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AVDictionary
Data Structures

Simple key:value store. More...

Data Structures

struct  AVDictionaryEntry
 

Macros

#define AV_DICT_MATCH_CASE   1
 Only get an entry with exact-case key match.
 
#define AV_DICT_IGNORE_SUFFIX   2
 Return first entry in a dictionary whose first part corresponds to the search key, ignoring the suffix of the found key string.
 
#define AV_DICT_DONT_STRDUP_KEY   4
 Take ownership of a key that's been allocated with av_malloc() or another memory allocation function.
 
#define AV_DICT_DONT_STRDUP_VAL   8
 Take ownership of a value that's been allocated with av_malloc() or another memory allocation function.
 
#define AV_DICT_DONT_OVERWRITE   16
 Don't overwrite existing entries.
 
#define AV_DICT_APPEND   32
 If the entry already exists, append to it.
 

Functions

AVDictionaryEntryav_dict_get (FF_CONST_AVUTIL53 AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
 Get a dictionary entry with matching key.
 
int av_dict_count (const AVDictionary *m)
 Get number of entries in dictionary.
 
int av_dict_set (AVDictionary **pm, const char *key, const char *value, int flags)
 Set the given entry in *pm, overwriting an existing entry.
 
int av_dict_set_int (AVDictionary **pm, const char *key, int64_t value, int flags)
 Convenience wrapper for av_dict_set that converts the value to a string and stores it.
 
int av_dict_parse_string (AVDictionary **pm, const char *str, const char *key_val_sep, const char *pairs_sep, int flags)
 Parse the key/value pairs list and add the parsed entries to a dictionary.
 
void av_dict_copy (AVDictionary **dst, FF_CONST_AVUTIL53 AVDictionary *src, int flags)
 Copy entries from one AVDictionary struct into another.
 
void av_dict_free (AVDictionary **m)
 Free all the memory allocated for an AVDictionary struct and all keys and values.
 

Detailed Description

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.

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
while (t = av_dict_get(d, "", t, AV_DICT_IGNORE_SUFFIX)) {
<....> // iterate over all entries in d
}

Macro Definition Documentation

#define AV_DICT_MATCH_CASE   1

Only get an entry with exact-case key match.

Only relevant in av_dict_get().

Definition at line 71 of file dict.h.

Referenced by av_dict_get(), ff_frame_thread_encoder_init(), ff_riff_write_info(), get_date_tag(), id3_has_changed_values(), mov_parse_stsd_audio(), remove_avoptions(), and riff_has_valid_tags().

#define AV_DICT_IGNORE_SUFFIX   2
#define AV_DICT_DONT_STRDUP_KEY   4

Take ownership of a key that's been allocated with av_malloc() or another memory allocation function.

Definition at line 74 of file dict.h.

Referenced by av_dict_parse_string(), av_dict_set(), decode_text_chunk(), ff_vorbis_comment(), mov_read_custom_2plus(), opt_show_entries(), parse_slave_options(), read_tag(), and read_ttag().

#define AV_DICT_DONT_STRDUP_VAL   8
#define AV_DICT_DONT_OVERWRITE   16

Don't overwrite existing entries.

Definition at line 78 of file dict.h.

Referenced by av_dict_set(), copy_metadata(), new_output_stream(), ogg_write_header(), open_output_file(), opt_target(), read_ttag(), set_encoder_id(), and transcode_init().

#define AV_DICT_APPEND   32

If the entry already exists, append to it.

Note that no delimiter is added, the strings are simply concatenated.

Definition at line 79 of file dict.h.

Referenced by av_dict_set(), ff_vorbis_comment(), new_video_stream(), and nist_read_header().

Function Documentation

AVDictionaryEntry* av_dict_get ( FF_CONST_AVUTIL53 AVDictionary m,
const char *  key,
const AVDictionaryEntry prev,
int  flags 
)

Get a dictionary entry with matching key.

The returned entry key or value must not be changed, or it will cause undefined behavior.

To iterate through all the dictionary entries, you can set the matching key to the null string "" and set the AV_DICT_IGNORE_SUFFIX flag.

Parameters
prevSet to the previous matching element to find the next. If set to NULL the first matching element is returned.
keymatching key
flagsa collection of AV_DICT_* flags controlling how the entry is retrieved
Returns
found entry or NULL in case no matching entry was found in the dictionary

Definition at line 38 of file dict.c.

Referenced by adts_aac_read_header(), asf_write_header1(), asf_write_markers(), assert_avoptions(), av_dict_copy(), av_dict_set(), av_dump_format(), av_opt_set_dict2(), av_packet_pack_dictionary(), avformat_match_stream_specifier(), avi_read_header(), avi_write_header(), bitstream_switching(), caf_write_header(), choose_pix_fmts(), config_output(), config_props(), configure_filtergraph(), dump_attachment(), dump_metadata(), dump_stream_format(), dv_init_mux(), dv_write_header(), export_orphan_timecode(), ff_ape_write_tag(), ff_frame_thread_encoder_init(), ff_id3v2_write_apic(), ff_metadata_conv(), ff_replaygain_export(), ff_riff_write_info(), ff_vorbis_comment(), ff_vorbiscomment_length(), ff_vorbiscomment_write(), ffm_write_header(), filter_codec_opts(), find_compressor(), flac_read_header(), flac_write_header(), flv_read_packet(), flv_write_header(), func_metadata(), get_date_tag(), get_duration(), get_metadata_val(), gxf_write_header(), gxf_write_umf_material_description(), id3_has_changed_values(), id3v1_create_tag(), id3v1_set_string(), id3v2_3_metadata_split_date(), init(), init_dict(), init_input_stream(), init_muxer(), lavfi_read_packet(), libx265_encode_init(), lrc_write_header(), main(), matroska_parse_flac(), mkv_check_tag(), mkv_write_attachments(), mkv_write_chapters(), mkv_write_header(), mkv_write_stereo_mode(), mkv_write_tag(), mkv_write_track(), mov_parse_stsd_audio(), mov_read_header(), mov_write_3gp_udta_tag(), mov_write_chpl_tag(), mov_write_hdlr_tag(), mov_write_header(), mov_write_int8_metadata(), mov_write_raw_metadata_tag(), mov_write_string_metadata(), mov_write_tkhd_tag(), mov_write_tmcd_tag(), mov_write_tmpo_tag(), mov_write_track_metadata(), mov_write_trkn_tag(), mov_write_uuidusmt_tag(), mp3_read_header(), mpc_read_header(), mpegts_write_header(), mpegts_write_pmt(), mxf_write_header(), open_input_file(), open_output_file(), open_slave(), prepare_sdp_description(), put_meta(), read_thread(), remove_avoptions(), riff_has_valid_tags(), rv10_write_header(), sap_write_header(), set_encoder_id(), show_tags(), smjpeg_write_header(), sox_write_header(), stream_component_open(), strip_specifiers(), subsegment_alignment(), write_adaptation_set(), write_chapter(), write_globalinfo(), write_metadata(), write_streaminfo(), write_table_entries_attrib(), write_table_redirector_legacy_attrib(), write_tags(), writer_open(), writer_print_integer(), writer_print_string(), wv_read_header(), and X264_init().

int av_dict_count ( const AVDictionary m)

Get number of entries in dictionary.

Parameters
mdictionary
Returns
number of entries in dictionary

Definition at line 33 of file dict.c.

Referenced by asf_write_header1(), caf_write_header(), dump_metadata(), and ff_vorbiscomment_write().

int av_dict_set ( AVDictionary **  pm,
const char *  key,
const char *  value,
int  flags 
)

Set the given entry in *pm, overwriting an existing entry.

Note: If AV_DICT_DONT_STRDUP_KEY or AV_DICT_DONT_STRDUP_VAL is set, these arguments will be freed on error.

Parameters
pmpointer to a pointer to a dictionary struct. If *pm is NULL a dictionary struct is allocated and put in *pm.
keyentry key to add to *pm (will be av_strduped depending on flags)
valueentry value to add to *pm (will be av_strduped depending on flags). Passing a NULL value will cause an existing entry to be deleted.
Returns
>= 0 on success otherwise an error code <0

Definition at line 68 of file dict.c.

Referenced by add_meta(), add_metadata(), add_metadata_from_renditions(), add_timecode_metadata(), amf_parse_object(), ape_tag_read_field(), asf_read_header(), asf_read_picture(), av_dict_copy(), av_dict_set_int(), av_opt_set_dict2(), av_packet_unpack_dictionary(), avformat_find_stream_info(), avi_metadata_creation_time(), avi_read_nikon(), avi_read_tag(), avpriv_new_chapter(), build_file_streams(), cine_read_header(), config(), config_props(), decode_frame(), decode_info_header(), decode_text_chunk(), dtshd_read_header(), dv_read_timecode(), export_orphan_timecode(), ff_flac_parse_picture(), ff_frame_thread_encoder_init(), ff_id3v2_parse_apic(), ff_metadata_conv(), ff_parse_mpeg2_descriptor(), ff_read_riff_info(), ff_rm_read_mdpr_codecdata(), ff_rtp_chain_mux_open(), ff_sauce_read(), ff_tadd_bytes_metadata(), ff_tadd_doubles_metadata(), ff_tadd_long_metadata(), ff_tadd_rational_metadata(), ff_tadd_shorts_metadata(), ff_tadd_string_metadata(), ff_vorbis_comment(), ff_wms_parse_sdp_a_line(), filter_codec_opts(), filter_frame(), flac_read_header(), flac_write_header(), get_attachment(), get_meta(), get_metadata(), get_string(), get_tag(), icecast_open(), id3v2_3_metadata_split_date(), iff_read_header(), init(), init_filter_graph(), init_input_stream(), init_muxer(), ism_seek(), ism_write_header(), libquvi_read_header(), lrc_read_header(), lrc_write_header(), main(), matroska_convert_tag(), matroska_metadata_creation_time(), matroska_parse_tracks(), matroska_read_header(), merge_date(), modplug_load_metadata(), mov_metadata_creation_time(), mov_metadata_gnre(), mov_metadata_loci(), mov_metadata_raw(), mov_metadata_track_or_disc_number(), mov_parse_stsd_data(), mov_parse_stsd_video(), mov_read_custom_2plus(), mov_read_ftyp(), mov_read_hdlr(), mov_read_header(), mov_read_mdhd(), mov_read_tkhd(), mov_read_udta_string(), mxf_add_timecode_metadata(), mxf_parse_structural_metadata(), new_output_stream(), new_video_stream(), nist_read_header(), nsv_parse_NSVf_header(), ogm_chapter(), open_codec_context(), open_input(), open_input_file(), open_output_file(), open_slave(), opt_bitrate(), opt_default(), opt_profile(), opt_show_entries(), opt_timecode(), output_frame(), parse_chunks(), parse_dsd_prop(), parse_ffconfig(), parse_icy(), parse_key_value_pair(), parse_playlist(), parse_slave_options(), parse_tag(), parse_timecode_in_framenum_format(), prepare_sdp_description(), process_options(), put_flac_codecpriv(), r3d_read_red1(), read_gab2_sub(), read_header(), read_info_chunk(), read_string(), read_tag(), read_ttag(), remove_avoptions(), rm_read_metadata(), rpl_read_header(), rtmp_open(), sap_write_header(), scan_file(), sdt_cb(), select_frame(), set_encoder_id(), set_meta(), smjpeg_read_header(), smvjpeg_decode_init(), sox_read_header(), stream_component_open(), strip_specifiers(), subviewer_read_header(), transcode_init(), try_decode_frame(), update(), update_metadata(), var_read_metadata(), vivo_read_header(), wc3_read_header(), webm_dash_manifest_cues(), and webm_dash_manifest_read_header().

int av_dict_set_int ( AVDictionary **  pm,
const char *  key,
int64_t  value,
int  flags 
)
int av_dict_parse_string ( AVDictionary **  pm,
const char *  str,
const char *  key_val_sep,
const char *  pairs_sep,
int  flags 
)

Parse the key/value pairs list and add the parsed entries to a dictionary.

In case of failure, all the successfully set entries are stored in *pm. You may need to manually free the created dictionary.

Parameters
key_val_sepa 0-terminated list of characters used to separate key from value
pairs_sepa 0-terminated list of characters used to separate two pairs from each other
flagsflags to use when adding to dictionary. AV_DICT_DONT_STRDUP_KEY and AV_DICT_DONT_STRDUP_VAL are ignored since the key/value tokens will always be duplicated.
Returns
0 on success, negative AVERROR code on failure

Definition at line 166 of file dict.c.

Referenced by libx265_encode_init(), writer_open(), and X264_init().

void av_dict_copy ( AVDictionary **  dst,
FF_CONST_AVUTIL53 AVDictionary src,
int  flags 
)

Copy entries from one AVDictionary struct into another.

Parameters
dstpointer to a pointer to a AVDictionary struct. If *dst is NULL, this function will allocate a struct for you and put it in *dst
srcpointer to source AVDictionary struct
flagsflags to use when setting entries in *dst
Note
metadata is read using the AV_DICT_IGNORE_SUFFIX flag

Definition at line 203 of file dict.c.

Referenced by av_frame_copy_props(), av_opt_get_dict_val(), av_opt_set_dict_val(), avcodec_open2(), avformat_open_input(), copy_chapters(), copy_metadata(), ff_frame_thread_encoder_init(), ff_http_do_new_request(), ff_mjpeg_decode_frame(), ff_wms_parse_sdp_a_line(), handle_id3(), hls_mux_init(), http_open(), http_prepare_data(), http_seek(), init_muxer(), mark_section_show_entries(), new_output_stream(), ogg_write_header(), open_audio(), open_input(), open_output_file(), open_slave(), open_video(), opt_default_new(), opt_target(), read_frame_internal(), segment_mux_init(), and webp_decode_frame().

void av_dict_free ( AVDictionary **  m)