rhubarb-lip-sync/src/mouthAnimation.cpp

#include "mouthAnimation.h"
#include "logging.h"
#include <unordered_set>
#include <unordered_map>
#include <boost/algorithm/clamp.hpp>
#include "Viseme.h"

using std::map;
using std::unordered_set;
using std::unordered_map;
using std::vector;
using boost::optional;
using std::chrono::duration_cast;
using boost::algorithm::clamp;

Timeline<Viseme> animate(optional<Phone> phone, centiseconds duration, centiseconds previousPhoneDuration) {
	constexpr Shape A = Shape::A;
	constexpr Shape B = Shape::B;
	constexpr Shape C = Shape::C;
	constexpr Shape D = Shape::D;
	constexpr Shape E = Shape::E;
	constexpr Shape F = Shape::F;
	constexpr Shape G = Shape::G;
	constexpr Shape H = Shape::H;
	constexpr Shape X = Shape::X;

	auto single = [&](Viseme viseme) {
		return Timeline<Viseme>{
			{ 0cs, duration, viseme }
		};
	};

	auto diphtong = [&](Viseme first, Viseme second) {
		centiseconds firstDuration = duration_cast<centiseconds>(duration * 0.6);
		return Timeline<Viseme>{
			{ 0cs, firstDuration, first },
			{ firstDuration, duration, second }
		};
	};

	auto bilabialStop = [&]() {
		centiseconds closedDuration = clamp(previousPhoneDuration / 2, 4cs, 16cs);
		return Timeline<Viseme>{
			{ -closedDuration, 0cs, { A } },
			{ 0cs, duration, {{ B, C, D, E, F }} }
		};
	};

	if (!phone)				return single({ X });

	switch (*phone) {
	case Phone::Unknown:	return single({ B });
	case Phone::AO:			return single({ E });
	case Phone::AA:			return single({ D });
	case Phone::IY:			return single({ B });
	case Phone::UW:			return single({ F });
	case Phone::EH:			return single({ C });
	case Phone::IH:			return single({ B });
	case Phone::UH:			return single({ E });
	case Phone::AH:			return single({ C });
	case Phone::AE:			return single({ D });
	case Phone::EY:			return diphtong({ C }, { B });
	case Phone::AY:			return diphtong({ D }, { B });
	case Phone::OW:			return diphtong({ E }, { F });
	case Phone::AW:			return diphtong({ D }, { F });
	case Phone::OY:			return diphtong({ E }, { B });
	case Phone::ER:			return single({ E });
	case Phone::P:
	case Phone::B:			return bilabialStop();
	case Phone::T:
	case Phone::D:
	case Phone::K:			return single({ { B, B, B, B, F } });
	case Phone::G:			return single({ { B, C, C, E, F } });
	case Phone::CH:
	case Phone::JH:			return single({ { B, B, B, B, F } });
	case Phone::F:
	case Phone::V:			return single({ G });
	case Phone::TH:
	case Phone::DH:
	case Phone::S:
	case Phone::Z:
	case Phone::SH:
	case Phone::ZH:			return single({ { B, B, B, B, F } });
	case Phone::HH:			return single({ { B, C, D, E, F } });
	case Phone::M:			return single({ A });
	case Phone::N:			return single({ { B, C, C, C, F } });
	case Phone::NG:			return single({ { B, C, D, E, F } });
	case Phone::L:			return single({ { H, H, H, E, F } });
	case Phone::R:			return single({ { B, B, B, B, F } });
	case Phone::Y:			return single({ B });
	case Phone::W:			return single({ F });
	default:
		throw std::invalid_argument("Unexpected phone.");
	}
}

ContinuousTimeline<Shape> animate(const BoundedTimeline<Phone> &phones) {
	// Convert phones to continuous timeline so that silences aren't skipped when iterating
	ContinuousTimeline<optional<Phone>> continuousPhones(phones.getRange(), boost::none);
	for (const auto& timedPhone : phones) {
		continuousPhones.set(timedPhone.getTimeRange(), timedPhone.getValue());
	}

	// Create timeline of visemes
	ContinuousTimeline<Viseme> visemes(phones.getRange(), { Shape::X });
	centiseconds previousPhoneDuration = 0cs;
	for (const auto& timedPhone : continuousPhones) {
		// Animate one phone
		optional<Phone> phone = timedPhone.getValue();
		centiseconds duration = timedPhone.getTimeRange().getLength();
		Timeline<Viseme> phoneVisemes = animate(phone, duration, previousPhoneDuration);

		// Result timing is relative to phone. Make absolute.
		phoneVisemes.shift(timedPhone.getStart());

		// Copy to viseme timeline
		for (const auto& timedViseme : phoneVisemes) {
			visemes.set(timedViseme);
		}

		previousPhoneDuration = duration;
	}

	// Create timeline of shapes.
	// Iterate visemes in *reverse* order so we always know what shape will follow.
	ContinuousTimeline<Shape> shapes(phones.getRange(), Shape::X);
	Shape lastShape = Shape::X;
	for (auto it = visemes.rbegin(); it != visemes.rend(); ++it) {
		Viseme viseme = it->getValue();

		// Convert viseme to phone
		Shape shape = viseme.getShape(it->getTimeRange().getLength(), lastShape);

		shapes.set(it->getTimeRange(), shape);
	}

	for (const auto& timedShape : shapes) {
		logging::logTimedEvent("shape", timedShape);
	}

	return shapes;
}