mcregion_to_anvil.py

## MCRegion to Anvil converter
##
## to use:
##
## Download http://libredstone.org/libredstone-0.0.0.tar.bz2, run
##     ./configure.sh
## and
##     make
## Make sure you have python and numpy installed. Then download
## this script into ./bindings/, cd into there, and run:
##
##     python mcregion_to_anvil.py path/to/old/ output/
##
## If you'd like, both paths can be the same, in which case level.dat
## is backed up to level.dat_mcr. Also if you'd like, you can `make
## install` libredstone then run this script from anywhere.
##
## It's like Jens' converter, but it produces a usable level.dat for
## (e.g.) Minecraft Overviewer. Also it's not java, which can be nice
## sometimes. Still no biomes though.

import redstone as rs
import numpy
import os.path, os
import sys
import shutil

if len(sys.argv) != 3:
    sys.stderr.write('Usage: {cmd} <src> <dest>\n'.format(cmd=sys.argv[0]))
    sys.exit(1)

_, src, dest = sys.argv
src = os.path.expanduser(src)
dest = os.path.expanduser(dest)

if not os.path.exists(src):
    sys.stderr.write('Usage: {cmd} <src> <dest>\n'.format(cmd=sys.argv[0]))
    sys.exit(1)

# make the destination directory
if not os.path.exists(dest):
    os.mkdir(dest)

#
# convert level.dat
#

if dest == src:
    shutil.copyfile(os.path.join(src, 'level.dat'), os.path.join(src, 'level.dat_mcr'))

dat = rs.NBT.parse_from_file(os.path.join(src, 'level.dat'))
dat['Data']['version'].value = 19133
dat.write_to_file(os.path.join(dest, 'level.dat'))

#
# create and convert region files
#

def old_data_bytes(s):
    dat = numpy.frombuffer(s, dtype=numpy.uint8)
    return dat.reshape((16, 16, 128))
def old_data_nibbles(s):
    dat = numpy.frombuffer(s, dtype=numpy.uint8)
    dat = dat.reshape((16, 16, 64))
    dat_expanded = numpy.empty((16, 16, 128), dtype=numpy.uint8)
    dat_expanded[:,:,::2] = dat & 0x0F
    dat_expanded[:,:,1::2] = (dat & 0xF0) >> 4
    return dat_expanded

def new_data_bytes(a):
    return numpy.swapaxes(a, 0, 2).tostring()
def new_data_nibbles(a):
    a = numpy.swapaxes(a, 0, 2)
    dat = numpy.empty((16, 16, 8), dtype=numpy.uint8)
    dat[:,:,:] = (a[:,:,::2] & 0x0F) | ((a[:,:,1::2] & 0x0F) << 4)
    return dat.tostring()

def convert_chunk(dat):
    # convert height map
    height = map(ord, dat['Level']['HeightMap'].value)
    dat['Level']['HeightMap'] = rs.Tag.new0(rs.TAG_INT_ARRAY)
    dat['Level']['HeightMap'].value = height
    
    # get current data arrays
    blocks = old_data_bytes(dat['Level']['Blocks'].value)
    data = old_data_nibbles(dat['Level']['Data'].value)
    skylight = old_data_nibbles(dat['Level']['SkyLight'].value)
    blocklight = old_data_nibbles(dat['Level']['BlockLight'].value)
    
    # delete current data arrays
    del dat['Level']['Blocks']
    del dat['Level']['Data']
    del dat['Level']['SkyLight']
    del dat['Level']['BlockLight']
    
    # add the Sections tag
    dat['Level']['Sections'] = rs.Tag.new0(rs.TAG_LIST)
    dat['Level']['Sections'].list_set_type(rs.TAG_COMPOUND)
    
    # iterate through all possible sections
    for y in xrange(8):
        sec_blocks = blocks[:,:,16*y:16*y + 16]
        if not sec_blocks.any():
            continue
        sec_data = data[:,:,16*y:16*y + 16]
        sec_skylight = skylight[:,:,16*y:16*y + 16]
        sec_blocklight = blocklight[:,:,16*y:16*y + 16]
        
        section = rs.Tag.new0(rs.TAG_COMPOUND)
        section['Y'] = rs.Tag.new0(rs.TAG_BYTE)
        section['Y'].value = y
        
        section['Blocks'] = rs.Tag.new0(rs.TAG_BYTE_ARRAY)
        section['Data'] = rs.Tag.new0(rs.TAG_BYTE_ARRAY)
        section['SkyLight'] = rs.Tag.new0(rs.TAG_BYTE_ARRAY)
        section['BlockLight'] = rs.Tag.new0(rs.TAG_BYTE_ARRAY)
        
        section['Blocks'].value = new_data_bytes(sec_blocks)
        section['Data'].value = new_data_nibbles(sec_data)
        section['SkyLight'].value = new_data_nibbles(sec_skylight)
        section['BlockLight'].value = new_data_nibbles(sec_blocklight)
        
        dat['Level']['Sections'].list_insert(0, section)
    dat['Level']['Sections'].list_reverse()
    
    return dat

destregiondir = os.path.join(dest, 'region')
if not os.path.exists(destregiondir):
    os.mkdir(destregiondir)
for mcr in os.listdir(os.path.join(src, 'region')):
    try:
        _, rx, rz, _ = mcr.split('.')
        rx = int(rx)
        rz = int(rz)
    except:
        continue
    srcmcr = os.path.join(src, 'region', mcr)
    destmca = os.path.join(dest, 'region', 'r.{x}.{z}.mca'.format(x=rx, z=rz))
    if os.path.exists(destmca):
        os.unlink(destmca)
    reg = rs.Region.open(srcmcr)
    destreg = rs.Region.open(destmca, True)
    print "converting", mcr
    for x in xrange(32):
        for z in xrange(32):
            if not reg.contains_chunk(x, z):
                continue
            dat = rs.NBT.parse_from_region(reg, x, z)
            newdat = convert_chunk(dat)
            newdat.write_to_region(destreg, x, z)
    destreg.flush()

Not working for me. I keep getting:

Traceback (most recent call last):
  File "mcregion_to_anvil.py", line 22, in <module>
    import redstone as rs
  File "/Users/jon/Downloads/libredstone-0.0.0/bindings/redstone.py", line 35, in <module>
    rs = ctypes.CDLL(find_library('redstone'))
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ctypes/__init__.py", line 365, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: dlopen(libredstone.dylib, 6): image not found

I ran python mcregion_to_anvil.py /Users/jon/Downloads/libredstone-0.0.0/bindings/input/target_world /Users/jon/Downloads/libredstone-0.0.0/bindings/output in the bindings folder, and output is where I want the converted file to appear.