FFmpeg
f_metadata.c
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1 /*
2  * Copyright (c) 2016 Paul B Mahol
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  * filter for manipulating frame metadata
24  */
25 
26 #include <float.h>
27 
28 #include "libavutil/avassert.h"
29 #include "libavutil/avstring.h"
30 #include "libavutil/eval.h"
31 #include "libavutil/internal.h"
32 #include "libavutil/opt.h"
33 #include "libavutil/timestamp.h"
34 #include "libavformat/avio.h"
35 #include "avfilter.h"
36 #include "audio.h"
37 #include "formats.h"
38 #include "internal.h"
39 #include "video.h"
40 
48 };
49 
59 };
60 
61 static const char *const var_names[] = {
62  "VALUE1",
63  "VALUE2",
64  NULL
65 };
66 
67 enum var_name {
71 };
72 
73 typedef struct MetadataContext {
74  const AVClass *class;
75 
76  int mode;
77  char *key;
78  char *value;
79  int function;
80 
81  char *expr_str;
84 
86  char *file_str;
87 
89  const char *value1, const char *value2);
90  void (*print)(AVFilterContext *ctx, const char *msg, ...) av_printf_format(2, 3);
91 
92  int direct; // reduces buffering when printing to user-supplied URL
94 
95 #define OFFSET(x) offsetof(MetadataContext, x)
96 #define DEFINE_OPTIONS(filt_name, FLAGS) \
97 static const AVOption filt_name##_options[] = { \
98  { "mode", "set a mode of operation", OFFSET(mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, METADATA_NB-1, FLAGS, "mode" }, \
99  { "select", "select frame", 0, AV_OPT_TYPE_CONST, {.i64 = METADATA_SELECT }, 0, 0, FLAGS, "mode" }, \
100  { "add", "add new metadata", 0, AV_OPT_TYPE_CONST, {.i64 = METADATA_ADD }, 0, 0, FLAGS, "mode" }, \
101  { "modify", "modify metadata", 0, AV_OPT_TYPE_CONST, {.i64 = METADATA_MODIFY }, 0, 0, FLAGS, "mode" }, \
102  { "delete", "delete metadata", 0, AV_OPT_TYPE_CONST, {.i64 = METADATA_DELETE }, 0, 0, FLAGS, "mode" }, \
103  { "print", "print metadata", 0, AV_OPT_TYPE_CONST, {.i64 = METADATA_PRINT }, 0, 0, FLAGS, "mode" }, \
104  { "key", "set metadata key", OFFSET(key), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, FLAGS }, \
105  { "value", "set metadata value", OFFSET(value), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, FLAGS }, \
106  { "function", "function for comparing values", OFFSET(function), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, METADATAF_NB-1, FLAGS, "function" }, \
107  { "same_str", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_SAME_STR }, 0, 3, FLAGS, "function" }, \
108  { "starts_with", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_STARTS_WITH }, 0, 0, FLAGS, "function" }, \
109  { "less", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_LESS }, 0, 3, FLAGS, "function" }, \
110  { "equal", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_EQUAL }, 0, 3, FLAGS, "function" }, \
111  { "greater", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_GREATER }, 0, 3, FLAGS, "function" }, \
112  { "expr", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_EXPR }, 0, 3, FLAGS, "function" }, \
113  { "ends_with", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_ENDS_WITH }, 0, 0, FLAGS, "function" }, \
114  { "expr", "set expression for expr function", OFFSET(expr_str), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, FLAGS }, \
115  { "file", "set file where to print metadata information", OFFSET(file_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS }, \
116  { "direct", "reduce buffering when printing to user-set file or pipe", OFFSET(direct), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, FLAGS }, \
117  { NULL } \
118 }
119 
120 static int same_str(MetadataContext *s, const char *value1, const char *value2)
121 {
122  return !strcmp(value1, value2);
123 }
124 
125 static int starts_with(MetadataContext *s, const char *value1, const char *value2)
126 {
127  return !strncmp(value1, value2, strlen(value2));
128 }
129 
130 static int ends_with(MetadataContext *s, const char *value1, const char *value2)
131 {
132  const int len1 = strlen(value1);
133  const int len2 = strlen(value2);
134 
135  return !strncmp(value1 + FFMAX(len1 - len2, 0), value2, len2);
136 }
137 
138 static int equal(MetadataContext *s, const char *value1, const char *value2)
139 {
140  float f1, f2;
141 
142  if (sscanf(value1, "%f", &f1) + sscanf(value2, "%f", &f2) != 2)
143  return 0;
144 
145  return fabsf(f1 - f2) < FLT_EPSILON;
146 }
147 
148 static int less(MetadataContext *s, const char *value1, const char *value2)
149 {
150  float f1, f2;
151 
152  if (sscanf(value1, "%f", &f1) + sscanf(value2, "%f", &f2) != 2)
153  return 0;
154 
155  return (f1 - f2) < FLT_EPSILON;
156 }
157 
158 static int greater(MetadataContext *s, const char *value1, const char *value2)
159 {
160  float f1, f2;
161 
162  if (sscanf(value1, "%f", &f1) + sscanf(value2, "%f", &f2) != 2)
163  return 0;
164 
165  return (f2 - f1) < FLT_EPSILON;
166 }
167 
168 static int parse_expr(MetadataContext *s, const char *value1, const char *value2)
169 {
170  double f1, f2;
171 
172  if (sscanf(value1, "%lf", &f1) + sscanf(value2, "%lf", &f2) != 2)
173  return 0;
174 
175  s->var_values[VAR_VALUE1] = f1;
176  s->var_values[VAR_VALUE2] = f2;
177 
178  return av_expr_eval(s->expr, s->var_values, NULL);
179 }
180 
181 static void print_log(AVFilterContext *ctx, const char *msg, ...)
182 {
183  va_list argument_list;
184 
185  va_start(argument_list, msg);
186  if (msg)
187  av_vlog(ctx, AV_LOG_INFO, msg, argument_list);
188  va_end(argument_list);
189 }
190 
191 static void print_file(AVFilterContext *ctx, const char *msg, ...)
192 {
193  MetadataContext *s = ctx->priv;
194  va_list argument_list;
195 
196  va_start(argument_list, msg);
197  if (msg) {
198  char buf[128];
199  vsnprintf(buf, sizeof(buf), msg, argument_list);
200  avio_write(s->avio_context, buf, av_strnlen(buf, sizeof(buf)));
201  }
202  va_end(argument_list);
203 }
204 
206 {
207  MetadataContext *s = ctx->priv;
208  int ret;
209 
210  if (!s->key && s->mode != METADATA_PRINT && s->mode != METADATA_DELETE) {
211  av_log(ctx, AV_LOG_WARNING, "Metadata key must be set\n");
212  return AVERROR(EINVAL);
213  }
214 
215  if ((s->mode == METADATA_MODIFY ||
216  s->mode == METADATA_ADD) && !s->value) {
217  av_log(ctx, AV_LOG_WARNING, "Missing metadata value\n");
218  return AVERROR(EINVAL);
219  }
220 
221  switch (s->function) {
222  case METADATAF_SAME_STR:
223  s->compare = same_str;
224  break;
226  s->compare = starts_with;
227  break;
228  case METADATAF_ENDS_WITH:
229  s->compare = ends_with;
230  break;
231  case METADATAF_LESS:
232  s->compare = less;
233  break;
234  case METADATAF_EQUAL:
235  s->compare = equal;
236  break;
237  case METADATAF_GREATER:
238  s->compare = greater;
239  break;
240  case METADATAF_EXPR:
241  s->compare = parse_expr;
242  break;
243  default:
244  av_assert0(0);
245  };
246 
247  if (s->function == METADATAF_EXPR) {
248  if (!s->expr_str) {
249  av_log(ctx, AV_LOG_WARNING, "expr option not set\n");
250  return AVERROR(EINVAL);
251  }
252  if ((ret = av_expr_parse(&s->expr, s->expr_str,
253  var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) {
254  av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n", s->expr_str);
255  return ret;
256  }
257  }
258 
259  if (s->mode == METADATA_PRINT && s->file_str) {
260  s->print = print_file;
261  } else {
262  s->print = print_log;
263  }
264 
265  s->avio_context = NULL;
266  if (s->file_str) {
267  if (!strcmp("-", s->file_str)) {
268  ret = avio_open(&s->avio_context, "pipe:1", AVIO_FLAG_WRITE);
269  } else {
271  }
272 
273  if (ret < 0) {
274  char buf[128];
275  av_strerror(ret, buf, sizeof(buf));
276  av_log(ctx, AV_LOG_ERROR, "Could not open %s: %s\n",
277  s->file_str, buf);
278  return ret;
279  }
280 
281  if (s->direct)
283  }
284 
285  return 0;
286 }
287 
289 {
290  MetadataContext *s = ctx->priv;
291 
292  av_expr_free(s->expr);
293  s->expr = NULL;
294  if (s->avio_context) {
296  }
297 }
298 
300 {
301  AVFilterContext *ctx = inlink->dst;
302  AVFilterLink *outlink = ctx->outputs[0];
303  MetadataContext *s = ctx->priv;
304  AVDictionary **metadata = &frame->metadata;
306 
307  if (!*metadata && s->mode != METADATA_ADD)
308  return ff_filter_frame(outlink, frame);
309 
310  e = av_dict_get(*metadata, !s->key ? "" : s->key, NULL,
311  !s->key ? AV_DICT_IGNORE_SUFFIX: 0);
312 
313  switch (s->mode) {
314  case METADATA_SELECT:
315  if (!s->value && e && e->value) {
316  return ff_filter_frame(outlink, frame);
317  } else if (s->value && e && e->value &&
318  s->compare(s, e->value, s->value)) {
319  return ff_filter_frame(outlink, frame);
320  }
321  break;
322  case METADATA_ADD:
323  if (e && e->value) {
324  ;
325  } else {
326  av_dict_set(metadata, s->key, s->value, 0);
327  }
328  return ff_filter_frame(outlink, frame);
329  case METADATA_MODIFY:
330  if (e && e->value) {
331  av_dict_set(metadata, s->key, s->value, 0);
332  }
333  return ff_filter_frame(outlink, frame);
334  case METADATA_PRINT:
335  if (!s->key && e) {
336  s->print(ctx, "frame:%-4"PRId64" pts:%-7s pts_time:%s\n",
337  inlink->frame_count_out, av_ts2str(frame->pts), av_ts2timestr(frame->pts, &inlink->time_base));
338  s->print(ctx, "%s=%s\n", e->key, e->value);
339  while ((e = av_dict_get(*metadata, "", e, AV_DICT_IGNORE_SUFFIX)) != NULL) {
340  s->print(ctx, "%s=%s\n", e->key, e->value);
341  }
342  } else if (e && e->value && (!s->value || (e->value && s->compare(s, e->value, s->value)))) {
343  s->print(ctx, "frame:%-4"PRId64" pts:%-7s pts_time:%s\n",
344  inlink->frame_count_out, av_ts2str(frame->pts), av_ts2timestr(frame->pts, &inlink->time_base));
345  s->print(ctx, "%s=%s\n", s->key, e->value);
346  }
347  return ff_filter_frame(outlink, frame);
348  case METADATA_DELETE:
349  if (!s->key) {
350  av_dict_free(metadata);
351  } else if (e && e->value && (!s->value || s->compare(s, e->value, s->value))) {
352  av_dict_set(metadata, s->key, NULL, 0);
353  }
354  return ff_filter_frame(outlink, frame);
355  default:
356  av_assert0(0);
357  };
358 
359  av_frame_free(&frame);
360 
361  return 0;
362 }
363 
364 #if CONFIG_AMETADATA_FILTER
365 
367 AVFILTER_DEFINE_CLASS(ametadata);
368 
369 static const AVFilterPad ainputs[] = {
370  {
371  .name = "default",
372  .type = AVMEDIA_TYPE_AUDIO,
373  .filter_frame = filter_frame,
374  },
375  { NULL }
376 };
377 
378 static const AVFilterPad aoutputs[] = {
379  {
380  .name = "default",
381  .type = AVMEDIA_TYPE_AUDIO,
382  },
383  { NULL }
384 };
385 
387  .name = "ametadata",
388  .description = NULL_IF_CONFIG_SMALL("Manipulate audio frame metadata."),
389  .priv_size = sizeof(MetadataContext),
390  .priv_class = &ametadata_class,
391  .init = init,
392  .uninit = uninit,
393  .inputs = ainputs,
394  .outputs = aoutputs,
396 };
397 #endif /* CONFIG_AMETADATA_FILTER */
398 
399 #if CONFIG_METADATA_FILTER
400 
402 AVFILTER_DEFINE_CLASS(metadata);
403 
404 static const AVFilterPad inputs[] = {
405  {
406  .name = "default",
407  .type = AVMEDIA_TYPE_VIDEO,
408  .filter_frame = filter_frame,
409  },
410  { NULL }
411 };
412 
413 static const AVFilterPad outputs[] = {
414  {
415  .name = "default",
416  .type = AVMEDIA_TYPE_VIDEO,
417  },
418  { NULL }
419 };
420 
422  .name = "metadata",
423  .description = NULL_IF_CONFIG_SMALL("Manipulate video frame metadata."),
424  .priv_size = sizeof(MetadataContext),
425  .priv_class = &metadata_class,
426  .init = init,
427  .uninit = uninit,
428  .inputs = inputs,
429  .outputs = outputs,
431 };
432 #endif /* CONFIG_METADATA_FILTER */
int avio_open(AVIOContext **s, const char *url, int flags)
Create and initialize a AVIOContext for accessing the resource indicated by url.
Definition: aviobuf.c:1127
#define NULL
Definition: coverity.c:32
void(* print)(AVFilterContext *ctx, const char *msg,...) av_printf_format(2
Definition: f_metadata.c:90
Bytestream IO Context.
Definition: avio.h:161
Buffered I/O operations.
static int starts_with(MetadataContext *s, const char *value1, const char *value2)
Definition: f_metadata.c:125
This structure describes decoded (raw) audio or video data.
Definition: frame.h:308
static int parse_expr(MetadataContext *s, const char *value1, const char *value2)
Definition: f_metadata.c:168
AVFilter ff_vf_metadata
size_t static size_t av_strnlen(const char *s, size_t len)
Get the count of continuous non zero chars starting from the beginning.
Definition: avstring.h:140
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
Main libavfilter public API header.
static const char *const var_names[]
Definition: f_metadata.c:61
static av_cold int init(AVFilterContext *ctx)
Definition: f_metadata.c:205
#define AV_OPT_FLAG_AUDIO_PARAM
Definition: opt.h:280
#define vsnprintf
Definition: snprintf.h:36
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:675
void(*) in direct)
Definition: f_metadata.c:90
#define DEFINE_OPTIONS(filt_name, FLAGS)
Definition: f_metadata.c:96
int(* compare)(struct MetadataContext *s, const char *value1, const char *value2)
Definition: f_metadata.c:88
int av_expr_parse(AVExpr **expr, const char *s, const char *const *const_names, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), int log_offset, void *log_ctx)
Parse an expression.
Definition: eval.c:685
#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
Some filters support a generic "enable" expression option that can be used to enable or disable a fil...
Definition: avfilter.h:125
const char * name
Pad name.
Definition: internal.h:60
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1091
#define av_cold
Definition: attributes.h:88
AVOptions.
timestamp utils, mostly useful for debugging/logging purposes
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:401
Definition: eval.c:157
AVDictionaryEntry * av_dict_get(const AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
Get a dictionary entry with matching key.
Definition: dict.c:40
AVIOContext * avio_context
Definition: f_metadata.c:85
AVDictionary * metadata
metadata.
Definition: frame.h:594
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:225
#define av_log(a,...)
char * expr_str
Definition: f_metadata.c:81
A filter pad used for either input or output.
Definition: internal.h:54
static int same_str(MetadataContext *s, const char *value1, const char *value2)
Definition: f_metadata.c:120
double var_values[VAR_VARS_NB]
Definition: f_metadata.c:83
char * file_str
Definition: f_metadata.c:86
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
static void print_file(AVFilterContext *ctx, const char *msg,...)
Definition: f_metadata.c:191
#define AV_OPT_FLAG_FILTERING_PARAM
a generic parameter which can be set by the user for filtering
Definition: opt.h:294
static void print_log(AVFilterContext *ctx, const char *msg,...)
Definition: f_metadata.c:181
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
#define av_ts2timestr(ts, tb)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:76
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
void * priv
private data for use by the filter
Definition: avfilter.h:353
void av_vlog(void *avcl, int level, const char *fmt, va_list vl)
Send the specified message to the log if the level is less than or equal to the current av_log_level...
Definition: log.c:424
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values. ...
Definition: dict.c:203
simple assert() macros that are a bit more flexible than ISO C assert().
#define FFMAX(a, b)
Definition: common.h:94
int direct
avio_read and avio_write should if possible be satisfied directly instead of going through a buffer...
Definition: avio.h:273
#define av_printf_format(fmtpos, attrpos)
Definition: attributes.h:161
var_name
Definition: aeval.c:46
common internal API header
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
static av_cold void uninit(AVFilterContext *ctx)
Definition: f_metadata.c:288
AVFormatContext * ctx
Definition: movenc.c:48
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
#define s(width, name)
Definition: cbs_vp9.c:257
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: f_metadata.c:299
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
#define AV_LOG_INFO
Standard information.
Definition: log.h:205
static int greater(MetadataContext *s, const char *value1, const char *value2)
Definition: f_metadata.c:158
void av_expr_free(AVExpr *e)
Free a parsed expression previously created with av_expr_parse().
Definition: eval.c:336
#define AV_OPT_FLAG_VIDEO_PARAM
Definition: opt.h:281
MetadataFunction
Definition: f_metadata.c:50
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 inputs
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:70
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
#define AVIO_FLAG_DIRECT
Use direct mode.
Definition: avio.h:701
const char * name
Filter name.
Definition: avfilter.h:148
static int equal(MetadataContext *s, const char *value1, const char *value2)
Definition: f_metadata.c:138
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
#define flags(name, subs,...)
Definition: cbs_av1.c:560
MetadataMode
Definition: f_metadata.c:41
int av_strerror(int errnum, char *errbuf, size_t errbuf_size)
Put a description of the AVERROR code errnum in errbuf.
Definition: error.c:105
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
int
static int less(MetadataContext *s, const char *value1, const char *value2)
Definition: f_metadata.c:148
char * key
Definition: dict.h:86
AVExpr * expr
Definition: f_metadata.c:82
char * value
Definition: dict.h:87
#define av_ts2str(ts)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:54
double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
Evaluate a previously parsed expression.
Definition: eval.c:766
#define AVFILTER_DEFINE_CLASS(fname)
Definition: internal.h:318
AVFilter ff_af_ametadata
An instance of a filter.
Definition: avfilter.h:338
#define AV_DICT_IGNORE_SUFFIX
Return first entry in a dictionary whose first part corresponds to the search key, ignoring the suffix of the found key string.
Definition: dict.h:70
internal API functions
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
int avio_closep(AVIOContext **s)
Close the resource accessed by the AVIOContext *s, free it and set the pointer pointing to it to NULL...
Definition: aviobuf.c:1182
static int ends_with(MetadataContext *s, const char *value1, const char *value2)
Definition: f_metadata.c:130
simple arithmetic expression evaluator