mem: remove memory stuff

Remove the memory stuff from the spa API, we can do thing more simple
and efficiently if we always allocate buffers outside of the plugins and
only implement an alloc function on the node when it can do something
clever.
Move serialize code to the props/format/buffer code
Make it possible to copy a format and properties.

spa/lib/format.c

@@ -23,15 +23,8 @@
 #include <string.h>
 
 #include <spa/format.h>
+#include <spa/debug.h>
 
-SpaResult
-spa_format_to_string (const SpaFormat *format, char **result)
-{
-  if (format == NULL || result == NULL)
-    return SPA_RESULT_INVALID_ARGUMENTS;
-
-  return SPA_RESULT_OK;
-}
 
 SpaResult
 spa_format_fixate (SpaFormat *format)
@@ -43,3 +36,52 @@ spa_format_fixate (SpaFormat *format)
 
   return SPA_RESULT_OK;
 }
+
+size_t
+spa_format_get_size (const SpaFormat *format)
+{
+  if (format == NULL)
+    return 0;
+
+  return spa_props_get_size (&format->props) - sizeof (SpaProps) + sizeof (SpaFormat);
+}
+
+size_t
+spa_format_serialize (void *dest, const SpaFormat *format)
+{
+  SpaFormat *tf;
+  size_t size;
+
+  if (format == NULL)
+    return 0;
+
+  tf = dest;
+  tf->media_type = format->media_type;
+  tf->media_subtype = format->media_subtype;
+
+  dest = SPA_MEMBER (tf, offsetof (SpaFormat, props), void);
+  size = spa_props_serialize (dest, &format->props) - sizeof (SpaProps) + sizeof (SpaFormat);
+
+  return size;
+}
+
+SpaFormat *
+spa_format_deserialize (void *src, off_t offset)
+{
+  SpaFormat *f;
+
+  f = SPA_MEMBER (src, offset, SpaFormat);
+  spa_props_deserialize (f, offsetof (SpaFormat, props));
+
+  return f;
+}
+
+SpaFormat *
+spa_format_copy_into (void *dest, const SpaFormat *format)
+{
+  if (format == NULL)
+    return NULL;
+
+  spa_format_serialize (dest, format);
+  return spa_format_deserialize (dest, 0);
+}