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 loging is stored.

    69      * for example a decoder that uses eval.c could pass its AVCodecContext to eval as such

    70      * parent context. And a av_log() implementation could then display the parent context

    71      * can be NULL of course

    72      */

    73     int parent_log_context_offset;

    74 

    75     /**

    76      * Return next AVOptions-enabled child or NULL

    77      */

    78     void* (*child_next)(void *obj, void *prev);

    79 

    80     /**

    81      * Return an AVClass corresponding to next potential

    82      * AVOptions-enabled child.

    83      *

    84      * The difference between child_next and this is that

    85      * child_next iterates over _already existing_ objects, while

    86      * child_class_next iterates over _all possible_ children.

    87      */

    88     const struct AVClass* (*child_class_next)(const struct AVClass *prev);

    89 } AVClass;

    90 

    91 /* av_log API */

    92 

    93 #define AV_LOG_QUIET    -8

    94 

    95 /**

    96  * Something went really wrong and we will crash now.

    97  */

    98 #define AV_LOG_PANIC     0

    99 

   100 /**

   101  * Something went wrong and recovery is not possible.

   102  * For example, no header was found for a format which depends

   103  * on headers or an illegal combination of parameters is used.

   104  */

   105 #define AV_LOG_FATAL     8

   106 

   107 /**

   108  * Something went wrong and cannot losslessly be recovered.

   109  * However, not all future data is affected.

   110  */

   111 #define AV_LOG_ERROR    16

   112 

   113 /**

   114  * Something somehow does not look correct. This may or may not

   115  * lead to problems. An example would be the use of '-vstrict -2'.

   116  */

   117 #define AV_LOG_WARNING  24

   118 

   119 #define AV_LOG_INFO     32

   120 #define AV_LOG_VERBOSE  40

   121 

   122 /**

   123  * Stuff which is only useful for libav* developers.

   124  */

   125 #define AV_LOG_DEBUG    48

   126 

   127 /**

   128  * Send the specified message to the log if the level is less than or equal

   129  * to the current av_log_level. By default, all logging messages are sent to

   130  * stderr. This behavior can be altered by setting a different av_vlog callback

   131  * function.

   132  *

   133  * @param avcl A pointer to an arbitrary struct of which the first field is a

   134  * pointer to an AVClass struct.

   135  * @param level The importance level of the message, lower values signifying

   136  * higher importance.

   137  * @param fmt The format string (printf-compatible) that specifies how

   138  * subsequent arguments are converted to output.

   139  * @see av_vlog

   140  */

   141 void av_log(void *avcl, int level, const char *fmt, ...) av_printf_format(3, 4);

   142 

   143 void av_vlog(void *avcl, int level, const char *fmt, va_list);

   144 int av_log_get_level(void);

   145 void av_log_set_level(int);

   146 void av_log_set_callback(void (*)(void*, int, const char*, va_list));

   147 void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl);

   148 const char* av_default_item_name(void* ctx);

   149 

   150 /**

   151  * av_dlog macros

   152  * Useful to print debug messages that shouldn't get compiled in normally.

   153  */

   154 

   155 #ifdef DEBUG

   156 #    define av_dlog(pctx, ...) av_log(pctx, AV_LOG_DEBUG, __VA_ARGS__)

   157 #else

   158 #    define av_dlog(pctx, ...)

   159 #endif

   160 

   161 /**

   162  * Skip repeated messages, this requires the user app to use av_log() instead of

   163  * (f)printf as the 2 would otherwise interfere and lead to

   164  * "Last message repeated x times" messages below (f)printf messages with some

   165  * bad luck.

   166  * Also to receive the last, "last repeated" line if any, the user app must

   167  * call av_log(NULL, AV_LOG_QUIET, ""); at the end

   168  */

   169 #define AV_LOG_SKIP_REPEATED 1

   170 void av_log_set_flags(int arg);

   171 

   172 #endif /* AVUTIL_LOG_H */