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log.h
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1 /*
2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
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 #ifndef AVUTIL_LOG_H
22 #define AVUTIL_LOG_H
23 
24 #include <stdarg.h>
25 #include "avutil.h"
26 #include "attributes.h"
27 
28 typedef enum {
46  AV_CLASS_CATEGORY_NB, ///< not part of ABI/API
48 
49 #define AV_IS_INPUT_DEVICE(category) \
50  (((category) == AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT) || \
51  ((category) == AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT) || \
52  ((category) == AV_CLASS_CATEGORY_DEVICE_INPUT))
53 
54 #define AV_IS_OUTPUT_DEVICE(category) \
55  (((category) == AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT) || \
56  ((category) == AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT) || \
57  ((category) == AV_CLASS_CATEGORY_DEVICE_OUTPUT))
58 
59 struct AVOptionRanges;
60 
61 /**
62  * Describe the class of an AVClass context structure. That is an
63  * arbitrary struct of which the first field is a pointer to an
64  * AVClass struct (e.g. AVCodecContext, AVFormatContext etc.).
65  */
66 typedef struct AVClass {
67  /**
68  * The name of the class; usually it is the same name as the
69  * context structure type to which the AVClass is associated.
70  */
71  const char* class_name;
72 
73  /**
74  * A pointer to a function which returns the name of a context
75  * instance ctx associated with the class.
76  */
77  const char* (*item_name)(void* ctx);
78 
79  /**
80  * a pointer to the first option specified in the class if any or NULL
81  *
82  * @see av_set_default_options()
83  */
84  const struct AVOption *option;
85 
86  /**
87  * LIBAVUTIL_VERSION with which this structure was created.
88  * This is used to allow fields to be added without requiring major
89  * version bumps everywhere.
90  */
91 
92  int version;
93 
94  /**
95  * Offset in the structure where log_level_offset is stored.
96  * 0 means there is no such variable
97  */
99 
100  /**
101  * Offset in the structure where a pointer to the parent context for
102  * logging is stored. For example a decoder could pass its AVCodecContext
103  * to eval as such a parent context, which an av_log() implementation
104  * could then leverage to display the parent context.
105  * The offset can be NULL.
106  */
108 
109  /**
110  * Return next AVOptions-enabled child or NULL
111  */
112  void* (*child_next)(void *obj, void *prev);
113 
114  /**
115  * Return an AVClass corresponding to the next potential
116  * AVOptions-enabled child.
117  *
118  * The difference between child_next and this is that
119  * child_next iterates over _already existing_ objects, while
120  * child_class_next iterates over _all possible_ children.
121  */
122  const struct AVClass* (*child_class_next)(const struct AVClass *prev);
123 
124  /**
125  * Category used for visualization (like color)
126  * This is only set if the category is equal for all objects using this class.
127  * available since version (51 << 16 | 56 << 8 | 100)
128  */
130 
131  /**
132  * Callback to return the category.
133  * available since version (51 << 16 | 59 << 8 | 100)
134  */
136 
137  /**
138  * Callback to return the supported/allowed ranges.
139  * available since version (52.12)
140  */
141  int (*query_ranges)(struct AVOptionRanges **, void *obj, const char *key, int flags);
142 } AVClass;
143 
144 /**
145  * @addtogroup lavu_log
146  *
147  * @{
148  *
149  * @defgroup lavu_log_constants Logging Constants
150  *
151  * @{
152  */
153 
154 /**
155  * Print no output.
156  */
157 #define AV_LOG_QUIET -8
158 
159 /**
160  * Something went really wrong and we will crash now.
161  */
162 #define AV_LOG_PANIC 0
163 
164 /**
165  * Something went wrong and recovery is not possible.
166  * For example, no header was found for a format which depends
167  * on headers or an illegal combination of parameters is used.
168  */
169 #define AV_LOG_FATAL 8
170 
171 /**
172  * Something went wrong and cannot losslessly be recovered.
173  * However, not all future data is affected.
174  */
175 #define AV_LOG_ERROR 16
176 
177 /**
178  * Something somehow does not look correct. This may or may not
179  * lead to problems. An example would be the use of '-vstrict -2'.
180  */
181 #define AV_LOG_WARNING 24
182 
183 /**
184  * Standard information.
185  */
186 #define AV_LOG_INFO 32
187 
188 /**
189  * Detailed information.
190  */
191 #define AV_LOG_VERBOSE 40
192 
193 /**
194  * Stuff which is only useful for libav* developers.
195  */
196 #define AV_LOG_DEBUG 48
197 
198 #define AV_LOG_MAX_OFFSET (AV_LOG_DEBUG - AV_LOG_QUIET)
199 
200 /**
201  * @}
202  */
203 
204 /**
205  * Sets additional colors for extended debugging sessions.
206  * @code
207  av_log(ctx, AV_LOG_DEBUG|AV_LOG_C(134), "Message in purple\n");
208  @endcode
209  * Requires 256color terminal support. Uses outside debugging is not
210  * recommended.
211  */
212 #define AV_LOG_C(x) ((x) << 8)
213 
214 /**
215  * Send the specified message to the log if the level is less than or equal
216  * to the current av_log_level. By default, all logging messages are sent to
217  * stderr. This behavior can be altered by setting a different logging callback
218  * function.
219  * @see av_log_set_callback
220  *
221  * @param avcl A pointer to an arbitrary struct of which the first field is a
222  * pointer to an AVClass struct.
223  * @param level The importance level of the message expressed using a @ref
224  * lavu_log_constants "Logging Constant".
225  * @param fmt The format string (printf-compatible) that specifies how
226  * subsequent arguments are converted to output.
227  */
228 void av_log(void *avcl, int level, const char *fmt, ...) av_printf_format(3, 4);
229 
230 
231 /**
232  * Send the specified message to the log if the level is less than or equal
233  * to the current av_log_level. By default, all logging messages are sent to
234  * stderr. This behavior can be altered by setting a different logging callback
235  * function.
236  * @see av_log_set_callback
237  *
238  * @param avcl A pointer to an arbitrary struct of which the first field is a
239  * pointer to an AVClass struct.
240  * @param level The importance level of the message expressed using a @ref
241  * lavu_log_constants "Logging Constant".
242  * @param fmt The format string (printf-compatible) that specifies how
243  * subsequent arguments are converted to output.
244  * @param vl The arguments referenced by the format string.
245  */
246 void av_vlog(void *avcl, int level, const char *fmt, va_list vl);
247 
248 /**
249  * Get the current log level
250  *
251  * @see lavu_log_constants
252  *
253  * @return Current log level
254  */
255 int av_log_get_level(void);
256 
257 /**
258  * Set the log level
259  *
260  * @see lavu_log_constants
261  *
262  * @param level Logging level
263  */
264 void av_log_set_level(int level);
265 
266 /**
267  * Set the logging callback
268  *
269  * @note The callback must be thread safe, even if the application does not use
270  * threads itself as some codecs are multithreaded.
271  *
272  * @see av_log_default_callback
273  *
274  * @param callback A logging function with a compatible signature.
275  */
276 void av_log_set_callback(void (*callback)(void*, int, const char*, va_list));
277 
278 /**
279  * Default logging callback
280  *
281  * It prints the message to stderr, optionally colorizing it.
282  *
283  * @param avcl A pointer to an arbitrary struct of which the first field is a
284  * pointer to an AVClass struct.
285  * @param level The importance level of the message expressed using a @ref
286  * lavu_log_constants "Logging Constant".
287  * @param fmt The format string (printf-compatible) that specifies how
288  * subsequent arguments are converted to output.
289  * @param vl The arguments referenced by the format string.
290  */
291 void av_log_default_callback(void *avcl, int level, const char *fmt,
292  va_list vl);
293 
294 /**
295  * Return the context name
296  *
297  * @param ctx The AVClass context
298  *
299  * @return The AVClass class_name
300  */
301 const char* av_default_item_name(void* ctx);
303 
304 /**
305  * Format a line of log the same way as the default callback.
306  * @param line buffer to receive the formated line
307  * @param line_size size of the buffer
308  * @param print_prefix used to store whether the prefix must be printed;
309  * must point to a persistent integer initially set to 1
310  */
311 void av_log_format_line(void *ptr, int level, const char *fmt, va_list vl,
312  char *line, int line_size, int *print_prefix);
313 
314 /**
315  * av_dlog macros
316  * Useful to print debug messages that shouldn't get compiled in normally.
317  */
318 
319 #ifdef DEBUG
320 # define av_dlog(pctx, ...) av_log(pctx, AV_LOG_DEBUG, __VA_ARGS__)
321 #else
322 # define av_dlog(pctx, ...) do { if (0) av_log(pctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
323 #endif
324 
325 /**
326  * Skip repeated messages, this requires the user app to use av_log() instead of
327  * (f)printf as the 2 would otherwise interfere and lead to
328  * "Last message repeated x times" messages below (f)printf messages with some
329  * bad luck.
330  * Also to receive the last, "last repeated" line if any, the user app must
331  * call av_log(NULL, AV_LOG_QUIET, "%s", ""); at the end
332  */
333 #define AV_LOG_SKIP_REPEATED 1
334 
335 /**
336  * Include the log severity in messages originating from codecs.
337  *
338  * Results in messages such as:
339  * [rawvideo @ 0xDEADBEEF] [error] encode did not produce valid pts
340  */
341 #define AV_LOG_PRINT_LEVEL 2
342 
343 void av_log_set_flags(int arg);
344 int av_log_get_flags(void);
345 
346 /**
347  * @}
348  */
349 
350 #endif /* AVUTIL_LOG_H */