link)
123 {
124 CropContext *crop = link->src->priv;
125
126 link->w = crop->w;
127 link->h = crop->h;
128
129 return 0;
130 }
131
132 static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
133 {
134 CropContext *crop = link->dst->priv;
135 AVFilterPicRef *ref2 = avfilter_ref_pic(picref, ~0);
136 int i;
137
138 ref2->w = crop->w;
139 ref2->h = crop->h;
140
141 ref2->data[0] += crop->y * ref2->linesize[0];
142 ref2->data[0] += (crop->x * crop->max_step[0]);
143
144 if (!(av_pix_fmt_descriptors[link->format].flags & PIX_FMT_PAL)) {
145 for (i = 1; i < 3; i ++) {
146 if (ref2->data[i]) {
147 ref2->data[i] += (crop->y >> crop->vsub) * ref2->linesize[i];
148 ref2->data[i] += (crop->x * crop->max_step[i]) >> crop->hsub;
149 }
150 }
151 }
152
153 /* alpha plane */
154 if (ref2->data[3]) {
155 ref2->data[3] += crop->y * ref2->linesize[3];
156 ref2->data[3] += (crop->x * crop->max_step[3]);
157 }
158
159 avfilter_start_frame(link->dst->outputs[0], ref2);
160 }
161
162 static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
163 {
164 AVFilterContext *ctx = link->dst;
165 CropContext *crop = ctx->priv;
166
167 if (y >= crop->y + crop->h || y + h <= crop->y)
168 return;
169
170 if (y < crop->y) {
171 h -= crop->y - y;
172 y = crop->y;
173 }
174 if (y + h > crop->y + crop->h)
175 h = crop->y + crop->h - y;
176
177 avfilter_draw_slice(ctx->outputs[0], y - crop->y, h, slice_dir);
178 }
179
180 AVFilter avfilter_vf_crop = {
181 .name = "crop",
182 .description = NULL_IF_CONFIG_SMALL("Crop the input video to x:y:width:height."),
183
184 .priv_size = sizeof(CropContext),
185
186 .query_formats = query_formats,
187 .init = init,
188
189 .inputs = (AVFilterPad[]) {{ .name = "default",
190 .type = AVMEDIA_TYPE_VIDEO,
191 .start_frame = start_frame,
192 .draw_slice = draw_slice,
193 .get_video_buffer = avfilter_null_get_video_buffer,
194 .config_props = config_input, },
195 { .name = NULL}},
196 .outputs = (AVFilterPad[]) {{ .name = "default",
197 .type = AVMEDIA_TYPE_VIDEO,
198 .config_props = config_output, },
199 { .name = NULL}},
200 };