Slice byte-stream into bit pieces

Question

I receive byte data from a RS-232 device with Serial.read();. Now I need to slice this down in bit-pieces:

• value1: 15bits
• value2: 7bits
• value3: 9bits
• value4: 12bits
• and so on

Data from the stream (switch them around for better understanding):

• Byte 1: 00101100 => 00110100 (least significant byte first)
• Byte 2: 10011011 => 11011001
• Byte 3: 00110011 => 11001100
• Byte 4: 11101000 => 00010111
• Byte 5: 01001100 => 00110010
• Byte 6: 01100111 => 11100110

Now the least significant is first.

• value1: 00110100.1101100[1] => 6956
  Need to cut of the last bit of the second byte
• value2: 1.110011[00] => 103
  Add the last bit of the second byte and cut off the last two bits of the third byte
• value3: 00.0001011[1] => 416
  Add the last two bits of the third byte and cut off the last bit of the fourth byte
• value4: 1.00110010.111[00110] => 3737
  Add the last bit of the fourth byte and cut off the last 5 bits of the fifth byte

Now the question: How do I realize this from programming side. I'm lost.

Answer 1

Note: This is an answer that OP originally edited into his question.

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I gather the data into an array of bytes data[125].

Then I gather the relevant bytes per value and stack them together:

long var = (data[4]<<8) + (data[3]);

I shift them so the relevant bytes start first

var=var>>3;

Afterwards I mask them with the RIGHT mask

var=var & 0xFF;

For the example in my question:

long var = (data[1]<<8) + (data[0]); // I need two bytes  
var=var>>1; // shift them to the right one bit  
var=var & 0x7FFF; // mask it with "0111 1111 1111 1111"