GST_MAKE_FOURCC()

#define GST_MAKE_FOURCC(a,b,c,d)        ((guint32)((a)|(b)<<8|(c)<<16|(d)<<24))

Transform four characters into a guint32 fourcc value with host endianness.

1

guint32 fourcc = GST_MAKE_FOURCC ('M', 'J', 'P', 'G');

GST_STR_FOURCC()

#define GST_STR_FOURCC(f)               ((guint32)(((f)[0])|((f)[1]<<8)|((f)[2]<<16)|((f)[3]<<24)))

Transform an input string into a guint32 fourcc value with host endianness. Caller is responsible for ensuring the input string consists of at least four characters.

1

guint32 fourcc = GST_STR_FOURCC ("MJPG");

GST_FOURCC_ARGS()

#define             GST_FOURCC_ARGS(fourcc)

Can be used together with GST_FOURCC_FORMAT to properly output a guint32 fourcc value in a printf()-style text message.

GST_VALUE_HOLDS_INT_RANGE()

#define GST_VALUE_HOLDS_INT_RANGE(x)      ((x) != NULL && G_VALUE_TYPE(x) == _gst_int_range_type)

Checks if the given GValue contains a GST_TYPE_INT_RANGE value.

gst_value_set_int_range ()

void
gst_value_set_int_range (GValue *value,
                         gint start,
                         gint end);

Sets value to the range specified by start and end .

gst_value_get_int_range_min ()

gint
gst_value_get_int_range_min (const GValue *value);

Gets the minimum of the range specified by value .

gst_value_get_int_range_max ()

gint
gst_value_get_int_range_max (const GValue *value);

Gets the maximum of the range specified by value .

gst_value_set_int_range_step ()

void
gst_value_set_int_range_step (GValue *value,
                              gint start,
                              gint end,
                              gint step);

Sets value to the range specified by start , end and step .

gst_value_get_int_range_step ()

gint
gst_value_get_int_range_step (const GValue *value);

Gets the step of the range specified by value .

GST_VALUE_HOLDS_BITMASK()

#define GST_VALUE_HOLDS_BITMASK(x)      ((x) != NULL && G_VALUE_TYPE(x) == _gst_bitmask_type)

Checks if the given GValue contains a GST_TYPE_BITMASK value.

gst_value_set_bitmask ()

void
gst_value_set_bitmask (GValue *value,
                       guint64 bitmask);

Sets value to the bitmask specified by bitmask .

gst_value_get_bitmask ()

guint64
gst_value_get_bitmask (const GValue *value);

Gets the bitmask specified by value .

GST_VALUE_HOLDS_FLAG_SET()

#define GST_VALUE_HOLDS_FLAG_SET(x)     (G_TYPE_CHECK_VALUE_TYPE ((x), GST_TYPE_FLAG_SET))

Checks if the given GValue contains a GST_TYPE_FLAG_SET value.

Since: 1.6

gst_structure_get_flagset ()

gboolean
gst_structure_get_flagset (const GstStructure *structure,
                           const gchar *fieldname,
                           guint *value_flags,
                           guint *value_mask);

Read the GstFlagSet flags and mask out of the structure into the provided pointers.

Since: 1.6

gst_value_get_flagset_flags ()

guint
gst_value_get_flagset_flags (const GValue *value);

Retrieve the flags field of a GstFlagSet value .

Since: 1.6

gst_value_get_flagset_mask ()

guint
gst_value_get_flagset_mask (const GValue *value);

Retrieve the mask field of a GstFlagSet value .

Since: 1.6

gst_value_set_flagset ()

void
gst_value_set_flagset (GValue *value,
                       guint flags,
                       guint mask);

Sets value to the flags and mask values provided in flags and mask . The flags value indicates the values of flags, the mask represents which bits in the flag value have been set, and which are "don't care"

Since: 1.6

GST_VALUE_HOLDS_INT64_RANGE()

#define GST_VALUE_HOLDS_INT64_RANGE(x)    ((x) != NULL && G_VALUE_TYPE(x) == _gst_int64_range_type)

Checks if the given GValue contains a GST_TYPE_INT64_RANGE value.

gst_value_set_int64_range ()

void
gst_value_set_int64_range (GValue *value,
                           gint64 start,
                           gint64 end);

Sets value to the range specified by start and end .

gst_value_get_int64_range_min ()

gint64
gst_value_get_int64_range_min (const GValue *value);

Gets the minimum of the range specified by value .

gst_value_get_int64_range_max ()

gint64
gst_value_get_int64_range_max (const GValue *value);

Gets the maximum of the range specified by value .

gst_value_set_int64_range_step ()

void
gst_value_set_int64_range_step (GValue *value,
                                gint64 start,
                                gint64 end,
                                gint64 step);

Sets value to the range specified by start , end and step .

gst_value_get_int64_range_step ()

gint64
gst_value_get_int64_range_step (const GValue *value);

Gets the step of the range specified by value .

GST_VALUE_HOLDS_DOUBLE_RANGE()

#define GST_VALUE_HOLDS_DOUBLE_RANGE(x)   ((x) != NULL && G_VALUE_TYPE(x) == _gst_double_range_type)

Checks if the given GValue contains a GST_TYPE_DOUBLE_RANGE value.

gst_value_set_double_range ()

void
gst_value_set_double_range (GValue *value,
                            gdouble start,
                            gdouble end);

Sets value to the range specified by start and end .

gst_value_get_double_range_min ()

gdouble
gst_value_get_double_range_min (const GValue *value);

Gets the minimum of the range specified by value .

gst_value_get_double_range_max ()

gdouble
gst_value_get_double_range_max (const GValue *value);

Gets the maximum of the range specified by value .

GST_VALUE_HOLDS_LIST()

#define GST_VALUE_HOLDS_LIST(x)         ((x) != NULL && G_VALUE_TYPE(x) == _gst_value_list_type)

Checks if the given GValue contains a GST_TYPE_LIST value.

GST_VALUE_HOLDS_ARRAY()

#define GST_VALUE_HOLDS_ARRAY(x)        ((x) != NULL && G_VALUE_TYPE(x) == _gst_value_array_type)

Checks if the given GValue contains a GST_TYPE_ARRAY value.

gst_value_list_append_value ()

void
gst_value_list_append_value (GValue *value,
                             const GValue *append_value);

Appends append_value to the GstValueList in value .

gst_value_list_append_and_take_value ()

void
gst_value_list_append_and_take_value (GValue *value,
                                      GValue *append_value);

Appends append_value to the GstValueList in value .

Since: 1.2

gst_value_list_prepend_value ()

void
gst_value_list_prepend_value (GValue *value,
                              const GValue *prepend_value);

Prepends prepend_value to the GstValueList in value .

gst_value_list_concat ()

void
gst_value_list_concat (GValue *dest,
                       const GValue *value1,
                       const GValue *value2);

Concatenates copies of value1 and value2 into a list. Values that are not of type GST_TYPE_LIST are treated as if they were lists of length 1. dest will be initialized to the type GST_TYPE_LIST.

gst_value_list_merge ()

void
gst_value_list_merge (GValue *dest,
                      const GValue *value1,
                      const GValue *value2);

Merges copies of value1 and value2 . Values that are not of type GST_TYPE_LIST are treated as if they were lists of length 1.

The result will be put into dest and will either be a list that will not contain any duplicates, or a non-list type (if value1 and value2 were equal).

gst_value_list_get_size ()

guint
gst_value_list_get_size (const GValue *value);

Gets the number of values contained in value .

gst_value_list_get_value ()

const GValue *
gst_value_list_get_value (const GValue *value,
                          guint index);

Gets the value that is a member of the list contained in value and has the index index .

GST_VALUE_HOLDS_FRACTION()

#define GST_VALUE_HOLDS_FRACTION(x)     ((x) != NULL && G_VALUE_TYPE(x) == _gst_fraction_type)

Checks if the given GValue contains a GST_TYPE_FRACTION value.

gst_value_set_fraction ()

void
gst_value_set_fraction (GValue *value,
                        gint numerator,
                        gint denominator);

Sets value to the fraction specified by numerator over denominator . The fraction gets reduced to the smallest numerator and denominator, and if necessary the sign is moved to the numerator.

gst_value_get_fraction_numerator ()

gint
gst_value_get_fraction_numerator (const GValue *value);

Gets the numerator of the fraction specified by value .

gst_value_get_fraction_denominator ()

gint
gst_value_get_fraction_denominator (const GValue *value);

Gets the denominator of the fraction specified by value .

gst_value_fraction_multiply ()

gboolean
gst_value_fraction_multiply (GValue *product,
                             const GValue *factor1,
                             const GValue *factor2);

Multiplies the two GValue items containing a GST_TYPE_FRACTION and sets product to the product of the two fractions.

gst_value_fraction_subtract ()

gboolean
gst_value_fraction_subtract (GValue *dest,
                             const GValue *minuend,
                             const GValue *subtrahend);

Subtracts the subtrahend from the minuend and sets dest to the result.

GST_VALUE_HOLDS_FRACTION_RANGE()

#define GST_VALUE_HOLDS_FRACTION_RANGE(x) ((x) != NULL && G_VALUE_TYPE(x) == _gst_fraction_range_type)

Checks if the given GValue contains a GST_TYPE_FRACTION_RANGE value.

gst_value_set_fraction_range ()

void
gst_value_set_fraction_range (GValue *value,
                              const GValue *start,
                              const GValue *end);

Sets value to the range specified by start and end .

gst_value_get_fraction_range_min ()

const GValue *
gst_value_get_fraction_range_min (const GValue *value);

Gets the minimum of the range specified by value .

gst_value_get_fraction_range_max ()

const GValue *
gst_value_get_fraction_range_max (const GValue *value);

Gets the maximum of the range specified by value .

gst_value_set_fraction_range_full ()

void
gst_value_set_fraction_range_full (GValue *value,
                                   gint numerator_start,
                                   gint denominator_start,
                                   gint numerator_end,
                                   gint denominator_end);

Sets value to the range specified by numerator_start /denominator_start and numerator_end /denominator_end .

GST_VALUE_HOLDS_DATE_TIME()

#define GST_VALUE_HOLDS_DATE_TIME(x)    ((x) != NULL && G_VALUE_TYPE(x) == _gst_date_time_type)

Checks if the given GValue contains a GST_TYPE_DATE_TIME value.

GST_VALUE_HOLDS_CAPS()

#define GST_VALUE_HOLDS_CAPS(x)         ((x) != NULL && G_VALUE_TYPE(x) == _gst_caps_type)

Checks if the given GValue contains a GST_TYPE_CAPS value.

gst_value_set_caps ()

void
gst_value_set_caps (GValue *value,
                    const GstCaps *caps);

Sets the contents of value to caps . A reference to the provided caps will be taken by the value .

gst_value_get_caps ()

const GstCaps *
gst_value_get_caps (const GValue *value);

Gets the contents of value . The reference count of the returned GstCaps will not be modified, therefore the caller must take one before getting rid of the value .

GST_VALUE_HOLDS_CAPS_FEATURES()

#define GST_VALUE_HOLDS_CAPS_FEATURES(x)        (G_VALUE_HOLDS((x), _gst_caps_features_type))

Checks if the given GValue contains a GST_TYPE_CAPS_FEATURES value.

gst_value_set_caps_features ()

void
gst_value_set_caps_features (GValue *value,
                             const GstCapsFeatures *features);

Sets the contents of value to features .

gst_value_get_caps_features ()

const GstCapsFeatures *
gst_value_get_caps_features (const GValue *value);

Gets the contents of value .

GST_VALUE_HOLDS_STRUCTURE()

#define GST_VALUE_HOLDS_STRUCTURE(x)            (G_VALUE_HOLDS((x), _gst_structure_type))

Checks if the given GValue contains a GST_TYPE_STRUCTURE value.

gst_value_set_structure ()

void
gst_value_set_structure (GValue *value,
                         const GstStructure *structure);

Sets the contents of value to structure .

gst_value_get_structure ()

const GstStructure *
gst_value_get_structure (const GValue *value);

Gets the contents of value .

GST_VALUE_HOLDS_BUFFER()

#define GST_VALUE_HOLDS_BUFFER(x)       ((x) != NULL && G_VALUE_TYPE(x) == _gst_buffer_type)

Checks if the given GValue contains a GST_TYPE_BUFFER value.

gst_value_get_buffer()

#define         gst_value_get_buffer(v)         GST_BUFFER_CAST (g_value_get_boxed(v))

Receives a GstBuffer as the value of v . Does not return a reference to the buffer, so the pointer is only valid for as long as the caller owns a reference to v .

gst_value_set_buffer()

#define         gst_value_set_buffer(v,b)       g_value_set_boxed((v),(b))

Sets b as the value of v . Caller retains reference to buffer.

gst_value_take_buffer()

#define         gst_value_take_buffer(v,b)      g_value_take_boxed(v,(b))

Sets b as the value of v . Caller gives away reference to buffer.

GST_VALUE_HOLDS_SAMPLE()

#define GST_VALUE_HOLDS_SAMPLE(x)       ((x) != NULL && G_VALUE_TYPE(x) == _gst_sample_type)

Checks if the given GValue contains a GST_TYPE_SAMPLE value.

gst_value_get_sample()

#define         gst_value_get_sample(v)         GST_SAMPLE_CAST (g_value_get_boxed(v))

Receives a GstSample as the value of v . Does not return a reference to the sample, so the pointer is only valid for as long as the caller owns a reference to v .

gst_value_set_sample()

#define         gst_value_set_sample(v,b)       g_value_set_boxed((v),(b))

Sets b as the value of v . Caller retains reference to sample.

gst_value_take_sample()

#define         gst_value_take_sample(v,b)      g_value_take_boxed(v,(b))

Sets b as the value of v . Caller gives away reference to sample.

GstValueCompareFunc ()

gint
(*GstValueCompareFunc) (const GValue *value1,
                        const GValue *value2);

Used together with gst_value_compare() to compare GValue items.

GstValueSerializeFunc ()

gchar *
(*GstValueSerializeFunc) (const GValue *value1);

Used by gst_value_serialize() to obtain a non-binary form of the GValue.

Free-function: g_free

GstValueDeserializeFunc ()

gboolean
(*GstValueDeserializeFunc) (GValue *dest,
                            const gchar *s);

Used by gst_value_deserialize() to parse a non-binary form into the GValue.

gst_value_is_fixed ()

gboolean
gst_value_is_fixed (const GValue *value);

Tests if the given GValue, if available in a GstStructure (or any other container) contains a "fixed" (which means: one value) or an "unfixed" (which means: multiple possible values, such as data lists or data ranges) value.

gst_value_register ()

void
gst_value_register (const GstValueTable *table);

Registers functions to perform calculations on GValue items of a given type. Each type can only be added once.

gst_value_init_and_copy ()

void
gst_value_init_and_copy (GValue *dest,
                         const GValue *src);

Initialises the target value to be of the same type as source and then copies the contents from source to target.

gst_value_serialize ()

gchar *
gst_value_serialize (const GValue *value);

tries to transform the given value into a string representation that allows getting back this string later on using gst_value_deserialize().

Free-function: g_free

gst_value_deserialize ()

gboolean
gst_value_deserialize (GValue *dest,
                       const gchar *src);

Tries to deserialize a string into the type specified by the given GValue. If the operation succeeds, TRUE is returned, FALSE otherwise.

gst_value_compare ()

gint
gst_value_compare (const GValue *value1,
                   const GValue *value2);

Compares value1 and value2 . If value1 and value2 cannot be compared, the function returns GST_VALUE_UNORDERED. Otherwise, if value1 is greater than value2 , GST_VALUE_GREATER_THAN is returned. If value1 is less than value2 , GST_VALUE_LESS_THAN is returned. If the values are equal, GST_VALUE_EQUAL is returned.

gst_value_can_compare ()

gboolean
gst_value_can_compare (const GValue *value1,
                       const GValue *value2);

Determines if value1 and value2 can be compared.

gst_value_union ()

gboolean
gst_value_union (GValue *dest,
                 const GValue *value1,
                 const GValue *value2);

Creates a GValue corresponding to the union of value1 and value2 .

gst_value_can_union ()

gboolean
gst_value_can_union (const GValue *value1,
                     const GValue *value2);

Determines if value1 and value2 can be non-trivially unioned. Any two values can be trivially unioned by adding both of them to a GstValueList. However, certain types have the possibility to be unioned in a simpler way. For example, an integer range and an integer can be unioned if the integer is a subset of the integer range. If there is the possibility that two values can be unioned, this function returns TRUE.

gst_value_subtract ()

gboolean
gst_value_subtract (GValue *dest,
                    const GValue *minuend,
                    const GValue *subtrahend);

Subtracts subtrahend from minuend and stores the result in dest . Note that this means subtraction as in sets, not as in mathematics.

gst_value_can_subtract ()

gboolean
gst_value_can_subtract (const GValue *minuend,
                        const GValue *subtrahend);

Checks if it's possible to subtract subtrahend from minuend .

gst_value_intersect ()

gboolean
gst_value_intersect (GValue *dest,
                     const GValue *value1,
                     const GValue *value2);

Calculates the intersection of two values. If the values have a non-empty intersection, the value representing the intersection is placed in dest , unless NULL. If the intersection is non-empty, dest is not modified.

gst_value_can_intersect ()

gboolean
gst_value_can_intersect (const GValue *value1,
                         const GValue *value2);

Determines if intersecting two values will produce a valid result. Two values will produce a valid intersection if they have the same type.

gst_value_is_subset ()

gboolean
gst_value_is_subset (const GValue *value1,
                     const GValue *value2);

Check that value1 is a subset of value2 .

Return: TRUE is value1 is a subset of value2

gst_value_array_append_value ()

void
gst_value_array_append_value (GValue *value,
                              const GValue *append_value);

Appends append_value to the GstValueArray in value .

gst_value_array_append_and_take_value ()

void
gst_value_array_append_and_take_value (GValue *value,
                                       GValue *append_value);

Appends append_value to the GstValueArray in value .

Since: 1.2

gst_value_array_get_size ()

guint
gst_value_array_get_size (const GValue *value);

Gets the number of values contained in value .

gst_value_array_get_value ()

const GValue *
gst_value_array_get_value (const GValue *value,
                           guint index);

Gets the value that is a member of the array contained in value and has the index index .

gst_value_array_prepend_value ()

void
gst_value_array_prepend_value (GValue *value,
                               const GValue *prepend_value);

Prepends prepend_value to the GstValueArray in value .

gst_value_fixate ()

gboolean
gst_value_fixate (GValue *dest,
                  const GValue *src);

Fixate src into a new value dest . For ranges, the first element is taken. For lists and arrays, the first item is fixated and returned. If src is already fixed, this function returns FALSE.

gst_flagset_register ()

GType
gst_flagset_register (GType flags_type);

Create a new sub-class of GST_TYPE_FLAG_SET which will pretty-print the human-readable flags when serializing, for easier debugging.

Since: 1.6

GST_FOURCC_FORMAT

#define GST_FOURCC_FORMAT "c%c%c%c"

Can be used together with GST_FOURCC_ARGS to properly output a guint32 fourcc value in a printf()-style text message.

1

printf ("fourcc: %" GST_FOURCC_FORMAT "\n", GST_FOURCC_ARGS (fcc));

GST_TYPE_INT_RANGE

#define GST_TYPE_INT_RANGE               (_gst_int_range_type)

a GValue type that represents an integer range

GST_TYPE_BITMASK

#define GST_TYPE_BITMASK                 (_gst_bitmask_type)

a GValue type that represents a 64-bit bitmask.

GST_TYPE_FLAG_SET

#define GST_TYPE_FLAG_SET                   (_gst_flagset_type)

a GValue type that represents a 32-bit flag bitfield, with 32-bit mask indicating which of the bits in the field are explicitly set. Useful for negotiation.

Since: 1.6

GST_FLAG_SET_MASK_EXACT

#define GST_FLAG_SET_MASK_EXACT ((guint)(-1))

GST_TYPE_INT64_RANGE

#define GST_TYPE_INT64_RANGE             (_gst_int64_range_type)

a GValue type that represents an gint64 range

GST_TYPE_DOUBLE_RANGE

#define GST_TYPE_DOUBLE_RANGE            (_gst_double_range_type)

a GValue type that represents a floating point range with double precision

GST_TYPE_LIST

#define GST_TYPE_LIST                    (_gst_value_list_type)

a GValue type that represents an unordered list of GValue values. This is used for example to express a list of possible values for a field in a caps structure, like a list of possible sample rates, of which only one will be chosen in the end. This means that all values in the list are meaningful on their own.

GST_TYPE_ARRAY

#define GST_TYPE_ARRAY                   (_gst_value_array_type)

a GValue type that represents an ordered list of GValue values. This is used to express a set of values that is meaningful only in their specific combination and order of values. Each value on its own is not particularly meaningful, only the ordered array in its entirety is meaningful. This is used for example to express channel layouts for multichannel audio where each channel needs to be mapped to a position in the room.

GST_TYPE_FRACTION

#define GST_TYPE_FRACTION                (_gst_fraction_type)

a GValue type that represents a fraction of an integer numerator over an integer denominator

GST_TYPE_FRACTION_RANGE

#define GST_TYPE_FRACTION_RANGE           (_gst_fraction_range_type)

a GValue type that represents a GstFraction range

GST_VALUE_LESS_THAN

#define GST_VALUE_LESS_THAN              (-1)

Indicates that the first value provided to a comparison function (gst_value_compare()) is lesser than the second one.

GST_VALUE_EQUAL

#define GST_VALUE_EQUAL                   0

Indicates that the first value provided to a comparison function (gst_value_compare()) is equal to the second one.

GST_VALUE_GREATER_THAN

#define GST_VALUE_GREATER_THAN            1

Indicates that the first value provided to a comparison function (gst_value_compare()) is greater than the second one.

GST_VALUE_UNORDERED

#define GST_VALUE_UNORDERED               2

Indicates that the comparison function (gst_value_compare()) can not determine a order for the two provided values.

struct GstValueTable

struct GstValueTable {
  GType type;
  GstValueCompareFunc compare;
  GstValueSerializeFunc serialize;
  GstValueDeserializeFunc deserialize;
};

VTable for the GValue type .