code: def decode(self, buffer):
      rle4 = self.args[1]
      data = bytearray()
      x = 0
      while len(data) < self.state.xsize * self.state.ysize:
          pixels = self.fd.read(1)
          byte = self.fd.read(1)
          if not pixels or not byte:
              break
          num_pixels = pixels[0]
          if num_pixels:
              # encoded mode
              if x + num_pixels > self.state.xsize:
                  # Too much data for row
                  num_pixels = max(0, self.state.xsize - x)
              if rle4:
                  first_pixel = o8(byte[0] >> 4)
                  second_pixel = o8(byte[0] & 0x0F)
                  for index in range(num_pixels):
                      if index % 2 == 0:
                          data += first_pixel
                      else:
                          data += second_pixel
              else:
                  data += byte * num_pixels
              x += num_pixels
          else:
              if byte[0] == 0:
                  # end of line
                  while len(data) % self.state.xsize != 0:
                      data += b"\x00"
                  x = 0
              elif byte[0] == 1:
                  # end of bitmap
                  break
              elif byte[0] == 2:
                  # delta
                  bytes_read = self.fd.read(2)
                  if len(bytes_read) < 2:
                      break
                  right, up = self.fd.read(2)
                  data += b"\x00" * (right + up * self.state.xsize)
                  x = len(data) % self.state.xsize
              else:
                  # absolute mode
                  if rle4:
                      # 2 pixels per byte
                      byte_count = byte[0] // 2
                      bytes_read = self.fd.read(byte_count)
                      for byte_read in bytes_read:
                          data += o8(byte_read >> 4)
                          data += o8(byte_read & 0x0F)
                  else:
                      byte_count = byte[0]
                      bytes_read = self.fd.read(byte_count)
                      data += bytes_read
                  if len(bytes_read) < byte_count:
                      break
                  x += byte[0]
  
                  # align to 16-bit word boundary
                  if self.fd.tell() % 2 != 0:
                      self.fd.seek(1, os.SEEK_CUR)
      rawmode = "L" if self.mode == "L" else "P"
      self.set_as_raw(bytes(data), (rawmode, 0, self.args[-1]))
      return -1, 0
  
imports: from __future__ import annotations
  import os
  from .None import Image, ImageFile, ImagePalette
  from ._binary import i16le
  from ._binary import i32le
  from ._binary import o8
  from ._binary import o16le
  from ._binary import o32le
label_desc: Use image node_id 1 for calling the BmpRleDecoder obj's underlying member method code with example usage: obj.decode(buffer) and returns: unknown,  int