Introduce VASurfaceAttribDRMFormatModifiers

This allows users to specify a list of modifiers when allocating a
new surface. The driver will pick a modifier from the list.

Closes: #502

va/va.h

@@ -1582,6 +1582,11 @@ typedef enum {
     /** \brief Surface usage hint, gives the driver a hint of intended usage 
      *  to optimize allocation (e.g. tiling) (int, read/write). */
     VASurfaceAttribUsageHint,
+    /** \brief List of possible DRM format modifiers (pointer, write).
+     *
+     * The value must be a pointer to a VADRMFormatModifierList.
+     */
+    VASurfaceAttribDRMFormatModifiers,
     /** \brief Number of surface attributes. */
     VASurfaceAttribCount
 } VASurfaceAttribType;

va/va_drmcommon.h

@@ -154,5 +154,20 @@ typedef struct _VADRMPRIMESurfaceDescriptor {
     } layers[4];
 } VADRMPRIMESurfaceDescriptor;
 
+/**
+ * \brief List of DRM format modifiers.
+ *
+ * To allocate surfaces with one of the modifiers specified in the array, call
+ * vaCreateSurfaces() with the VASurfaceAttribDRMFormatModifiers attribute set
+ * to point to an array of num_surfaces instances of this structure. The driver
+ * will select the optimal modifier in the list.
+ */
+typedef struct _VADRMFormatModifierList {
+	/** Number of modifiers. */
+	uint32_t num_modifiers;
+	/** Array of modifiers. */
+	uint64_t *modifiers;
+} VADRMFormatModifierList;
+
 
 #endif /* VA_DRM_COMMON_H */