codec/h264/h264dec/cavlc.go: added process to comgine level and run information

codec/h264/h264dec/cavlc.go

@@ -127,3 +127,21 @@ func parseLevelInformation(br *bits.BitReader, totalCoeff, trailingOnes int) ([]
 	}
 	return levelVal, nil
 }
+
+// combineLevelRunInfo combines the level and run information obtained prior
+// using the process defined in section 9.2.4 of the specifications and returns
+// the corresponding coeffLevel list.
+func combineLevelRunInfo(levelVal, runVal []int, totalCoeff int) []int {
+	coeffNum := -1
+	i := totalCoeff - 1
+	var coeffLevel []int
+	for j := 0; j < totalCoeff; j++ {
+		coeffNum += runVal[i] + 1
+		if coeffNum >= len(coeffLevel) {
+			coeffLevel = append(coeffLevel, make([]int, (coeffNum+1)-len(coeffLevel))...)
+		}
+		coeffLevel[coeffNum] = levelVal[i]
+		i++
+	}
+	return coeffLevel
+}