format: improve format parsing

spa/lib/format.c

@@ -0,0 +1,61 @@
+/* Simple Plugin API
+ * Copyright (C) 2016 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * 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.
+ */
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <spa/format-builder.h>
+#include <spa/video/format-utils.h>
+#include <lib/props.h>
+#include <lib/mapper.h>
+
+SpaResult
+spa_format_filter (const SpaFormat  *format,
+                   const SpaFormat  *filter,
+                   SpaPODBuilder    *result)
+{
+  SpaPODFrame f;
+  SpaResult res;
+
+  if (format == NULL || result == NULL)
+    return SPA_RESULT_INVALID_ARGUMENTS;
+
+  if (filter == NULL) {
+    spa_pod_builder_raw_padded (result, format, SPA_POD_SIZE (format));
+    return SPA_RESULT_OK;
+  }
+
+  if (SPA_FORMAT_MEDIA_TYPE (filter) != SPA_FORMAT_MEDIA_TYPE (format) ||
+      SPA_FORMAT_MEDIA_SUBTYPE (filter) != SPA_FORMAT_MEDIA_SUBTYPE (format))
+    return SPA_RESULT_INVALID_MEDIA_TYPE;
+
+  spa_pod_builder_push_format (result, &f, filter->body.obj_body.type,
+                               SPA_FORMAT_MEDIA_TYPE (filter),
+                               SPA_FORMAT_MEDIA_SUBTYPE (filter));
+  res = spa_props_filter (result,
+                          SPA_POD_CONTENTS (SpaFormat, format),
+                          SPA_POD_CONTENTS_SIZE (SpaFormat, format),
+                          SPA_POD_CONTENTS (SpaFormat, filter),
+                          SPA_POD_CONTENTS_SIZE (SpaFormat, filter));
+  spa_pod_builder_pop (result, &f);
+
+  return res;
+}