gstreamer/gst/gstcapsfeatures.c

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/* GStreamer
* Copyright (C) 2013 Collabora Ltd.
* Author: Sebastian Dröge <sebastian.droege@collabora.co.uk>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstcapsfeatures
* @short_description: A set of features in caps
* @see_also: #GstCaps
*
* #GstCapsFeatures can optionally be set on a #GstCaps to add requirements
* for additional features for a specific #GstStructure. Caps structures with
* the same name but with a non-equal set of caps features are not compatible.
* If a pad supports multiple sets of features it has to add multiple equal
* structures with different feature sets to the caps.
*
* Empty #GstCapsFeatures are equivalent with the #GstCapsFeatures that only
* contain #GST_CAPS_FEATURE_MEMORY_SYSTEM_MEMORY. ANY #GstCapsFeatures as
* created by gst_caps_features_new_any() are equal to any other #GstCapsFeatures
* and can be used to specify that any #GstCapsFeatures would be supported, e.g.
* for elements that don't touch buffer memory. #GstCaps with ANY #GstCapsFeatures
* are considered non-fixed and during negotiation some #GstCapsFeatures have
* to be selected.
*
* Examples for caps features would be the requirement of a specific #GstMemory
* types or the requirement of having a specific #GstMeta on the buffer. Features
* are given as a string of the format "memory:GstMemoryTypeName" or
* "meta:GstMetaAPIName".
*
* Since: 1.2
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "gst_private.h"
#include "gstcapsfeatures.h"
#include <gst/gst.h>
GST_DEBUG_CATEGORY_STATIC (gst_caps_features_debug);
#define GST_CAT_DEFAULT gst_caps_features_debug
struct _GstCapsFeatures
{
GType type;
gint *parent_refcount;
GArray *array;
gboolean is_any;
};
GType _gst_caps_features_type = 0;
static gint static_caps_features_parent_refcount = G_MAXINT;
GstCapsFeatures *_gst_caps_features_any = NULL;
GstCapsFeatures *_gst_caps_features_memory_system_memory = NULL;
static GQuark _gst_caps_feature_memory_system_memory = 0;
G_DEFINE_BOXED_TYPE (GstCapsFeatures, gst_caps_features,
gst_caps_features_copy, gst_caps_features_free);
#define IS_MUTABLE(features) \
(!features->parent_refcount || \
g_atomic_int_get (features->parent_refcount) == 1)
static void
gst_caps_features_transform_to_string (const GValue * src_value,
GValue * dest_value);
void
_priv_gst_caps_features_initialize (void)
{
GST_DEBUG_CATEGORY_INIT (gst_caps_features_debug, "caps-features", 0,
"GstCapsFeatures debug");
_gst_caps_features_type = gst_caps_features_get_type ();
_gst_caps_feature_memory_system_memory =
g_quark_from_static_string (GST_CAPS_FEATURE_MEMORY_SYSTEM_MEMORY);
g_value_register_transform_func (_gst_caps_features_type, G_TYPE_STRING,
gst_caps_features_transform_to_string);
_gst_caps_features_any = gst_caps_features_new_any ();
gst_caps_features_set_parent_refcount (_gst_caps_features_any,
&static_caps_features_parent_refcount);
_gst_caps_features_memory_system_memory =
gst_caps_features_new_id (_gst_caps_feature_memory_system_memory, 0);
gst_caps_features_set_parent_refcount
(_gst_caps_features_memory_system_memory,
&static_caps_features_parent_refcount);
}
gboolean
gst_is_caps_features (gconstpointer obj)
{
const GstCapsFeatures *features = obj;
return (obj != NULL && features->type == _gst_caps_features_type);
}
static gboolean
gst_caps_feature_name_is_valid (const gchar * feature)
{
#ifndef G_DISABLE_CHECKS
while (TRUE) {
if (g_ascii_isalpha (*feature))
feature++;
else if (*feature == ':')
break;
else
return FALSE;
}
if (*feature != ':')
return FALSE;
feature++;
if (*feature == '\0' || !g_ascii_isalpha (*feature))
return FALSE;
while (TRUE) {
if (g_ascii_isalnum (*feature))
feature++;
else if (*feature == '\0')
break;
else
return FALSE;
}
#endif
return TRUE;
}
/**
* gst_caps_features_new_empty:
*
* Creates a new, empty #GstCapsFeatures.
*
* Free-function: gst_caps_features_free
*
* Returns: (transfer full): a new, empty #GstCapsFeatures
*
* Since: 1.2
*/
GstCapsFeatures *
gst_caps_features_new_empty (void)
{
GstCapsFeatures *features;
features = g_slice_new (GstCapsFeatures);
features->type = _gst_caps_features_type;
features->parent_refcount = NULL;
features->array = g_array_new (FALSE, FALSE, sizeof (GQuark));
features->is_any = FALSE;
GST_TRACE ("created caps features %p", features);
return features;
}
/**
* gst_caps_features_new_any:
*
* Creates a new, ANY #GstCapsFeatures. This will be equal
* to any other #GstCapsFeatures but caps with these are
* unfixed.
*
* Free-function: gst_caps_features_free
*
* Returns: (transfer full): a new, ANY #GstCapsFeatures
*
* Since: 1.2
*/
GstCapsFeatures *
gst_caps_features_new_any (void)
{
GstCapsFeatures *features;
features = gst_caps_features_new_empty ();
features->is_any = TRUE;
return features;
}
/**
* gst_caps_features_new:
* @feature1: name of first feature to set
* @...: additional features
*
* Creates a new #GstCapsFeatures with the given features.
* The last argument must be %NULL.
*
* Free-function: gst_caps_features_free
*
* Returns: (transfer full): a new, empty #GstCapsFeatures
*
* Since: 1.2
*/
GstCapsFeatures *
gst_caps_features_new (const gchar * feature1, ...)
{
GstCapsFeatures *features;
va_list varargs;
g_return_val_if_fail (feature1 != NULL, NULL);
va_start (varargs, feature1);
features = gst_caps_features_new_valist (feature1, varargs);
va_end (varargs);
return features;
}
/**
* gst_caps_features_new_valist:
* @feature1: name of first feature to set
* @varargs: variable argument list
*
* Creates a new #GstCapsFeatures with the given features.
*
* Free-function: gst_caps_features_free
*
* Returns: (transfer full): a new, empty #GstCapsFeatures
*
* Since: 1.2
*/
GstCapsFeatures *
gst_caps_features_new_valist (const gchar * feature1, va_list varargs)
{
GstCapsFeatures *features;
g_return_val_if_fail (feature1 != NULL, NULL);
features = gst_caps_features_new_empty ();
while (feature1) {
gst_caps_features_add (features, feature1);
feature1 = va_arg (varargs, const gchar *);
}
return features;
}
/**
* gst_caps_features_new_id:
* @feature1: name of first feature to set
* @...: additional features
*
* Creates a new #GstCapsFeatures with the given features.
* The last argument must be 0.
*
* Free-function: gst_caps_features_free
*
* Returns: (transfer full): a new, empty #GstCapsFeatures
*
* Since: 1.2
*/
GstCapsFeatures *
gst_caps_features_new_id (GQuark feature1, ...)
{
GstCapsFeatures *features;
va_list varargs;
g_return_val_if_fail (feature1 != 0, NULL);
va_start (varargs, feature1);
features = gst_caps_features_new_id_valist (feature1, varargs);
va_end (varargs);
return features;
}
/**
* gst_caps_features_new_id_valist:
* @feature1: name of first feature to set
* @varargs: variable argument list
*
* Creates a new #GstCapsFeatures with the given features.
*
* Free-function: gst_caps_features_free
*
* Returns: (transfer full): a new, empty #GstCapsFeatures
*
* Since: 1.2
*/
GstCapsFeatures *
gst_caps_features_new_id_valist (GQuark feature1, va_list varargs)
{
GstCapsFeatures *features;
g_return_val_if_fail (feature1 != 0, NULL);
features = gst_caps_features_new_empty ();
while (feature1) {
gst_caps_features_add_id (features, feature1);
feature1 = va_arg (varargs, GQuark);
}
return features;
}
/**
* gst_caps_features_set_parent_refcount:
* @features: a #GstCapsFeatures
* @refcount: (in): a pointer to the parent's refcount
*
* Sets the parent_refcount field of #GstCapsFeatures. This field is used to
* determine whether a caps features is mutable or not. This function should only be
* called by code implementing parent objects of #GstCapsFeatures, as described in
* the MT Refcounting section of the design documents.
*
* Returns: %TRUE if the parent refcount could be set.
*
* Since: 1.2
*/
gboolean
gst_caps_features_set_parent_refcount (GstCapsFeatures * features,
gint * refcount)
{
g_return_val_if_fail (features != NULL, FALSE);
/* if we have a parent_refcount already, we can only clear
* if with a NULL refcount */
if (features->parent_refcount) {
if (refcount != NULL) {
g_return_val_if_fail (refcount == NULL, FALSE);
return FALSE;
}
} else {
if (refcount == NULL) {
g_return_val_if_fail (refcount != NULL, FALSE);
return FALSE;
}
}
features->parent_refcount = refcount;
return TRUE;
}
/**
* gst_caps_features_copy:
* @features: a #GstCapsFeatures to duplicate
*
* Duplicates a #GstCapsFeatures and all its values.
*
* Free-function: gst_caps_features_free
*
* Returns: (transfer full): a new #GstCapsFeatures.
*
* Since: 1.2
*/
GstCapsFeatures *
gst_caps_features_copy (const GstCapsFeatures * features)
{
GstCapsFeatures *copy;
guint i, n;
g_return_val_if_fail (features != NULL, NULL);
copy = gst_caps_features_new_empty ();
n = gst_caps_features_get_size (features);
for (i = 0; i < n; i++)
gst_caps_features_add_id (copy, gst_caps_features_get_nth_id (features, i));
copy->is_any = features->is_any;
return copy;
}
/**
* gst_caps_features_free:
* @features: (in) (transfer full): the #GstCapsFeatures to free
*
* Frees a #GstCapsFeatures and all its values. The caps features must not
* have a parent when this function is called.
*
* Since: 1.2
*/
void
gst_caps_features_free (GstCapsFeatures * features)
{
g_return_if_fail (features != NULL);
g_return_if_fail (features->parent_refcount == NULL);
g_array_free (features->array, TRUE);
#ifdef USE_POISONING
memset (features, 0xff, sizeof (GstCapsFeatures));
#endif
GST_TRACE ("free caps features %p", features);
g_slice_free (GstCapsFeatures, features);
}
/**
* gst_caps_features_to_string:
* @features: a #GstCapsFeatures
*
* Converts @features to a human-readable string representation.
*
* For debugging purposes its easier to do something like this:
* |[
* GST_LOG ("features is %" GST_PTR_FORMAT, features);
* ]|
* This prints the features in human readable form.
*
* Free-function: g_free
*
* Returns: (transfer full): a pointer to string allocated by g_malloc().
* g_free() after usage.
*
* Since: 1.2
*/
gchar *
gst_caps_features_to_string (const GstCapsFeatures * features)
{
GString *s;
g_return_val_if_fail (features != NULL, NULL);
s = g_string_sized_new (FEATURES_ESTIMATED_STRING_LEN (features));
priv_gst_caps_features_append_to_gstring (features, s);
return g_string_free (s, FALSE);
}
void
priv_gst_caps_features_append_to_gstring (const GstCapsFeatures * features,
GString * s)
{
guint i, n;
g_return_if_fail (features != NULL);
if (features->array->len == 0 && features->is_any) {
g_string_append (s, "ANY");
return;
}
n = features->array->len;
for (i = 0; i < n; i++) {
GQuark *quark = &g_array_index (features->array, GQuark, i);
g_string_append (s, g_quark_to_string (*quark));
if (i + 1 < n)
g_string_append (s, ", ");
}
}
/**
* gst_caps_features_from_string:
* @features: a string representation of a #GstCapsFeatures.
*
* Creates a #GstCapsFeatures from a string representation.
*
* Free-function: gst_caps_features_free
*
* Returns: (transfer full) (nullable): a new #GstCapsFeatures or
* %NULL when the string could not be parsed. Free with
* gst_caps_features_free() after use.
*
* Since: 1.2
*/
GstCapsFeatures *
gst_caps_features_from_string (const gchar * features)
{
GstCapsFeatures *ret;
gboolean escape = FALSE;
const gchar *features_orig = features;
const gchar *feature;
ret = gst_caps_features_new_empty ();
if (!features || *features == '\0')
return ret;
if (strcmp (features, "ANY") == 0) {
ret->is_any = TRUE;
return ret;
}
/* Skip trailing spaces */
while (*features == ' ')
features++;
feature = features;
while (TRUE) {
gchar c = *features;
if (c == '\\') {
escape = TRUE;
features++;
continue;
} else if ((!escape && c == ',') || c == '\0') {
guint len = features - feature + 1;
gchar *tmp;
gchar *p;
if (len == 1) {
g_warning ("Failed deserialize caps features '%s'", features_orig);
gst_caps_features_free (ret);
return NULL;
}
tmp = g_malloc (len);
memcpy (tmp, feature, len - 1);
tmp[len - 1] = '\0';
p = tmp + len - 1;
while (*p == ' ') {
*p = '\0';
p--;
}
if (strstr (tmp, " ") != NULL || *tmp == '\0') {
g_free (tmp);
g_warning ("Failed deserialize caps features '%s'", features_orig);
gst_caps_features_free (ret);
return NULL;
}
gst_caps_features_add (ret, tmp);
g_free (tmp);
if (c == '\0')
break;
/* Skip to the next value */
features++;
while (*features == ' ')
features++;
feature = features;
} else {
escape = FALSE;
features++;
}
}
return ret;
}
/**
* gst_caps_features_get_size:
* @features: a #GstCapsFeatures.
*
* Returns the number of features in @features.
*
* Returns: The number of features in @features.
*
* Since: 1.2
*/
guint
gst_caps_features_get_size (const GstCapsFeatures * features)
{
g_return_val_if_fail (features != NULL, 0);
return features->array->len;
}
/**
* gst_caps_features_get_nth:
* @features: a #GstCapsFeatures.
* @i: index of the feature
*
* Returns the @i-th feature of @features.
*
* Returns: The @i-th feature of @features.
*
* Since: 1.2
*/
const gchar *
gst_caps_features_get_nth (const GstCapsFeatures * features, guint i)
{
const gchar *feature;
GQuark quark;
g_return_val_if_fail (features != NULL, NULL);
quark = gst_caps_features_get_nth_id (features, i);
if (!quark)
return NULL;
feature = g_quark_to_string (quark);
return feature;
}
/**
* gst_caps_features_get_nth_id:
* @features: a #GstCapsFeatures.
* @i: index of the feature
*
* Returns the @i-th feature of @features.
*
* Returns: The @i-th feature of @features.
*
* Since: 1.2
*/
GQuark
gst_caps_features_get_nth_id (const GstCapsFeatures * features, guint i)
{
GQuark *quark;
g_return_val_if_fail (features != NULL, 0);
g_return_val_if_fail (i < features->array->len, 0);
quark = &g_array_index (features->array, GQuark, i);
return *quark;
}
/**
* gst_caps_features_contains:
* @features: a #GstCapsFeatures.
* @feature: a feature
*
* Check if @features contains @feature.
*
* Returns: %TRUE if @features contains @feature.
*
* Since: 1.2
*/
gboolean
gst_caps_features_contains (const GstCapsFeatures * features,
const gchar * feature)
{
g_return_val_if_fail (features != NULL, FALSE);
g_return_val_if_fail (feature != NULL, FALSE);
return gst_caps_features_contains_id (features,
g_quark_from_string (feature));
}
/**
* gst_caps_features_contains_id:
* @features: a #GstCapsFeatures.
* @feature: a feature
*
* Check if @features contains @feature.
*
* Returns: %TRUE if @features contains @feature.
*
* Since: 1.2
*/
gboolean
gst_caps_features_contains_id (const GstCapsFeatures * features, GQuark feature)
{
guint i, n;
g_return_val_if_fail (features != NULL, FALSE);
g_return_val_if_fail (feature != 0, FALSE);
if (features->is_any)
return TRUE;
n = features->array->len;
if (n == 0)
return feature == _gst_caps_feature_memory_system_memory;
for (i = 0; i < n; i++) {
if (gst_caps_features_get_nth_id (features, i) == feature)
return TRUE;
}
return FALSE;
}
/**
* gst_caps_features_is_equal:
* @features1: a #GstCapsFeatures.
* @features2: a #GstCapsFeatures.
*
* Check if @features1 and @features2 are equal.
*
* Returns: %TRUE if @features1 and @features2 are equal.
*
* Since: 1.2
*/
gboolean
gst_caps_features_is_equal (const GstCapsFeatures * features1,
const GstCapsFeatures * features2)
{
guint i, n;
g_return_val_if_fail (features1 != NULL, FALSE);
g_return_val_if_fail (features2 != NULL, FALSE);
if (features1->is_any || features2->is_any)
return TRUE;
/* Check for the sysmem==empty case */
if (features1->array->len == 0 && features2->array->len == 0)
return TRUE;
if (features1->array->len == 0 && features2->array->len == 1
&& gst_caps_features_contains_id (features2,
_gst_caps_feature_memory_system_memory))
return TRUE;
if (features2->array->len == 0 && features1->array->len == 1
&& gst_caps_features_contains_id (features1,
_gst_caps_feature_memory_system_memory))
return TRUE;
if (features1->array->len != features2->array->len)
return FALSE;
n = features1->array->len;
for (i = 0; i < n; i++)
if (!gst_caps_features_contains_id (features2,
gst_caps_features_get_nth_id (features1, i)))
return FALSE;
return TRUE;
}
/**
* gst_caps_features_is_any:
* @features: a #GstCapsFeatures.
*
* Check if @features is %GST_CAPS_FEATURES_ANY.
*
* Returns: %TRUE if @features is %GST_CAPS_FEATURES_ANY.
*
* Since: 1.2
*/
gboolean
gst_caps_features_is_any (const GstCapsFeatures * features)
{
g_return_val_if_fail (features != NULL, FALSE);
return features->is_any;
}
/**
* gst_caps_features_add:
* @features: a #GstCapsFeatures.
* @feature: a feature.
*
* Adds @feature to @features.
*
* Since: 1.2
*/
void
gst_caps_features_add (GstCapsFeatures * features, const gchar * feature)
{
g_return_if_fail (features != NULL);
g_return_if_fail (IS_MUTABLE (features));
g_return_if_fail (feature != NULL);
g_return_if_fail (!features->is_any);
gst_caps_features_add_id (features, g_quark_from_string (feature));
}
/**
* gst_caps_features_add_id:
* @features: a #GstCapsFeatures.
* @feature: a feature.
*
* Adds @feature to @features.
*
* Since: 1.2
*/
void
gst_caps_features_add_id (GstCapsFeatures * features, GQuark feature)
{
g_return_if_fail (features != NULL);
g_return_if_fail (IS_MUTABLE (features));
g_return_if_fail (feature != 0);
g_return_if_fail (!features->is_any);
if (!gst_caps_feature_name_is_valid (g_quark_to_string (feature))) {
g_warning ("Invalid caps feature name: %s", g_quark_to_string (feature));
return;
}
/* If features is empty it will contain sysmem, however
* we want to add it explicitely if it is tried to be
* added as first features
*/
if (features->array->len > 0
&& gst_caps_features_contains_id (features, feature))
return;
g_array_append_val (features->array, feature);
}
/**
* gst_caps_features_remove:
* @features: a #GstCapsFeatures.
* @feature: a feature.
*
* Removes @feature from @features.
*
* Since: 1.2
*/
void
gst_caps_features_remove (GstCapsFeatures * features, const gchar * feature)
{
g_return_if_fail (features != NULL);
g_return_if_fail (IS_MUTABLE (features));
g_return_if_fail (feature != NULL);
gst_caps_features_remove_id (features, g_quark_from_string (feature));
}
/**
* gst_caps_features_remove_id:
* @features: a #GstCapsFeatures.
* @feature: a feature.
*
* Removes @feature from @features.
*
* Since: 1.2
*/
void
gst_caps_features_remove_id (GstCapsFeatures * features, GQuark feature)
{
guint i, n;
g_return_if_fail (features != NULL);
g_return_if_fail (IS_MUTABLE (features));
g_return_if_fail (feature != 0);
n = features->array->len;
for (i = 0; i < n; i++) {
GQuark quark = gst_caps_features_get_nth_id (features, i);
if (quark == feature) {
g_array_remove_index_fast (features->array, i);
return;
}
}
}
static void
gst_caps_features_transform_to_string (const GValue * src_value,
GValue * dest_value)
{
g_return_if_fail (src_value != NULL);
g_return_if_fail (dest_value != NULL);
dest_value->data[0].v_pointer =
gst_caps_features_to_string (src_value->data[0].v_pointer);
}