GstProtectionMeta
#include <gst/gstprotection.h>
GstProtectionMeta * gst_buffer_add_protection_meta (GstBuffer *buffer, GstStructure *info);
GstBuffer *buffer
GstStructure *info
#define gst_buffer_get_protection_meta(b)
const gchar * gst_protection_select_system (const gchar **system_identifiers);
const gchar **system_identifiers
struct GstProtectionMeta { GstMeta meta; GstStructure *info; };
#define GST_PROTECTION_SYSTEM_ID_CAPS_FIELD "protection-system"