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[] = {
71 struct SwsContext *sws; ///< software scaler context
72 struct SwsContext *isws[2]; ///< software scaler context for interlaced material
75 * New dimensions. Special values are:
76 * 0 = original width/height
77 * -1 = keep original aspect
80 char *flags_str; ///sws flags string
81 unsigned int flags; ///sws flags
83 int hsub, vsub; ///< chroma subsampling
84 int slice_y; ///< top of current output slice
85 int input_is_pal; ///< set to 1 if the input format is paletted
86 int output_is_pal; ///< set to 1 if the output format is paletted
89 char *w_expr; ///< width expression string
90 char *h_expr; ///< height expression string
93 #define OFFSET(x) offsetof(ScaleContext, x)
94 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
96 static const AVOption scale_options[] = {
97 { "w", "set width expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, 0, 0, FLAGS },
98 { "width", "set width expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, 0, 0, FLAGS },
99 { "h", "set height expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, 0, 0, FLAGS },
100 { "height", "set height expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, 0, 0, FLAGS },
101 { "flags", "set libswscale flags", OFFSET(flags_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, INT_MAX, FLAGS },
102 { "interl", "set interlacing", OFFSET(interlaced), AV_OPT_TYPE_INT, {.i64 = 0 }, -1, 1, FLAGS },
106 AVFILTER_DEFINE_CLASS(scale);
108 static av_cold int init(AVFilterContext *ctx, const char *args)
110 ScaleContext *scale = ctx->priv;
111 static const char *shorthand[] = { "w", "h", NULL };
114 scale->class = &scale_class;
115 av_opt_set_defaults(scale);
117 if ((ret = av_opt_set_from_string(scale, args, shorthand, "=", ":")) < 0)
120 av_log(ctx, AV_LOG_VERBOSE, "w:%s h:%s flags:%s interl:%d\n",
121 scale->w_expr, scale->h_expr, scale->flags_str, scale->interlaced);
123 scale->flags = SWS_BILINEAR;
124 if (scale->flags_str) {
125 const AVClass *class = sws_get_class();
126 const AVOption *o = av_opt_find(&class, "sws_flags", NULL, 0,
127 AV_OPT_SEARCH_FAKE_OBJ);
128 int ret = av_opt_eval_flags(&class, o, scale->flags_str, &scale->flags);
136 static av_cold void uninit(AVFilterContext *ctx)
138 ScaleContext *scale = ctx->priv;
139 sws_freeContext(scale->sws);
140 sws_freeContext(scale->isws[0]);
141 sws_freeContext(scale->isws[1]);
146 static int query_formats(AVFilterContext *ctx)
148 AVFilterFormats *formats;
149 enum AVPixelFormat pix_fmt;
152 if (ctx->inputs[0]) {
154 for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++)
155 if ( sws_isSupportedInput(pix_fmt)
156 && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
157 ff_formats_unref(&formats);
160 ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
162 if (ctx->outputs[0]) {
164 for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++)
165 if ( (sws_isSupportedOutput(pix_fmt) || pix_fmt == AV_PIX_FMT_PAL8)
166 && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
167 ff_formats_unref(&formats);
170 ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
176 static int config_props(AVFilterLink *outlink)
178 AVFilterContext *ctx = outlink->src;
179 AVFilterLink *inlink = outlink->src->inputs[0];
180 enum AVPixelFormat outfmt = outlink->format;
181 ScaleContext *scale = ctx->priv;
182 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
184 double var_values[VARS_NB], res;
188 var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
189 var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
190 var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
191 var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
192 var_values[VAR_A] = (double) inlink->w / inlink->h;
193 var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
194 (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
195 var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
196 var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
197 var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
199 /* evaluate width and height */
200 av_expr_parse_and_eval(&res, (expr = scale->w_expr),
201 var_names, var_values,
202 NULL, NULL, NULL, NULL, NULL, 0, ctx);
203 scale->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
204 if ((ret = av_expr_parse_and_eval(&res, (expr = scale->h_expr),
205 var_names, var_values,
206 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
208 scale->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
209 /* evaluate again the width, as it may depend on the output height */
210 if ((ret = av_expr_parse_and_eval(&res, (expr = scale->w_expr),
211 var_names, var_values,
212 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
219 /* sanity check params */
220 if (w < -1 || h < -1) {
221 av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n");
222 return AVERROR(EINVAL);
224 if (w == -1 && h == -1)
225 scale->w = scale->h = 0;
232 w = av_rescale(h, inlink->w, inlink->h);
234 h = av_rescale(w, inlink->h, inlink->w);
236 if (w > INT_MAX || h > INT_MAX ||
237 (h * inlink->w) > INT_MAX ||
238 (w * inlink->h) > INT_MAX)
239 av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
244 /* TODO: make algorithm configurable */
246 scale->input_is_pal = desc->flags & PIX_FMT_PAL ||
247 desc->flags & PIX_FMT_PSEUDOPAL;
248 if (outfmt == AV_PIX_FMT_PAL8) outfmt = AV_PIX_FMT_BGR8;
249 scale->output_is_pal = av_pix_fmt_desc_get(outfmt)->flags & PIX_FMT_PAL ||
250 av_pix_fmt_desc_get(outfmt)->flags & PIX_FMT_PSEUDOPAL;
253 sws_freeContext(scale->sws);
254 if (inlink->w == outlink->w && inlink->h == outlink->h &&
255 inlink->format == outlink->format)
258 scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
259 outlink->w, outlink->h, outfmt,
260 scale->flags, NULL, NULL, NULL);
262 sws_freeContext(scale->isws[0]);
263 scale->isws[0] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
264 outlink->w, outlink->h/2, outfmt,
265 scale->flags, NULL, NULL, NULL);
267 sws_freeContext(scale->isws[1]);
268 scale->isws[1] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
269 outlink->w, outlink->h/2, outfmt,
270 scale->flags, NULL, NULL, NULL);
271 if (!scale->sws || !scale->isws[0] || !scale->isws[1])
272 return AVERROR(EINVAL);
275 if (inlink->sample_aspect_ratio.num){
276 outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink->w, outlink->w * inlink->h}, inlink->sample_aspect_ratio);
278 outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
280 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",
281 inlink ->w, inlink ->h, av_get_pix_fmt_name( inlink->format),
282 inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den,
283 outlink->w, outlink->h, av_get_pix_fmt_name(outlink->format),
284 outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den,
289 av_log(NULL, AV_LOG_ERROR,
290 "Error when evaluating the expression '%s'.\n"
291 "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
292 expr, scale->w_expr, scale->h_expr);
296 static int start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
298 ScaleContext *scale = link->dst->priv;
299 AVFilterLink *outlink = link->dst->outputs[0];
300 AVFilterBufferRef *outpicref, *for_next_filter;
301 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
305 if( picref->video->w != link->w
306 || picref->video->h != link->h
307 || picref->format != link->format) {
309 snprintf(buf, sizeof(buf)-1, "%d", outlink->w);
310 av_opt_set(scale, "w", buf, 0);
311 snprintf(buf, sizeof(buf)-1, "%d", outlink->h);
312 av_opt_set(scale, "h", buf, 0);
314 link->dst->inputs[0]->format = picref->format;
315 link->dst->inputs[0]->w = picref->video->w;
316 link->dst->inputs[0]->h = picref->video->h;
318 if ((ret = config_props(outlink)) < 0)
319 av_assert0(0); //what to do here ?
324 outpicref = avfilter_ref_buffer(picref, ~0);
326 return AVERROR(ENOMEM);
327 return ff_start_frame(outlink, outpicref);
330 scale->hsub = desc->log2_chroma_w;
331 scale->vsub = desc->log2_chroma_h;
333 outpicref = ff_get_video_buffer(outlink, AV_PERM_WRITE|AV_PERM_ALIGN, outlink->w, outlink->h);
335 return AVERROR(ENOMEM);
337 avfilter_copy_buffer_ref_props(outpicref, picref);
338 outpicref->video->w = outlink->w;
339 outpicref->video->h = outlink->h;
341 if(scale->output_is_pal)
342 avpriv_set_systematic_pal2((uint32_t*)outpicref->data[1], outlink->format == AV_PIX_FMT_PAL8 ? AV_PIX_FMT_BGR8 : outlink->format);
344 av_reduce(&outpicref->video->sample_aspect_ratio.num, &outpicref->video->sample_aspect_ratio.den,
345 (int64_t)picref->video->sample_aspect_ratio.num * outlink->h * link->w,
346 (int64_t)picref->video->sample_aspect_ratio.den * outlink->w * link->h,
350 for_next_filter = avfilter_ref_buffer(outpicref, ~0);
352 ret = ff_start_frame(outlink, for_next_filter);
354 ret = AVERROR(ENOMEM);
357 avfilter_unref_bufferp(&outpicref);
361 outlink->out_buf = outpicref;
365 static int scale_slice(AVFilterLink *link, struct SwsContext *sws, int y, int h, int mul, int field)
367 ScaleContext *scale = link->dst->priv;
368 AVFilterBufferRef *cur_pic = link->cur_buf;
369 AVFilterBufferRef *out_buf = link->dst->outputs[0]->out_buf;
370 const uint8_t *in[4];
372 int in_stride[4],out_stride[4];
376 int vsub= ((i+1)&2) ? scale->vsub : 0;
377 in_stride[i] = cur_pic->linesize[i] * mul;
378 out_stride[i] = out_buf->linesize[i] * mul;
379 in[i] = cur_pic->data[i] + ((y>>vsub)+field) * cur_pic->linesize[i];
380 out[i] = out_buf->data[i] + field * out_buf->linesize[i];
382 if(scale->input_is_pal)
383 in[1] = cur_pic->data[1];
384 if(scale->output_is_pal)
385 out[1] = out_buf->data[1];
387 return sws_scale(sws, in, in_stride, y/mul, h,
391 static int draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
393 ScaleContext *scale = link->dst->priv;
397 return ff_draw_slice(link->dst->outputs[0], y, h, slice_dir);
400 if (scale->slice_y == 0 && slice_dir == -1)
401 scale->slice_y = link->dst->outputs[0]->h;
403 if(scale->interlaced>0 || (scale->interlaced<0 && link->cur_buf->video->interlaced)){
404 av_assert0(y%(2<<scale->vsub) == 0);
405 out_h = scale_slice(link, scale->isws[0], y, (h+1)/2, 2, 0);
406 out_h+= scale_slice(link, scale->isws[1], y, h /2, 2, 1);
408 out_h = scale_slice(link, scale->sws, y, h, 1, 0);
412 scale->slice_y -= out_h;
413 ret = ff_draw_slice(link->dst->outputs[0], scale->slice_y, out_h, slice_dir);
415 scale->slice_y += out_h;
419 static const AVFilterPad avfilter_vf_scale_inputs[] = {
422 .type = AVMEDIA_TYPE_VIDEO,
423 .start_frame = start_frame,
424 .draw_slice = draw_slice,
425 .min_perms = AV_PERM_READ,
430 static const AVFilterPad avfilter_vf_scale_outputs[] = {
433 .type = AVMEDIA_TYPE_VIDEO,
434 .config_props = config_props,
439 AVFilter avfilter_vf_scale = {
441 .description = NULL_IF_CONFIG_SMALL("Scale the input video to width:height size and/or convert the image format."),
446 .query_formats = query_formats,
448 .priv_size = sizeof(ScaleContext),
450 .inputs = avfilter_vf_scale_inputs,
451 .outputs = avfilter_vf_scale_outputs,