diff --git a/audio/Duration.cpp b/audio/Duration.cpp
index a6df014..e69de29 100644
--- a/audio/Duration.cpp
+++ b/audio/Duration.cpp
@@ -1,155 +0,0 @@
-/** @file
- * @author Edouard DUPIN 
- * @copyright 2011, Edouard DUPIN, all right reserved
- * @license APACHE v2.0 (see license file)
- */
-
-
-#include <audio/Time.hpp>
-#include <audio/Duration.hpp>
-#include <audio/debug.hpp>
-
-audio::Duration::Duration(int _val) {
-	m_data = std::chrono::nanoseconds(_val);
-}
-
-audio::Duration::Duration(int64_t _valSec, int64_t _valNano) {
-	m_data = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::seconds(_valSec));
-	m_data += std::chrono::nanoseconds(_valNano);
-}
-
-audio::Duration::Duration(int64_t _val) {
-	m_data = std::chrono::nanoseconds(_val);
-}
-
-audio::Duration::Duration(double _val) {
-	m_data = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::seconds(int64_t(_val)));
-	m_data += std::chrono::nanoseconds(int64_t(((_val - int64_t(_val)) * 1000000000.0)));
-}
-
-audio::Duration::Duration(std::chrono::nanoseconds _val) {
-	m_data = std::chrono::duration_cast<std::chrono::nanoseconds>(_val);
-}
-
-audio::Duration::Duration(std::chrono::microseconds _val) {
-	m_data = std::chrono::duration_cast<std::chrono::nanoseconds>(_val);
-}
-
-audio::Duration::Duration(std::chrono::milliseconds _val) {
-	m_data = std::chrono::duration_cast<std::chrono::nanoseconds>(_val);
-}
-
-audio::Duration::Duration(std::chrono::seconds _val) {
-	m_data = std::chrono::duration_cast<std::chrono::nanoseconds>(_val);
-}
-
-int64_t audio::Duration::count() const {
-	return m_data.count();
-}
-
-const audio::Duration& audio::Duration::operator= (const audio::Duration& _obj) {
-	m_data = _obj.m_data;
-	return *this;
-}
-bool audio::Duration::operator== (const audio::Duration& _obj) const {
-	return _obj.m_data == m_data;
-}
-bool audio::Duration::operator!= (const audio::Duration& _obj) const {
-	return _obj.m_data != m_data;
-}
-bool audio::Duration::operator< (const audio::Duration& _obj) const {
-	return m_data < _obj.m_data;
-}
-bool audio::Duration::operator<= (const audio::Duration& _obj) const {
-	return m_data <= _obj.m_data;
-}
-bool audio::Duration::operator> (const audio::Duration& _obj) const {
-	return m_data > _obj.m_data;
-}
-bool audio::Duration::operator>= (const audio::Duration& _obj) const {
-	return m_data >= _obj.m_data;
-}
-const audio::Duration& audio::Duration::operator+= (const audio::Duration& _obj) {
-	m_data += _obj.m_data;
-	return *this;
-}
-audio::Duration audio::Duration::operator+ (const audio::Duration& _obj) const {
-	audio::Duration tmpp(m_data);
-	tmpp.m_data += _obj.m_data;
-	return tmpp;
-}
-const audio::Duration& audio::Duration::operator-= (const audio::Duration& _obj) {
-	m_data -= _obj.m_data;
-	return *this;
-}
-audio::Duration audio::Duration::operator- (const audio::Duration& _obj) const {
-	audio::Duration tmpp(m_data);
-	tmpp.m_data -= _obj.m_data;
-	return tmpp;
-}
-
-audio::Duration& audio::Duration::operator++() {
-	m_data += std::chrono::nanoseconds(1);
-	return *this;
-}
-audio::Duration audio::Duration::operator++(int _unused) {
-	audio::Duration result(m_data);
-	m_data += std::chrono::nanoseconds(1);
-	return result;
-}
-audio::Duration& audio::Duration::operator--() {
-	m_data -= std::chrono::nanoseconds(1);
-	return *this;
-}
-audio::Duration audio::Duration::operator--(int _unused) {
-	m_data -= std::chrono::nanoseconds(1);
-	audio::Duration result(m_data);
-	return result;
-}
-
-
-std::ostream& audio::operator <<(std::ostream& _os, const audio::Duration& _obj) {
-	int64_t totalSecond = _obj.count()/1000000000;
-	int64_t millisecond = (_obj.count()%1000000000)/1000000;
-	int64_t microsecond = (_obj.count()%1000000)/1000;
-	int64_t nanosecond = _obj.count()%1000;
-	//_os << totalSecond << "s " << millisecond << "ms " << microsecond << "µs " << nanosecond << "ns";
-	int32_t second = totalSecond % 60;
-	int32_t minute = (totalSecond/60)%60;
-	int32_t hour = (totalSecond/3600)%24;
-	int32_t day = (totalSecond/(24*3600))%365;
-	int32_t year = totalSecond/(24*3600*365);
-	bool start = false;
-	if (year != 0) {
-		start = true;
-		_os << year << "y ";
-	}
-	if (day != 0 || start == true) {
-		start = true;
-		_os << day << "d ";
-	}
-	if (hour != 0 || start == true) {
-		start = true;
-		_os << hour << "h ";
-	}
-	if (minute != 0 || start == true) {
-		start = true;
-		_os << minute << ":";
-	}
-	if (second != 0 || start == true) {
-		start = true;
-		_os << second << "s ";
-	}
-	if (millisecond != 0 || start == true) {
-		start = true;
-		_os << millisecond << "ms ";
-	}
-	if (microsecond != 0 || start == true) {
-		start = true;
-		_os << microsecond << "us ";
-	}
-	_os << nanosecond << "ns ";
-	return _os;
-}
-
-
diff --git a/audio/Duration.hpp b/audio/Duration.hpp
index a922cb2..982d923 100644
--- a/audio/Duration.hpp
+++ b/audio/Duration.hpp
@@ -6,43 +6,12 @@
 #pragma once
 
 #include <etk/types.hpp>
-#include <chrono>
+#include <echrono/echrono.hpp>
+#include <echrono/Steady.hpp>
+#include <echrono/Duration.hpp>
+#include <echrono/Time.hpp>
 
 namespace audio {
-	class Duration {
-		private:
-			std::chrono::nanoseconds m_data;
-		public:
-			Duration() { };
-			Duration(int _val); //value in nanosecond
-			Duration(int64_t _val); //value in nanosecond
-			Duration(int64_t _valSec, int64_t _valNano); //value in second and nanosecond
-			Duration(double _val); //value in second
-			Duration(std::chrono::nanoseconds _val);
-			Duration(std::chrono::microseconds _val);
-			Duration(std::chrono::milliseconds _val);
-			Duration(std::chrono::seconds _val);
-			~Duration() { };
-			int64_t count() const;
-			const std::chrono::nanoseconds& get() const {
-				return m_data;
-			}
-			const Duration& operator= (const Duration& _obj);
-			bool operator== (const Duration& _obj) const;
-			bool operator!= (const Duration& _obj) const;
-			bool operator< (const audio::Duration& _obj) const;
-			bool operator<= (const audio::Duration& _obj) const;
-			bool operator> (const audio::Duration& _obj) const;
-			bool operator>= (const audio::Duration& _obj) const;
-			const Duration& operator+= (const Duration& _obj);
-			Duration operator+ (const Duration& _obj) const;
-			const Duration& operator-= (const Duration& _obj);
-			Duration operator- (const Duration& _obj) const;
-			Duration& operator++();
-			Duration operator++(int _unused);
-			Duration& operator--();
-			Duration operator--(int _unused);
-	};
-	std::ostream& operator <<(std::ostream& _os, const audio::Duration& _obj);
+	using Duration=echrono::Duration;
 }
 
diff --git a/audio/Time.cpp b/audio/Time.cpp
index 489a7e3..d922779 100644
--- a/audio/Time.cpp
+++ b/audio/Time.cpp
@@ -3,135 +3,3 @@
  * @copyright 2011, Edouard DUPIN, all right reserved
  * @license APACHE v2.0 (see license file)
  */
-
-
-#include <audio/Time.hpp>
-#include <audio/Duration.hpp>
-#include <audio/debug.hpp>
-
-audio::Time::Time(int64_t _valSec, int64_t _valNano) {
-	m_data = std::chrono::steady_clock::time_point(std::chrono::seconds(_valSec));
-	m_data += std::chrono::nanoseconds(_valNano);
-	//AUDIO_PRINT("sec= " << _valSec << " nano=" << _valNano << " ==> " << m_data);
-}
-audio::Time::Time(const std::chrono::steady_clock::time_point& _val) {
-	m_data = _val;
-}
-
-audio::Time audio::Time::now() {
-	return audio::Time(std::chrono::steady_clock::now());
-}
-
-const audio::Time& audio::Time::operator= (const audio::Time& _obj) {
-	m_data = _obj.m_data;
-	return *this;
-}
-
-bool audio::Time::operator== (const audio::Time& _obj) const {
-	return m_data == _obj.m_data;
-}
-
-bool audio::Time::operator!= (const audio::Time& _obj) const {
-	return m_data != _obj.m_data;
-}
-
-bool audio::Time::operator< (const audio::Time& _obj) const {
-	return m_data < _obj.m_data;
-}
-
-bool audio::Time::operator<= (const audio::Time& _obj) const {
-	return m_data <= _obj.m_data;
-}
-
-bool audio::Time::operator> (const audio::Time& _obj) const {
-	return m_data > _obj.m_data;
-}
-
-bool audio::Time::operator>= (const audio::Time& _obj) const {
-	return m_data >= _obj.m_data;
-}
-
-const audio::Time& audio::Time::operator+= (const audio::Duration& _obj) {
-	#if defined(__TARGET_OS__MacOs) || defined(__TARGET_OS__IOs)
-		std::chrono::microseconds ms = std::chrono::duration_cast<std::chrono::microseconds>(_obj.get());
-		m_data += ms;
-	#else
-		m_data += _obj.get();
-	#endif
-	return *this;
-}
-
-audio::Time audio::Time::operator+ (const audio::Duration& _obj) const {
-	audio::Time time(m_data);
-	time += _obj;
-	return time;
-}
-
-const audio::Time& audio::Time::operator-= (const audio::Duration& _obj) {
-	#if defined(__TARGET_OS__MacOs) || defined(__TARGET_OS__IOs)
-		std::chrono::microseconds ms = std::chrono::duration_cast<std::chrono::microseconds>(_obj.get());
-		m_data -= ms;
-	#else
-		m_data -= _obj.get();
-	#endif
-	return *this;
-}
-
-audio::Time audio::Time::operator- (const audio::Duration& _obj) const {
-	audio::Time time(m_data);
-	time -= _obj;
-	return time;
-}
-
-audio::Duration audio::Time::operator- (const audio::Time& _obj) const {
-	std::chrono::nanoseconds ns = std::chrono::duration_cast<std::chrono::nanoseconds>(m_data.time_since_epoch());
-	std::chrono::nanoseconds ns2 = std::chrono::duration_cast<std::chrono::nanoseconds>(_obj.m_data.time_since_epoch());
-	audio::Duration duration(ns);
-	audio::Duration duration2(ns2);
-	return duration - duration2;
-}
-
-std::ostream& audio::operator <<(std::ostream& _os, const audio::Time& _obj) {
-	std::chrono::nanoseconds ns = std::chrono::duration_cast<std::chrono::nanoseconds>(_obj.get().time_since_epoch());
-	int64_t totalSecond = ns.count()/1000000000;
-	int64_t millisecond = (ns.count()%1000000000)/1000000;
-	int64_t microsecond = (ns.count()%1000000)/1000;
-	int64_t nanosecond = ns.count()%1000;
-	//_os << totalSecond << "s " << millisecond << "ms " << microsecond << "µs " << nanosecond << "ns";
-	int32_t second = totalSecond % 60;
-	int32_t minute = (totalSecond/60)%60;
-	int32_t hour = (totalSecond/3600)%24;
-	int32_t day = (totalSecond/(24*3600))%365;
-	int32_t year = totalSecond/(24*3600*365);
-	bool start = false;
-	if (year != 0) {
-		start = true;
-		_os << year << "y ";
-	}
-	if (day != 0 || start == true) {
-		start = true;
-		_os << day << "d ";
-	}
-	if (hour != 0 || start == true) {
-		start = true;
-		_os << hour << "h ";
-	}
-	if (minute != 0 || start == true) {
-		start = true;
-		_os << minute << ":";
-	}
-	if (second != 0 || start == true) {
-		start = true;
-		_os << second << "s ";
-	}
-	if (millisecond != 0 || start == true) {
-		start = true;
-		_os << millisecond << "ms ";
-	}
-	if (microsecond != 0 || start == true) {
-		start = true;
-		_os << microsecond << "us ";
-	}
-	_os << nanosecond << "ns ";
-	return _os;
-}
diff --git a/audio/Time.hpp b/audio/Time.hpp
index ff2791a..ae55bd8 100644
--- a/audio/Time.hpp
+++ b/audio/Time.hpp
@@ -7,36 +7,12 @@
 
 #include <string>
 #include <etk/types.hpp>
-#include <chrono>
+#include <echrono/echrono.hpp>
+#include <echrono/Steady.hpp>
+#include <echrono/Duration.hpp>
+#include <echrono/Time.hpp>
 
 namespace audio {
-	class Duration;
-	class Time {
-		private:
-			std::chrono::steady_clock::time_point m_data;
-		public:
-			Time() {};
-			//Time(const audio::Duration& _val) {}; //value in second
-			Time(int64_t _valSec, int64_t _valNano);
-			Time(const std::chrono::steady_clock::time_point& _val);
-			~Time() {};
-			const std::chrono::steady_clock::time_point& get() const {
-				return m_data;
-			}
-			static Time now();
-			const Time& operator= (const audio::Time& _obj );
-			bool operator== (const audio::Time& _obj) const;
-			bool operator!= (const audio::Time& _obj) const;
-			bool operator< (const audio::Time& _obj) const;
-			bool operator<= (const audio::Time& _obj) const;
-			bool operator> (const audio::Time& _obj) const;
-			bool operator>= (const audio::Time& _obj) const;
-			const Time& operator+= (const audio::Duration& _obj);
-			Time operator+ (const audio::Duration& _obj) const;
-			const Time& operator-= (const audio::Duration& _obj);
-			Time operator- (const audio::Duration& _obj) const;
-			Duration operator- (const audio::Time& _obj) const;
-	};
-	std::ostream& operator <<(std::ostream& _os, const audio::Time& _obj);
+	using Time=echrono::Steady;
 }
 
diff --git a/lutin_audio.py b/lutin_audio.py
index 3000e31..e380c16 100644
--- a/lutin_audio.py
+++ b/lutin_audio.py
@@ -61,7 +61,9 @@ def configure(target, my_module):
 	    'audio/double_t.hpp'
 	    ])
 	my_module.add_depend([
-	    'etk'
+	    'etk',
+	    'elog',
+	    'echrono',
 	    ])
 	my_module.add_path(".")
 	return True