Commit 31/07/2025

src/somecodes/Codes.kt

@@ -1,10 +1,35 @@
 package somecodes
 
+@Suppress("unused")
 class Codes {
 
     companion object{
         fun ValidString(s : String?) : Boolean {
             return s != null && s.isNotEmpty() && s.isNotBlank()
         }
+
+        /**
+         * Codec header for Zello audio packet is base64 encoded string from {samplingrate (16 Little Endian), frames_per_packet, frame_size_ms}
+         * @param samplingrate Sampling rate in Hz (e.g., 8000, 16000, 32000, etc.)
+         * @param frames_per_packet Number of frames per packet (usually 1 or 2)
+         * @param frame_size_ms Size of each frame in milliseconds (e.g., 20, 30, 40, etc.)
+         */
+        fun toCodecHeader(samplingrate: Int, frames_per_packet: Byte, frame_size_ms: Byte) : String{
+            val xx = ByteArray(4)
+            xx[0] = (samplingrate and 0xFF).toByte() // Little Endian
+            xx[1] = ((samplingrate shr 8) and 0xFF).toByte()
+            xx[2] = frames_per_packet
+            xx[3] = frame_size_ms
+            return java.util.Base64.getEncoder().encodeToString(xx)
+        }
+
+        fun fromCodecHeader(header: String) : Triple<Int, Byte, Byte>? {
+            val decoded = java.util.Base64.getDecoder().decode(header)
+            if (decoded.size != 4) return null
+            val samplingrate = (decoded[0].toInt() and 0xFF) or ((decoded[1].toInt() and 0xFF) shl 8)
+            val frames_per_packet = decoded[2]
+            val frame_size_ms = decoded[3]
+            return Triple(samplingrate, frames_per_packet, frame_size_ms)
+        }
     }
 }