Method: SwfUtil::SWFHeader#parse_header

Defined in:
lib/swfheader/swf-header.rb

#parse_header(file) ⇒ Object 



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# File 'lib/swfheader/swf-header.rb', line 10

def parse_header(file)
  @size=read_full_size(file)
  buffer=File.open(file,"rb") do |f|
    f.read
  end
  if !is_swf?(buffer)
    raise RuntimeError.new,"File does not appear to be a swf file",caller
  else
    @signature=buffer[0,3]
  end
  if is_compressed?(buffer[0])
    buffer=SWFDecompressor.new.uncompress(buffer)
    @compression_type=COMPRESSED
  else
    @compression_type=UNCOMPRESSED
  end
  @version=buffer[3]
  @nbits = ((buffer[8]&0xff)>>3)
  pbo = read_packed_bits( buffer, 8, 5, @nbits ) 
  pbo2 = read_packed_bits( buffer, pbo.nextByteIndex,pbo.nextBitIndex, @nbits ) 
  
  pbo3 = read_packed_bits( buffer, pbo2.nextByteIndex,pbo2.nextBitIndex, @nbits ) 
  
  pbo4 = read_packed_bits( buffer, pbo3.nextByteIndex,pbo3.nextBitIndex, @nbits ) 
  @xmax = pbo2.value
  @ymax = pbo4.value 
  
  @width = convert_twips_to_pixels( @xmax ) 
  @height = convert_twips_to_pixels( @ymax ) 
  
  byte_pointer = pbo4.nextByteIndex + 2 
  
  @frame_rate = buffer[byte_pointer]
  byte_pointer+=1
  fc1 = buffer[byte_pointer] & 0xFF
  byte_pointer+=1
  
  fc2 = buffer[byte_pointer] & 0xFF
  byte_pointer+=1
  @frame_count=(fc2<<8)+fc1 

  byte_pointer+=2
  avm_bit = buffer[byte_pointer] & 0x08
  @avm_version = (avm_bit == 0) ? "AVM1" : "AVM2"
  
  buffer=nil
end