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
33 #include "libavutil/avstring.h"
34 #include "libavutil/eval.h"
35 #include "libavutil/internal.h"
36 #include "libavutil/mathematics.h"
37 #include "libavutil/opt.h"
38 #include "libavutil/pixdesc.h"
39 #include "libavutil/imgutils.h"
40 #include "libavutil/avassert.h"
41 #include "libswscale/swscale.h"
43 static const char *const var_names[] = {
70 struct SwsContext *sws; ///< software scaler context
71 struct SwsContext *isws[2]; ///< software scaler context for interlaced material
74 * New dimensions. Special values are:
75 * 0 = original width/height
76 * -1 = keep original aspect
79 unsigned int flags; ///sws flags
81 int hsub, vsub; ///< chroma subsampling
82 int slice_y; ///< top of current output slice
83 int input_is_pal; ///< set to 1 if the input format is paletted
84 int output_is_pal; ///< set to 1 if the output format is paletted
87 char w_expr[256]; ///< width expression string
88 char h_expr[256]; ///< height expression string
91 static av_cold int init(AVFilterContext *ctx, const char *args)
93 ScaleContext *scale = ctx->priv;
96 av_strlcpy(scale->w_expr, "iw", sizeof(scale->w_expr));
97 av_strlcpy(scale->h_expr, "ih", sizeof(scale->h_expr));
99 scale->flags = SWS_BILINEAR;
101 sscanf(args, "%255[^:]:%255[^:]", scale->w_expr, scale->h_expr);
102 p = strstr(args,"flags=");
104 const AVClass *class = sws_get_class();
105 const AVOption *o = av_opt_find(&class, "sws_flags", NULL, 0,
106 AV_OPT_SEARCH_FAKE_OBJ);
107 int ret = av_opt_eval_flags(&class, o, p + 6, &scale->flags);
112 if(strstr(args,"interl=1")){
114 }else if(strstr(args,"interl=-1"))
115 scale->interlaced=-1;
121 static av_cold void uninit(AVFilterContext *ctx)
123 ScaleContext *scale = ctx->priv;
124 sws_freeContext(scale->sws);
125 sws_freeContext(scale->isws[0]);
126 sws_freeContext(scale->isws[1]);
130 static int query_formats(AVFilterContext *ctx)
132 AVFilterFormats *formats;
133 enum AVPixelFormat pix_fmt;
136 if (ctx->inputs[0]) {
138 for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++)
139 if ( sws_isSupportedInput(pix_fmt)
140 && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
141 ff_formats_unref(&formats);
144 ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
146 if (ctx->outputs[0]) {
148 for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++)
149 if ( (sws_isSupportedOutput(pix_fmt) || pix_fmt == AV_PIX_FMT_PAL8)
150 && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
151 ff_formats_unref(&formats);
154 ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
160 static int config_props(AVFilterLink *outlink)
162 AVFilterContext *ctx = outlink->src;
163 AVFilterLink *inlink = outlink->src->inputs[0];
164 enum AVPixelFormat outfmt = outlink->format;
165 ScaleContext *scale = ctx->priv;
166 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
168 double var_values[VARS_NB], res;
172 var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
173 var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
174 var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
175 var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
176 var_values[VAR_A] = (double) inlink->w / inlink->h;
177 var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
178 (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
179 var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
180 var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
181 var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
183 /* evaluate width and height */
184 av_expr_parse_and_eval(&res, (expr = scale->w_expr),
185 var_names, var_values,
186 NULL, NULL, NULL, NULL, NULL, 0, ctx);
187 scale->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
188 if ((ret = av_expr_parse_and_eval(&res, (expr = scale->h_expr),
189 var_names, var_values,
190 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
192 scale->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
193 /* evaluate again the width, as it may depend on the output height */
194 if ((ret = av_expr_parse_and_eval(&res, (expr = scale->w_expr),
195 var_names, var_values,
196 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
203 /* sanity check params */
204 if (w < -1 || h < -1) {
205 av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n");
206 return AVERROR(EINVAL);
208 if (w == -1 && h == -1)
209 scale->w = scale->h = 0;
216 w = av_rescale(h, inlink->w, inlink->h);
218 h = av_rescale(w, inlink->h, inlink->w);
220 if (w > INT_MAX || h > INT_MAX ||
221 (h * inlink->w) > INT_MAX ||
222 (w * inlink->h) > INT_MAX)
223 av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
228 /* TODO: make algorithm configurable */
230 scale->input_is_pal = desc->flags & PIX_FMT_PAL ||
231 desc->flags & PIX_FMT_PSEUDOPAL;
232 if (outfmt == AV_PIX_FMT_PAL8) outfmt = AV_PIX_FMT_BGR8;
233 scale->output_is_pal = av_pix_fmt_desc_get(outfmt)->flags & PIX_FMT_PAL ||
234 av_pix_fmt_desc_get(outfmt)->flags & PIX_FMT_PSEUDOPAL;
237 sws_freeContext(scale->sws);
238 if (inlink->w == outlink->w && inlink->h == outlink->h &&
239 inlink->format == outlink->format)
242 scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
243 outlink->w, outlink->h, outfmt,
244 scale->flags, NULL, NULL, NULL);
246 sws_freeContext(scale->isws[0]);
247 scale->isws[0] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
248 outlink->w, outlink->h/2, outfmt,
249 scale->flags, NULL, NULL, NULL);
251 sws_freeContext(scale->isws[1]);
252 scale->isws[1] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
253 outlink->w, outlink->h/2, outfmt,
254 scale->flags, NULL, NULL, NULL);
255 if (!scale->sws || !scale->isws[0] || !scale->isws[1])
256 return AVERROR(EINVAL);
259 if (inlink->sample_aspect_ratio.num){
260 outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink->w, outlink->w * inlink->h}, inlink->sample_aspect_ratio);
262 outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
264 av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d fmt:%s sar:%d/%d -> w:%d h:%d fmt:%s sar:%d/%d flags:0x%0x\n",
265 inlink ->w, inlink ->h, av_get_pix_fmt_name( inlink->format),
266 inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den,
267 outlink->w, outlink->h, av_get_pix_fmt_name(outlink->format),
268 outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den,
273 av_log(NULL, AV_LOG_ERROR,
274 "Error when evaluating the expression '%s'.\n"
275 "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
276 expr, scale->w_expr, scale->h_expr);
280 static int start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
282 ScaleContext *scale = link->dst->priv;
283 AVFilterLink *outlink = link->dst->outputs[0];
284 AVFilterBufferRef *outpicref, *for_next_filter;
285 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
288 if( picref->video->w != link->w
289 || picref->video->h != link->h
290 || picref->format != link->format) {
292 snprintf(scale->w_expr, sizeof(scale->w_expr)-1, "%d", outlink->w);
293 snprintf(scale->h_expr, sizeof(scale->h_expr)-1, "%d", outlink->h);
295 link->dst->inputs[0]->format = picref->format;
296 link->dst->inputs[0]->w = picref->video->w;
297 link->dst->inputs[0]->h = picref->video->h;
299 if ((ret = config_props(outlink)) < 0)
300 av_assert0(0); //what to do here ?
305 outpicref = avfilter_ref_buffer(picref, ~0);
307 return AVERROR(ENOMEM);
308 return ff_start_frame(outlink, outpicref);
311 scale->hsub = desc->log2_chroma_w;
312 scale->vsub = desc->log2_chroma_h;
314 outpicref = ff_get_video_buffer(outlink, AV_PERM_WRITE|AV_PERM_ALIGN, outlink->w, outlink->h);
316 return AVERROR(ENOMEM);
318 avfilter_copy_buffer_ref_props(outpicref, picref);
319 outpicref->video->w = outlink->w;
320 outpicref->video->h = outlink->h;
322 if(scale->output_is_pal)
323 avpriv_set_systematic_pal2((uint32_t*)outpicref->data[1], outlink->format == AV_PIX_FMT_PAL8 ? AV_PIX_FMT_BGR8 : outlink->format);
325 av_reduce(&outpicref->video->sample_aspect_ratio.num, &outpicref->video->sample_aspect_ratio.den,
326 (int64_t)picref->video->sample_aspect_ratio.num * outlink->h * link->w,
327 (int64_t)picref->video->sample_aspect_ratio.den * outlink->w * link->h,
331 for_next_filter = avfilter_ref_buffer(outpicref, ~0);
333 ret = ff_start_frame(outlink, for_next_filter);
335 ret = AVERROR(ENOMEM);
338 avfilter_unref_bufferp(&outpicref);
342 outlink->out_buf = outpicref;
346 static int scale_slice(AVFilterLink *link, struct SwsContext *sws, int y, int h, int mul, int field)
348 ScaleContext *scale = link->dst->priv;
349 AVFilterBufferRef *cur_pic = link->cur_buf;
350 AVFilterBufferRef *out_buf = link->dst->outputs[0]->out_buf;
351 const uint8_t *in[4];
353 int in_stride[4],out_stride[4];
357 int vsub= ((i+1)&2) ? scale->vsub : 0;
358 in_stride[i] = cur_pic->linesize[i] * mul;
359 out_stride[i] = out_buf->linesize[i] * mul;
360 in[i] = cur_pic->data[i] + ((y>>vsub)+field) * cur_pic->linesize[i];
361 out[i] = out_buf->data[i] + field * out_buf->linesize[i];
363 if(scale->input_is_pal)
364 in[1] = cur_pic->data[1];
365 if(scale->output_is_pal)
366 out[1] = out_buf->data[1];
368 return sws_scale(sws, in, in_stride, y/mul, h,
372 static int draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
374 ScaleContext *scale = link->dst->priv;
378 return ff_draw_slice(link->dst->outputs[0], y, h, slice_dir);
381 if (scale->slice_y == 0 && slice_dir == -1)
382 scale->slice_y = link->dst->outputs[0]->h;
384 if(scale->interlaced>0 || (scale->interlaced<0 && link->cur_buf->video->interlaced)){
385 av_assert0(y%(2<<scale->vsub) == 0);
386 out_h = scale_slice(link, scale->isws[0], y, (h+1)/2, 2, 0);
387 out_h+= scale_slice(link, scale->isws[1], y, h /2, 2, 1);
389 out_h = scale_slice(link, scale->sws, y, h, 1, 0);
393 scale->slice_y -= out_h;
394 ret = ff_draw_slice(link->dst->outputs[0], scale->slice_y, out_h, slice_dir);
396 scale->slice_y += out_h;
400 static const AVFilterPad avfilter_vf_scale_inputs[] = {
403 .type = AVMEDIA_TYPE_VIDEO,
404 .start_frame = start_frame,
405 .draw_slice = draw_slice,
406 .min_perms = AV_PERM_READ,
411 static const AVFilterPad avfilter_vf_scale_outputs[] = {
414 .type = AVMEDIA_TYPE_VIDEO,
415 .config_props = config_props,
420 AVFilter avfilter_vf_scale = {
422 .description = NULL_IF_CONFIG_SMALL("Scale the input video to width:height size and/or convert the image format."),
427 .query_formats = query_formats,
429 .priv_size = sizeof(ScaleContext),
431 .inputs = avfilter_vf_scale_inputs,
432 .outputs = avfilter_vf_scale_outputs,