libavutil/log.h

   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 "attributes.h"
  26 #include "version.h"
  27
  28 typedef enum {
  29     AV_CLASS_CATEGORY_NA = 0,
  30     AV_CLASS_CATEGORY_INPUT,
  31     AV_CLASS_CATEGORY_OUTPUT,
  32     AV_CLASS_CATEGORY_MUXER,
  33     AV_CLASS_CATEGORY_DEMUXER,
  34     AV_CLASS_CATEGORY_ENCODER,
  35     AV_CLASS_CATEGORY_DECODER,
  36     AV_CLASS_CATEGORY_FILTER,
  37     AV_CLASS_CATEGORY_BITSTREAM_FILTER,
  38     AV_CLASS_CATEGORY_SWSCALER,
  39     AV_CLASS_CATEGORY_SWRESAMPLER,
  40     AV_CLASS_CATEGORY_HWDEVICE,
  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 enum AVClassStateFlags {
  51     /**
  52      * Object initialization has finished and it is now in the 'runtime' stage.
  53      * This affects e.g. what options can be set on the object (only
  54      * AV_OPT_FLAG_RUNTIME_PARAM options can be set on initialized objects).
  55      */
  56     AV_CLASS_STATE_INITIALIZED         = (1 << 0),
  57 };
  58
  59 #define AV_IS_INPUT_DEVICE(category) \
  60     (((category) == AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT) || \
  61      ((category) == AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT) || \
  62      ((category) == AV_CLASS_CATEGORY_DEVICE_INPUT))
  63
  64 #define AV_IS_OUTPUT_DEVICE(category) \
  65     (((category) == AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT) || \
  66      ((category) == AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT) || \
  67      ((category) == AV_CLASS_CATEGORY_DEVICE_OUTPUT))
  68
  69 struct AVOptionRanges;
  70
  71 /**
  72  * Describe the class of an AVClass context structure. That is an
  73  * arbitrary struct of which the first field is a pointer to an
  74  * AVClass struct (e.g. AVCodecContext, AVFormatContext etc.).
  75  */
  76 typedef struct AVClass {
  77     /**
  78      * The name of the class; usually it is the same name as the
  79      * context structure type to which the AVClass is associated.
  80      */
  81     const char* class_name;
  82
  83     /**
  84      * A pointer to a function which returns the name of a context
  85      * instance ctx associated with the class.
  86      */
  87     const char* (*item_name)(void* ctx);
  88
  89     /**
  90      * An array of options for the structure or NULL.
  91      * When non-NULL, the array must be terminated by an option with a NULL
  92      * name.
  93      *
  94      * @see av_set_default_options()
  95      */
  96     const struct AVOption *option;
  97
  98     /**
  99      * LIBAVUTIL_VERSION with which this structure was created.
 100      * This is used to allow fields to be added to AVClass without requiring
 101      * major version bumps everywhere.
 102      */
 103
 104     int version;
 105
 106     /**
 107      * Offset in the structure where the log level offset is stored. The log
 108      * level offset is an int added to the log level for logging with this
 109      * object as the context.
 110      *
 111      * 0 means there is no such variable.
 112      */
 113     int log_level_offset_offset;
 114
 115     /**
 116      * Offset in the structure where a pointer to the parent context for
 117      * logging is stored. For example a decoder could pass its AVCodecContext
 118      * to eval as such a parent context, which an ::av_log() implementation
 119      * could then leverage to display the parent context.
 120      *
 121      * When the pointer is NULL, or this offset is zero, the object is assumed
 122      * to have no parent.
 123      */
 124     int parent_log_context_offset;
 125
 126     /**
 127      * Category used for visualization (like color).
 128      *
 129      * Only used when ::get_category() is NULL. Use this field when all
 130      * instances of this class have the same category, use ::get_category()
 131      * otherwise.
 132      */
 133     AVClassCategory category;
 134
 135     /**
 136      * Callback to return the instance category. Use this callback when
 137      * different instances of this class may have different categories,
 138      * ::category otherwise.
 139      */
 140     AVClassCategory (*get_category)(void* ctx);
 141
 142     /**
 143      * Callback to return the supported/allowed ranges.
 144      */
 145     int (*query_ranges)(struct AVOptionRanges **, void *obj, const char *key, int flags);
 146
 147     /**
 148      * Return next AVOptions-enabled child or NULL
 149      */
 150     void* (*child_next)(void *obj, void *prev);
 151
 152     /**
 153      * Iterate over the AVClasses corresponding to potential AVOptions-enabled
 154      * children.
 155      *
 156      * @param iter pointer to opaque iteration state. The caller must initialize
 157      *             *iter to NULL before the first call.
 158      * @return AVClass for the next AVOptions-enabled child or NULL if there are
 159      *         no more such children.
 160      *
 161      * @note The difference between ::child_next() and ::child_class_iterate()
 162      *       is that ::child_next() iterates over _actual_ children of an
 163      *       _existing_ object instance, while ::child_class_iterate() iterates
 164      *       over the classes of all _potential_ children of any possible
 165      *       instance of this class.
 166      */
 167     const struct AVClass* (*child_class_iterate)(void **iter);
 168
 169     /**
 170      * When non-zero, offset in the object to an unsigned int holding object
 171      * state flags, a combination of AVClassStateFlags values. The flags are
 172      * updated by the object to signal its state to the generic code.
 173      *
 174      * Added in version 59.41.100.
 175      */
 176     int state_flags_offset;
 177 } AVClass;
 178
 179 /**
 180  * @addtogroup lavu_log
 181  *
 182  * @{
 183  *
 184  * @defgroup lavu_log_constants Logging Constants
 185  *
 186  * @{
 187  */
 188
 189 /**
 190  * Print no output.
 191  */
 192 #define AV_LOG_QUIET    -8
 193
 194 /**
 195  * Something went really wrong and we will crash now.
 196  */
 197 #define AV_LOG_PANIC     0
 198
 199 /**
 200  * Something went wrong and recovery is not possible.
 201  * For example, no header was found for a format which depends
 202  * on headers or an illegal combination of parameters is used.
 203  */
 204 #define AV_LOG_FATAL     8
 205
 206 /**
 207  * Something went wrong and cannot losslessly be recovered.
 208  * However, not all future data is affected.
 209  */
 210 #define AV_LOG_ERROR    16
 211
 212 /**
 213  * Something somehow does not look correct. This may or may not
 214  * lead to problems. An example would be the use of '-vstrict -2'.
 215  */
 216 #define AV_LOG_WARNING  24
 217
 218 /**
 219  * Standard information.
 220  */
 221 #define AV_LOG_INFO     32
 222
 223 /**
 224  * Detailed information.
 225  */
 226 #define AV_LOG_VERBOSE  40
 227
 228 /**
 229  * Stuff which is only useful for libav* developers.
 230  */
 231 #define AV_LOG_DEBUG    48
 232
 233 /**
 234  * Extremely verbose debugging, useful for libav* development.
 235  */
 236 #define AV_LOG_TRACE    56
 237
 238 #define AV_LOG_MAX_OFFSET (AV_LOG_TRACE - AV_LOG_QUIET)
 239
 240 /**
 241  * @}
 242  */
 243
 244 /**
 245  * Sets additional colors for extended debugging sessions.
 246  * @code
 247    av_log(ctx, AV_LOG_DEBUG|AV_LOG_C(134), "Message in purple\n");
 248    @endcode
 249  * Requires 256color terminal support. Uses outside debugging is not
 250  * recommended.
 251  */
 252 #define AV_LOG_C(x) ((x) << 8)
 253
 254 /**
 255  * Send the specified message to the log if the level is less than or equal
 256  * to the current av_log_level. By default, all logging messages are sent to
 257  * stderr. This behavior can be altered by setting a different logging callback
 258  * function.
 259  * @see av_log_set_callback
 260  *
 261  * @param avcl A pointer to an arbitrary struct of which the first field is a
 262  *        pointer to an AVClass struct or NULL if general log.
 263  * @param level The importance level of the message expressed using a @ref
 264  *        lavu_log_constants "Logging Constant".
 265  * @param fmt The format string (printf-compatible) that specifies how
 266  *        subsequent arguments are converted to output.
 267  */
 268 void av_log(void *avcl, int level, const char *fmt, ...) av_printf_format(3, 4);
 269
 270 /**
 271  * Send the specified message to the log once with the initial_level and then with
 272  * the subsequent_level. By default, all logging messages are sent to
 273  * stderr. This behavior can be altered by setting a different logging callback
 274  * function.
 275  * @see av_log
 276  *
 277  * @param avcl A pointer to an arbitrary struct of which the first field is a
 278  *        pointer to an AVClass struct or NULL if general log.
 279  * @param initial_level importance level of the message expressed using a @ref
 280  *        lavu_log_constants "Logging Constant" for the first occurrence.
 281  * @param subsequent_level importance level of the message expressed using a @ref
 282  *        lavu_log_constants "Logging Constant" after the first occurrence.
 283  * @param fmt The format string (printf-compatible) that specifies how
 284  *        subsequent arguments are converted to output.
 285  * @param state a variable to keep trak of if a message has already been printed
 286  *        this must be initialized to 0 before the first use. The same state
 287  *        must not be accessed by 2 Threads simultaneously.
 288  */
 289 void av_log_once(void* avcl, int initial_level, int subsequent_level, int *state, const char *fmt, ...) av_printf_format(5, 6);
 290
 291
 292 /**
 293  * Send the specified message to the log if the level is less than or equal
 294  * to the current av_log_level. By default, all logging messages are sent to
 295  * stderr. This behavior can be altered by setting a different logging callback
 296  * function.
 297  * @see av_log_set_callback
 298  *
 299  * @param avcl A pointer to an arbitrary struct of which the first field is a
 300  *        pointer to an AVClass struct.
 301  * @param level The importance level of the message expressed using a @ref
 302  *        lavu_log_constants "Logging Constant".
 303  * @param fmt The format string (printf-compatible) that specifies how
 304  *        subsequent arguments are converted to output.
 305  * @param vl The arguments referenced by the format string.
 306  */
 307 void av_vlog(void *avcl, int level, const char *fmt, va_list vl);
 308
 309 /**
 310  * Get the current log level
 311  *
 312  * @see lavu_log_constants
 313  *
 314  * @return Current log level
 315  */
 316 int av_log_get_level(void);
 317
 318 /**
 319  * Set the log level
 320  *
 321  * @see lavu_log_constants
 322  *
 323  * @param level Logging level
 324  */
 325 void av_log_set_level(int level);
 326
 327 /**
 328  * Set the logging callback
 329  *
 330  * @note The callback must be thread safe, even if the application does not use
 331  *       threads itself as some codecs are multithreaded.
 332  *
 333  * @see av_log_default_callback
 334  *
 335  * @param callback A logging function with a compatible signature.
 336  */
 337 void av_log_set_callback(void (*callback)(void*, int, const char*, va_list));
 338
 339 /**
 340  * Default logging callback
 341  *
 342  * It prints the message to stderr, optionally colorizing it.
 343  *
 344  * @param avcl A pointer to an arbitrary struct of which the first field is a
 345  *        pointer to an AVClass struct.
 346  * @param level The importance level of the message expressed using a @ref
 347  *        lavu_log_constants "Logging Constant".
 348  * @param fmt The format string (printf-compatible) that specifies how
 349  *        subsequent arguments are converted to output.
 350  * @param vl The arguments referenced by the format string.
 351  */
 352 void av_log_default_callback(void *avcl, int level, const char *fmt,
 353                              va_list vl);
 354
 355 /**
 356  * Return the context name
 357  *
 358  * @param  ctx The AVClass context
 359  *
 360  * @return The AVClass class_name
 361  */
 362 const char* av_default_item_name(void* ctx);
 363 AVClassCategory av_default_get_category(void *ptr);
 364
 365 /**
 366  * Format a line of log the same way as the default callback.
 367  * @param line          buffer to receive the formatted line
 368  * @param line_size     size of the buffer
 369  * @param print_prefix  used to store whether the prefix must be printed;
 370  *                      must point to a persistent integer initially set to 1
 371  */
 372 void av_log_format_line(void *ptr, int level, const char *fmt, va_list vl,
 373                         char *line, int line_size, int *print_prefix);
 374
 375 /**
 376  * Format a line of log the same way as the default callback.
 377  * @param line          buffer to receive the formatted line;
 378  *                      may be NULL if line_size is 0
 379  * @param line_size     size of the buffer; at most line_size-1 characters will
 380  *                      be written to the buffer, plus one null terminator
 381  * @param print_prefix  used to store whether the prefix must be printed;
 382  *                      must point to a persistent integer initially set to 1
 383  * @return Returns a negative value if an error occurred, otherwise returns
 384  *         the number of characters that would have been written for a
 385  *         sufficiently large buffer, not including the terminating null
 386  *         character. If the return value is not less than line_size, it means
 387  *         that the log message was truncated to fit the buffer.
 388  */
 389 int av_log_format_line2(void *ptr, int level, const char *fmt, va_list vl,
 390                         char *line, int line_size, int *print_prefix);
 391
 392 /**
 393  * Skip repeated messages, this requires the user app to use av_log() instead of
 394  * (f)printf as the 2 would otherwise interfere and lead to
 395  * "Last message repeated x times" messages below (f)printf messages with some
 396  * bad luck.
 397  * Also to receive the last, "last repeated" line if any, the user app must
 398  * call av_log(NULL, AV_LOG_QUIET, "%s", ""); at the end
 399  */
 400 #define AV_LOG_SKIP_REPEATED 1
 401
 402 /**
 403  * Include the log severity in messages originating from codecs.
 404  *
 405  * Results in messages such as:
 406  * [rawvideo @ 0xDEADBEEF] [error] encode did not produce valid pts
 407  */
 408 #define AV_LOG_PRINT_LEVEL 2
 409
 410 /**
 411  * Include system time in log output.
 412  */
 413 #define AV_LOG_PRINT_TIME 4
 414
 415 /**
 416  * Include system date and time in log output.
 417  */
 418 #define AV_LOG_PRINT_DATETIME 8
 419
 420 void av_log_set_flags(int arg);
 421 int av_log_get_flags(void);
 422
 423 /**
 424  * @}
 425  */
 426
 427 #endif /* AVUTIL_LOG_H */