Add pad filter.
[libav.git] / libavfilter / vf_scale.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 * scale video filter
24 */
25
26 #include "avfilter.h"
27 #include "libavutil/pixdesc.h"
28 #include "libswscale/swscale.h"
29
30 typedef struct {
31 struct SwsContext *sws; ///< software scaler context
32
33 /**
34 * New dimensions. Special values are:
35 * 0 = original width/height
36 * -1 = keep original aspect
37 */
38 int w, h;
39 unsigned int flags; ///sws flags
40
41 int hsub, vsub; ///< chroma subsampling
42 int slice_y; ///< top of current output slice
43 int input_is_pal; ///< set to 1 if the input format is paletted
44 } ScaleContext;
45
46 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
47 {
48 ScaleContext *scale = ctx->priv;
49
50 scale->flags = SWS_BILINEAR;
51 if (args){
52 sscanf(args, "%d:%d", &scale->w, &scale->h);
53 sscanf(strstr(args,"flags="), "flags=%i", &scale->flags);
54 }
55
56 /* sanity check params */
57 if (scale->w < -1 || scale->h < -1) {
58 av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n");
59 return -1;
60 }
61 if (scale->w == -1 && scale->h == -1)
62 scale->w = scale->h = 0;
63
64 return 0;
65 }
66
67 static av_cold void uninit(AVFilterContext *ctx)
68 {
69 ScaleContext *scale = ctx->priv;
70 sws_freeContext(scale->sws);
71 scale->sws = NULL;
72 }
73
74 static int query_formats(AVFilterContext *ctx)
75 {
76 AVFilterFormats *formats;
77 enum PixelFormat pix_fmt;
78 int ret;
79
80 if (ctx->inputs[0]) {
81 formats = NULL;
82 for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
83 if ( sws_isSupportedInput(pix_fmt)
84 && (ret = avfilter_add_colorspace(&formats, pix_fmt)) < 0) {
85 avfilter_formats_unref(&formats);
86 return ret;
87 }
88 avfilter_formats_ref(formats, &ctx->inputs[0]->out_formats);
89 }
90 if (ctx->outputs[0]) {
91 formats = NULL;
92 for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
93 if ( sws_isSupportedOutput(pix_fmt)
94 && (ret = avfilter_add_colorspace(&formats, pix_fmt)) < 0) {
95 avfilter_formats_unref(&formats);
96 return ret;
97 }
98 avfilter_formats_ref(formats, &ctx->outputs[0]->in_formats);
99 }
100
101 return 0;
102 }
103
104 static int config_props(AVFilterLink *outlink)
105 {
106 AVFilterContext *ctx = outlink->src;
107 AVFilterLink *inlink = outlink->src->inputs[0];
108 ScaleContext *scale = ctx->priv;
109 int64_t w, h;
110
111 if (!(w = scale->w))
112 w = inlink->w;
113 if (!(h = scale->h))
114 h = inlink->h;
115 if (w == -1)
116 w = av_rescale(h, inlink->w, inlink->h);
117 if (h == -1)
118 h = av_rescale(w, inlink->h, inlink->w);
119
120 if (w > INT_MAX || h > INT_MAX ||
121 (h * inlink->w) > INT_MAX ||
122 (w * inlink->h) > INT_MAX)
123 av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
124
125 outlink->w = w;
126 outlink->h = h;
127
128 /* TODO: make algorithm configurable */
129 scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
130 outlink->w, outlink->h, outlink->format,
131 scale->flags, NULL, NULL, NULL);
132
133 av_log(ctx, AV_LOG_INFO, "w:%d h:%d fmt:%s\n",
134 outlink->w, outlink->h, av_pix_fmt_descriptors[outlink->format].name);
135
136 scale->input_is_pal = av_pix_fmt_descriptors[inlink->format].flags & PIX_FMT_PAL;
137
138 return !scale->sws;
139 }
140
141 static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
142 {
143 ScaleContext *scale = link->dst->priv;
144 AVFilterLink *outlink = link->dst->outputs[0];
145 AVFilterPicRef *outpicref;
146
147 scale->hsub = av_pix_fmt_descriptors[link->format].log2_chroma_w;
148 scale->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
149
150 outpicref = avfilter_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
151 outpicref->pts = picref->pts;
152 outpicref->pos = picref->pos;
153 outpicref->interlaced = picref->interlaced;
154 outpicref->top_field_first = picref->top_field_first;
155
156 outlink->outpic = outpicref;
157
158 av_reduce(&outpicref->pixel_aspect.num, &outpicref->pixel_aspect.den,
159 (int64_t)picref->pixel_aspect.num * outlink->h * link->w,
160 (int64_t)picref->pixel_aspect.den * outlink->w * link->h,
161 INT_MAX);
162
163 scale->slice_y = 0;
164 avfilter_start_frame(outlink, avfilter_ref_pic(outpicref, ~0));
165 }
166
167 static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
168 {
169 ScaleContext *scale = link->dst->priv;
170 int out_h;
171 AVFilterPicRef *cur_pic = link->cur_pic;
172 uint8_t *data[4];
173
174 if (scale->slice_y == 0 && slice_dir == -1)
175 scale->slice_y = link->dst->outputs[0]->h;
176
177 data[0] = cur_pic->data[0] + y * cur_pic->linesize[0];
178 data[1] = scale->input_is_pal ?
179 cur_pic->data[1] :
180 cur_pic->data[1] + (y>>scale->vsub) * cur_pic->linesize[1];
181 data[2] = cur_pic->data[2] + (y>>scale->vsub) * cur_pic->linesize[2];
182 data[3] = cur_pic->data[3] + y * cur_pic->linesize[3];
183
184 out_h = sws_scale(scale->sws, data, cur_pic->linesize, y, h,
185 link->dst->outputs[0]->outpic->data,
186 link->dst->outputs[0]->outpic->linesize);
187
188 if (slice_dir == -1)
189 scale->slice_y -= out_h;
190 avfilter_draw_slice(link->dst->outputs[0], scale->slice_y, out_h, slice_dir);
191 if (slice_dir == 1)
192 scale->slice_y += out_h;
193 }
194
195 AVFilter avfilter_vf_scale = {
196 .name = "scale",
197 .description = "Scale the input video to width:height size and/or convert the image format.",
198
199 .init = init,
200 .uninit = uninit,
201
202 .query_formats = query_formats,
203
204 .priv_size = sizeof(ScaleContext),
205
206 .inputs = (AVFilterPad[]) {{ .name = "default",
207 .type = AVMEDIA_TYPE_VIDEO,
208 .start_frame = start_frame,
209 .draw_slice = draw_slice,
210 .min_perms = AV_PERM_READ, },
211 { .name = NULL}},
212 .outputs = (AVFilterPad[]) {{ .name = "default",
213 .type = AVMEDIA_TYPE_VIDEO,
214 .config_props = config_props, },
215 { .name = NULL}},
216 };