2 * copyright (c) 2007 Bobby Bingham
4 * This file is part of FFmpeg.
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.
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.
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
27 #include "libavutil/pixdesc.h"
28 #include "libswscale/swscale.h"
31 struct SwsContext *sws; ///< software scaler context
34 * New dimensions. Special values are:
35 * 0 = original width/height
36 * -1 = keep original aspect
40 int hsub, vsub; ///< chroma subsampling
41 int slice_y; ///< top of current output slice
42 int input_is_pal; ///< set to 1 if the input format is paletted
45 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
47 ScaleContext *scale = ctx->priv;
50 sscanf(args, "%d:%d", &scale->w, &scale->h);
52 /* sanity check params */
53 if (scale->w < -1 || scale->h < -1) {
54 av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n");
57 if (scale->w == -1 && scale->h == -1)
58 scale->w = scale->h = 0;
63 static av_cold void uninit(AVFilterContext *ctx)
65 ScaleContext *scale = ctx->priv;
66 sws_freeContext(scale->sws);
70 static int query_formats(AVFilterContext *ctx)
72 AVFilterFormats *formats;
73 enum PixelFormat pix_fmt;
78 for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
79 if ( sws_isSupportedInput(pix_fmt)
80 && (ret = avfilter_add_colorspace(&formats, pix_fmt)) < 0) {
81 avfilter_formats_unref(&formats);
84 avfilter_formats_ref(formats, &ctx->inputs[0]->out_formats);
86 if (ctx->outputs[0]) {
88 for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
89 if ( sws_isSupportedOutput(pix_fmt)
90 && (ret = avfilter_add_colorspace(&formats, pix_fmt)) < 0) {
91 avfilter_formats_unref(&formats);
94 avfilter_formats_ref(formats, &ctx->outputs[0]->in_formats);
100 static int config_props(AVFilterLink *outlink)
102 AVFilterContext *ctx = outlink->src;
103 AVFilterLink *inlink = outlink->src->inputs[0];
104 ScaleContext *scale = ctx->priv;
112 w = av_rescale(h, inlink->w, inlink->h);
114 h = av_rescale(w, inlink->h, inlink->w);
116 if (w > INT_MAX || h > INT_MAX ||
117 (h * inlink->w) > INT_MAX ||
118 (w * inlink->h) > INT_MAX)
119 av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
124 /* TODO: make algorithm configurable */
125 scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
126 outlink->w, outlink->h, outlink->format,
127 SWS_BILINEAR, NULL, NULL, NULL);
129 av_log(ctx, AV_LOG_INFO, "w:%d h:%d fmt:%s\n",
130 outlink->w, outlink->h, av_pix_fmt_descriptors[outlink->format].name);
132 scale->input_is_pal = av_pix_fmt_descriptors[inlink->format].flags & PIX_FMT_PAL;
137 static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
139 ScaleContext *scale = link->dst->priv;
140 AVFilterLink *outlink = link->dst->outputs[0];
141 AVFilterPicRef *outpicref;
143 scale->hsub = av_pix_fmt_descriptors[link->format].log2_chroma_w;
144 scale->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
146 outpicref = avfilter_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
147 outpicref->pts = picref->pts;
148 outpicref->pos = picref->pos;
149 outlink->outpic = outpicref;
151 av_reduce(&outpicref->pixel_aspect.num, &outpicref->pixel_aspect.den,
152 (int64_t)picref->pixel_aspect.num * outlink->h * link->w,
153 (int64_t)picref->pixel_aspect.den * outlink->w * link->h,
157 avfilter_start_frame(outlink, avfilter_ref_pic(outpicref, ~0));
160 static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
162 ScaleContext *scale = link->dst->priv;
164 AVFilterPicRef *cur_pic = link->cur_pic;
167 if (scale->slice_y == 0 && slice_dir == -1)
168 scale->slice_y = link->dst->outputs[0]->h;
170 data[0] = cur_pic->data[0] + y * cur_pic->linesize[0];
171 data[1] = scale->input_is_pal ?
173 cur_pic->data[1] + (y>>scale->vsub) * cur_pic->linesize[1];
174 data[2] = cur_pic->data[2] + (y>>scale->vsub) * cur_pic->linesize[2];
175 data[3] = cur_pic->data[3] + y * cur_pic->linesize[3];
177 out_h = sws_scale(scale->sws, data, cur_pic->linesize, y, h,
178 link->dst->outputs[0]->outpic->data,
179 link->dst->outputs[0]->outpic->linesize);
182 scale->slice_y -= out_h;
183 avfilter_draw_slice(link->dst->outputs[0], scale->slice_y, out_h, slice_dir);
185 scale->slice_y += out_h;
188 AVFilter avfilter_vf_scale = {
190 .description = "Scale the input video to width:height size and/or convert the image format.",
195 .query_formats = query_formats,
197 .priv_size = sizeof(ScaleContext),
199 .inputs = (AVFilterPad[]) {{ .name = "default",
200 .type = AVMEDIA_TYPE_VIDEO,
201 .start_frame = start_frame,
202 .draw_slice = draw_slice,
203 .min_perms = AV_PERM_READ, },
205 .outputs = (AVFilterPad[]) {{ .name = "default",
206 .type = AVMEDIA_TYPE_VIDEO,
207 .config_props = config_props, },