(*
* AVDictionary
* copyright (c) 2011 Karl-Michael Schindler <karl-michael.schindler@web.de>
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* This is a part of the Pascal port of ffmpeg.
*
* Conversion of libavutil/dict.h
* avutil version 51.34.101
*
*)
unit dict;
{$IFDEF FPC}
{$MODE DELPHI}
{$PACKENUM 4} (* use 4-byte enums *)
{$PACKRECORDS C} (* C/C++-compatible record packing *)
{$ELSE}
{$MINENUMSIZE 4} (* use 4-byte enums *)
{$ENDIF}
interface
uses
ctypes,
UConfig;
(**
* @file
* Public dictionary API.
* @deprecated
* AVDictionary is provided for compatibility with libav. It is both in
* implementation as well as API inefficient. It does not scale and is
* extremely slow with large dictionaries.
* It is recommended that new code uses our tree container from tree.c/h
* where applicable, which uses AVL trees to achieve O(log n) performance.
*)
(**
* @addtogroup lavu_dict AVDictionary
* @ingroup lavu_data
*
* @brief Simple key:value store
*
* @{
* Dictionaries are used for storing key:value pairs. To create
* an AVDictionary, simply pass an address of a NULL pointer to
* av_dict_set(). NULL can be used as an empty dictionary wherever
* a pointer to an AVDictionary is required.
* Use av_dict_get() to retrieve an entry or iterate over all
* entries and finally av_dict_free() to free the dictionary
* and all its contents.
*
* @code
* AVDictionary *d = NULL; // "create" an empty dictionary
* av_dict_set(&d, "foo", "bar", 0); // add an entry
*
* char *k = av_strdup("key"); // if your strings are already allocated,
* char *v = av_strdup("value"); // you can avoid copying them like this
* av_dict_set(&d, k, v, AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
*
* AVDictionaryEntry *t = NULL;
* while (t = av_dict_get(d, "", t, AV_DICT_IGNORE_SUFFIX)) {
* <....> // iterate over all entries in d
* }
*
* av_dict_free(&d);
* @endcode
*
*)
const
AV_DICT_MATCH_CASE = 1;
AV_DICT_IGNORE_SUFFIX = 2;
AV_DICT_DONT_STRDUP_KEY = 4; (**< Take ownership of a key that's been
allocated with av_malloc() and children. */
AV_DICT_DONT_STRDUP_VAL = 8; (**< Take ownership of a value that's been
allocated with av_malloc() and chilren. */
AV_DICT_DONT_OVERWRITE = 16; ///< Don't overwrite existing entries.
AV_DICT_APPEND = 32; (**< If the entry already exists, append to it. Note that no
delimiter is added, the strings are simply concatenated. *)
type
PAVDictionaryEntry = ^TAVDictionaryEntry;
TAVDictionaryEntry = record
key: PAnsiChar;
value: PAnsiChar;
end;
(* with the "help" of libavutil/internal.h: *)
PAVDictionary = ^TAVDictionary;
TAVDictionary = record
count: cint;
elems: PAVDictionaryEntry;
end;
(**
* Get a dictionary entry with matching key.
*
* @param prev Set to the previous matching element to find the next.
* If set to NULL the first matching element is returned.
* @param flags Allows case as well as suffix-insensitive comparisons.
* @return Found entry or NULL, changing key or value leads to undefined behavior.
*)
function av_dict_get(m: PAVDictionary; {const} key: PAnsiChar; {const} prev: PAVDictionaryEntry; flags: cint): PAVDictionaryEntry;
cdecl; external av__util;
(**
* Set the given entry in *pm, overwriting an existing entry.
*
* @param pm pointer to a pointer to a dictionary struct. If *pm is NULL
* a dictionary struct is allocated and put in *pm.
* @param key entry key to add to *pm (will be av_strduped depending on flags)
* @param value entry value to add to *pm (will be av_strduped depending on flags).
* Passing a NULL value will cause an existing tag to be deleted.
* @return >= 0 on success otherwise an error code <0
*)
function av_dict_set(var pm: PAVDictionary; {const} key: PAnsiChar; {const} value: PAnsiChar; flags: cint): cint;
cdecl; external av__util;
(**
* Copy entries from one AVDictionary struct into another.
* @param dst pointer to a pointer to a AVDictionary struct. If *dst is NULL,
* this function will allocate a struct for you and put it in *dst
* @param src pointer to source AVDictionary struct
* @param flags flags to use when setting entries in *dst
* @note metadata is read using the AV_DICT_IGNORE_SUFFIX flag
*)
procedure av_dict_copy(var dst: PAVDictionary; src: PAVDictionary; flags: cint);
cdecl; external av__util;
(**
* Free all the memory allocated for an AVDictionary struct
* and all keys and values.
*)
procedure av_dict_free(var m: PAVDictionary);
cdecl; external av__util;
(**
* @}
*)
implementation
end.
