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 */
33typedef 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 */
141void av_log(void *avcl, int level, const char *fmt, ...) av_printf_format(3, 4);
142
143void av_vlog(void *avcl, int level, const char *fmt, va_list);
144int av_log_get_level(void);
145void av_log_set_level(int);
146void av_log_set_callback(void (*)(void*, int, const char*, va_list));
147void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl);
148const 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
170void av_log_set_flags(int arg);
171
172#endif /* AVUTIL_LOG_H */
173