+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Implements support for *GoPro* colorspaces conversions and transfer functions.
+"""
+
+from __future__ import division
+
+import array
+import os
+
+import PyOpenColorIO as ocio
+
+import aces_ocio.generate_lut as genlut
+from aces_ocio.utilities import (ColorSpace, sanitize)
+
+__author__ = 'ACES Developers'
+__copyright__ = 'Copyright (C) 2014 - 2015 - ACES Developers'
+__license__ = ''
+__maintainer__ = 'ACES Developers'
+__email__ = 'aces@oscars.org'
+__status__ = 'Production'
+
+__all__ = ['create_protune',
+ 'create_colorspaces']
+
+
+def create_protune(gamut,
+ transfer_function,
+ name,
+ lut_directory,
+ lut_resolution_1d,
+ aliases):
+ """
+ Object description.
+
+ Protune to ACES.
+
+ Parameters
+ ----------
+ parameter : type
+ Parameter description.
+
+ Returns
+ -------
+ type
+ Return value description.
+ """
+
+ name = '%s - %s' % (transfer_function, gamut)
+ if transfer_function == '':
+ name = 'Linear - %s' % gamut
+ if gamut == '':
+ name = '%s' % transfer_function
+
+ cs = ColorSpace(name)
+ cs.description = name
+ cs.aliases = aliases
+ cs.equality_group = ''
+ cs.family = 'GoPro'
+ cs.is_data = False
+
+ # A linear space needs allocation variables
+ if transfer_function == '':
+ cs.allocation_type = ocio.Constants.ALLOCATION_LG2
+ cs.allocation_vars = [-8, 5, 0.00390625]
+
+ def protune_to_linear(normalized_code_value):
+ c1 = 113.0
+ c2 = 1.0
+ c3 = 112.0
+ linear = ((pow(c1, (normalized_code_value)) - c2) / c3)
+
+ return linear
+
+ cs.to_reference_transforms = []
+
+ if transfer_function == 'Protune Flat':
+ data = array.array('f', '\0' * lut_resolution_1d * 4)
+ for c in range(lut_resolution_1d):
+ data[c] = protune_to_linear(float(c) / (lut_resolution_1d - 1))
+
+ lut = '%s_to_linear.spi1d' % transfer_function
+ lut = sanitize(lut)
+ genlut.write_SPI_1d(
+ os.path.join(lut_directory, lut),
+ 0,
+ 1,
+ data,
+ lut_resolution_1d,
+ 1)
+
+ cs.to_reference_transforms.append({
+ 'type': 'lutFile',
+ 'path': lut,
+ 'interpolation': 'linear',
+ 'direction': 'forward'})
+
+ if gamut == 'Protune Gamut':
+ cs.to_reference_transforms.append({
+ 'type': 'matrix',
+ 'matrix': [ 0.533448429, 0.32413911, 0.142412421, 0,
+ -0.050729924, 1.07572006, -0.024990416, 0,
+ 0.071419661, -0.290521962, 1.219102381, 0,
+ 0, 0, 0, 1],
+ 'direction': 'forward'})
+
+ cs.from_reference_transforms = []
+ return cs
+
+
+def create_colorspaces(lut_directory, lut_resolution_1d):
+ """
+ Generates the colorspace conversions.
+
+ Parameters
+ ----------
+ parameter : type
+ Parameter description.
+
+ Returns
+ -------
+ type
+ Return value description.
+ """
+
+ colorspaces = []
+
+ # Full conversion
+ protune_1 = create_protune(
+ 'Protune Native',
+ 'Protune Flat',
+ 'Protune',
+ lut_directory,
+ lut_resolution_1d,
+ ["protuneflat_protunegamut"])
+ colorspaces.append(protune_1)
+
+ # Linearization Only
+ protune_2 = create_protune(
+ '',
+ 'Protune Flat',
+ 'Protune',
+ lut_directory,
+ lut_resolution_1d,
+ ["crv_protuneflat"])
+ colorspaces.append(protune_2)
+
+ # Primaries Only
+ protune_3 = create_protune(
+ 'Protune Native',
+ '',
+ 'Protune',
+ lut_directory,
+ lut_resolution_1d,
+ ["lin_protunegamut"])
+ colorspaces.append(protune_3)
+
+ return colorspaces