analyze_dt_lens.py

#!/usr/bin/env python

import collections
import os
import sqlite3
import struct


LENSFUN_PARAM_NAMES = """
modify_flags
inverse
scale
crop
focal
aperture
distance
target_geom
camera
lens
tca_override
tca_r
tca_b
"""

LensOp = collections.namedtuple('LensOp', LENSFUN_PARAM_NAMES)


LENSFUN_PARAMS_FMT = 'iifffffi%ds%dsiff'

# version 1 comes from ancient times and seems to be forgotten by now
ID_SIZES = {2: 52, 3: 128}


def make_lensfun_struct(size):
    fmt = LENSFUN_PARAMS_FMT % (size, size)
    return struct.Struct(fmt)


LENS_OP_STRUCTS = {
    2: make_lensfun_struct(52),
    3: make_lensfun_struct(128)
}


# A list of bitmask flags used for ordering various image corrections.
LF_MODIFY = {
    'TCA':        0x01,
    'VIGNETTING': 0x02,
    'CCI':        0x04,
    'DISTORTION': 0x08,
    'GEOMETRY':   0x10,
    'SCALE':      0x20
}
#typedef enum dt_iop_lensfun_modflag_t
#{
#  LENSFUN_MODFLAG_NONE = 0,
#  LENSFUN_MODFLAG_ALL = DISTORTION | TCA | VIGNETTING,
#  LENSFUN_MODFLAG_DIST_TCA = DISTORTION | TCA,
#  LENSFUN_MODFLAG_DIST_VIGN = DISTORTION | VIGNETTING,
#  LENSFUN_MODFLAG_TCA_VIGN = TCA | VIGNETTING,
#  LENSFUN_MODFLAG_DIST = DISTORTION,
#  LENSFUN_MODFLAG_TCA = TCA,
#  LENSFUN_MODFLAG_VIGN = VIGNETTING,
#  LENSFUN_MODFLAG_MASK = DISTORTION | TCA | VIGNETTING
#}

LF_NAMES = {v: k for k, v in LF_MODIFY.items()}


def nullstrip(s):
    """Return a string truncated at the first null character."""
    try:
        return s[:s.index('\x00')]
    except ValueError:  # No nulls were found, which is okay.
        return s


def print_op(op):
    print op
    print nullstrip(op.camera)
    print nullstrip(op.lens)
    for k, v in LF_MODIFY.items():
        if op.modify_flags | v:
            print k
    print op.modify_flags & ~(LF_MODIFY['VIGNETTING']|LF_MODIFY['TCA'])


def get_op():
    dburl = os.getenv('HOME') + '/.config/darktable/library.db'
    with sqlite3.connect(dburl) as conn:
        c = conn.cursor()
        c.execute("select module, op_params from history where operation='lens'")
        m, p = c.fetchone()
        s = LENS_OP_STRUCTS[m]
        op = LensOp(*s.unpack(p))
        print_op(op)


if __name__ == '__main__':
    get_op()