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/imgutils.h"
32 #include "libavutil/avassert.h"
33 #include "libswscale/swscale.h"
35 static const char *const var_names[] = {
62 struct SwsContext *sws; ///< software scaler context
63 struct SwsContext *isws[2]; ///< software scaler context for interlaced material
66 * New dimensions. Special values are:
67 * 0 = original width/height
68 * -1 = keep original aspect
71 unsigned int flags; ///sws flags
73 int hsub, vsub; ///< chroma subsampling
74 int slice_y; ///< top of current output slice
75 int input_is_pal; ///< set to 1 if the input format is paletted
76 int output_is_pal; ///< set to 1 if the output format is paletted
79 char w_expr[256]; ///< width expression string
80 char h_expr[256]; ///< height expression string
83 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
85 ScaleContext *scale = ctx->priv;
88 av_strlcpy(scale->w_expr, "iw", sizeof(scale->w_expr));
89 av_strlcpy(scale->h_expr, "ih", sizeof(scale->h_expr));
91 scale->flags = SWS_BILINEAR;
93 sscanf(args, "%255[^:]:%255[^:]", scale->w_expr, scale->h_expr);
94 p = strstr(args,"flags=");
95 if (p) scale->flags = strtoul(p+6, NULL, 0);
96 if(strstr(args,"interl=1")){
98 }else if(strstr(args,"interl=-1"))
105 static av_cold void uninit(AVFilterContext *ctx)
107 ScaleContext *scale = ctx->priv;
108 sws_freeContext(scale->sws);
109 sws_freeContext(scale->isws[0]);
110 sws_freeContext(scale->isws[1]);
114 static int query_formats(AVFilterContext *ctx)
116 AVFilterFormats *formats;
117 enum PixelFormat pix_fmt;
120 if (ctx->inputs[0]) {
122 for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
123 if ( sws_isSupportedInput(pix_fmt)
124 && (ret = avfilter_add_format(&formats, pix_fmt)) < 0) {
125 avfilter_formats_unref(&formats);
128 avfilter_formats_ref(formats, &ctx->inputs[0]->out_formats);
130 if (ctx->outputs[0]) {
132 for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
133 if ( (sws_isSupportedOutput(pix_fmt) || pix_fmt == PIX_FMT_PAL8)
134 && (ret = avfilter_add_format(&formats, pix_fmt)) < 0) {
135 avfilter_formats_unref(&formats);
138 avfilter_formats_ref(formats, &ctx->outputs[0]->in_formats);
144 static int config_props(AVFilterLink *outlink)
146 AVFilterContext *ctx = outlink->src;
147 AVFilterLink *inlink = outlink->src->inputs[0];
148 enum PixelFormat outfmt = outlink->format;
149 ScaleContext *scale = ctx->priv;
151 double var_values[VARS_NB], res;
155 var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
156 var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
157 var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
158 var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
159 var_values[VAR_A] = (float) inlink->w / inlink->h;
160 var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
161 (float) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
162 var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
163 var_values[VAR_HSUB] = 1<<av_pix_fmt_descriptors[inlink->format].log2_chroma_w;
164 var_values[VAR_VSUB] = 1<<av_pix_fmt_descriptors[inlink->format].log2_chroma_h;
166 /* evaluate width and height */
167 av_expr_parse_and_eval(&res, (expr = scale->w_expr),
168 var_names, var_values,
169 NULL, NULL, NULL, NULL, NULL, 0, ctx);
170 scale->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
171 if ((ret = av_expr_parse_and_eval(&res, (expr = scale->h_expr),
172 var_names, var_values,
173 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
175 scale->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
176 /* evaluate again the width, as it may depend on the output height */
177 if ((ret = av_expr_parse_and_eval(&res, (expr = scale->w_expr),
178 var_names, var_values,
179 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
186 /* sanity check params */
187 if (w < -1 || h < -1) {
188 av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n");
189 return AVERROR(EINVAL);
191 if (w == -1 && h == -1)
192 scale->w = scale->h = 0;
199 w = av_rescale(h, inlink->w, inlink->h);
201 h = av_rescale(w, inlink->h, inlink->w);
203 if (w > INT_MAX || h > INT_MAX ||
204 (h * inlink->w) > INT_MAX ||
205 (w * inlink->h) > INT_MAX)
206 av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
211 /* TODO: make algorithm configurable */
213 scale->input_is_pal = av_pix_fmt_descriptors[inlink->format].flags & PIX_FMT_PAL ||
214 av_pix_fmt_descriptors[inlink->format].flags & PIX_FMT_PSEUDOPAL;
215 if (outfmt == PIX_FMT_PAL8) outfmt = PIX_FMT_BGR8;
216 scale->output_is_pal = av_pix_fmt_descriptors[outfmt].flags & PIX_FMT_PAL ||
217 av_pix_fmt_descriptors[outfmt].flags & PIX_FMT_PSEUDOPAL;
220 sws_freeContext(scale->sws);
221 if (inlink->w == outlink->w && inlink->h == outlink->h &&
222 inlink->format == outlink->format)
225 scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
226 outlink->w, outlink->h, outfmt,
227 scale->flags, NULL, NULL, NULL);
229 sws_freeContext(scale->isws[0]);
230 scale->isws[0] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
231 outlink->w, outlink->h/2, outfmt,
232 scale->flags, NULL, NULL, NULL);
234 sws_freeContext(scale->isws[1]);
235 scale->isws[1] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
236 outlink->w, outlink->h/2, outfmt,
237 scale->flags, NULL, NULL, NULL);
238 if (!scale->sws || !scale->isws[0] || !scale->isws[1])
239 return AVERROR(EINVAL);
242 if (inlink->sample_aspect_ratio.num){
243 outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink->w, outlink->w * inlink->h}, inlink->sample_aspect_ratio);
245 outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
247 av_log(ctx, AV_LOG_INFO, "w:%d h:%d fmt:%s sar:%d/%d -> w:%d h:%d fmt:%s sar:%d/%d flags:0x%0x\n",
248 inlink ->w, inlink ->h, av_pix_fmt_descriptors[ inlink->format].name,
249 inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den,
250 outlink->w, outlink->h, av_pix_fmt_descriptors[outlink->format].name,
251 outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den,
256 av_log(NULL, AV_LOG_ERROR,
257 "Error when evaluating the expression '%s'.\n"
258 "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
259 expr, scale->w_expr, scale->h_expr);
263 static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
265 ScaleContext *scale = link->dst->priv;
266 AVFilterLink *outlink = link->dst->outputs[0];
267 AVFilterBufferRef *outpicref;
270 avfilter_start_frame(outlink, avfilter_ref_buffer(picref, ~0));
274 scale->hsub = av_pix_fmt_descriptors[link->format].log2_chroma_w;
275 scale->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
277 outpicref = avfilter_get_video_buffer(outlink, AV_PERM_WRITE|AV_PERM_ALIGN, outlink->w, outlink->h);
278 avfilter_copy_buffer_ref_props(outpicref, picref);
279 outpicref->video->w = outlink->w;
280 outpicref->video->h = outlink->h;
282 outlink->out_buf = outpicref;
283 if(scale->output_is_pal)
284 ff_set_systematic_pal2(outpicref->data[1], outlink->format == PIX_FMT_PAL8 ? PIX_FMT_BGR8 : outlink->format);
286 av_reduce(&outpicref->video->sample_aspect_ratio.num, &outpicref->video->sample_aspect_ratio.den,
287 (int64_t)picref->video->sample_aspect_ratio.num * outlink->h * link->w,
288 (int64_t)picref->video->sample_aspect_ratio.den * outlink->w * link->h,
292 avfilter_start_frame(outlink, avfilter_ref_buffer(outpicref, ~0));
295 static int scale_slice(AVFilterLink *link, struct SwsContext *sws, int y, int h, int mul, int field)
297 ScaleContext *scale = link->dst->priv;
298 AVFilterBufferRef *cur_pic = link->cur_buf;
299 AVFilterBufferRef *out_buf = link->dst->outputs[0]->out_buf;
300 const uint8_t *in[4];
302 int in_stride[4],out_stride[4];
306 int vsub= ((i+1)&2) ? scale->vsub : 0;
307 in_stride[i] = cur_pic->linesize[i] * mul;
308 out_stride[i] = out_buf->linesize[i] * mul;
309 in[i] = cur_pic->data[i] + ((y>>vsub)+field) * cur_pic->linesize[i];
310 out[i] = out_buf->data[i] + field * out_buf->linesize[i];
312 if(scale->input_is_pal)
313 in[1] = cur_pic->data[1];
314 if(scale->output_is_pal)
315 out[1] = out_buf->data[1];
317 return sws_scale(sws, in, in_stride, y/mul, h,
321 static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
323 ScaleContext *scale = link->dst->priv;
327 avfilter_draw_slice(link->dst->outputs[0], y, h, slice_dir);
331 if (scale->slice_y == 0 && slice_dir == -1)
332 scale->slice_y = link->dst->outputs[0]->h;
334 if(scale->interlaced>0 || (scale->interlaced<0 && link->cur_buf->video->interlaced)){
335 av_assert0(y%(2<<scale->vsub) == 0);
336 out_h = scale_slice(link, scale->isws[0], y, (h+1)/2, 2, 0);
337 out_h+= scale_slice(link, scale->isws[1], y, h /2, 2, 1);
339 out_h = scale_slice(link, scale->sws, y, h, 1, 0);
343 scale->slice_y -= out_h;
344 avfilter_draw_slice(link->dst->outputs[0], scale->slice_y, out_h, slice_dir);
346 scale->slice_y += out_h;
349 AVFilter avfilter_vf_scale = {
351 .description = NULL_IF_CONFIG_SMALL("Scale the input video to width:height size and/or convert the image format."),
356 .query_formats = query_formats,
358 .priv_size = sizeof(ScaleContext),
360 .inputs = (const AVFilterPad[]) {{ .name = "default",
361 .type = AVMEDIA_TYPE_VIDEO,
362 .start_frame = start_frame,
363 .draw_slice = draw_slice,
364 .min_perms = AV_PERM_READ, },
366 .outputs = (const AVFilterPad[]) {{ .name = "default",
367 .type = AVMEDIA_TYPE_VIDEO,
368 .config_props = config_props, },