Support Metacube metadata blocks, specifically timestamps.

[cubemap] / metacube2.h

diff --git a/metacube2.h b/metacube2.h
index 43de8b7480de172fe621d5865df053cb8ebf1e68..5b6077e8ae4d08d232cd8840f119c7ac5ac41f6b 100644 (file)
--- a/metacube2.h
+++ b/metacube2.h
@@ -14,13 +14,42 @@
 #define METACUBE_FLAGS_HEADER 0x1
 #define METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START 0x2
 
+/*
+ * Metadata packets; should not be counted as data, but rather
+ * parsed (or ignored if you don't understand them).
+ *
+ * Metadata packets start with a uint64_t (network byte order)
+ * that describe the type; the rest is defined by the type.
+ */
+#define METACUBE_FLAGS_METADATA 0x4
+
 struct metacube2_block_header {
        char sync[8];    /* METACUBE2_SYNC */
        uint32_t size;   /* Network byte order. Does not include header. */
        uint16_t flags;  /* Network byte order. METACUBE_FLAGS_*. */
-       uint16_t csum;   /* Network byte order. CRC16 of size and flags. */
+       uint16_t csum;   /* Network byte order. CRC16 of size and flags.
+                            If METACUBE_FLAGS_METADATA is set, inverted
+                            so that older clients will ignore it as broken. */
 };
 
 uint16_t metacube2_compute_crc(const struct metacube2_block_header *hdr);
 
+/*
+ * The only currently defined metadata type. Set by the encoder,
+ * and can be measured for latency purposes (e.g., if the network
+ * can't keep up, the latency will tend to increase.
+ */
+#define METACUBE_METADATA_TYPE_ENCODER_TIMESTAMP 0x1
+
+struct metacube2_timestamp_packet {
+       uint64_t type;  /* METACUBE_METADATA_TYPE_ENCODER_TIMESTAMP, in network byte order. */
+
+       /*
+        * Time since the UTC epoch. Basically a struct timespec.
+        * Both are in network byte order.
+        */
+       uint64_t tv_sec;
+       uint64_t tv_nsec;
+};
+
 #endif  /* !defined(_METACUBE_H) */