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 #include "version.h"
28 
29 typedef enum {
30     AV_CLASS_CATEGORY_NA = 0,
31     AV_CLASS_CATEGORY_INPUT,
32     AV_CLASS_CATEGORY_OUTPUT,
33     AV_CLASS_CATEGORY_MUXER,
34     AV_CLASS_CATEGORY_DEMUXER,
35     AV_CLASS_CATEGORY_ENCODER,
36     AV_CLASS_CATEGORY_DECODER,
37     AV_CLASS_CATEGORY_FILTER,
38     AV_CLASS_CATEGORY_BITSTREAM_FILTER,
39     AV_CLASS_CATEGORY_SWSCALER,
40     AV_CLASS_CATEGORY_SWRESAMPLER,
41     AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT = 40,
42     AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
43     AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT,
44     AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,
45     AV_CLASS_CATEGORY_DEVICE_OUTPUT,
46     AV_CLASS_CATEGORY_DEVICE_INPUT,
47     AV_CLASS_CATEGORY_NB  ///< not part of ABI/API
48 }AVClassCategory;
49 
50 #define AV_IS_INPUT_DEVICE(category) \
51     (((category) == AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT) || \
52      ((category) == AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT) || \
53      ((category) == AV_CLASS_CATEGORY_DEVICE_INPUT))
54 
55 #define AV_IS_OUTPUT_DEVICE(category) \
56     (((category) == AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT) || \
57      ((category) == AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT) || \
58      ((category) == AV_CLASS_CATEGORY_DEVICE_OUTPUT))
59 
60 struct AVOptionRanges;
61 
62 /**
63  * Describe the class of an AVClass context structure. That is an
64  * arbitrary struct of which the first field is a pointer to an
65  * AVClass struct (e.g. AVCodecContext, AVFormatContext etc.).
66  */
67 typedef struct AVClass {
68     /**
69      * The name of the class; usually it is the same name as the
70      * context structure type to which the AVClass is associated.
71      */
72     const char* class_name;
73 
74     /**
75      * A pointer to a function which returns the name of a context
76      * instance ctx associated with the class.
77      */
78     const char* (*item_name)(void* ctx);
79 
80     /**
81      * a pointer to the first option specified in the class if any or NULL
82      *
83      * @see av_set_default_options()
84      */
85     const struct AVOption *option;
86 
87     /**
88      * LIBAVUTIL_VERSION with which this structure was created.
89      * This is used to allow fields to be added without requiring major
90      * version bumps everywhere.
91      */
92 
93     int version;
94 
95     /**
96      * Offset in the structure where log_level_offset is stored.
97      * 0 means there is no such variable
98      */
99     int log_level_offset_offset;
100 
101     /**
102      * Offset in the structure where a pointer to the parent context for
103      * logging is stored. For example a decoder could pass its AVCodecContext
104      * to eval as such a parent context, which an av_log() implementation
105      * could then leverage to display the parent context.
106      * The offset can be NULL.
107      */
108     int parent_log_context_offset;
109 
110     /**
111      * Return next AVOptions-enabled child or NULL
112      */
113     void* (*child_next)(void *obj, void *prev);
114 
115     /**
116      * Return an AVClass corresponding to the next potential
117      * AVOptions-enabled child.
118      *
119      * The difference between child_next and this is that
120      * child_next iterates over _already existing_ objects, while
121      * child_class_next iterates over _all possible_ children.
122      */
123     const struct AVClass* (*child_class_next)(const struct AVClass *prev);
124 
125     /**
126      * Category used for visualization (like color)
127      * This is only set if the category is equal for all objects using this class.
128      * available since version (51 << 16 | 56 << 8 | 100)
129      */
130     AVClassCategory category;
131 
132     /**
133      * Callback to return the category.
134      * available since version (51 << 16 | 59 << 8 | 100)
135      */
136     AVClassCategory (*get_category)(void* ctx);
137 
138     /**
139      * Callback to return the supported/allowed ranges.
140      * available since version (52.12)
141      */
142     int (*query_ranges)(struct AVOptionRanges **, void *obj, const char *key, int flags);
143 } AVClass;
144 
145 /**
146  * @addtogroup lavu_log
147  *
148  * @{
149  *
150  * @defgroup lavu_log_constants Logging Constants
151  *
152  * @{
153  */
154 
155 /**
156  * Print no output.
157  */
158 #define AV_LOG_QUIET    -8
159 
160 /**
161  * Something went really wrong and we will crash now.
162  */
163 #define AV_LOG_PANIC     0
164 
165 /**
166  * Something went wrong and recovery is not possible.
167  * For example, no header was found for a format which depends
168  * on headers or an illegal combination of parameters is used.
169  */
170 #define AV_LOG_FATAL     8
171 
172 /**
173  * Something went wrong and cannot losslessly be recovered.
174  * However, not all future data is affected.
175  */
176 #define AV_LOG_ERROR    16
177 
178 /**
179  * Something somehow does not look correct. This may or may not
180  * lead to problems. An example would be the use of '-vstrict -2'.
181  */
182 #define AV_LOG_WARNING  24
183 
184 /**
185  * Standard information.
186  */
187 #define AV_LOG_INFO     32
188 
189 /**
190  * Detailed information.
191  */
192 #define AV_LOG_VERBOSE  40
193 
194 /**
195  * Stuff which is only useful for libav* developers.
196  */
197 #define AV_LOG_DEBUG    48
198 
199 /**
200  * Extremely verbose debugging, useful for libav* development.
201  */
202 #define AV_LOG_TRACE    56
203 
204 #define AV_LOG_MAX_OFFSET (AV_LOG_TRACE - AV_LOG_QUIET)
205 
206 /**
207  * @}
208  */
209 
210 /**
211  * Sets additional colors for extended debugging sessions.
212  * @code
213    av_log(ctx, AV_LOG_DEBUG|AV_LOG_C(134), "Message in purple\n");
214    @endcode
215  * Requires 256color terminal support. Uses outside debugging is not
216  * recommended.
217  */
218 #define AV_LOG_C(x) ((x) << 8)
219 
220 /**
221  * Send the specified message to the log if the level is less than or equal
222  * to the current av_log_level. By default, all logging messages are sent to
223  * stderr. This behavior can be altered by setting a different logging callback
224  * function.
225  * @see av_log_set_callback
226  *
227  * @param avcl A pointer to an arbitrary struct of which the first field is a
228  *        pointer to an AVClass struct or NULL if general log.
229  * @param level The importance level of the message expressed using a @ref
230  *        lavu_log_constants "Logging Constant".
231  * @param fmt The format string (printf-compatible) that specifies how
232  *        subsequent arguments are converted to output.
233  */
234 void av_log(void *avcl, int level, const char *fmt, ...) av_printf_format(3, 4);
235 
236 
237 /**
238  * Send the specified message to the log if the level is less than or equal
239  * to the current av_log_level. By default, all logging messages are sent to
240  * stderr. This behavior can be altered by setting a different logging callback
241  * function.
242  * @see av_log_set_callback
243  *
244  * @param avcl A pointer to an arbitrary struct of which the first field is a
245  *        pointer to an AVClass struct.
246  * @param level The importance level of the message expressed using a @ref
247  *        lavu_log_constants "Logging Constant".
248  * @param fmt The format string (printf-compatible) that specifies how
249  *        subsequent arguments are converted to output.
250  * @param vl The arguments referenced by the format string.
251  */
252 void av_vlog(void *avcl, int level, const char *fmt, va_list vl);
253 
254 /**
255  * Get the current log level
256  *
257  * @see lavu_log_constants
258  *
259  * @return Current log level
260  */
261 int av_log_get_level(void);
262 
263 /**
264  * Set the log level
265  *
266  * @see lavu_log_constants
267  *
268  * @param level Logging level
269  */
270 void av_log_set_level(int level);
271 
272 /**
273  * Set the logging callback
274  *
275  * @note The callback must be thread safe, even if the application does not use
276  *       threads itself as some codecs are multithreaded.
277  *
278  * @see av_log_default_callback
279  *
280  * @param callback A logging function with a compatible signature.
281  */
282 void av_log_set_callback(void (*callback)(void*, int, const char*, va_list));
283 
284 /**
285  * Default logging callback
286  *
287  * It prints the message to stderr, optionally colorizing it.
288  *
289  * @param avcl A pointer to an arbitrary struct of which the first field is a
290  *        pointer to an AVClass struct.
291  * @param level The importance level of the message expressed using a @ref
292  *        lavu_log_constants "Logging Constant".
293  * @param fmt The format string (printf-compatible) that specifies how
294  *        subsequent arguments are converted to output.
295  * @param vl The arguments referenced by the format string.
296  */
297 void av_log_default_callback(void *avcl, int level, const char *fmt,
298                              va_list vl);
299 
300 /**
301  * Return the context name
302  *
303  * @param  ctx The AVClass context
304  *
305  * @return The AVClass class_name
306  */
307 const char* av_default_item_name(void* ctx);
308 AVClassCategory av_default_get_category(void *ptr);
309 
310 /**
311  * Format a line of log the same way as the default callback.
312  * @param line          buffer to receive the formatted line
313  * @param line_size     size of the buffer
314  * @param print_prefix  used to store whether the prefix must be printed;
315  *                      must point to a persistent integer initially set to 1
316  */
317 void av_log_format_line(void *ptr, int level, const char *fmt, va_list vl,
318                         char *line, int line_size, int *print_prefix);
319 
320 /**
321  * Format a line of log the same way as the default callback.
322  * @param line          buffer to receive the formatted line;
323  *                      may be NULL if line_size is 0
324  * @param line_size     size of the buffer; at most line_size-1 characters will
325  *                      be written to the buffer, plus one null terminator
326  * @param print_prefix  used to store whether the prefix must be printed;
327  *                      must point to a persistent integer initially set to 1
328  * @return Returns a negative value if an error occurred, otherwise returns
329  *         the number of characters that would have been written for a
330  *         sufficiently large buffer, not including the terminating null
331  *         character. If the return value is not less than line_size, it means
332  *         that the log message was truncated to fit the buffer.
333  */
334 int av_log_format_line2(void *ptr, int level, const char *fmt, va_list vl,
335                         char *line, int line_size, int *print_prefix);
336 
337 /**
338  * Skip repeated messages, this requires the user app to use av_log() instead of
339  * (f)printf as the 2 would otherwise interfere and lead to
340  * "Last message repeated x times" messages below (f)printf messages with some
341  * bad luck.
342  * Also to receive the last, "last repeated" line if any, the user app must
343  * call av_log(NULL, AV_LOG_QUIET, "%s", ""); at the end
344  */
345 #define AV_LOG_SKIP_REPEATED 1
346 
347 /**
348  * Include the log severity in messages originating from codecs.
349  *
350  * Results in messages such as:
351  * [rawvideo @ 0xDEADBEEF] [error] encode did not produce valid pts
352  */
353 #define AV_LOG_PRINT_LEVEL 2
354 
355 void av_log_set_flags(int arg);
356 int av_log_get_flags(void);
357 
358 /**
359  * @}
360  */
361 
362 #endif /* AVUTIL_LOG_H */
363