text: /*
   * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #ifndef AVUTIL_LOG_H
  #define AVUTIL_LOG_H
  
  #include <stdarg.h>
  #include "avutil.h"
  #include "attributes.h"
  
  typedef enum {
      AV_CLASS_CATEGORY_NA = 0,
      AV_CLASS_CATEGORY_INPUT,
      AV_CLASS_CATEGORY_OUTPUT,
      AV_CLASS_CATEGORY_MUXER,
      AV_CLASS_CATEGORY_DEMUXER,
      AV_CLASS_CATEGORY_ENCODER,
      AV_CLASS_CATEGORY_DECODER,
      AV_CLASS_CATEGORY_FILTER,
      AV_CLASS_CATEGORY_BITSTREAM_FILTER,
      AV_CLASS_CATEGORY_SWSCALER,
      AV_CLASS_CATEGORY_SWRESAMPLER,
      AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT = 40,
      AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
      AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT,
      AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,
      AV_CLASS_CATEGORY_DEVICE_OUTPUT,
      AV_CLASS_CATEGORY_DEVICE_INPUT,
      AV_CLASS_CATEGORY_NB, ///< not part of ABI/API
  }AVClassCategory;
  
  #define AV_IS_INPUT_DEVICE(category) \
      (((category) == AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT) || \
       ((category) == AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT) || \
       ((category) == AV_CLASS_CATEGORY_DEVICE_INPUT))
  
  #define AV_IS_OUTPUT_DEVICE(category) \
      (((category) == AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT) || \
       ((category) == AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT) || \
       ((category) == AV_CLASS_CATEGORY_DEVICE_OUTPUT))
  
  struct AVOptionRanges;
  
  /**
   * Describe the class of an AVClass context structure. That is an
   * arbitrary struct of which the first field is a pointer to an
   * AVClass struct (e.g. AVCodecContext, AVFormatContext etc.).
   */
  typedef struct AVClass {
      /**
       * The name of the class; usually it is the same name as the
       * context structure type to which the AVClass is associated.
       */
      const char* class_name;
  
      /**
       * A pointer to a function which returns the name of a context
       * instance ctx associated with the class.
       */
      const char* (*item_name)(void* ctx);
  
      /**
       * a pointer to the first option specified in the class if any or NULL
       *
       * @see av_set_default_options()
       */
      const struct AVOption *option;
  
      /**
       * LIBAVUTIL_VERSION with which this structure was created.
       * This is used to allow fields to be added without requiring major
  :     * version bumps everywhere.
       */
  
      int version;
  
      /**
       * Offset in the structure where log_level_offset is stored.
       * 0 means there is no such variable
       */
      int log_level_offset_offset;
  
      /**
       * Offset in the structure where a pointer to the parent context for
       * logging is stored. For example a decoder could pass its AVCodecContext
       * to eval as such a parent context, which an av_log() implementation
       * could then leverage to display the parent context.
       * The offset can be NULL.
       */
      int parent_log_context_offset;
  
      /**
       * Return next AVOptions-enabled child or NULL
       */
      void* (*child_next)(void *obj, void *prev);
  
      /**
       * Return an AVClass corresponding to the next potential
       * AVOptions-enabled child.
       *
       * The difference between child_next and this is that
       * child_next iterates over _already existing_ objects, while
       * child_class_next iterates over _all possible_ children.
       */
      const struct AVClass* (*child_class_next)(const struct AVClass *prev);
  
      /**
       * Category used for visualization (like color)
       * This is only set if the category is equal for all objects using this class.
       * available since version (51 << 16 | 56 << 8 | 100)
       */
      AVClassCategory category;
  
      /**
       * Callback to return the category.
       * available since version (51 << 16 | 59 << 8 | 100)
       */
      AVClassCategory (*get_category)(void* ctx);
  
      /**
       * Callback to return the supported/allowed ranges.
       * available since version (52.12)
       */
      int (*query_ranges)(struct AVOptionRanges **, void *obj, const char *key, int flags);
  } AVClass;
  
  /**
   * @addtogroup lavu_log
   *
   * @{
   *
   * @defgroup lavu_log_constants Logging Constants
   *
   * @{
   */
  
  /**
   * Print no output.
   */
  #define AV_LOG_QUIET    -8
  
  /**
   * Something went really wrong and we will crash now.
   */
  #define AV_LOG_PANIC     0
  
  /**
   * Something went wrong and recovery is not possible.
   * For example, no header was found for a format which depends
   * on headers or an illegal combination of parameters is used.
   */
  #define AV_LOG_FATAL     8
  
  /**
   * Something went wrong and cannot losslessly be recovered.
   * However, not all future data is affected.
   */
  #define AV_LOG_ERROR    16
  
  /**
   * Something somehow does not look correct. This may or may not
   * lead to problems. An example would be the use of '-vstrict -2'.
   */
  #define AV_LOG_WARNING  24
  
  /**
   * Standard information.
   */
  #define AV_LOG_INFO     32
  
  /**
   * Detailed information.
   */
  #define AV_LOG_VERBOSE  40
  
  /**
   * Stuff which is only useful for libav* developers.
   */
  #define AV_LOG_DEBUG    48
  
  #define AV_LOG_MAX_OFFSET (AV_LOG_DEBUG - AV_LOG_QUIET)
  
  /**
   * @}
   */
  
  /**
   * Sets additional colors for extended debugging sessions.
   * @code
     av_log(ctx, AV_LOG_DEBUG|AV_LOG_C(134), "Message in purple\n");
     @endcode
   * Requires 256color terminal support. Uses outside debugging is not
   * recommended.
   */
  #define AV_LOG_C(x) ((x) << 8)
  
  /**
   * Send the specified message to the log if the level is less than or equal
   * to the current av_log_level. By default, all logging messages are sent to
   * stderr. This behavior can be altered by setting a different logging callback
   * function.
   * @see av_log_set_callback
   *
   * @param avcl A pointer to an arbitrary struct of which the first field is a
   *        pointer to an AVClass struct.
   * @param level The importance level of the message expressed using a @ref
   *        lavu_log_constants "Logging Constant".
   * @param fmt The format string (printf-compatible) that specifies how
   *        subsequent arguments are converted to output.
   */
  void av_log(void *avcl, int level, const char *fmt, ...) av_printf_format(3, 4);
  
  
  /**
   * Send the specified message to the log if the level is less than or equal
   * to the current av_log_level. By default, all logging messages are sent to
   * stderr. This behavior can be altered by setting a different logging callback
   * function.
   * @see av_log_set_callback
   *
   * @param avcl A pointer to an arbitrary struct of which the first field is a
   *        pointer to an AVClass struct.
   * @param level The importance level of the message expressed using a @ref
   *        lavu_log_constants "Logging Constant".
   * @param fmt The format string (printf-compatible) that specifies how
   *        subsequent arguments are converted to output.
   * @param vl The arguments referenced by the format string.
   */
  void av_vlog(void *avcl, int level, const char *fmt, va_list vl);
  
  /**
   * Get the current log level
   *
   * @see lavu_log_constants
   *
   * @return Current log level
   */
  int av_log_get_level(void);
  
  /**
   * Set the log level
   *
   * @see lavu_log_constants
   *
   * @param level Logging level
   */
  void av_log_set_level(int level);
  
  /**
   * Set the logging callback
   *
   * @note The callback must be thread safe, even if the application does not use
   *       threads itself as some codecs are multithreaded.
   *
   * @see av_log_default_callback
   *
   * @param callback A logging function with a compatible signature.
   */
  void av_log_set_callback(void (*callback)(void*, int, const char*, va_list));
  
  /**
   * Default logging callback
   *
   * It prints the message to stderr, optionally colorizing it.
   *
   * @param avcl A pointer to an arbitrary struct of which the first field is a
   *        pointer to an AVClass struct.
   * @param level The importance level of the message expressed using a @ref
   *        lavu_log_constants "Logging Constant".
   * @param fmt The format string (printf-compatible) that specifies how
   *        subsequent arguments are converted to output.
   * @param vl The arguments referenced by the format string.
   */
  void av_log_default_callback(void *avcl, int level, const char *fmt,
                               va_list vl);
  
  /**
   * Return the context name
   *
   * @param  ctx The AVClass context
   *
   * @return The AVClass class_name
   */
  const char* av_default_item_name(void* ctx);
  AVClassCategory av_default_get_category(void *ptr);
  
  /**
   * Format a line of log the same way as the default callback.
   * @param line          buffer to receive the formated line
   * @param line_size     size of the buffer
   * @param print_prefix  used to store whether the prefix must be printed;
   *                      must point to a persistent integer initially set to 1
   */
  void av_log_format_line(void *ptr, int level, const char *fmt, va_list vl,
                          char *line, int line_size, int *print_prefix);
  
  /**
   * av_dlog macros
   * Useful to print debug messages that shouldn't get compiled in normally.
   */
  
  #ifdef DEBUG
  #    define av_dlog(pctx, ...) av_log(pctx, AV_LOG_DEBUG, __VA_ARGS__)
  #else
  #    define av_dlog(pctx, ...) do { if (0) av_log(pctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
  #endif
  
  /**
   * Skip repeated messages, this requires the user app to use av_log() instead of
   * (f)printf as the 2 would otherwise interfere and lead to
   * "Last message repeated x times" messages below (f)printf messages with some
   * bad luck.
   * Also to receive the last, "last repeated" line if any, the user app must
   * call av_log(NULL, AV_LOG_QUIET, "%s", ""); at the end
   */
  #define AV_LOG_SKIP_REPEATED 1
  
  /**
   * Include the log severity in messages originating from codecs.
   *
   * Results in messages such as:
   * [rawvideo @ 0xDEADBEEF] [error] encode did not produce valid pts
   */
  #define AV_LOG_PRINT_LEVEL 2
  
  void av_log_set_flags(int arg);
  int av_log_get_flags(void);
  
  /**
   * @}
   */
  
  #endif /* AVUTIL_LOG_H */
  