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 "filters.h"
39 #include "video.h"
40 
41 static const char *const var_names[] = {
42  "w",
43  "h",
44  "a",
45  "dar",
46  "sar",
47  "hsub",
48  "vsub",
49  NULL
50 };
51 
52 enum var_name {
53  VAR_W,
54  VAR_H,
55  VAR_A,
56  VAR_DAR,
57  VAR_SAR,
58  VAR_HSUB,
59  VAR_VSUB,
60  VARS_NB
61 };
62 
63 typedef struct AspectContext {
64  const AVClass *class;
65  AVRational dar;
66  AVRational sar;
67  int max;
68  char *ratio_expr;
69 } AspectContext;
70 
71 static int filter_frame(AVFilterLink *link, AVFrame *frame)
72 {
73  AspectContext *s = link->dst->priv;
74 
75  frame->sample_aspect_ratio = s->sar;
76  return ff_filter_frame(link->dst->outputs[0], frame);
77 }
78 
79 #define OFFSET(x) offsetof(AspectContext, x)
80 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
81 
82 static inline void compute_dar(AVRational *dar, AVRational sar, int w, int h)
83 {
84  if (sar.num && sar.den) {
85  av_reduce(&dar->num, &dar->den, sar.num * (int64_t)w, sar.den * (int64_t)h, INT_MAX);
86  } else {
87  av_reduce(&dar->num, &dar->den, w, h, INT_MAX);
88  }
89 }
90 
91 static int get_aspect_ratio(AVFilterLink *inlink, AVRational *aspect_ratio)
92 {
93  AVFilterContext *ctx = inlink->dst;
94  AspectContext *s = inlink->dst->priv;
95  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
96  double var_values[VARS_NB], res;
97  int ret;
98 
99  var_values[VAR_W] = inlink->w;
100  var_values[VAR_H] = inlink->h;
101  var_values[VAR_A] = (double) inlink->w / inlink->h;
102  var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
103  (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
104  var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
105  var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
106  var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
107 
108  /* evaluate new aspect ratio*/
109  ret = av_expr_parse_and_eval(&res, s->ratio_expr,
110  var_names, var_values,
111  NULL, NULL, NULL, NULL, NULL, 0, ctx);
112  if (ret < 0) {
113  ret = av_parse_ratio(aspect_ratio, s->ratio_expr, s->max, 0, ctx);
114  } else
115  *aspect_ratio = av_d2q(res, s->max);
116 
117  if (ret < 0) {
118  av_log(ctx, AV_LOG_ERROR,
119  "Error when evaluating the expression '%s'\n", s->ratio_expr);
120  return ret;
121  }
122  if (aspect_ratio->num < 0 || aspect_ratio->den <= 0) {
123  av_log(ctx, AV_LOG_ERROR,
124  "Invalid string '%s' for aspect ratio\n", s->ratio_expr);
125  return AVERROR(EINVAL);
126  }
127  return 0;
128 }
129 
130 static const AVFilterPad aspect_inputs[] = {
131  {
132  .name = "default",
133  .type = AVMEDIA_TYPE_VIDEO,
134  .filter_frame = filter_frame,
135  },
136 };
137 
138 #if CONFIG_SETDAR_FILTER
139 
140 static int setdar_config_props(AVFilterLink *outlink)
141 {
142  AVFilterContext *ctx = outlink->src;
143  AVFilterLink *inlink = ctx->inputs[0];
144  AspectContext *s = ctx->priv;
145  AVRational dar;
146  AVRational old_dar;
147  AVRational old_sar = inlink->sample_aspect_ratio;
148  int ret;
149 
150  if ((ret = get_aspect_ratio(inlink, &s->dar)))
151  return ret;
152 
153  if (s->dar.num && s->dar.den) {
154  av_reduce(&s->sar.num, &s->sar.den,
155  s->dar.num * inlink->h,
156  s->dar.den * inlink->w, INT_MAX);
157  outlink->sample_aspect_ratio = s->sar;
158  dar = s->dar;
159  } else {
160  outlink->sample_aspect_ratio = (AVRational){ 1, 1 };
161  dar = (AVRational){ inlink->w, inlink->h };
162  }
163 
164  compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
165  av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d dar:%d/%d sar:%d/%d -> dar:%d/%d sar:%d/%d\n",
166  inlink->w, inlink->h, old_dar.num, old_dar.den, old_sar.num, old_sar.den,
167  dar.num, dar.den, outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den);
168 
169  return 0;
170 }
171 
172 static const AVOption setdar_options[] = {
173  { "dar", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
174  { "ratio", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
175  { "r", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
176  { "max", "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
177  { NULL }
178 };
179 
180 AVFILTER_DEFINE_CLASS(setdar);
181 
182 static const AVFilterPad avfilter_vf_setdar_outputs[] = {
183  {
184  .name = "default",
185  .type = AVMEDIA_TYPE_VIDEO,
186  .config_props = setdar_config_props,
187  },
188 };
189 
190 const AVFilter ff_vf_setdar = {
191  .name = "setdar",
192  .description = NULL_IF_CONFIG_SMALL("Set the frame display aspect ratio."),
193  .priv_size = sizeof(AspectContext),
194  .priv_class = &setdar_class,
195  .flags = AVFILTER_FLAG_METADATA_ONLY,
196  FILTER_INPUTS(aspect_inputs),
197  FILTER_OUTPUTS(avfilter_vf_setdar_outputs),
198 };
199 
200 #endif /* CONFIG_SETDAR_FILTER */
201 
202 #if CONFIG_SETSAR_FILTER
203 
204 static int setsar_config_props(AVFilterLink *outlink)
205 {
206  AVFilterContext *ctx = outlink->src;
207  AVFilterLink *inlink = ctx->inputs[0];
208  AspectContext *s = ctx->priv;
209  AVRational old_sar = inlink->sample_aspect_ratio;
210  AVRational old_dar, dar;
211  int ret;
212 
213  if ((ret = get_aspect_ratio(inlink, &s->sar)))
214  return ret;
215 
216  outlink->sample_aspect_ratio = s->sar;
217 
218  compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
219  compute_dar(&dar, s->sar, inlink->w, inlink->h);
220  av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d dar:%d/%d -> sar:%d/%d dar:%d/%d\n",
221  inlink->w, inlink->h, old_sar.num, old_sar.den, old_dar.num, old_dar.den,
222  outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den, dar.num, dar.den);
223 
224  return 0;
225 }
226 
227 static const AVOption setsar_options[] = {
228  { "sar", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
229  { "ratio", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
230  { "r", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
231  { "max", "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
232  { NULL }
233 };
234 
235 AVFILTER_DEFINE_CLASS(setsar);
236 
237 static const AVFilterPad avfilter_vf_setsar_outputs[] = {
238  {
239  .name = "default",
240  .type = AVMEDIA_TYPE_VIDEO,
241  .config_props = setsar_config_props,
242  },
243 };
244 
245 const AVFilter ff_vf_setsar = {
246  .name = "setsar",
247  .description = NULL_IF_CONFIG_SMALL("Set the pixel sample aspect ratio."),
248  .priv_size = sizeof(AspectContext),
249  .priv_class = &setsar_class,
250  .flags = AVFILTER_FLAG_METADATA_ONLY,
251  FILTER_INPUTS(aspect_inputs),
252  FILTER_OUTPUTS(avfilter_vf_setsar_outputs),
253 };
254 
255 #endif /* CONFIG_SETSAR_FILTER */
FLAGS
#define FLAGS
Definition: vf_aspect.c:80
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_name
var_name
Definition: noise.c:47
VAR_SAR
@ VAR_SAR
Definition: vf_aspect.c:57
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1062
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:3170
int64_t
long long int64_t
Definition: coverity.c:34
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
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: filters.h:262
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:389
pixdesc.h
w
uint8_t w
Definition: llviddspenc.c:38
AVOption
AVOption.
Definition: opt.h:429
AV_LOG_VERBOSE
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:225
float.h
VAR_A
@ VAR_A
Definition: vf_aspect.c:55
max
#define max(a, b)
Definition: cuda_runtime.h:33
mathematics.h
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:205
get_aspect_ratio
static int get_aspect_ratio(AVFilterLink *inlink, AVRational *aspect_ratio)
Definition: vf_aspect.c:91
video.h
AspectContext::dar
AVRational dar
Definition: vf_aspect.c:65
ff_vf_setsar
const AVFilter ff_vf_setsar
VAR_VSUB
@ VAR_VSUB
Definition: vf_aspect.c:59
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: filters.h:38
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:209
VAR_HSUB
@ VAR_HSUB
Definition: vf_aspect.c:58
s
#define s(width, name)
Definition: cbs_vp9.c:198
VAR_DAR
@ VAR_DAR
Definition: vf_aspect.c:56
filters.h
ctx
AVFormatContext * ctx
Definition: movenc.c:49
AspectContext::ratio_expr
char * ratio_expr
Definition: vf_aspect.c:68
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: filters.h:263
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:75
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:82
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
AVFILTER_DEFINE_CLASS
#define AVFILTER_DEFINE_CLASS(fname)
Definition: filters.h:273
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:94
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:803
AspectContext
Definition: vf_aspect.c:63
AspectContext::sar
AVRational sar
Definition: vf_aspect.c:66
filter_frame
static int filter_frame(AVFilterLink *link, AVFrame *frame)
Definition: vf_aspect.c:71
common.h
VARS_NB
@ VARS_NB
Definition: vf_aspect.c:60
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:67
AVFilterPad::name
const char * name
Pad name.
Definition: filters.h:44
AVFilter
Filter definition.
Definition: avfilter.h:201
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:79
AVRational::den
int den
Denominator.
Definition: rational.h:60
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Underlying C type is int.
Definition: opt.h:259
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:168
AVFilterContext
An instance of a filter.
Definition: avfilter.h:457
VAR_H
@ VAR_H
Definition: vf_aspect.c:54
desc
const char * desc
Definition: libsvtav1.c:79
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
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:482
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
h
h
Definition: vp9dsp_template.c:2070
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Underlying C type is a uint8_t* that is either NULL or points to a C string allocated with the av_mal...
Definition: opt.h:276
aspect_inputs
static const AVFilterPad aspect_inputs[]
Definition: vf_aspect.c:130
VAR_W
@ VAR_W
Definition: vf_aspect.c:53
Generated on Thu Nov 7 2024 19:22:22 for FFmpeg by   doxygen 1.8.17