util.go

package rtcp

import "fmt"

// getPadding Returns the padding required to make the length a multiple of 4
func getPadding(len int) int {
	if len%4 == 0 {
		return 0
	}
	return 4 - (len % 4)
}

// appendBit will left-shift and append n bits of val
func appendNBitsToUint16(src, n, val uint16) uint16 {
	return (src << n) | (val & (0xFFFF >> (16 - n)))
}

// appendBit32 will left-shift and append n bits of val
func appendNBitsToUint32(src, n, val uint32) uint32 {
	return (src << n) | (val & (0xFFFFFFFF >> (32 - n)))
}

// getNBit get n bits from 1 byte, begin with a position
func getNBitsFromByte(b byte, begin, n uint16) uint16 {
	endShift := 8 - (begin + n)
	mask := (0xFF >> begin) & uint8(0xFF<<endShift)
	return uint16(b&mask) >> endShift
}

// get24BitFromBytes get 24bits from `[3]byte` slice
func get24BitsFromBytes(b []byte) uint32 {
	return uint32(b[0])<<16 + uint32(b[1])<<8 + uint32(b[2])
}

// dumpBinary dump []byte to string
func dumpBinary(b []byte) string {
	out := ""
	for i, v := range b {
		out += fmt.Sprintf("0b%08b,", v)
		if (i+1)%4 == 0 {
			out += "\n"
		}
	}
	return out
}