vf_format: rework format list parsing
[libav.git] / libavfilter / vf_scale.c
CommitLineData
c3eabb7d 1/*
3fa77bde 2 * Copyright (c) 2007 Bobby Bingham
c3eabb7d 3 *
2912e87a 4 * This file is part of Libav.
c3eabb7d 5 *
2912e87a 6 * Libav is free software; you can redistribute it and/or
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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.
10 *
2912e87a 11 * Libav is distributed in the hope that it will be useful,
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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.
15 *
16 * You should have received a copy of the GNU Lesser General Public
2912e87a 17 * License along with Libav; if not, write to the Free Software
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18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21/**
ba87f080 22 * @file
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23 * scale video filter
24 */
25
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26#include <stdio.h>
27#include <string.h>
28
c3eabb7d 29#include "avfilter.h"
b74a1da4 30#include "formats.h"
9d0bfc50 31#include "internal.h"
803391f7 32#include "video.h"
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33#include "libavutil/avstring.h"
34#include "libavutil/eval.h"
1d9c2dc8 35#include "libavutil/internal.h"
0ebcdf5c 36#include "libavutil/mathematics.h"
90f65dc6 37#include "libavutil/opt.h"
b4b66456 38#include "libavutil/pixdesc.h"
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39#include "libswscale/swscale.h"
40
b0f29db5 41static const char *const var_names[] = {
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42 "PI",
43 "PHI",
44 "E",
45 "in_w", "iw",
46 "in_h", "ih",
47 "out_w", "ow",
48 "out_h", "oh",
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49 "a", "dar",
50 "sar",
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51 "hsub",
52 "vsub",
53 NULL
54};
55
56enum var_name {
57 VAR_PI,
58 VAR_PHI,
59 VAR_E,
60 VAR_IN_W, VAR_IW,
61 VAR_IN_H, VAR_IH,
62 VAR_OUT_W, VAR_OW,
63 VAR_OUT_H, VAR_OH,
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64 VAR_A, VAR_DAR,
65 VAR_SAR,
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66 VAR_HSUB,
67 VAR_VSUB,
68 VARS_NB
69};
70
58400ac1 71typedef struct ScaleContext {
c334c113 72 const AVClass *class;
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73 struct SwsContext *sws; ///< software scaler context
74
75 /**
76 * New dimensions. Special values are:
77 * 0 = original width/height
78 * -1 = keep original aspect
79 */
80 int w, h;
8155bbc9 81 unsigned int flags; ///sws flags
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82
83 int hsub, vsub; ///< chroma subsampling
84 int slice_y; ///< top of current output slice
c3eabb7d 85 int input_is_pal; ///< set to 1 if the input format is paletted
68e23c08 86
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87 char *w_expr; ///< width expression string
88 char *h_expr; ///< height expression string
89 char *flags_str;
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90} ScaleContext;
91
c43a7eca 92static av_cold int init(AVFilterContext *ctx)
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93{
94 ScaleContext *scale = ctx->priv;
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95
96 if (scale->flags_str) {
97 const AVClass *class = sws_get_class();
98 const AVOption *o = av_opt_find(&class, "sws_flags", NULL, 0,
99 AV_OPT_SEARCH_FAKE_OBJ);
100 int ret = av_opt_eval_flags(&class, o, scale->flags_str, &scale->flags);
101
102 if (ret < 0)
103 return ret;
8155bbc9 104 }
c3eabb7d 105
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106 return 0;
107}
108
109static av_cold void uninit(AVFilterContext *ctx)
110{
111 ScaleContext *scale = ctx->priv;
112 sws_freeContext(scale->sws);
113 scale->sws = NULL;
114}
115
116static int query_formats(AVFilterContext *ctx)
117{
118 AVFilterFormats *formats;
716d413c 119 enum AVPixelFormat pix_fmt;
27d8f6b6 120 int ret;
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121
122 if (ctx->inputs[0]) {
27d8f6b6 123 formats = NULL;
716d413c 124 for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++)
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JG
125 if ((sws_isSupportedInput(pix_fmt) ||
126 sws_isSupportedEndiannessConversion(pix_fmt))
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127 && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
128 ff_formats_unref(&formats);
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129 return ret;
130 }
b74a1da4 131 ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
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132 }
133 if (ctx->outputs[0]) {
27d8f6b6 134 formats = NULL;
716d413c 135 for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++)
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JG
136 if ((sws_isSupportedOutput(pix_fmt) ||
137 sws_isSupportedEndiannessConversion(pix_fmt))
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138 && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
139 ff_formats_unref(&formats);
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140 return ret;
141 }
b74a1da4 142 ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
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143 }
144
145 return 0;
146}
147
148static int config_props(AVFilterLink *outlink)
149{
150 AVFilterContext *ctx = outlink->src;
151 AVFilterLink *inlink = outlink->src->inputs[0];
152 ScaleContext *scale = ctx->priv;
59ee9f78 153 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
c3eabb7d 154 int64_t w, h;
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155 double var_values[VARS_NB], res;
156 char *expr;
157 int ret;
158
159 var_values[VAR_PI] = M_PI;
160 var_values[VAR_PHI] = M_PHI;
161 var_values[VAR_E] = M_E;
162 var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
163 var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
164 var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
165 var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
3a14b160 166 var_values[VAR_A] = (double) inlink->w / inlink->h;
46b29397 167 var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
ba04177e 168 (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
3a14b160 169 var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
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170 var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
171 var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
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172
173 /* evaluate width and height */
174 av_expr_parse_and_eval(&res, (expr = scale->w_expr),
175 var_names, var_values,
176 NULL, NULL, NULL, NULL, NULL, 0, ctx);
177 scale->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
178 if ((ret = av_expr_parse_and_eval(&res, (expr = scale->h_expr),
179 var_names, var_values,
180 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
181 goto fail;
182 scale->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
183 /* evaluate again the width, as it may depend on the output height */
184 if ((ret = av_expr_parse_and_eval(&res, (expr = scale->w_expr),
185 var_names, var_values,
186 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
187 goto fail;
188 scale->w = res;
189
190 w = scale->w;
191 h = scale->h;
192
193 /* sanity check params */
194 if (w < -1 || h < -1) {
195 av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n");
196 return AVERROR(EINVAL);
197 }
198 if (w == -1 && h == -1)
199 scale->w = scale->h = 0;
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200
201 if (!(w = scale->w))
202 w = inlink->w;
203 if (!(h = scale->h))
204 h = inlink->h;
205 if (w == -1)
206 w = av_rescale(h, inlink->w, inlink->h);
207 if (h == -1)
208 h = av_rescale(w, inlink->h, inlink->w);
209
210 if (w > INT_MAX || h > INT_MAX ||
211 (h * inlink->w) > INT_MAX ||
212 (w * inlink->h) > INT_MAX)
213 av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
214
215 outlink->w = w;
216 outlink->h = h;
217
218 /* TODO: make algorithm configurable */
1a49a169 219 av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d fmt:%s -> w:%d h:%d fmt:%s flags:0x%0x\n",
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220 inlink ->w, inlink ->h, av_get_pix_fmt_name(inlink->format),
221 outlink->w, outlink->h, av_get_pix_fmt_name(outlink->format),
38efdb2c 222 scale->flags);
c3eabb7d 223
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224 scale->input_is_pal = desc->flags & AV_PIX_FMT_FLAG_PAL ||
225 desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL;
c3eabb7d 226
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227 if (scale->sws)
228 sws_freeContext(scale->sws);
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229 if (inlink->w == outlink->w && inlink->h == outlink->h &&
230 inlink->format == outlink->format)
231 scale->sws = NULL;
232 else {
233 scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
234 outlink->w, outlink->h, outlink->format,
235 scale->flags, NULL, NULL, NULL);
236 if (!scale->sws)
237 return AVERROR(EINVAL);
238 }
d760a316 239
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240
241 if (inlink->sample_aspect_ratio.num)
242 outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h*inlink->w,
243 outlink->w*inlink->h},
244 inlink->sample_aspect_ratio);
245 else
246 outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
247
dccdd93e 248 return 0;
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249
250fail:
251 av_log(NULL, AV_LOG_ERROR,
252 "Error when evaluating the expression '%s'\n", expr);
253 return ret;
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254}
255
7e350379 256static int filter_frame(AVFilterLink *link, AVFrame *in)
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257{
258 ScaleContext *scale = link->dst->priv;
259 AVFilterLink *outlink = link->dst->outputs[0];
7e350379 260 AVFrame *out;
59ee9f78 261 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
c3eabb7d 262
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263 if (!scale->sws)
264 return ff_filter_frame(outlink, in);
416fd90e 265
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266 scale->hsub = desc->log2_chroma_w;
267 scale->vsub = desc->log2_chroma_h;
b37aa4de 268
7e350379 269 out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
565e4993 270 if (!out) {
7e350379 271 av_frame_free(&in);
ebc8d974 272 return AVERROR(ENOMEM);
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273 }
274
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275 av_frame_copy_props(out, in);
276 out->width = outlink->w;
277 out->height = outlink->h;
c3eabb7d 278
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279 av_reduce(&out->sample_aspect_ratio.num, &out->sample_aspect_ratio.den,
280 (int64_t)in->sample_aspect_ratio.num * outlink->h * link->w,
281 (int64_t)in->sample_aspect_ratio.den * outlink->w * link->h,
565e4993 282 INT_MAX);
c3eabb7d 283
7e350379 284 sws_scale(scale->sws, in->data, in->linesize, 0, in->height,
565e4993 285 out->data, out->linesize);
416fd90e 286
7e350379 287 av_frame_free(&in);
565e4993 288 return ff_filter_frame(outlink, out);
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289}
290
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291#define OFFSET(x) offsetof(ScaleContext, x)
292#define FLAGS AV_OPT_FLAG_VIDEO_PARAM
293static const AVOption options[] = {
294 { "w", "Output video width", OFFSET(w_expr), AV_OPT_TYPE_STRING, { .str = "iw" }, .flags = FLAGS },
295 { "h", "Output video height", OFFSET(h_expr), AV_OPT_TYPE_STRING, { .str = "ih" }, .flags = FLAGS },
296 { "flags", "Flags to pass to libswscale", OFFSET(flags_str), AV_OPT_TYPE_STRING, { .str = "bilinear" }, .flags = FLAGS },
297 { NULL },
298};
299
300static const AVClass scale_class = {
301 .class_name = "scale",
302 .item_name = av_default_item_name,
303 .option = options,
304 .version = LIBAVUTIL_VERSION_INT,
305};
306
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307static const AVFilterPad avfilter_vf_scale_inputs[] = {
308 {
309 .name = "default",
310 .type = AVMEDIA_TYPE_VIDEO,
565e4993 311 .filter_frame = filter_frame,
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312 },
313 { NULL }
314};
315
316static const AVFilterPad avfilter_vf_scale_outputs[] = {
317 {
318 .name = "default",
319 .type = AVMEDIA_TYPE_VIDEO,
320 .config_props = config_props,
321 },
322 { NULL }
323};
324
cd43ca04 325AVFilter ff_vf_scale = {
c3eabb7d 326 .name = "scale",
a6881c6a 327 .description = NULL_IF_CONFIG_SMALL("Scale the input video to width:height size and/or convert the image format."),
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328
329 .init = init,
330 .uninit = uninit,
331
332 .query_formats = query_formats,
333
334 .priv_size = sizeof(ScaleContext),
c334c113 335 .priv_class = &scale_class,
c3eabb7d 336
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337 .inputs = avfilter_vf_scale_inputs,
338 .outputs = avfilter_vf_scale_outputs,
c3eabb7d 339};