Module CuedSpeech.whenhand.transition

Class WhenTransitionPredictorRules

Description

Predict hand transition moments with a rule-based system.

It is inspired from the synchronization model in Attina (2005) and the automatic system in (Duchnowski et al. 2000). It is also inspired by (Bratakos et al., 1998): "A critical delay to display the hand cue is +165ms. The max delay is +100ms. A non-significant delay is +33ms.":

Maroula S. Bratakos, Paul Duchnowski and Louis D. Braida Toward the Automatic Generation of Cued Speech Cued Speech Journal VI 1998 p1-37. (c) 1998 National Cued Speech Association, Inc.

The system implements the following rules to estimate [M1;M2]: - Like (Duchnowski et al. 1998), the structure of the key does not matter. - M2 is before A1, like in (Duchnowski et al. 1998) but not that much - The position transition of the first key after a silence (from neutral) is very early before the sound. The 2nd key of a speech segment is also proportionally earlier than the next ones. See predictposgeneric(). - The position transition from the last key of a speech segment to the neutral one (to a long silence), is delayed. See predictposto_neutral(). - They are estimated proportionally to the average duration of observed A1A3 intervals.

Constructor

Instantiate a custom hand transition moment's predictor.

View Source

def __init__(self):
    """Instantiate a custom hand transition moment's predictor.

    """
    super(WhenTransitionPredictorRules, self).__init__()
    self._description = MSG_DESCRIPTION_RULES

Public functions

predict_position

Predict [M1;M2] the moments when the hand is moving.

Parameters

rank: (int) The rank of the key. 0=silence, 1=1st key after a silence, etc.

Returns

(m1: float, m2: float)

View Source

def predict_position(self, rank: int=4, **kwargs) -> tuple:
    """Predict [M1;M2] the moments when the hand is moving.

        :param rank: (int) The rank of the key. 0=silence, 1=1st key after a silence, etc.
        :return: (m1: float, m2: float)

        """
    if rank == 0:
        return self._predict_pos_to_neutral()
    (m1, m2) = self._predict_pos_generic(rank)
    m2 = min(m2, self.a3)
    m1 = min(m1, m2)
    return (m1, m2)

predict_shape

Predict [D1;D2] the moments when fingers are changing.

It is considered but not proved that:

D1 is after M1; and
D2 is before M2;
[D1;D2] is a relative fast change and must occur asap.

SPPAS 4.22, which was evaluated at ALPC 2024, was: - d2a1 = a3a1 * 0.4 - d1a1 = if rank == 1: d1a1 = max(0.500, a3a1 * 1.25) if rank == 2: d1a1 = max(0.250, a3a1) else: d1a1 = a3a1 * 0.7

Parameters

rank: (int) The rank of the key. 0=silence, 1=1st key after a silence, etc.

Returns

(d1: float, d2: float)

View Source

def predict_shape(self, rank: int=3, **kwargs) -> tuple:
    """Predict [D1;D2] the moments when fingers are changing.

        It is considered but not proved that:

        - D1 is after M1; and
        - D2 is before M2;
        - [D1;D2] is a relative fast change and must occur asap.

        SPPAS 4.22, which was evaluated at ALPC 2024, was:
            - d2a1 = a3a1 * 0.4
             - d1a1 =
             if rank == 1: d1a1 = max(0.500, a3a1 * 1.25)
             if rank == 2: d1a1 = max(0.250, a3a1)
             else: d1a1 = a3a1 * 0.7

        :param rank: (int) The rank of the key. 0=silence, 1=1st key after a silence, etc.
        :return: (d1: float, d2: float)

        """
    a3a1 = self.get_a1a3_avg_duration()
    if rank == 0:
        return self._predict_shp_to_neutral()
    elif rank == 1:
        d1a1 = max(0.45, a3a1 * 1.1)
        d2a1 = a3a1 * 0.8
    elif rank == 2:
        d1a1 = max(0.3, a3a1 * 0.95)
        d2a1 = a3a1 * 0.65
    elif rank == 3:
        d1a1 = max(0.2, a3a1 * 0.8)
        d2a1 = a3a1 * 0.5
    else:
        d1a1 = a3a1 * 0.7
        d2a1 = a3a1 * 0.4
    d1 = max(0.0, self.a1 - d1a1)
    d2 = max(d1, self.a1 - d2a1)
    return (d1, d2)

Private functions

_predict_pos_to_neutral

Predict [M1;M2] for a destination key NN.

[A1;A3] is a silence, so the transition is from a previous sounded key (CV, -V or C-) to the neutral one. This transition is delayed compared to the other ones.

Returns

tuple(float, float)

View Source

def _predict_pos_to_neutral(self) -> tuple:
    """Predict [M1;M2] for a destination key NN.

        [A1;A3] is a silence, so the transition is from a previous sounded key
        (CV, -V or C-) to the neutral one. This transition is delayed compared
        to the other ones.

        :return: tuple(float, float)

        """
    a3a1 = self.get_static_duration()
    m1 = self.a1 + a3a1 * 0.2
    m2 = m1 + a3a1 * 0.8
    return (m1, m2)

_predict_pos_generic

Predict [M1;M2] for a destination key CV or C-.

SPPAS 4.22, which was evaluated at ALPC 2024, was: - m2a1 = a3a1 * 0.05 - m1a1 = if rank == 1: m1a1 = max(0.500, a3a1 * 1.25) if rank == 2: m1a1 = max(0.250, a3a1) else: a3a1 * 0.9

m2a1 is a compromise value between the 100ms before a1 of (Duchnowski et al., 2000), and the 10% after a1 of (Attina, 2005).

Parameters

rank: (int) Rank of the key into the speech segment

Returns

tuple(float, float)

View Source

def _predict_pos_generic(self, rank: int=3) -> tuple:
    """Predict [M1;M2] for a destination key CV or C-.

        SPPAS 4.22, which was evaluated at ALPC 2024, was:
            - m2a1 = a3a1 * 0.05
            - m1a1 =
                if rank == 1: m1a1 = max(0.500, a3a1 * 1.25)
                if rank == 2: m1a1 = max(0.250, a3a1)
                else: a3a1 * 0.9

        m2a1 is a compromise value between the 100ms before a1 of (Duchnowski
        et al., 2000), and the 10% after a1 of (Attina, 2005).

        :param rank: (int) Rank of the key into the speech segment
        :return: tuple(float, float)

        """
    a3a1 = self.get_a1a3_avg_duration()
    if rank == 1:
        m1a1 = max(0.5, a3a1 * 1.4)
        m2a1 = min(0.15, a3a1 * 0.2)
    elif rank == 2:
        m1a1 = max(0.35, a3a1 * 1.15)
        m2a1 = min(0.15, a3a1 * 0.15)
    elif rank == 3:
        m1a1 = max(0.25, a3a1)
        m2a1 = min(0.1, a3a1 * 0.1)
    else:
        m1a1 = a3a1 * 0.9
        m2a1 = a3a1 * 0.05
    m1 = max(0.0, self.a1 - m1a1)
    m2 = max(m1, self.a1 - m2a1)
    return (m1, m2)

_predict_shp_to_neutral

Predict [D1;D2] for a destination key NN.

[A1;A3] is a silence, so the transition is from a previous sounded key (CV, -V or C-) to the neutral one.

Returns

tuple(float, float)

View Source

def _predict_shp_to_neutral(self) -> tuple:
    """Predict [D1;D2] for a destination key NN.

        [A1;A3] is a silence, so the transition is from a previous sounded key
        (CV, -V or C-) to the neutral one.

        :return: tuple(float, float)

        """
    a3a1 = self.get_static_duration()
    d1 = self.a1 + a3a1 * 0.3
    d2 = d1 + a3a1 * 0.4
    return (d1, d2)