gst/gsttaglist.c: Add some more docs, comments and FIXME 0.11s here and there and also fix some typos.

Original commit message from CVS:
* gst/gsttaglist.c:
Add some more docs, comments and FIXME 0.11s here and there
and  also fix some typos.
This commit is contained in:
Tim-Philipp Müller 2006-07-20 16:10:17 +00:00
parent 2544f6279e
commit 95563518f4
2 changed files with 76 additions and 33 deletions

View file

@ -1,3 +1,9 @@
2006-07-20 Tim-Philipp Müller <tim at centricular dot net>
* gst/gsttaglist.c:
Add some more docs, comments and FIXME 0.11s here and there
and also fix some typos.
2006-07-20 Tim-Philipp Müller <tim at centricular dot net>
* gst/gstsegment.h:

View file

@ -44,6 +44,10 @@
#define GST_TAG_IS_VALID(tag) (gst_tag_get_info (tag) != NULL)
/* FIXME 0.11: use GParamSpecs or something similar for tag registrations,
* possibly even gst_tag_register(). Especially value ranges might be
* useful for some tags. */
typedef struct
{
GType type; /* type the data is in */
@ -271,12 +275,29 @@ gst_tag_lookup (GQuark entry)
* @type: the type this data is in
* @nick: human-readable name
* @blurb: a human-readable description about this tag
* @func: function for merging multiple values of this tag
* @func: function for merging multiple values of this tag, or NULL
*
* Registers a new tag type for the use with GStreamer's type system. If a type
* with that name is already registered, that one is used.
* The old registration may have used a different type however. So don't rely
* on your supplied values.
*
* Important: if you do not supply a merge function the implication will be
* that there can only be one single value for this tag in a tag list and
* any additional values will silenty be discarded when being added (unless
* #GST_TAG_MERGE_REPLACE, #GST_TAG_MERGE_REPLACE_ALL, or
* #GST_TAG_MERGE_PREPEND is used as merge mode, in which case the new
* value will replace the old one in the list).
*
* The merge function will be called from gst_tag_list_copy_value() when
* it is required that one or more values for a tag be condensed into
* one single value. This may happen from gst_tag_list_get_string(),
* gst_tag_list_get_int(), gst_tag_list_get_double() etc. What will happen
* exactly in that case depends on how the tag was registered and if a
* merge function was supplied and if so which one.
*
* Two default merge functions are provided: gst_tag_merge_use_first() and
* gst_tag_merge_strings_with_commas().
*/
void
gst_tag_register (const gchar * name, GstTagFlag flag, GType type,
@ -771,7 +792,7 @@ gst_tag_list_add_valist_values (GstTagList * list, GstTagMergeMode mode,
* @list: list to remove tag from
* @tag: tag to remove
*
* Removes the goven tag from the taglist.
* Removes the given tag from the taglist.
*/
void
gst_tag_list_remove_tag (GstTagList * list, const gchar * tag)
@ -825,7 +846,7 @@ gst_tag_list_foreach (const GstTagList * list, GstTagForeachFunc func,
/**
* gst_tag_list_get_value_index:
* @list: a #GStTagList
* @list: a #GstTagList
* @tag: tag to read out
* @index: number of entry to read out
*
@ -901,6 +922,15 @@ gst_tag_list_copy_value (GValue * dest, const GstTagList * list,
return TRUE;
}
/* FIXME 0.11: this whole merge function business is overdesigned, and the
* _get_foo() API is misleading as well - how many application developers will
* expect gst_tag_list_get_string (list, GST_TAG_ARTIST, &val) might return a
* string with multiple comma-separated artists? _get_foo() should just be
* a convenience wrapper around _get_foo_index (list, tag, 0, &val),
* supplemented by a special _tag_list_get_string_merged() function if needed
* (unless someone can actually think of real use cases where the merge
* function is not 'use first' for non-strings and merge for strings) */
/***** evil macros to get all the gst_tag_list_get_*() functions right *****/
#define TAG_MERGE_FUNCS(name,type) \
@ -938,10 +968,14 @@ gst_tag_list_get_ ## name ## _index (const GstTagList *list, \
return TRUE; \
}
/* FIXME 0.11: maybe get rid of _get_char*(), _get_uchar*(), _get_long*(),
* _get_ulong*() and _get_pointer*()? - they are not really useful/common
* enough to warrant convenience accessor functions */
#define COPY_FUNC /**/
/**
* gst_tag_list_get_char:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -953,7 +987,7 @@ gst_tag_list_get_ ## name ## _index (const GstTagList *list, \
*/
/**
* gst_tag_list_get_char_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -967,7 +1001,7 @@ gst_tag_list_get_ ## name ## _index (const GstTagList *list, \
TAG_MERGE_FUNCS (char, gchar)
/**
* gst_tag_list_get_uchar:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -979,7 +1013,7 @@ TAG_MERGE_FUNCS (char, gchar)
*/
/**
* gst_tag_list_get_uchar_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -993,7 +1027,7 @@ TAG_MERGE_FUNCS (char, gchar)
TAG_MERGE_FUNCS (uchar, guchar)
/**
* gst_tag_list_get_boolean:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -1005,7 +1039,7 @@ TAG_MERGE_FUNCS (uchar, guchar)
*/
/**
* gst_tag_list_get_boolean_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -1019,7 +1053,7 @@ TAG_MERGE_FUNCS (uchar, guchar)
TAG_MERGE_FUNCS (boolean, gboolean)
/**
* gst_tag_list_get_int:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -1031,7 +1065,7 @@ TAG_MERGE_FUNCS (boolean, gboolean)
*/
/**
* gst_tag_list_get_int_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -1045,7 +1079,7 @@ TAG_MERGE_FUNCS (boolean, gboolean)
TAG_MERGE_FUNCS (int, gint)
/**
* gst_tag_list_get_uint:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -1057,7 +1091,7 @@ TAG_MERGE_FUNCS (int, gint)
*/
/**
* gst_tag_list_get_uint_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -1071,7 +1105,7 @@ TAG_MERGE_FUNCS (int, gint)
TAG_MERGE_FUNCS (uint, guint)
/**
* gst_tag_list_get_long:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -1083,7 +1117,7 @@ TAG_MERGE_FUNCS (uint, guint)
*/
/**
* gst_tag_list_get_long_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -1097,7 +1131,7 @@ TAG_MERGE_FUNCS (uint, guint)
TAG_MERGE_FUNCS (long, glong)
/**
* gst_tag_list_get_ulong:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -1109,7 +1143,7 @@ TAG_MERGE_FUNCS (long, glong)
*/
/**
* gst_tag_list_get_ulong_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -1123,7 +1157,7 @@ TAG_MERGE_FUNCS (long, glong)
TAG_MERGE_FUNCS (ulong, gulong)
/**
* gst_tag_list_get_int64:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -1135,7 +1169,7 @@ TAG_MERGE_FUNCS (ulong, gulong)
*/
/**
* gst_tag_list_get_int64_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -1149,7 +1183,7 @@ TAG_MERGE_FUNCS (ulong, gulong)
TAG_MERGE_FUNCS (int64, gint64)
/**
* gst_tag_list_get_uint64:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -1161,7 +1195,7 @@ TAG_MERGE_FUNCS (int64, gint64)
*/
/**
* gst_tag_list_get_uint64_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -1175,7 +1209,7 @@ TAG_MERGE_FUNCS (int64, gint64)
TAG_MERGE_FUNCS (uint64, guint64)
/**
* gst_tag_list_get_float:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -1187,7 +1221,7 @@ TAG_MERGE_FUNCS (uint64, guint64)
*/
/**
* gst_tag_list_get_float_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -1201,7 +1235,7 @@ TAG_MERGE_FUNCS (uint64, guint64)
TAG_MERGE_FUNCS (float, gfloat)
/**
* gst_tag_list_get_double:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -1213,7 +1247,7 @@ TAG_MERGE_FUNCS (float, gfloat)
*/
/**
* gst_tag_list_get_double_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -1227,7 +1261,7 @@ TAG_MERGE_FUNCS (float, gfloat)
TAG_MERGE_FUNCS (double, gdouble)
/**
* gst_tag_list_get_pointer:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -1239,7 +1273,7 @@ TAG_MERGE_FUNCS (double, gdouble)
*/
/**
* gst_tag_list_get_pointer_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -1255,12 +1289,15 @@ TAG_MERGE_FUNCS (pointer, gpointer)
#define COPY_FUNC g_strdup
/**
* gst_tag_list_get_string:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
* Copies the contents for the given tag into the value, merging multiple values
* into one if multiple values are associated with the tag.
* Copies the contents for the given tag into the value, possibly merging
* multiple values into one if multiple values are associated with the tag.
*
* Use gst_tag_list_get_string_index (list, tag, 0, value) if you want
* to retrieve the first string associated with this tag unmodified.
*
* The resulting string in @value should be freed by the caller using g_free
* when no longer needed
@ -1270,7 +1307,7 @@ TAG_MERGE_FUNCS (pointer, gpointer)
*/
/**
* gst_tag_list_get_string_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result
@ -1288,7 +1325,7 @@ TAG_MERGE_FUNCS (string, gchar *)
/**
* gst_tag_list_get_date:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @value: location for the result
*
@ -1317,7 +1354,7 @@ gst_tag_list_get_date (const GstTagList * list, const gchar * tag,
/**
* gst_tag_list_get_date_index:
* @list: a #GStTagList to get the tag from
* @list: a #GstTagList to get the tag from
* @tag: tag to read out
* @index: number of entry to read out
* @value: location for the result