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/avstring.h"
28 #include "libavutil/eval.h"
29 #include "libavutil/mathematics.h"
30 #include "libavutil/pixdesc.h"
31 #include "libavutil/avassert.h"
32 #include "libswscale/swscale.h"
34 static const char * const var_names[] = {
61 struct SwsContext *sws; ///< software scaler context
62 struct SwsContext *isws[2]; ///< software scaler context for interlaced material
65 * New dimensions. Special values are:
66 * 0 = original width/height
67 * -1 = keep original aspect
70 unsigned int flags; ///sws flags
72 int hsub, vsub; ///< chroma subsampling
73 int slice_y; ///< top of current output slice
74 int input_is_pal; ///< set to 1 if the input format is paletted
77 char w_expr[256]; ///< width expression string
78 char h_expr[256]; ///< height expression string
81 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
83 ScaleContext *scale = ctx->priv;
86 av_strlcpy(scale->w_expr, "iw", sizeof(scale->w_expr));
87 av_strlcpy(scale->h_expr, "ih", sizeof(scale->h_expr));
89 scale->flags = SWS_BILINEAR;
91 sscanf(args, "%255[^:]:%255[^:]", scale->w_expr, scale->h_expr);
92 p = strstr(args,"flags=");
93 if (p) scale->flags = strtoul(p+6, NULL, 0);
94 if(strstr(args,"interl=1")){
96 }else if(strstr(args,"interl=-1"))
103 static av_cold void uninit(AVFilterContext *ctx)
105 ScaleContext *scale = ctx->priv;
106 sws_freeContext(scale->sws);
107 sws_freeContext(scale->isws[0]);
108 sws_freeContext(scale->isws[1]);
112 static int query_formats(AVFilterContext *ctx)
114 AVFilterFormats *formats;
115 enum PixelFormat pix_fmt;
118 if (ctx->inputs[0]) {
120 for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
121 if ( sws_isSupportedInput(pix_fmt)
122 && (ret = avfilter_add_format(&formats, pix_fmt)) < 0) {
123 avfilter_formats_unref(&formats);
126 avfilter_formats_ref(formats, &ctx->inputs[0]->out_formats);
128 if (ctx->outputs[0]) {
130 for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
131 if ( (sws_isSupportedOutput(pix_fmt) || pix_fmt == PIX_FMT_PAL8)
132 && (ret = avfilter_add_format(&formats, pix_fmt)) < 0) {
133 avfilter_formats_unref(&formats);
136 avfilter_formats_ref(formats, &ctx->outputs[0]->in_formats);
142 static int config_props(AVFilterLink *outlink)
144 AVFilterContext *ctx = outlink->src;
145 AVFilterLink *inlink = outlink->src->inputs[0];
146 enum PixelFormat outfmt = outlink->format;
147 ScaleContext *scale = ctx->priv;
149 double var_values[VARS_NB], res;
153 var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
154 var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
155 var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
156 var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
157 var_values[VAR_A] = (float) inlink->w / inlink->h;
158 var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
159 (float) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
160 var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
161 var_values[VAR_HSUB] = 1<<av_pix_fmt_descriptors[inlink->format].log2_chroma_w;
162 var_values[VAR_VSUB] = 1<<av_pix_fmt_descriptors[inlink->format].log2_chroma_h;
164 /* evaluate width and height */
165 av_expr_parse_and_eval(&res, (expr = scale->w_expr),
166 var_names, var_values,
167 NULL, NULL, NULL, NULL, NULL, 0, ctx);
168 scale->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
169 if ((ret = av_expr_parse_and_eval(&res, (expr = scale->h_expr),
170 var_names, var_values,
171 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
173 scale->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
174 /* evaluate again the width, as it may depend on the output height */
175 if ((ret = av_expr_parse_and_eval(&res, (expr = scale->w_expr),
176 var_names, var_values,
177 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
184 /* sanity check params */
185 if (w < -1 || h < -1) {
186 av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n");
187 return AVERROR(EINVAL);
189 if (w == -1 && h == -1)
190 scale->w = scale->h = 0;
197 w = av_rescale(h, inlink->w, inlink->h);
199 h = av_rescale(w, inlink->h, inlink->w);
201 if (w > INT_MAX || h > INT_MAX ||
202 (h * inlink->w) > INT_MAX ||
203 (w * inlink->h) > INT_MAX)
204 av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
209 /* TODO: make algorithm configurable */
210 av_log(ctx, AV_LOG_INFO, "w:%d h:%d fmt:%s -> w:%d h:%d fmt:%s flags:0x%0x\n",
211 inlink ->w, inlink ->h, av_pix_fmt_descriptors[ inlink->format].name,
212 outlink->w, outlink->h, av_pix_fmt_descriptors[outlink->format].name,
215 scale->input_is_pal = av_pix_fmt_descriptors[inlink->format].flags & PIX_FMT_PAL;
216 if (outfmt == PIX_FMT_PAL8) outfmt = PIX_FMT_BGR8;
219 sws_freeContext(scale->sws);
220 scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
221 outlink->w, outlink->h, outfmt,
222 scale->flags, NULL, NULL, NULL);
224 sws_freeContext(scale->isws[0]);
225 scale->isws[0] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
226 outlink->w, outlink->h/2, outfmt,
227 scale->flags, NULL, NULL, NULL);
229 sws_freeContext(scale->isws[1]);
230 scale->isws[1] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
231 outlink->w, outlink->h/2, outfmt,
232 scale->flags, NULL, NULL, NULL);
233 if (!scale->sws || !scale->isws[0] || !scale->isws[1])
234 return AVERROR(EINVAL);
236 if (inlink->sample_aspect_ratio.num){
237 outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink->w, outlink->w * inlink->h}, inlink->sample_aspect_ratio);
239 outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
244 av_log(NULL, AV_LOG_ERROR,
245 "Error when evaluating the expression '%s'.\n"
246 "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
247 expr, scale->w_expr, scale->h_expr);
251 static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
253 ScaleContext *scale = link->dst->priv;
254 AVFilterLink *outlink = link->dst->outputs[0];
255 AVFilterBufferRef *outpicref;
257 scale->hsub = av_pix_fmt_descriptors[link->format].log2_chroma_w;
258 scale->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
260 outpicref = avfilter_get_video_buffer(outlink, AV_PERM_WRITE|AV_PERM_ALIGN, outlink->w, outlink->h);
261 avfilter_copy_buffer_ref_props(outpicref, picref);
262 outpicref->video->w = outlink->w;
263 outpicref->video->h = outlink->h;
265 outlink->out_buf = outpicref;
267 av_reduce(&outpicref->video->sample_aspect_ratio.num, &outpicref->video->sample_aspect_ratio.den,
268 (int64_t)picref->video->sample_aspect_ratio.num * outlink->h * link->w,
269 (int64_t)picref->video->sample_aspect_ratio.den * outlink->w * link->h,
273 avfilter_start_frame(outlink, avfilter_ref_buffer(outpicref, ~0));
276 static int scale_slice(AVFilterLink *link, struct SwsContext *sws, int y, int h, int mul, int field)
278 ScaleContext *scale = link->dst->priv;
279 AVFilterBufferRef *cur_pic = link->cur_buf;
280 AVFilterBufferRef *out_buf = link->dst->outputs[0]->out_buf;
281 const uint8_t *in[4];
283 int in_stride[4],out_stride[4];
287 int vsub= ((i+1)&2) ? scale->vsub : 0;
288 in_stride[i] = cur_pic->linesize[i] * mul;
289 out_stride[i] = out_buf->linesize[i] * mul;
290 in[i] = cur_pic->data[i] + ((y>>vsub)+field) * cur_pic->linesize[i];
291 out[i] = out_buf->data[i] + field * out_buf->linesize[i];
293 if(scale->input_is_pal){
294 in[1] = cur_pic->data[1];
295 out[1] = out_buf->data[1];
298 return sws_scale(sws, in, in_stride, y/mul, h,
302 static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
304 ScaleContext *scale = link->dst->priv;
307 if (scale->slice_y == 0 && slice_dir == -1)
308 scale->slice_y = link->dst->outputs[0]->h;
310 if(scale->interlaced>0 || (scale->interlaced<0 && link->cur_buf->video->interlaced)){
311 av_assert0(y%(2<<scale->vsub) == 0);
312 out_h = scale_slice(link, scale->isws[0], y, (h+1)/2, 2, 0);
313 out_h+= scale_slice(link, scale->isws[1], y, h /2, 2, 1);
315 out_h = scale_slice(link, scale->sws, y, h, 1, 0);
319 scale->slice_y -= out_h;
320 avfilter_draw_slice(link->dst->outputs[0], scale->slice_y, out_h, slice_dir);
322 scale->slice_y += out_h;
325 AVFilter avfilter_vf_scale = {
327 .description = NULL_IF_CONFIG_SMALL("Scale the input video to width:height size and/or convert the image format."),
332 .query_formats = query_formats,
334 .priv_size = sizeof(ScaleContext),
336 .inputs = (const AVFilterPad[]) {{ .name = "default",
337 .type = AVMEDIA_TYPE_VIDEO,
338 .start_frame = start_frame,
339 .draw_slice = draw_slice,
340 .min_perms = AV_PERM_READ, },
342 .outputs = (const AVFilterPad[]) {{ .name = "default",
343 .type = AVMEDIA_TYPE_VIDEO,
344 .config_props = config_props, },