GettingTags

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• Getting Tags
  • The mp4tagpub_t structure
  • mp4tag_duration
  • mp4tag_get_tag_by_name
  • mp4tag_iterate_init
  • mp4tag_iterate

Getting Tags

The mp4tagpub_t structure

typedef struct {
  const char  *tag;
  const char  *data;
  const char  *covername;
  size_t      datalen;
  int         dataidx;
  int         covertype;
  bool        binary;
} mp4tagpub_t;

The mp4tagpub_t structure is filled in by mp4tag_get_tag_by_name
and mp4tag_iterate.

tag : The name of the tag.

data : The value of the tag.

covername : If the tag is 'covr', the cover image name may also be returned. If there is no cover image name, or the tag is not 'covr', covername is NULL.

datalen : The size of the value.

dataidx : The index of the cover image or string array. The first item will have a value of zero.

covertype : The type of the cover image. May be MP4TAG_COVER_JPG
or MP4TAG_COVER_PNG.

binary : If true, the data is in binary format.

---

mp4tag_duration

Returns the duration in milliseconds.

#include <stdint.h>
int64_t mp4tag_duration (libmp4tag_t *libmp4tag)

libmp4tag : The libmp4tag_t structure returned from mp4tag_open.

Returns: duration in milliseconds or 0.

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mp4tag_get_tag_by_name

int mp4tag_get_tag_by_name (libmp4tag_t *libmp4tag, const char *tag, mp4tagpub_t *mp4tagpub)

libmp4tag : The libmp4tag_t structure returned from mp4tag_open.

tag : The name of the tag to retrieve.

mp4tagpub : A pointer to a mp4tagpub_t structure to fill in.

Returns: MP4TAG_OK or other error code.

---

mp4tag_iterate_init

int mp4tag_iterate_init (libmp4tag_t *libmp4tag)

libmp4tag : The libmp4tag_t structure returned from mp4tag_open.

Returns: MP4TAG_OK or other error code.

---

mp4tag_iterate

int mp4tag_iterate (libmp4tag_t *libmp4tag, mp4tagpub_t *mp4tagpub)

libmp4tag : The libmp4tag_t structure returned from mp4tag_open.

mp4tagpub : A pointer to a mp4tagpub_t structure to fill in.

Returns: MP4TAG_OK, MP4TAG_FINISH or other error code.