diff --git a/webrtc/modules/rtp_rtcp/source/forward_error_correction.cc b/webrtc/modules/rtp_rtcp/source/forward_error_correction.cc
index 6bc80e95d2..e666421e21 100644
--- a/webrtc/modules/rtp_rtcp/source/forward_error_correction.cc
+++ b/webrtc/modules/rtp_rtcp/source/forward_error_correction.cc
@@ -306,10 +306,10 @@ int ForwardErrorCorrection::InsertZerosInBitMasks(
   ++media_packets_it;
 
   // Insert the first column.
-  CopyColumn(tmp_packet_mask_, new_mask_bytes, packet_mask, num_mask_bytes,
-             num_fec_packets, 0, 0);
-  int new_bit_index = 1;
-  int old_bit_index = 1;
+  internal::CopyColumn(tmp_packet_mask_, new_mask_bytes, packet_mask_,
+                       num_mask_bytes, num_fec_packets, 0, 0);
+  size_t new_bit_index = 1;
+  size_t old_bit_index = 1;
   // Insert zeros in the bit mask for every hole in the sequence.
   while (media_packets_it != media_packets.end()) {
     if (new_bit_index == 8 * kMaskSizeLBitSet) {
@@ -317,15 +317,17 @@ int ForwardErrorCorrection::InsertZerosInBitMasks(
       break;
     }
     uint16_t seq_num = ParseSequenceNumber((*media_packets_it)->data);
-    const int zeros_to_insert =
+    const int num_zeros_to_insert =
         static_cast<uint16_t>(seq_num - prev_seq_num - 1);
-    if (zeros_to_insert > 0) {
-      InsertZeroColumns(zeros_to_insert, tmp_packet_mask_, new_mask_bytes,
-                        num_fec_packets, new_bit_index);
+    if (num_zeros_to_insert > 0) {
+      internal::InsertZeroColumns(num_zeros_to_insert, tmp_packet_mask_,
+                                  new_mask_bytes, num_fec_packets,
+                                  new_bit_index);
     }
-    new_bit_index += zeros_to_insert;
-    CopyColumn(tmp_packet_mask_, new_mask_bytes, packet_mask, num_mask_bytes,
-               num_fec_packets, new_bit_index, old_bit_index);
+    new_bit_index += num_zeros_to_insert;
+    internal::CopyColumn(tmp_packet_mask_, new_mask_bytes, packet_mask_,
+                         num_mask_bytes, num_fec_packets, new_bit_index,
+                         old_bit_index);
     ++new_bit_index;
     ++old_bit_index;
     prev_seq_num = seq_num;
@@ -343,38 +345,6 @@ int ForwardErrorCorrection::InsertZerosInBitMasks(
   return new_bit_index;
 }
 
-void ForwardErrorCorrection::InsertZeroColumns(int num_zeros,
-                                               uint8_t* new_mask,
-                                               int new_mask_bytes,
-                                               int num_fec_packets,
-                                               int new_bit_index) {
-  for (uint16_t row = 0; row < num_fec_packets; ++row) {
-    const int new_byte_index = row * new_mask_bytes + new_bit_index / 8;
-    const int max_shifts = (7 - (new_bit_index % 8));
-    new_mask[new_byte_index] <<= std::min(num_zeros, max_shifts);
-  }
-}
-
-void ForwardErrorCorrection::CopyColumn(uint8_t* new_mask,
-                                        int new_mask_bytes,
-                                        uint8_t* old_mask,
-                                        int old_mask_bytes,
-                                        int num_fec_packets,
-                                        int new_bit_index,
-                                        int old_bit_index) {
-  // Copy column from the old mask to the beginning of the new mask and shift it
-  // out from the old mask.
-  for (uint16_t row = 0; row < num_fec_packets; ++row) {
-    int new_byte_index = row * new_mask_bytes + new_bit_index / 8;
-    int old_byte_index = row * old_mask_bytes + old_bit_index / 8;
-    new_mask[new_byte_index] |= ((old_mask[old_byte_index] & 0x80) >> 7);
-    if (new_bit_index % 8 != 7) {
-      new_mask[new_byte_index] <<= 1;
-    }
-    old_mask[old_byte_index] <<= 1;
-  }
-}
-
 void ForwardErrorCorrection::GenerateFecUlpHeaders(
     const PacketList& media_packets,
     uint8_t* packet_mask,
diff --git a/webrtc/modules/rtp_rtcp/source/forward_error_correction.h b/webrtc/modules/rtp_rtcp/source/forward_error_correction.h
index 57eec7a01a..ac2cfa76b6 100644
--- a/webrtc/modules/rtp_rtcp/source/forward_error_correction.h
+++ b/webrtc/modules/rtp_rtcp/source/forward_error_correction.h
@@ -229,26 +229,6 @@ class ForwardErrorCorrection {
                             uint8_t* packet_mask, int num_mask_bytes,
                             int num_fec_packets);
 
-  // Inserts |num_zeros| zero columns into |new_mask| at position
-  // |new_bit_index|. If the current byte of |new_mask| can't fit all zeros, the
-  // byte will be filled with zeros from |new_bit_index|, but the next byte will
-  // be untouched.
-  static void InsertZeroColumns(int num_zeros, uint8_t* new_mask,
-                                int new_mask_bytes, int num_fec_packets,
-                                int new_bit_index);
-
-  // Copies the left most bit column from the byte pointed to by
-  // |old_bit_index| in |old_mask| to the right most column of the byte pointed
-  // to by |new_bit_index| in |new_mask|. |old_mask_bytes| and |new_mask_bytes|
-  // represent the number of bytes used per row for each mask. |num_fec_packets|
-  // represent the number of rows of the masks.
-  // The copied bit is shifted out from |old_mask| and is shifted one step to
-  // the left in |new_mask|. |new_mask| will contain "xxxx xxn0" after this
-  // operation, where x are previously inserted bits and n is the new bit.
-  static void CopyColumn(uint8_t* new_mask, int new_mask_bytes,
-                         uint8_t* old_mask, int old_mask_bytes,
-                         int num_fec_packets, int new_bit_index,
-                         int old_bit_index);
 
   void GenerateFecUlpHeaders(const PacketList& media_packets,
                              uint8_t* packet_mask, int num_fec_packets,
diff --git a/webrtc/modules/rtp_rtcp/source/forward_error_correction_internal.cc b/webrtc/modules/rtp_rtcp/source/forward_error_correction_internal.cc
index fae59078b1..790e705bc4 100644
--- a/webrtc/modules/rtp_rtcp/source/forward_error_correction_internal.cc
+++ b/webrtc/modules/rtp_rtcp/source/forward_error_correction_internal.cc
@@ -13,6 +13,8 @@
 #include <assert.h>
 #include <string.h>
 
+#include <algorithm>
+
 #include "webrtc/modules/rtp_rtcp/source/fec_private_tables_bursty.h"
 #include "webrtc/modules/rtp_rtcp/source/fec_private_tables_random.h"
 
@@ -392,5 +394,37 @@ void GeneratePacketMasks(int num_media_packets,
   }  // End of UEP modification
 }  // End of GetPacketMasks
 
+void InsertZeroColumns(int num_zeros,
+                       uint8_t* new_mask,
+                       int new_mask_bytes,
+                       int num_fec_packets,
+                       int new_bit_index) {
+  for (uint16_t row = 0; row < num_fec_packets; ++row) {
+    const int new_byte_index = row * new_mask_bytes + new_bit_index / 8;
+    const int max_shifts = (7 - (new_bit_index % 8));
+    new_mask[new_byte_index] <<= std::min(num_zeros, max_shifts);
+  }
+}
+
+void CopyColumn(uint8_t* new_mask,
+                int new_mask_bytes,
+                uint8_t* old_mask,
+                int old_mask_bytes,
+                int num_fec_packets,
+                int new_bit_index,
+                int old_bit_index) {
+  // Copy column from the old mask to the beginning of the new mask and shift it
+  // out from the old mask.
+  for (uint16_t row = 0; row < num_fec_packets; ++row) {
+    int new_byte_index = row * new_mask_bytes + new_bit_index / 8;
+    int old_byte_index = row * old_mask_bytes + old_bit_index / 8;
+    new_mask[new_byte_index] |= ((old_mask[old_byte_index] & 0x80) >> 7);
+    if (new_bit_index % 8 != 7) {
+      new_mask[new_byte_index] <<= 1;
+    }
+    old_mask[old_byte_index] <<= 1;
+  }
+}
+
 }  // namespace internal
 }  // namespace webrtc
diff --git a/webrtc/modules/rtp_rtcp/source/forward_error_correction_internal.h b/webrtc/modules/rtp_rtcp/source/forward_error_correction_internal.h
index 48117514ec..82f02c21e5 100644
--- a/webrtc/modules/rtp_rtcp/source/forward_error_correction_internal.h
+++ b/webrtc/modules/rtp_rtcp/source/forward_error_correction_internal.h
@@ -65,6 +65,33 @@ void GeneratePacketMasks(int num_media_packets, int num_fec_packets,
                          const PacketMaskTable& mask_table,
                          uint8_t* packet_mask);
 
+// Inserts |num_zeros| zero columns into |new_mask| at position
+// |new_bit_index|. If the current byte of |new_mask| can't fit all zeros, the
+// byte will be filled with zeros from |new_bit_index|, but the next byte will
+// be untouched.
+void InsertZeroColumns(int num_zeros,
+                       uint8_t* new_mask,
+                       int new_mask_bytes,
+                       int num_fec_packets,
+                       int new_bit_index);
+
+// Copies the left most bit column from the byte pointed to by
+// |old_bit_index| in |old_mask| to the right most column of the byte pointed
+// to by |new_bit_index| in |new_mask|. |old_mask_bytes| and |new_mask_bytes|
+// represent the number of bytes used per row for each mask. |num_fec_packets|
+// represent the number of rows of the masks.
+// The copied bit is shifted out from |old_mask| and is shifted one step to
+// the left in |new_mask|. |new_mask| will contain "xxxx xxn0" after this
+// operation, where x are previously inserted bits and n is the new bit.
+void CopyColumn(uint8_t* new_mask,
+                int new_mask_bytes,
+                uint8_t* old_mask,
+                int old_mask_bytes,
+                int num_fec_packets,
+                int new_bit_index,
+                int old_bit_index);
+
 }  // namespace internal
 }  // namespace webrtc
+
 #endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_FORWARD_ERROR_CORRECTION_INTERNAL_H_