diff --git a/modules/rtp_rtcp/BUILD.gn b/modules/rtp_rtcp/BUILD.gn
index a29249edaf..6ade021c19 100644
--- a/modules/rtp_rtcp/BUILD.gn
+++ b/modules/rtp_rtcp/BUILD.gn
@@ -40,6 +40,7 @@ rtc_source_set("rtp_rtcp_format") {
     "source/rtcp_packet/tmmbr.h",
     "source/rtcp_packet/transport_feedback.h",
     "source/rtcp_packet/voip_metric.h",
+    "source/rtp_generic_frame_descriptor.h",
     "source/rtp_header_extensions.h",
     "source/rtp_packet.h",
     "source/rtp_packet_received.h",
@@ -73,6 +74,7 @@ rtc_source_set("rtp_rtcp_format") {
     "source/rtcp_packet/tmmbr.cc",
     "source/rtcp_packet/transport_feedback.cc",
     "source/rtcp_packet/voip_metric.cc",
+    "source/rtp_generic_frame_descriptor.cc",
     "source/rtp_header_extension_map.cc",
     "source/rtp_header_extensions.cc",
     "source/rtp_packet.cc",
diff --git a/modules/rtp_rtcp/source/rtp_generic_frame_descriptor.cc b/modules/rtp_rtcp/source/rtp_generic_frame_descriptor.cc
new file mode 100644
index 0000000000..caa81625c3
--- /dev/null
+++ b/modules/rtp_rtcp/source/rtp_generic_frame_descriptor.cc
@@ -0,0 +1,70 @@
+/*
+ *  Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "modules/rtp_rtcp/source/rtp_generic_frame_descriptor.h"
+
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+constexpr size_t RtpGenericFrameDescriptor::kMaxNumFrameDependencies;
+
+RtpGenericFrameDescriptor::RtpGenericFrameDescriptor() = default;
+
+int RtpGenericFrameDescriptor::TemporalLayer() const {
+  RTC_DCHECK(FirstPacketInSubFrame());
+  return temporal_layer_;
+}
+
+void RtpGenericFrameDescriptor::SetTemporalLayer(int temporal_layer) {
+  RTC_DCHECK_GE(temporal_layer, 0);
+  RTC_DCHECK_LE(temporal_layer, 7);
+  temporal_layer_ = temporal_layer;
+}
+
+uint8_t RtpGenericFrameDescriptor::SpatialLayersBitmask() const {
+  RTC_DCHECK(FirstPacketInSubFrame());
+  return spatial_layers_;
+}
+
+void RtpGenericFrameDescriptor::SetSpatialLayersBitmask(
+    uint8_t spatial_layers) {
+  RTC_DCHECK(FirstPacketInSubFrame());
+  spatial_layers_ = spatial_layers;
+}
+
+uint16_t RtpGenericFrameDescriptor::FrameId() const {
+  RTC_DCHECK(FirstPacketInSubFrame());
+  return frame_id_;
+}
+
+void RtpGenericFrameDescriptor::SetFrameId(uint16_t frame_id) {
+  RTC_DCHECK(FirstPacketInSubFrame());
+  frame_id_ = frame_id;
+}
+
+rtc::ArrayView<const uint16_t>
+RtpGenericFrameDescriptor::FrameDepedenciesDiffs() const {
+  RTC_DCHECK(FirstPacketInSubFrame());
+  return rtc::MakeArrayView(frame_deps_id_diffs_, num_frame_deps_);
+}
+
+bool RtpGenericFrameDescriptor::AddFrameDependencyDiff(uint16_t fdiff) {
+  RTC_DCHECK(FirstPacketInSubFrame());
+  if (num_frame_deps_ == kMaxNumFrameDependencies)
+    return false;
+  RTC_DCHECK_LT(fdiff, 1 << 14);
+  RTC_DCHECK_GT(fdiff, 0);
+  frame_deps_id_diffs_[num_frame_deps_] = fdiff;
+  num_frame_deps_++;
+  return true;
+}
+
+}  // namespace webrtc
diff --git a/modules/rtp_rtcp/source/rtp_generic_frame_descriptor.h b/modules/rtp_rtcp/source/rtp_generic_frame_descriptor.h
new file mode 100644
index 0000000000..07536e7af6
--- /dev/null
+++ b/modules/rtp_rtcp/source/rtp_generic_frame_descriptor.h
@@ -0,0 +1,70 @@
+/*
+ *  Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef MODULES_RTP_RTCP_SOURCE_RTP_GENERIC_FRAME_DESCRIPTOR_H_
+#define MODULES_RTP_RTCP_SOURCE_RTP_GENERIC_FRAME_DESCRIPTOR_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "api/array_view.h"
+
+namespace webrtc {
+
+// Data to put on the wire for FrameDescriptor rtp header extension.
+class RtpGenericFrameDescriptor {
+ public:
+  RtpGenericFrameDescriptor();
+
+  bool FirstPacketInSubFrame() const { return beginning_of_subframe_; }
+  void SetFirstPacketInSubFrame(bool first) { beginning_of_subframe_ = first; }
+  bool LastPacketInSubFrame() const { return end_of_subframe_; }
+  void SetLastPacketInSubFrame(bool last) { end_of_subframe_ = last; }
+
+  bool FirstSubFrameInFrame() const { return beginning_of_frame_; }
+  void SetFirstSubFrameInFrame(bool first) { beginning_of_frame_ = first; }
+  bool LastSubFrameInFrame() const { return end_of_frame_; }
+  void SetLastSubFrameInFrame(bool last) { end_of_frame_ = last; }
+
+  // Properties below undefined if !FirstPacketInSubFrame()
+  // Valid range for temporal layer: [0, 7]
+  int TemporalLayer() const;
+  void SetTemporalLayer(int temporal_layer);
+
+  // Frame might by used, possible indrectly, for spatial layer sid iff
+  // (bitmask & (1 << sid)) != 0
+  uint8_t SpatialLayersBitmask() const;
+  void SetSpatialLayersBitmask(uint8_t spatial_layers);
+
+  uint16_t FrameId() const;
+  void SetFrameId(uint16_t frame_id);
+
+  rtc::ArrayView<const uint16_t> FrameDepedenciesDiffs() const;
+  void ClearFrameDependencies() { num_frame_deps_ = 0; }
+  // Returns false on failure, i.e. number of dependencies is too large.
+  bool AddFrameDependencyDiff(uint16_t fdiff);
+
+ private:
+  static constexpr size_t kMaxNumFrameDependencies = 8;
+
+  bool beginning_of_subframe_ = false;
+  bool end_of_subframe_ = false;
+  bool beginning_of_frame_ = false;
+  bool end_of_frame_ = false;
+
+  uint16_t frame_id_ = 0;
+  uint8_t spatial_layers_ = 1;
+  uint8_t temporal_layer_ = 0;
+  size_t num_frame_deps_ = 0;
+  uint16_t frame_deps_id_diffs_[kMaxNumFrameDependencies];
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_RTP_RTCP_SOURCE_RTP_GENERIC_FRAME_DESCRIPTOR_H_