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/*
* 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
*/
/**
* @file
* text utilities
*/
#ifndef AVFILTER_TEXTUTILS_H
#define AVFILTER_TEXTUTILS_H
#include "libavutil/bprint.h"
#include "libavutil/eval.h"
#include "libavutil/log.h"
#include "libavutil/parseutils.h"
/**
* Function used to expand a template sequence in the format
* %{FUNCTION_NAME[:PARAMS]}, defined in the TextExpander object.
*/
typedef struct FFExpandTextFunction {
/**
* name of the function
*/
const char *name;
/**
* minimum and maximum number of arguments accepted by the
* function in the PARAMS
*/
unsigned argc_min, argc_max;
/**
* actual function used to perform the expansion
*/
int (*func)(void *ctx, AVBPrint *bp, const char *function_name, unsigned argc, char **args);
} FFExpandTextFunction;
/**
* Text expander context, used to encapsulate the logic to expand a
* given text template.
*
* A backslash character @samp{\} in a text template, followed by any
* character, always expands to the second character.
* Sequences of the form %{FUNCTION_NAME[:PARAMS]} are expanded using a
* function defined in the object. The text between the braces is a
* function name, possibly followed by arguments separated by ':'. If
* the arguments contain special characters or delimiters (':' or
* '}'), they should be escaped.
*/
typedef struct FFExpandTextContext {
/**
* log context to pass to the function, used for logging and for
* accessing the context for the function
*/
void *log_ctx;
/**
* list of functions to use to expand sequences in the format
* FUNCTION_NAME{PARAMS}
*/
FFExpandTextFunction *functions;
/**
* number of functions
*/
unsigned int functions_nb;
} FFExpandTextContext;
/**
* Expand text template.
*
* Expand text template defined in text using the logic defined in a text
* expander object.
*
* @param expand_text text expansion context used to expand the text
* @param text template text to expand
* @param bp BPrint object where the expanded text is written to
* @return negative value corresponding to an AVERROR error code in case of
* errors, a non-negative value otherwise
*/
int ff_expand_text(FFExpandTextContext *expand_text, char *text, AVBPrint *bp);
/**
* Print PTS representation to an AVBPrint object.
*
* @param log_ctx pointer to av_log object
* @param bp AVBPrint object where the PTS textual representation is written to
* @param pts PTS value expressed as a double to represent
* @param delta delta time parsed by av_parse_time(), added to the PTS
* @param fmt string representing the format to use for printing, can be
* "flt" - use a float representation with 6 decimal digits,
* "hms" - use HH:MM:SS.MMM format,
* "hms24hh" - same as "hms" but wraps the hours in 24hh format
* (so that it is expressed in the range 00-23),
* "localtime" or "gmtime" - expand the PTS according to the
* @code{strftime()} function rules, using either the corresponding
* @code{localtime()} or @code{gmtime()} time
* @param strftime_fmt: @code{strftime()} format to use to represent the PTS in
* case the format "localtime" or "gmtime" was selected, if not specified
* defaults to "%Y-%m-%d %H:%M:%S"
* @return negative value corresponding to an AVERROR error code in case of
* errors, a non-negative value otherwise
*/
int ff_print_pts(void *log_ctx, AVBPrint *bp, double pts, const char *delta,
const char *fmt, const char *strftime_fmt);
/**
* Print time representation to an AVBPrint object.
*
* @param log_ctx pointer to av_log object
* @param bp AVBPrint object where the time textual representation is written to
* @param strftime_fmt: strftime() format to use to represent the time in case
* if not specified defaults to "%Y-%m-%d %H:%M:%S". The format string is
* extended to support the %[1-6]N after %S which prints fractions of the
* second with optionally specified number of digits, if not specified
* defaults to 3.
* @param localtime use local time to compute the time if non-zero, otherwise
* use UTC
* @return negative value corresponding to an AVERROR error code in case of
* errors, a non-negative value otherwise
*/
int ff_print_time(void *log_ctx, AVBPrint *bp, const char *strftime_fmt, char localtime);
typedef double (*ff_eval_func2)(void *, double a, double b);
/**
* Evaluate and print expression to an AVBprint object.
* The output is written as a double representation.
*
* This is a wrapper around av_expr_parse_and_eval() and following the
* same rules.
*
* @param log_ctx pointer to av_log object
* @param bp AVBPrint object where the evaluated expression is written to
* @param expr the expression to be evaluated
* @param fun_names names of the ff_eval_func2 functions used to evaluate the expression
* @param fun_values values of the ff_eval_func2 functions used to evaluate the expression
* @param var_names names of the variables used in the expression
* @param var_values values of the variables used in the expression
* @param eval_ctx evaluation context to be passed to some functions
*
* @return negative value corresponding to an AVERROR error code in case of
* errors, a non-negative value otherwise
*/
int ff_print_eval_expr(void *log_ctx, AVBPrint *bp,
const char *expr,
const char * const *fun_names, const ff_eval_func2 *fun_values,
const char * const *var_names, const double *var_values,
void *eval_ctx);
/**
* Evaluate and print expression to an AVBprint object, using the
* specified format.
*
* This is a wrapper around av_expr_parse_and_eval() and following the
* same rules.
*
* The format is specified as a printf format character, optionally
* preceded by the positions numbers for zero-padding.
*
* The following formats are accepted:
* - x: use lowercase hexadecimal representation
* - X: use uppercase hexadecimal representation
* - d: use decimal representation
* - u: use unsigned decimal representation
*
* @param log_ctx pointer to av_log object
* @param bp AVBPrint object where the evaluated expression is written to
* @param expr the expression to be evaluated
* @param fun_names names of the ff_eval_func2 functions used to evaluate the expression
* @param fun_values values of the ff_eval_func2 functions used to evaluate the expression
* @param var_names names of the variables used in the expression
* @param var_values values of the variables used in the expression
* @param eval_ctx evaluation context to be passed to some functions
* @param format a character representing the format, to be chosen in xXdu
* @param positions final size of the value representation with 0-padding
* @return negative value corresponding to an AVERROR error code in case of
* errors, a non-negative value otherwise
*/
int ff_print_formatted_eval_expr(void *log_ctx, AVBPrint *bp,
const char *expr,
const char * const *fun_names, const ff_eval_func2 *fun_values,
const char * const *var_names, const double *var_values,
void *eval_ctx,
const char format, int positions);
/**
* Check if the character is a newline.
*
* @param c character to check
* @return non-negative value in case c is a newline, 0 otherwise
*/
static inline int ff_is_newline(uint32_t c)
{
return c == '\n' || c == '\r' || c == '\f' || c == '\v';
}
/**
* Load text file into the buffer pointed by text.
*
* @param log_ctx pointer to av_log object
* @param textfile filename containing the text to load
* @param text pointer to the text buffer where the loaded text will be
* loaded
* @param text_size pointer to the value to set with the loaded text data,
* including the terminating 0 character
* @return negative value corresponding to an AVERROR error code in case of
* errors, a non-negative value otherwise
*/
int ff_load_textfile(void *log_ctx, const char *textfile,
unsigned char **text, size_t *text_size);
#endif /* AVFILTER_TEXTUTILS__H */
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