log.h (7407B)
1 /* 2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> 3 * 4 * This file is part of Libav. 5 * 6 * Libav 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 * Libav 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 Libav; 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 /** 29 * Describe the class of an AVClass context structure. That is an 30 * arbitrary struct of which the first field is a pointer to an 31 * AVClass struct (e.g. AVCodecContext, AVFormatContext etc.). 32 */ 33 typedef struct AVClass { 34 /** 35 * The name of the class; usually it is the same name as the 36 * context structure type to which the AVClass is associated. 37 */ 38 const char* class_name; 39 40 /** 41 * A pointer to a function which returns the name of a context 42 * instance ctx associated with the class. 43 */ 44 const char* (*item_name)(void* ctx); 45 46 /** 47 * a pointer to the first option specified in the class if any or NULL 48 * 49 * @see av_set_default_options() 50 */ 51 const struct AVOption *option; 52 53 /** 54 * LIBAVUTIL_VERSION with which this structure was created. 55 * This is used to allow fields to be added without requiring major 56 * version bumps everywhere. 57 */ 58 59 int version; 60 61 /** 62 * Offset in the structure where log_level_offset is stored. 63 * 0 means there is no such variable 64 */ 65 int log_level_offset_offset; 66 67 /** 68 * Offset in the structure where a pointer to the parent context for 69 * logging is stored. For example a decoder could pass its AVCodecContext 70 * to eval as such a parent context, which an av_log() implementation 71 * could then leverage to display the parent context. 72 * The offset can be NULL. 73 */ 74 int parent_log_context_offset; 75 76 /** 77 * Return next AVOptions-enabled child or NULL 78 */ 79 void* (*child_next)(void *obj, void *prev); 80 81 /** 82 * Return an AVClass corresponding to the next potential 83 * AVOptions-enabled child. 84 * 85 * The difference between child_next and this is that 86 * child_next iterates over _already existing_ objects, while 87 * child_class_next iterates over _all possible_ children. 88 */ 89 const struct AVClass* (*child_class_next)(const struct AVClass *prev); 90 } AVClass; 91 92 /** 93 * @addtogroup lavu_log 94 * 95 * @{ 96 * 97 * @defgroup lavu_log_constants Logging Constants 98 * 99 * @{ 100 */ 101 102 /** 103 * Print no output. 104 */ 105 #define AV_LOG_QUIET -8 106 107 /** 108 * Something went really wrong and we will crash now. 109 */ 110 #define AV_LOG_PANIC 0 111 112 /** 113 * Something went wrong and recovery is not possible. 114 * For example, no header was found for a format which depends 115 * on headers or an illegal combination of parameters is used. 116 */ 117 #define AV_LOG_FATAL 8 118 119 /** 120 * Something went wrong and cannot losslessly be recovered. 121 * However, not all future data is affected. 122 */ 123 #define AV_LOG_ERROR 16 124 125 /** 126 * Something somehow does not look correct. This may or may not 127 * lead to problems. An example would be the use of '-vstrict -2'. 128 */ 129 #define AV_LOG_WARNING 24 130 131 /** 132 * Standard information. 133 */ 134 #define AV_LOG_INFO 32 135 136 /** 137 * Detailed information. 138 */ 139 #define AV_LOG_VERBOSE 40 140 141 /** 142 * Stuff which is only useful for libav* developers. 143 */ 144 #define AV_LOG_DEBUG 48 145 146 /** 147 * @} 148 */ 149 150 /** 151 * Send the specified message to the log if the level is less than or equal 152 * to the current av_log_level. By default, all logging messages are sent to 153 * stderr. This behavior can be altered by setting a different logging callback 154 * function. 155 * @see av_log_set_callback 156 * 157 * @param avcl A pointer to an arbitrary struct of which the first field is a 158 * pointer to an AVClass struct. 159 * @param level The importance level of the message expressed using a @ref 160 * lavu_log_constants "Logging Constant". 161 * @param fmt The format string (printf-compatible) that specifies how 162 * subsequent arguments are converted to output. 163 */ 164 void av_log(void *avcl, int level, const char *fmt, ...) av_printf_format(3, 4); 165 166 167 /** 168 * Send the specified message to the log if the level is less than or equal 169 * to the current av_log_level. By default, all logging messages are sent to 170 * stderr. This behavior can be altered by setting a different logging callback 171 * function. 172 * @see av_log_set_callback 173 * 174 * @param avcl A pointer to an arbitrary struct of which the first field is a 175 * pointer to an AVClass struct. 176 * @param level The importance level of the message expressed using a @ref 177 * lavu_log_constants "Logging Constant". 178 * @param fmt The format string (printf-compatible) that specifies how 179 * subsequent arguments are converted to output. 180 * @param vl The arguments referenced by the format string. 181 */ 182 void av_vlog(void *avcl, int level, const char *fmt, va_list vl); 183 184 /** 185 * Get the current log level 186 * 187 * @see lavu_log_constants 188 * 189 * @return Current log level 190 */ 191 int av_log_get_level(void); 192 193 /** 194 * Set the log level 195 * 196 * @see lavu_log_constants 197 * 198 * @param level Logging level 199 */ 200 void av_log_set_level(int level); 201 202 /** 203 * Set the logging callback 204 * 205 * @see av_log_default_callback 206 * 207 * @param callback A logging function with a compatible signature. 208 */ 209 void av_log_set_callback(void (*callback)(void*, int, const char*, va_list)); 210 211 /** 212 * Default logging callback 213 * 214 * It prints the message to stderr, optionally colorizing it. 215 * 216 * @param avcl A pointer to an arbitrary struct of which the first field is a 217 * pointer to an AVClass struct. 218 * @param level The importance level of the message expressed using a @ref 219 * lavu_log_constants "Logging Constant". 220 * @param fmt The format string (printf-compatible) that specifies how 221 * subsequent arguments are converted to output. 222 * @param vl The arguments referenced by the format string. 223 */ 224 void av_log_default_callback(void *avcl, int level, const char *fmt, 225 va_list vl); 226 227 /** 228 * Return the context name 229 * 230 * @param ctx The AVClass context 231 * 232 * @return The AVClass class_name 233 */ 234 const char* av_default_item_name(void* ctx); 235 236 /** 237 * av_dlog macros 238 * Useful to print debug messages that shouldn't get compiled in normally. 239 */ 240 241 #ifdef DEBUG 242 # define av_dlog(pctx, ...) av_log(pctx, AV_LOG_DEBUG, __VA_ARGS__) 243 #else 244 # define av_dlog(pctx, ...) 245 #endif 246 247 /** 248 * Skip repeated messages, this requires the user app to use av_log() instead of 249 * (f)printf as the 2 would otherwise interfere and lead to 250 * "Last message repeated x times" messages below (f)printf messages with some 251 * bad luck. 252 * Also to receive the last, "last repeated" line if any, the user app must 253 * call av_log(NULL, AV_LOG_QUIET, ""); at the end 254 */ 255 #define AV_LOG_SKIP_REPEATED 1 256 void av_log_set_flags(int arg); 257 258 /** 259 * @} 260 */ 261 262 #endif /* AVUTIL_LOG_H */