3aae1c334ebea896de36ea0900552ddb3f2379ec
[libav.git] / libavfilter / vf_slicify.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 libavfilter/vf_slicify.c
23 * video slicing filter
24 */
25
26 #include "avfilter.h"
27
28 typedef struct {
29 int h; ///< output slice height
30 int vshift; ///< vertical chroma subsampling shift
31 } SliceContext;
32
33 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
34 {
35 SliceContext *slice = ctx->priv;
36
37 slice->h = 16;
38 if (args)
39 sscanf(args, "%d", &slice->h);
40
41 return 0;
42 }
43
44 static int config_props(AVFilterLink *link)
45 {
46 SliceContext *slice = link->dst->priv;
47 int tmp;
48
49 avcodec_get_chroma_sub_sample(link->format, &tmp, &slice->vshift);
50
51 /* ensure that slices play nice with chroma subsampling, and enforce
52 * a reasonable minimum size for the slices */
53 slice->h = FFMAX(8, slice->h & (-1 << slice->vshift));
54
55 av_log(link->dst, AV_LOG_INFO, "h:%d\n", slice->h);
56
57 return 0;
58 }
59
60 static AVFilterPicRef *get_video_buffer(AVFilterLink *link, int perms,
61 int w, int h)
62 {
63 return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);
64 }
65
66 static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
67 {
68 avfilter_start_frame(link->dst->outputs[0], picref);
69 }
70
71 static void end_frame(AVFilterLink *link)
72 {
73 avfilter_end_frame(link->dst->outputs[0]);
74 }
75
76 static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
77 {
78 SliceContext *slice = link->dst->priv;
79 int y2;
80
81 for (y2 = y; y2 + slice->h <= y + h; y2 += slice->h)
82 avfilter_draw_slice(link->dst->outputs[0], y2, slice->h, slice_dir);
83
84 if (y2 < y + h)
85 avfilter_draw_slice(link->dst->outputs[0], y2, y + h - y2, slice_dir);
86 }
87
88 AVFilter avfilter_vf_slicify = {
89 .name = "slicify",
90 .description = "Pass the images of input video on to next video filter as multiple slices.",
91
92 .init = init,
93
94 .priv_size = sizeof(SliceContext),
95
96 .inputs = (AVFilterPad[]) {{ .name = "default",
97 .type = CODEC_TYPE_VIDEO,
98 .get_video_buffer = get_video_buffer,
99 .start_frame = start_frame,
100 .draw_slice = draw_slice,
101 .config_props = config_props,
102 .end_frame = end_frame, },
103 { .name = NULL}},
104 .outputs = (AVFilterPad[]) {{ .name = "default",
105 .type = CODEC_TYPE_VIDEO, },
106 { .name = NULL}},
107 };