diff --git a/include/mynteye/types.h b/include/mynteye/types.h
index 3272e4d..4fa6261 100644
--- a/include/mynteye/types.h
+++ b/include/mynteye/types.h
@@ -248,9 +248,9 @@ std::ostream &operator<<(std::ostream &os, const StreamRequest &request);
 
 /**
  * @ingroup calibration
- * Image intrinsics.
+ * Stream intrinsics,
  */
-struct MYNTEYE_API ImgIntrinsics {
+struct MYNTEYE_API Intrinsics {
   /** width of the image in pixels */
   std::uint16_t width;
   /** height of the image in pixels */
@@ -269,13 +269,13 @@ struct MYNTEYE_API ImgIntrinsics {
   double coeffs[5];
 };
 
-std::ostream &operator<<(std::ostream &os, const ImgIntrinsics &in);
+std::ostream &operator<<(std::ostream &os, const Intrinsics &in);
 
 /**
  * @ingroup calibration
- * IMU sensor intrinsics: scale, drift and variances.
+ * IMU intrinsics: scale, drift and variances.
  */
-struct MYNTEYE_API ImuSensorIntrinsics {
+struct MYNTEYE_API ImuIntrinsics {
   /**
    * Scale X     cross axis  cross axis
    * cross axis  Scale Y     cross axis
@@ -291,18 +291,18 @@ struct MYNTEYE_API ImuSensorIntrinsics {
   double bias[3];
 };
 
-std::ostream &operator<<(std::ostream &os, const ImuSensorIntrinsics &in);
+std::ostream &operator<<(std::ostream &os, const ImuIntrinsics &in);
 
 /**
  * @ingroup calibration
- * IMU intrinsics, including accelerometer and gyroscope.
+ * Motion intrinsics, including accelerometer and gyroscope.
  */
-struct MYNTEYE_API ImuIntrinsics {
-  ImuSensorIntrinsics accel;
-  ImuSensorIntrinsics gyro;
+struct MYNTEYE_API MotionIntrinsics {
+  ImuIntrinsics accel;
+  ImuIntrinsics gyro;
 };
 
-std::ostream &operator<<(std::ostream &os, const ImuIntrinsics &in);
+std::ostream &operator<<(std::ostream &os, const MotionIntrinsics &in);
 
 /**
  * @ingroup calibration
@@ -315,26 +315,6 @@ struct MYNTEYE_API Extrinsics {
 
 std::ostream &operator<<(std::ostream &os, const Extrinsics &ex);
 
-/**
- * @ingroup calibration
- * Image extrinsics.
- */
-struct MYNTEYE_API ImgExtrinsics {
-  Extrinsics left_to_right;
-};
-
-std::ostream &operator<<(std::ostream &os, const ImgExtrinsics &ex);
-
-/**
- * @ingroup calibration
- * IMU extrinsics.
- */
-struct MYNTEYE_API ImuExtrinsics {
-  Extrinsics left_to_imu;
-};
-
-std::ostream &operator<<(std::ostream &os, const ImuExtrinsics &ex);
-
 /**
  * @defgroup datatypes Datatypes
  * @brief Public data types.
diff --git a/src/device/device.cc b/src/device/device.cc
index 7e0c249..4ac51e2 100644
--- a/src/device/device.cc
+++ b/src/device/device.cc
@@ -151,36 +151,60 @@ std::string Device::GetInfo(const Info &info) const {
   }
 }
 
-ImgIntrinsics Device::GetImgIntrinsics() const {
-  return img_intrinsics_;
+Intrinsics Device::GetIntrinsics(const Stream &stream) const {
+  try {
+    return stream_intrinsics_.at(stream);
+  } catch (const std::out_of_range &e) {
+    LOG(WARNING) << "Intrinsics of " << stream << " not found";
+    return {};
+  }
 }
 
-ImgExtrinsics Device::GetImgExtrinsics() const {
-  return img_extrinsics_;
+Extrinsics Device::GetExtrinsics(const Stream &from, const Stream &to) const {
+  try {
+    return stream_from_extrinsics_.at(from).at(to);
+  } catch (const std::out_of_range &e) {
+    LOG(WARNING) << "Extrinsics from " << from << " to " << to << " not found";
+    return {};
+  }
 }
 
-void Device::SetImgIntrinsics(const ImgIntrinsics &in) {
-  img_intrinsics_ = std::move(in);
+MotionIntrinsics Device::GetMotionIntrinsics() const {
+  if (motion_intrinsics_) {
+    return *motion_intrinsics_;
+  } else {
+    LOG(WARNING) << "Motion intrinsics not found";
+    return {};
+  }
 }
 
-void Device::SetImgExtrinsics(const ImgExtrinsics &ex) {
-  img_extrinsics_ = std::move(ex);
+Extrinsics Device::GetMotionExtrinsics(const Stream &from) const {
+  try {
+    return motion_from_extrinsics_.at(from);
+  } catch (const std::out_of_range &e) {
+    LOG(WARNING) << "Motion extrinsics from " << from << " not found";
+    return {};
+  }
 }
 
-ImuIntrinsics Device::GetImuIntrinsics() const {
-  return imu_intrinsics_;
+void Device::SetIntrinsics(const Stream &stream, const Intrinsics &in) {
+  stream_intrinsics_[stream] = in;
 }
 
-ImuExtrinsics Device::GetImuExtrinsics() const {
-  return imu_extrinsics_;
+void Device::SetExtrinsics(
+    const Stream &from, const Stream &to, const Extrinsics &ex) {
+  stream_from_extrinsics_[from][to] = ex;
 }
 
-void Device::SetImuIntrinsics(const ImuIntrinsics &in) {
-  imu_intrinsics_ = std::move(in);
+void Device::SetMotionIntrinsics(const MotionIntrinsics &in) {
+  if (motion_intrinsics_ == nullptr) {
+    motion_intrinsics_ = std::make_shared<MotionIntrinsics>();
+  }
+  *motion_intrinsics_ = in;
 }
 
-void Device::SetImuExtrinsics(const ImuExtrinsics &ex) {
-  imu_extrinsics_ = std::move(ex);
+void Device::SetMotionExtrinsics(const Stream &from, const Extrinsics &ex) {
+  motion_from_extrinsics_[from] = ex;
 }
 
 void Device::LogOptionInfos() const {
@@ -426,7 +450,7 @@ void Device::ReadAllInfos() {
   if (!channels_->GetFiles(device_info_.get(), &img_params, &imu_params)) {
     LOG(FATAL) << "Read device infos failed :(";
   }
-  VLOG(2) << "Device name: " << device_info_->name
+  VLOG(2) << "Device info: {name: " << device_info_->name
           << ", serial_number: " << device_info_->serial_number
           << ", firmware_version: "
           << device_info_->firmware_version.to_string()
@@ -435,56 +459,28 @@ void Device::ReadAllInfos() {
           << ", spec_version: " << device_info_->spec_version.to_string()
           << ", lens_type: " << device_info_->lens_type.to_string()
           << ", imu_type: " << device_info_->imu_type.to_string()
-          << ", nominal_baseline: " << device_info_->nominal_baseline;
+          << ", nominal_baseline: " << device_info_->nominal_baseline << "}";
 
   device_info_->name = uvc::get_name(*device_);
   if (img_params.ok) {
-    img_intrinsics_ = img_params.in;
-    img_extrinsics_ = img_params.ex;
-    VLOG(2) << "ImgIntrinsics " << img_intrinsics_;
-    VLOG(2) << "ImgExtrinsics " << img_extrinsics_;
+    SetIntrinsics(Stream::LEFT, img_params.in_left);
+    SetIntrinsics(Stream::RIGHT, img_params.in_right);
+    SetExtrinsics(Stream::LEFT, Stream::RIGHT, img_params.ex_left_to_right);
+    VLOG(2) << "Intrinsics left: {" << GetIntrinsics(Stream::LEFT) << "}";
+    VLOG(2) << "Intrinsics right: {" << GetIntrinsics(Stream::RIGHT) << "}";
+    VLOG(2) << "Extrinsics left to right: {"
+            << GetExtrinsics(Stream::LEFT, Stream::RIGHT) << "}";
   } else {
-    LOG(WARNING) << "Img intrinsics & extrinsics not exist";
+    LOG(WARNING) << "Intrinsics & extrinsics not exist";
   }
   if (imu_params.ok) {
-    imu_intrinsics_ = imu_params.in;
-    imu_extrinsics_ = imu_params.ex;
-    VLOG(2) << "ImuIntrinsics " << imu_intrinsics_;
-    VLOG(2) << "ImuExtrinsics " << imu_extrinsics_;
+    SetMotionIntrinsics({imu_params.in_accel, imu_params.in_gyro});
+    SetMotionExtrinsics(Stream::LEFT, imu_params.ex_left_to_imu);
+    VLOG(2) << "Motion intrinsics: {" << GetMotionIntrinsics() << "}";
+    VLOG(2) << "Motion extrinsics left to imu: {"
+            << GetMotionExtrinsics(Stream::LEFT) << "}";
   } else {
-    LOG(WARNING) << "Imu intrinsics & extrinsics not exist";
-  }
-}
-
-void Device::WriteDeviceInfo(const DeviceInfo &device_info) {
-  CHECK_NOTNULL(channels_);
-  DeviceInfo info = device_info;
-  if (channels_->SetFiles(&info, nullptr, nullptr)) {
-    device_info_->lens_type = info.lens_type;
-    device_info_->imu_type = info.imu_type;
-    device_info_->nominal_baseline = info.nominal_baseline;
-  }
-}
-
-void Device::WriteImgParams(
-    const ImgIntrinsics &intrinsics, const ImgExtrinsics &extrinsics) {
-  CHECK_NOTNULL(channels_);
-  Channels::img_params_t img_params{false, intrinsics, extrinsics};
-  if (channels_->SetFiles(
-          nullptr, &img_params, nullptr, &device_info_->spec_version)) {
-    img_intrinsics_ = intrinsics;
-    img_extrinsics_ = extrinsics;
-  }
-}
-
-void Device::WriteImuParams(
-    const ImuIntrinsics &intrinsics, const ImuExtrinsics &extrinsics) {
-  CHECK_NOTNULL(channels_);
-  Channels::imu_params_t imu_params{false, intrinsics, extrinsics};
-  if (channels_->SetFiles(
-          nullptr, nullptr, &imu_params, &device_info_->spec_version)) {
-    imu_intrinsics_ = intrinsics;
-    imu_extrinsics_ = extrinsics;
+    LOG(WARNING) << "Motion intrinsics & extrinsics not exist";
   }
 }
 
diff --git a/src/device/device.h b/src/device/device.h
index e124640..59d8d77 100644
--- a/src/device/device.h
+++ b/src/device/device.h
@@ -57,15 +57,16 @@ class Device {
   std::shared_ptr<DeviceInfo> GetInfo() const;
   std::string GetInfo(const Info &info) const;
 
-  ImgIntrinsics GetImgIntrinsics() const;
-  ImgExtrinsics GetImgExtrinsics() const;
-  void SetImgIntrinsics(const ImgIntrinsics &in);
-  void SetImgExtrinsics(const ImgExtrinsics &ex);
+  Intrinsics GetIntrinsics(const Stream &stream) const;
+  Extrinsics GetExtrinsics(const Stream &from, const Stream &to) const;
+  MotionIntrinsics GetMotionIntrinsics() const;
+  Extrinsics GetMotionExtrinsics(const Stream &from) const;
 
-  ImuIntrinsics GetImuIntrinsics() const;
-  ImuExtrinsics GetImuExtrinsics() const;
-  void SetImuIntrinsics(const ImuIntrinsics &in);
-  void SetImuExtrinsics(const ImuExtrinsics &ex);
+  void SetIntrinsics(const Stream &stream, const Intrinsics &in);
+  void SetExtrinsics(
+      const Stream &from, const Stream &to, const Extrinsics &ex);
+  void SetMotionIntrinsics(const MotionIntrinsics &in);
+  void SetMotionExtrinsics(const Stream &from, const Extrinsics &ex);
 
   void LogOptionInfos() const;
   OptionInfo GetOptionInfo(const Option &option) const;
@@ -120,10 +121,11 @@ class Device {
   std::shared_ptr<uvc::device> device_;
   std::shared_ptr<DeviceInfo> device_info_;
 
-  ImgIntrinsics img_intrinsics_;
-  ImgExtrinsics img_extrinsics_;
-  ImuIntrinsics imu_intrinsics_;
-  ImuExtrinsics imu_extrinsics_;
+  std::map<Stream, Intrinsics> stream_intrinsics_;
+  std::map<Stream, std::map<Stream, Extrinsics>> stream_from_extrinsics_;
+
+  std::shared_ptr<MotionIntrinsics> motion_intrinsics_;
+  std::map<Stream, Extrinsics> motion_from_extrinsics_;
 
   stream_callbacks_t stream_callbacks_;
   motion_callback_t motion_callback_;
@@ -140,11 +142,9 @@ class Device {
 
   void ReadAllInfos();
 
-  void WriteDeviceInfo(const DeviceInfo &device_info);
-  void WriteImgParams(
-      const ImgIntrinsics &intrinsics, const ImgExtrinsics &extrinsics);
-  void WriteImuParams(
-      const ImuIntrinsics &intrinsics, const ImuExtrinsics &extrinsics);
+  std::shared_ptr<Channels> channels() {
+    return channels_;
+  }
 
   // friend DeviceWriter;
 };
diff --git a/src/internal/channels.cc b/src/internal/channels.cc
index 59852e6..38f6c60 100644
--- a/src/internal/channels.cc
+++ b/src/internal/channels.cc
@@ -386,49 +386,64 @@ std::size_t from_data(Channels::device_info_t *info, const std::uint8_t *data) {
 }
 
 std::size_t from_data(
-    Channels::img_params_t *img_params, const std::uint8_t *data,
-    const Version *spec_version) {
+    Intrinsics *in, const std::uint8_t *data, const Version *spec_version) {
   std::size_t i = 0;
 
-  auto &&in = img_params->in;
   // width, 2
-  in.width = _from_data<std::uint16_t>(data + i);
+  in->width = _from_data<std::uint16_t>(data + i);
   i += 2;
   // height, 2
-  in.height = _from_data<std::uint16_t>(data + i);
+  in->height = _from_data<std::uint16_t>(data + i);
   i += 2;
   // fx, 8
-  in.fx = _from_data<double>(data + i);
+  in->fx = _from_data<double>(data + i);
   i += 8;
   // fy, 8
-  in.fy = _from_data<double>(data + i);
+  in->fy = _from_data<double>(data + i);
   i += 8;
   // cx, 8
-  in.cx = _from_data<double>(data + i);
+  in->cx = _from_data<double>(data + i);
   i += 8;
   // cy, 8
-  in.cy = _from_data<double>(data + i);
+  in->cy = _from_data<double>(data + i);
   i += 8;
   // model, 1
-  in.model = data[i];
+  in->model = data[i];
   i += 1;
   // coeffs, 40
   for (std::size_t j = 0; j < 5; j++) {
-    in.coeffs[j] = _from_data<double>(data + i + j * 8);
+    in->coeffs[j] = _from_data<double>(data + i + j * 8);
   }
   i += 40;
 
-  auto &&ex = img_params->ex.left_to_right;
-  // rotation
+  UNUSED(spec_version)
+  return i;
+}
+
+std::size_t from_data(
+    ImuIntrinsics *in, const std::uint8_t *data, const Version *spec_version) {
+  std::size_t i = 0;
+
+  // scale
   for (std::size_t j = 0; j < 3; j++) {
     for (std::size_t k = 0; k < 3; k++) {
-      ex.rotation[j][k] = _from_data<double>(data + i + (j * 3 + k) * 8);
+      in->scale[j][k] = _from_data<double>(data + i + (j * 3 + k) * 8);
     }
   }
   i += 72;
-  // translation
+  // drift
   for (std::size_t j = 0; j < 3; j++) {
-    ex.translation[j] = _from_data<double>(data + i + j * 8);
+    in->drift[j] = _from_data<double>(data + i + j * 8);
+  }
+  i += 24;
+  // noise
+  for (std::size_t j = 0; j < 3; j++) {
+    in->noise[j] = _from_data<double>(data + i + j * 8);
+  }
+  i += 24;
+  // bias
+  for (std::size_t j = 0; j < 3; j++) {
+    in->bias[j] = _from_data<double>(data + i + j * 8);
   }
   i += 24;
 
@@ -437,67 +452,19 @@ std::size_t from_data(
 }
 
 std::size_t from_data(
-    Channels::imu_params_t *imu_params, const std::uint8_t *data,
-    const Version *spec_version) {
+    Extrinsics *ex, const std::uint8_t *data, const Version *spec_version) {
   std::size_t i = 0;
 
-  auto &&in = imu_params->in;
-  // acc_scale
-  for (std::size_t j = 0; j < 3; j++) {
-    for (std::size_t k = 0; k < 3; k++) {
-      in.accel.scale[j][k] = _from_data<double>(data + i + (j * 3 + k) * 8);
-    }
-  }
-  i += 72;
-  // gyro_scale
-  for (std::size_t j = 0; j < 3; j++) {
-    for (std::size_t k = 0; k < 3; k++) {
-      in.gyro.scale[j][k] = _from_data<double>(data + i + (j * 3 + k) * 8);
-    }
-  }
-  i += 72;
-  // acc_drift
-  for (std::size_t j = 0; j < 3; j++) {
-    in.accel.drift[j] = _from_data<double>(data + i + j * 8);
-  }
-  i += 24;
-  // gyro_drift
-  for (std::size_t j = 0; j < 3; j++) {
-    in.gyro.drift[j] = _from_data<double>(data + i + j * 8);
-  }
-  i += 24;
-  // acc_noise
-  for (std::size_t j = 0; j < 3; j++) {
-    in.accel.noise[j] = _from_data<double>(data + i + j * 8);
-  }
-  i += 24;
-  // gyro_noise
-  for (std::size_t j = 0; j < 3; j++) {
-    in.gyro.noise[j] = _from_data<double>(data + i + j * 8);
-  }
-  i += 24;
-  // acc_bias
-  for (std::size_t j = 0; j < 3; j++) {
-    in.accel.bias[j] = _from_data<double>(data + i + j * 8);
-  }
-  i += 24;
-  // gyro_bias
-  for (std::size_t j = 0; j < 3; j++) {
-    in.gyro.bias[j] = _from_data<double>(data + i + j * 8);
-  }
-  i += 24;
-
-  auto &&ex = imu_params->ex.left_to_imu;
   // rotation
   for (std::size_t j = 0; j < 3; j++) {
     for (std::size_t k = 0; k < 3; k++) {
-      ex.rotation[j][k] = _from_data<double>(data + i + (j * 3 + k) * 8);
+      ex->rotation[j][k] = _from_data<double>(data + i + (j * 3 + k) * 8);
     }
   }
   i += 72;
   // translation
   for (std::size_t j = 0; j < 3; j++) {
-    ex.translation[j] = _from_data<double>(data + i + j * 8);
+    ex->translation[j] = _from_data<double>(data + i + j * 8);
   }
   i += 24;
 
@@ -505,6 +472,26 @@ std::size_t from_data(
   return i;
 }
 
+std::size_t from_data(
+    Channels::img_params_t *img_params, const std::uint8_t *data,
+    const Version *spec_version) {
+  std::size_t i = 0;
+  i += from_data(&img_params->in_left, data + i, spec_version);
+  i += from_data(&img_params->in_right, data + i, spec_version);
+  i += from_data(&img_params->ex_left_to_right, data + i, spec_version);
+  return i;
+}
+
+std::size_t from_data(
+    Channels::imu_params_t *imu_params, const std::uint8_t *data,
+    const Version *spec_version) {
+  std::size_t i = 0;
+  i += from_data(&imu_params->in_accel, data + i, spec_version);
+  i += from_data(&imu_params->in_gyro, data + i, spec_version);
+  i += from_data(&imu_params->ex_left_to_imu, data + i, spec_version);
+  return i;
+}
+
 }  // namespace
 
 bool Channels::GetFiles(
@@ -669,54 +656,99 @@ std::size_t to_data(
 }
 
 std::size_t to_data(
-    const Channels::img_params_t *img_params, std::uint8_t *data,
-    const Version *spec_version) {
-  std::size_t i = 3;  // skip id, size
+    const Intrinsics *in, std::uint8_t *data, const Version *spec_version) {
+  std::size_t i = 0;
 
-  auto &&in = img_params->in;
   // width, 2
-  _to_data(in.width, data + i);
+  _to_data(in->width, data + i);
   i += 2;
   // height, 2
-  _to_data(in.height, data + i);
+  _to_data(in->height, data + i);
   i += 2;
   // fx, 8
-  _to_data(in.fx, data + i);
+  _to_data(in->fx, data + i);
   i += 8;
   // fy, 8
-  _to_data(in.fy, data + i);
+  _to_data(in->fy, data + i);
   i += 8;
   // cx, 8
-  _to_data(in.cx, data + i);
+  _to_data(in->cx, data + i);
   i += 8;
   // cy, 8
-  _to_data(in.cy, data + i);
+  _to_data(in->cy, data + i);
   i += 8;
   // model, 1
-  data[i] = in.model;
+  data[i] = in->model;
   i += 1;
   // coeffs, 40
   for (std::size_t j = 0; j < 5; j++) {
-    _to_data(in.coeffs[j], data + i + j * 8);
+    _to_data(in->coeffs[j], data + i + j * 8);
   }
   i += 40;
 
-  auto &&ex = img_params->ex.left_to_right;
+  UNUSED(spec_version)
+  return i;
+}
+
+std::size_t to_data(
+    const ImuIntrinsics *in, std::uint8_t *data, const Version *spec_version) {
+  std::size_t i = 0;
+
+  // scale
+  for (std::size_t j = 0; j < 3; j++) {
+    for (std::size_t k = 0; k < 3; k++) {
+      _to_data(in->scale[j][k], data + i + (j * 3 + k) * 8);
+    }
+  }
+  i += 72;
+  // drift
+  for (std::size_t j = 0; j < 3; j++) {
+    _to_data(in->drift[j], data + i + j * 8);
+  }
+  i += 24;
+  // noise
+  for (std::size_t j = 0; j < 3; j++) {
+    _to_data(in->noise[j], data + i + j * 8);
+  }
+  i += 24;
+  // bias
+  for (std::size_t j = 0; j < 3; j++) {
+    _to_data(in->bias[j], data + i + j * 8);
+  }
+  i += 24;
+
+  UNUSED(spec_version)
+  return i;
+}
+
+std::size_t to_data(
+    const Extrinsics *ex, std::uint8_t *data, const Version *spec_version) {
+  std::size_t i = 0;
+
   // rotation
   for (std::size_t j = 0; j < 3; j++) {
     for (std::size_t k = 0; k < 3; k++) {
-      _to_data(ex.rotation[j][k], data + i + (j * 3 + k) * 8);
+      _to_data(ex->rotation[j][k], data + i + (j * 3 + k) * 8);
     }
   }
   i += 72;
   // translation
   for (std::size_t j = 0; j < 3; j++) {
-    _to_data(ex.translation[j], data + i + j * 8);
+    _to_data(ex->translation[j], data + i + j * 8);
   }
   i += 24;
 
   UNUSED(spec_version)
+  return i;
+}
 
+std::size_t to_data(
+    const Channels::img_params_t *img_params, std::uint8_t *data,
+    const Version *spec_version) {
+  std::size_t i = 3;  // skip id, size
+  i += to_data(&img_params->in_left, data + i, spec_version);
+  i += to_data(&img_params->in_right, data + i, spec_version);
+  i += to_data(&img_params->ex_left_to_right, data + i, spec_version);
   // others
   std::size_t size = i - 3;
   data[0] = Channels::FID_IMG_PARAMS;
@@ -729,69 +761,9 @@ std::size_t to_data(
     const Channels::imu_params_t *imu_params, std::uint8_t *data,
     const Version *spec_version) {
   std::size_t i = 3;  // skip id, size
-
-  auto &&in = imu_params->in;
-  // acc_scale
-  for (std::size_t j = 0; j < 3; j++) {
-    for (std::size_t k = 0; k < 3; k++) {
-      _to_data(in.accel.scale[j][k], data + i + (j * 3 + k) * 8);
-    }
-  }
-  i += 72;
-  // gyro_scale
-  for (std::size_t j = 0; j < 3; j++) {
-    for (std::size_t k = 0; k < 3; k++) {
-      _to_data(in.gyro.scale[j][k], data + i + (j * 3 + k) * 8);
-    }
-  }
-  i += 72;
-  // acc_drift
-  for (std::size_t j = 0; j < 3; j++) {
-    _to_data(in.accel.drift[j], data + i + j * 8);
-  }
-  i += 24;
-  // gyro_drift
-  for (std::size_t j = 0; j < 3; j++) {
-    _to_data(in.gyro.drift[j], data + i + j * 8);
-  }
-  i += 24;
-  // acc_noise
-  for (std::size_t j = 0; j < 3; j++) {
-    _to_data(in.accel.noise[j], data + i + j * 8);
-  }
-  i += 24;
-  // gyro_noise
-  for (std::size_t j = 0; j < 3; j++) {
-    _to_data(in.gyro.noise[j], data + i + j * 8);
-  }
-  i += 24;
-  // acc_bias
-  for (std::size_t j = 0; j < 3; j++) {
-    _to_data(in.accel.bias[j], data + i + j * 8);
-  }
-  i += 24;
-  // gyro_bias
-  for (std::size_t j = 0; j < 3; j++) {
-    _to_data(in.gyro.bias[j], data + i + j * 8);
-  }
-  i += 24;
-
-  auto &&ex = imu_params->ex.left_to_imu;
-  // rotation
-  for (std::size_t j = 0; j < 3; j++) {
-    for (std::size_t k = 0; k < 3; k++) {
-      _to_data(ex.rotation[j][k], data + i + (j * 3 + k) * 8);
-    }
-  }
-  i += 72;
-  // translation
-  for (std::size_t j = 0; j < 3; j++) {
-    _to_data(ex.translation[j], data + i + j * 8);
-  }
-  i += 24;
-
-  UNUSED(spec_version)
-
+  i += to_data(&imu_params->in_accel, data + i, spec_version);
+  i += to_data(&imu_params->in_gyro, data + i, spec_version);
+  i += to_data(&imu_params->ex_left_to_imu, data + i, spec_version);
   // others
   std::size_t size = i - 3;
   data[0] = Channels::FID_IMU_PARAMS;
diff --git a/src/internal/channels.h b/src/internal/channels.h
index d881310..e887f22 100644
--- a/src/internal/channels.h
+++ b/src/internal/channels.h
@@ -57,14 +57,16 @@ class Channels {
 
   typedef struct ImgParams {
     bool ok;
-    ImgIntrinsics in;
-    ImgExtrinsics ex;
+    Intrinsics in_left;
+    Intrinsics in_right;
+    Extrinsics ex_left_to_right;
   } img_params_t;
 
   typedef struct ImuParams {
     bool ok;
-    ImuIntrinsics in;
-    ImuExtrinsics ex;
+    ImuIntrinsics in_accel;
+    ImuIntrinsics in_gyro;
+    Extrinsics ex_left_to_imu;
   } imu_params_t;
 
   explicit Channels(std::shared_ptr<uvc::device> device);
diff --git a/src/public/types.cc b/src/public/types.cc
index 21ebf5d..a6aa160 100644
--- a/src/public/types.cc
+++ b/src/public/types.cc
@@ -145,7 +145,7 @@ std::ostream &operator<<(std::ostream &os, const StreamRequest &request) {
             << ", format: " << request.format << ", fps: " << request.fps;
 }
 
-std::ostream &operator<<(std::ostream &os, const ImgIntrinsics &in) {
+std::ostream &operator<<(std::ostream &os, const Intrinsics &in) {
   os << "width: " << in.width << ", height: " << in.height << ", fx: " << in.fx
      << ", fy: " << in.fy << ", cx: " << in.cx << ", cy: " << in.cy
      << ", model: " << static_cast<int>(in.model) << ", coeffs: [";
@@ -154,7 +154,7 @@ std::ostream &operator<<(std::ostream &os, const ImgIntrinsics &in) {
   return os << in.coeffs[4] << "]";
 }
 
-std::ostream &operator<<(std::ostream &os, const ImuSensorIntrinsics &in) {
+std::ostream &operator<<(std::ostream &os, const ImuIntrinsics &in) {
   os << "scale: [";
   for (int i = 0; i <= 2; i++)
     os << in.scale[0][i] << ", ";
@@ -182,7 +182,7 @@ std::ostream &operator<<(std::ostream &os, const ImuSensorIntrinsics &in) {
   return os;
 }
 
-std::ostream &operator<<(std::ostream &os, const ImuIntrinsics &in) {
+std::ostream &operator<<(std::ostream &os, const MotionIntrinsics &in) {
   return os << "accel: {" << in.accel << "}, gyro: {" << in.gyro << "}";
 }
 
@@ -204,12 +204,4 @@ std::ostream &operator<<(std::ostream &os, const Extrinsics &ex) {
   return os;
 }
 
-std::ostream &operator<<(std::ostream &os, const ImgExtrinsics &ex) {
-  return os << "left_to_right: {" << ex.left_to_right << "}";
-}
-
-std::ostream &operator<<(std::ostream &os, const ImuExtrinsics &ex) {
-  return os << "left_to_imu: {" << ex.left_to_imu << "}";
-}
-
 MYNTEYE_END_NAMESPACE