rtp: add SAP parsing

src/modules/module-rtp/sap.h

@@ -0,0 +1,58 @@
+/* PipeWire
+ *
+ * Copyright © 2022 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef PIPEWIRE_SAP_H
+#define PIPEWIRE_SAP_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct sap_header {
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+	unsigned c:1;
+	unsigned e:1;
+	unsigned t:1;
+	unsigned r:1;
+	unsigned a:1;
+	unsigned v:3;
+#elif __BYTE_ORDER == __BIG_ENDIAN
+	unsigned v:3;
+	unsigned a:1;
+	unsigned r:1;
+	unsigned t:1;
+	unsigned e:1;
+	unsigned c:1;
+#else
+#error "Unknown byte order"
+#endif
+	uint8_t auth_len;
+	uint16_t msg_id_hash;
+} __attribute__ ((packed));
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PIPEWIRE_SAP_H */