PDFUtils.getNumsFromBytes

All Samples(4) | Call(2) | Derive(0) | Import(2)

Makes the conversion between bytes and numbers, depending on the number of bits used per component.

@param bytes: String representing the bytes to be converted
@param bitsPerComponent: Number of bits needed to represent a component
@return: A tuple (status,statusContent), where statusContent is a list of numbers in case status = 0 or an error in case status = -1

Show Implementation

        def getNumsFromBytes(bytes, bitsPerComponent = 8):
    '''
        Makes the conversion between bytes and numbers, depending on the number of bits used per component.
        
        @param bytes: String representing the bytes to be converted
        @param bitsPerComponent: Number of bits needed to represent a component
        @return: A tuple (status,statusContent), where statusContent is a list of numbers in case status = 0 or an error in case status = -1
    '''
    if not isinstance(bytes,str):
        return (-1,'bytes must be a string')
    if not isinstance(bitsPerComponent,int):
        return (-1,'bitsPerComponent must be an integer')
    outputComponents = []
    bitsStream = ''
    for byte in bytes:
        try:
            bitsRepresentation = bin(ord(byte))
            bitsRepresentation = bitsRepresentation.replace('0b','')
            bitsRepresentation = '0'*(8-len(bitsRepresentation)) + bitsRepresentation
            bitsStream += bitsRepresentation
        except:
            return (-1,'Error in conversion from bytes to bits')
    
    try:
        for i in range(0,len(bitsStream),bitsPerComponent):
            bytes = ''
            bits = bitsStream[i:i+bitsPerComponent]
            num = int(bits,2)
            outputComponents.append(num)
    except:
        return (-1,'Error in conversion from bits to bytes')
    return (0,outputComponents)

src/t/h/thug-HEAD/src/peepdf/PDFFilters.py thug(Download)

 
import sys, zlib, lzw, struct
from PDFUtils import getNumsFromBytes, getBytesFromBits, getBitsFromNum
from ccitt import CCITTFax

		for rowIndex in range(numRows):
			row = decodedStream[rowIndex*bytesPerRow:rowIndex*bytesPerRow+bytesPerRow]
			ret,colorNums = getNumsFromBytes(row, bits)
			if ret == -1:
				return (ret,colorNums)

src/c/l/classyPDF-HEAD/peepdf_classy/PDFFilters.py classyPDF(Download)

 
import sys, zlib, lzw, struct
from PDFUtils import getNumsFromBytes, getBytesFromBits, getBitsFromNum
 
def decodeStream(stream, filter, parameters = {}):

		for rowIndex in range(numRows):
			row = decodedStream[rowIndex*bytesPerRow:rowIndex*bytesPerRow+bytesPerRow]
			ret,colorNums = getNumsFromBytes(row, bits)
			if ret == -1:
				return (ret,colorNums)