1 files changed, 30 insertions, 1 deletions
diff --git a/src/utils.h b/src/utils.h
index c7ddc1e..aa8dc8a 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -2,6 +2,7 @@
 #define UTILS_H_
 
 #include <math.h>
+#include <stdint.h>
 
 #define MIN(a,b) (((a)<(b))?(a):(b))
 #define MAX(a,b) (((a)>(b))?(a):(b))
@@ -10,8 +11,36 @@
 
 #define linear_to_dB(x) (log10(x) * 20)
 
-
+/* Calculate the little string containing a bargraph
+ * 'VU-meter' from the peak value measured
+ */
 const char* level(int channel, int* peak);
 
+/* This defines the on-wire representation of a ZMQ message header.
+ *
+ * The data follows right after this header */
+struct zmq_frame_header_t
+{
+    uint16_t version; // we support version=1 now
+    uint16_t encoder; // see ZMQ_ENCODER_XYZ
+
+    /* length of the 'data' field */
+    uint32_t datasize;
+
+    /* Audio level, peak, linear PCM */
+    int16_t audiolevel_left;
+    int16_t audiolevel_right;
+
+    /* Data follows this header */
+} __attribute__ ((packed));
+
+#define ZMQ_ENCODER_FDK 1
+
+/* The expected frame size incl data of the given frame */
+#define ZMQ_FRAME_SIZE(f) (sizeof(zmq_frame_header_t) + f->datasize)
+
+#define ZMQ_FRAME_DATA(f) ( ((uint8_t*)f)+sizeof(zmq_frame_header_t) )
+
+
 #endif