FFmpeg
vf_aspect.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2010 Bobby Bingham
3  *
4  * This file is part of FFmpeg.
5  *
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.
10  *
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.
15  *
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
19  */
20 
21 /**
22  * @file
23  * aspect ratio modification video filters
24  */
25 
26 #include "config_components.h"
27 
28 #include <float.h>
29 
30 #include "libavutil/common.h"
31 #include "libavutil/eval.h"
32 #include "libavutil/mathematics.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/parseutils.h"
35 #include "libavutil/pixdesc.h"
36 
37 #include "avfilter.h"
38 #include "internal.h"
39 #include "video.h"
40 
41 static const char *const var_names[] = {
42  "w",
43  "h",
44  "a", "dar",
45  "sar",
46  "hsub",
47  "vsub",
48  NULL
49 };
50 
51 enum var_name {
59 };
60 
61 typedef struct AspectContext {
62  const AVClass *class;
65  int max;
66  char *ratio_expr;
68 
70 {
71  AspectContext *s = link->dst->priv;
72 
73  frame->sample_aspect_ratio = s->sar;
74  return ff_filter_frame(link->dst->outputs[0], frame);
75 }
76 
77 #define OFFSET(x) offsetof(AspectContext, x)
78 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
79 
80 static inline void compute_dar(AVRational *dar, AVRational sar, int w, int h)
81 {
82  if (sar.num && sar.den) {
83  av_reduce(&dar->num, &dar->den, sar.num * (int64_t)w, sar.den * (int64_t)h, INT_MAX);
84  } else {
85  av_reduce(&dar->num, &dar->den, w, h, INT_MAX);
86  }
87 }
88 
89 static int get_aspect_ratio(AVFilterLink *inlink, AVRational *aspect_ratio)
90 {
91  AVFilterContext *ctx = inlink->dst;
92  AspectContext *s = inlink->dst->priv;
94  double var_values[VARS_NB], res;
95  int ret;
96 
97  var_values[VAR_W] = inlink->w;
98  var_values[VAR_H] = inlink->h;
99  var_values[VAR_A] = (double) inlink->w / inlink->h;
100  var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
101  (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
102  var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
103  var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
104  var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
105 
106  /* evaluate new aspect ratio*/
107  ret = av_expr_parse_and_eval(&res, s->ratio_expr,
108  var_names, var_values,
109  NULL, NULL, NULL, NULL, NULL, 0, ctx);
110  if (ret < 0) {
111  ret = av_parse_ratio(aspect_ratio, s->ratio_expr, s->max, 0, ctx);
112  } else
113  *aspect_ratio = av_d2q(res, s->max);
114 
115  if (ret < 0) {
117  "Error when evaluating the expression '%s'\n", s->ratio_expr);
118  return ret;
119  }
120  if (aspect_ratio->num < 0 || aspect_ratio->den <= 0) {
122  "Invalid string '%s' for aspect ratio\n", s->ratio_expr);
123  return AVERROR(EINVAL);
124  }
125  return 0;
126 }
127 
128 #if CONFIG_SETDAR_FILTER
129 
130 static int setdar_config_props(AVFilterLink *outlink)
131 {
132  AVFilterContext *ctx = outlink->src;
133  AVFilterLink *inlink = ctx->inputs[0];
134  AspectContext *s = ctx->priv;
135  AVRational dar;
136  AVRational old_dar;
137  AVRational old_sar = inlink->sample_aspect_ratio;
138  int ret;
139 
140  if ((ret = get_aspect_ratio(inlink, &s->dar)))
141  return ret;
142 
143  if (s->dar.num && s->dar.den) {
144  av_reduce(&s->sar.num, &s->sar.den,
145  s->dar.num * inlink->h,
146  s->dar.den * inlink->w, INT_MAX);
147  outlink->sample_aspect_ratio = s->sar;
148  dar = s->dar;
149  } else {
150  outlink->sample_aspect_ratio = (AVRational){ 1, 1 };
151  dar = (AVRational){ inlink->w, inlink->h };
152  }
153 
154  compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
155  av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d dar:%d/%d sar:%d/%d -> dar:%d/%d sar:%d/%d\n",
156  inlink->w, inlink->h, old_dar.num, old_dar.den, old_sar.num, old_sar.den,
157  dar.num, dar.den, outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den);
158 
159  return 0;
160 }
161 
162 static const AVOption setdar_options[] = {
163  { "dar", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
164  { "ratio", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
165  { "r", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
166  { "max", "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
167  { NULL }
168 };
169 
170 AVFILTER_DEFINE_CLASS(setdar);
171 
172 static const AVFilterPad avfilter_vf_setdar_inputs[] = {
173  {
174  .name = "default",
175  .type = AVMEDIA_TYPE_VIDEO,
176  .filter_frame = filter_frame,
177  },
178 };
179 
180 static const AVFilterPad avfilter_vf_setdar_outputs[] = {
181  {
182  .name = "default",
183  .type = AVMEDIA_TYPE_VIDEO,
184  .config_props = setdar_config_props,
185  },
186 };
187 
188 const AVFilter ff_vf_setdar = {
189  .name = "setdar",
190  .description = NULL_IF_CONFIG_SMALL("Set the frame display aspect ratio."),
191  .priv_size = sizeof(AspectContext),
192  .priv_class = &setdar_class,
194  FILTER_INPUTS(avfilter_vf_setdar_inputs),
195  FILTER_OUTPUTS(avfilter_vf_setdar_outputs),
196 };
197 
198 #endif /* CONFIG_SETDAR_FILTER */
199 
200 #if CONFIG_SETSAR_FILTER
201 
202 static int setsar_config_props(AVFilterLink *outlink)
203 {
204  AVFilterContext *ctx = outlink->src;
205  AVFilterLink *inlink = ctx->inputs[0];
206  AspectContext *s = ctx->priv;
207  AVRational old_sar = inlink->sample_aspect_ratio;
208  AVRational old_dar, dar;
209  int ret;
210 
211  if ((ret = get_aspect_ratio(inlink, &s->sar)))
212  return ret;
213 
214  outlink->sample_aspect_ratio = s->sar;
215 
216  compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
217  compute_dar(&dar, s->sar, inlink->w, inlink->h);
218  av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d dar:%d/%d -> sar:%d/%d dar:%d/%d\n",
219  inlink->w, inlink->h, old_sar.num, old_sar.den, old_dar.num, old_dar.den,
220  outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den, dar.num, dar.den);
221 
222  return 0;
223 }
224 
225 static const AVOption setsar_options[] = {
226  { "sar", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
227  { "ratio", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
228  { "r", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
229  { "max", "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
230  { NULL }
231 };
232 
233 AVFILTER_DEFINE_CLASS(setsar);
234 
235 static const AVFilterPad avfilter_vf_setsar_inputs[] = {
236  {
237  .name = "default",
238  .type = AVMEDIA_TYPE_VIDEO,
239  .filter_frame = filter_frame,
240  },
241 };
242 
243 static const AVFilterPad avfilter_vf_setsar_outputs[] = {
244  {
245  .name = "default",
246  .type = AVMEDIA_TYPE_VIDEO,
247  .config_props = setsar_config_props,
248  },
249 };
250 
251 const AVFilter ff_vf_setsar = {
252  .name = "setsar",
253  .description = NULL_IF_CONFIG_SMALL("Set the pixel sample aspect ratio."),
254  .priv_size = sizeof(AspectContext),
255  .priv_class = &setsar_class,
257  FILTER_INPUTS(avfilter_vf_setsar_inputs),
258  FILTER_OUTPUTS(avfilter_vf_setsar_outputs),
259 };
260 
261 #endif /* CONFIG_SETSAR_FILTER */
FLAGS
#define FLAGS
Definition: vf_aspect.c:78
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
VAR_SAR
@ VAR_SAR
Definition: vf_aspect.c:55
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1009
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2858
inlink
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
Definition: filter_design.txt:212
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
pixdesc.h
w
uint8_t w
Definition: llviddspenc.c:38
AVOption
AVOption.
Definition: opt.h:251
AV_LOG_VERBOSE
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:196
float.h
VAR_A
@ VAR_A
Definition: vf_aspect.c:54
max
#define max(a, b)
Definition: cuda_runtime.h:33
mathematics.h
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:175
get_aspect_ratio
static int get_aspect_ratio(AVFilterLink *inlink, AVRational *aspect_ratio)
Definition: vf_aspect.c:89
video.h
AspectContext::dar
AVRational dar
Definition: vf_aspect.c:63
ff_vf_setsar
const AVFilter ff_vf_setsar
VAR_VSUB
@ VAR_VSUB
Definition: vf_aspect.c:57
ff_vf_setdar
const AVFilter ff_vf_setdar
av_reduce
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
Definition: rational.c:35
AVRational::num
int num
Numerator.
Definition: rational.h:59
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:49
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
VAR_HSUB
@ VAR_HSUB
Definition: vf_aspect.c:56
s
#define s(width, name)
Definition: cbs_vp9.c:256
VAR_DAR
@ VAR_DAR
Definition: vf_aspect.c:54
var_name
var_name
Definition: noise_bsf.c:46
ctx
AVFormatContext * ctx
Definition: movenc.c:48
AspectContext::ratio_expr
char * ratio_expr
Definition: vf_aspect.c:66
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:190
link
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a link
Definition: filter_design.txt:23
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
compute_dar
static void compute_dar(AVRational *dar, AVRational sar, int w, int h)
Definition: vf_aspect.c:80
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
parseutils.h
double
double
Definition: af_crystalizer.c:132
av_parse_ratio
int av_parse_ratio(AVRational *q, const char *str, int max, int log_offset, void *log_ctx)
Parse str and store the parsed ratio in q.
Definition: parseutils.c:45
eval.h
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:115
av_expr_parse_and_eval
int av_expr_parse_and_eval(double *d, const char *s, const char *const *const_names, const double *const_values, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), void *opaque, int log_offset, void *log_ctx)
Parse and evaluate an expression.
Definition: eval.c:776
AspectContext
Definition: vf_aspect.c:61
AspectContext::sar
AVRational sar
Definition: vf_aspect.c:64
internal.h
AVFILTER_DEFINE_CLASS
#define AVFILTER_DEFINE_CLASS(fname)
Definition: internal.h:325
filter_frame
static int filter_frame(AVFilterLink *link, AVFrame *frame)
Definition: vf_aspect.c:69
common.h
VARS_NB
@ VARS_NB
Definition: vf_aspect.c:58
av_d2q
AVRational av_d2q(double d, int max)
Convert a double precision floating point number to a rational.
Definition: rational.c:106
AspectContext::max
int max
Definition: vf_aspect.c:65
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:55
AVFilter
Filter definition.
Definition: avfilter.h:171
ret
ret
Definition: filter_design.txt:187
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
OFFSET
#define OFFSET(x)
Definition: vf_aspect.c:77
AVRational::den
int den
Denominator.
Definition: rational.h:60
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:225
avfilter.h
AVFILTER_FLAG_METADATA_ONLY
#define AVFILTER_FLAG_METADATA_ONLY
The filter is a "metadata" filter - it does not modify the frame data in any way.
Definition: avfilter.h:143
AVFilterContext
An instance of a filter.
Definition: avfilter.h:415
VAR_H
@ VAR_H
Definition: vf_aspect.c:53
desc
const char * desc
Definition: libsvtav1.c:83
var_names
static const char *const var_names[]
Definition: vf_aspect.c:41
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVPixFmtDescriptor
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:69
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:191
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
h
h
Definition: vp9dsp_template.c:2038
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Definition: opt.h:229
VAR_W
@ VAR_W
Definition: vf_aspect.c:52