1 files changed, 63 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/rtp_rtcp/source/leb128.cc b/third_party/libwebrtc/modules/rtp_rtcp/source/leb128.cc
new file mode 100644
index 0000000000..131ec4b523
--- /dev/null
+++ b/third_party/libwebrtc/modules/rtp_rtcp/source/leb128.cc
@@ -0,0 +1,63 @@
+/*
+ *  Copyright (c) 2023 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/leb128.h"
+
+#include <cstdint>
+
+namespace webrtc {
+
+int Leb128Size(uint64_t value) {
+  int size = 0;
+  while (value >= 0x80) {
+    ++size;
+    value >>= 7;
+  }
+  return size + 1;
+}
+
+uint64_t ReadLeb128(const uint8_t*& read_at, const uint8_t* end) {
+  uint64_t value = 0;
+  int fill_bits = 0;
+  while (read_at != end && fill_bits < 64 - 7) {
+    uint8_t leb128_byte = *read_at;
+    value |= uint64_t{leb128_byte & 0x7Fu} << fill_bits;
+    ++read_at;
+    fill_bits += 7;
+    if ((leb128_byte & 0x80) == 0) {
+      return value;
+    }
+  }
+  // Read 9 bytes and didn't find the terminator byte. Check if 10th byte
+  // is that terminator, however to fit result into uint64_t it may carry only
+  // single bit.
+  if (read_at != end && *read_at <= 1) {
+    value |= uint64_t{*read_at} << fill_bits;
+    ++read_at;
+    return value;
+  }
+  // Failed to find terminator leb128 byte.
+  read_at = nullptr;
+  return 0;
+}
+
+int WriteLeb128(uint64_t value, uint8_t* buffer) {
+  int size = 0;
+  while (value >= 0x80) {
+    buffer[size] = 0x80 | (value & 0x7F);
+    ++size;
+    value >>= 7;
+  }
+  buffer[size] = value;
+  ++size;
+  return size;
+}
+
+}  // namespace webrtc