prop-builder: add helper to make properties and formats

Use this to make a format filter. Use the filter to negotiate
a format automatically.

spa/tests/meson.build

@@ -9,3 +9,8 @@
 #           dependencies : [dl_lib, sdl_dep, pthread_lib],
 #           link_with : spalib,
 #           install : false)
+executable('test-props', 'test-props.c',
+           include_directories : [spa_inc, spa_libinc ],
+           dependencies : [dl_lib, sdl_dep, pthread_lib],
+           link_with : spalib,
+           install : false)

spa/tests/test-props.c

@@ -0,0 +1,59 @@
+/* Spa
+ * Copyright (C) 2017 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 <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <spa/id-map.h>
+#include <spa/log.h>
+#include <spa/node.h>
+#include <spa/loop.h>
+#include <spa/video/format.h>
+#include <lib/debug.h>
+#include <lib/props.h>
+#include <lib/prop-builder.h>
+#include <lib/video-raw.h>
+#include <lib/mapper.h>
+
+int
+main (int argc, char *argv[])
+{
+  SpaPropBuilder b;
+  SpaPropBuilderInfo i[10];
+  SpaPropBuilderRange r[10];
+  SpaFormatVideo *f;
+
+  spa_prop_builder_init (&b, sizeof (SpaFormatVideo), offsetof (SpaFormatVideo, format.props));
+
+  spa_format_video_builder_add (&b, &i[0], SPA_PROP_ID_VIDEO_FORMAT, offsetof (SpaFormatVideo, info.raw));
+  spa_format_video_builder_add_range (&b, &r[0], SPA_VIDEO_FORMAT_I420);
+  spa_format_video_builder_add_range (&b, &r[1], SPA_VIDEO_FORMAT_YV12);
+
+  b.dest = alloca (b.size);
+  f = spa_prop_builder_finish (&b);
+  f->format.media_type = SPA_MEDIA_TYPE_VIDEO;
+  f->format.media_subtype = SPA_MEDIA_SUBTYPE_RAW;
+
+  spa_debug_format (&f->format);
+
+  return 0;
+}