diff --git a/src/avprotocol/libsdp/grammars.ts b/src/avprotocol/libsdp/grammars.ts
index 8a69f7e8..c09a9b51 100644
--- a/src/avprotocol/libsdp/grammars.ts
+++ b/src/avprotocol/libsdp/grammars.ts
@@ -1,3 +1,28 @@
+/*
+ * libmedia sdp grammars
+ *
+ * 版权所有 (C) 2024 赵高兴
+ * Copyright (C) 2024 Gaoxing Zhao
+ *
+ * 此文件是 libmedia 的一部分
+ * This file is part of libmedia.
+ * 
+ * libmedia 是自由软件；您可以根据 GNU Lesser General Public License（GNU LGPL）3.1
+ * 或任何其更新的版本条款重新分发或修改它
+ * libmedia is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3.1 of the License, or (at your option) any later version.
+ * 
+ * libmedia 希望能够为您提供帮助，但不提供任何明示或暗示的担保，包括但不限于适销性或特定用途的保证
+ * 您应自行承担使用 libmedia 的风险，并且需要遵守 GNU Lesser General Public License 中的条款和条件。
+ * libmedia is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ */
+
 import { Data } from 'common/types/type'
 import * as is from 'common/util/is'
 
diff --git a/src/avprotocol/libsdp/libsdp.ts b/src/avprotocol/libsdp/libsdp.ts
index 558a0ef8..091b5c0d 100644
--- a/src/avprotocol/libsdp/libsdp.ts
+++ b/src/avprotocol/libsdp/libsdp.ts
@@ -1,3 +1,28 @@
+/*
+ * libmedia sdp util
+ *
+ * 版权所有 (C) 2024 赵高兴
+ * Copyright (C) 2024 Gaoxing Zhao
+ *
+ * 此文件是 libmedia 的一部分
+ * This file is part of libmedia.
+ * 
+ * libmedia 是自由软件；您可以根据 GNU Lesser General Public License（GNU LGPL）3.1
+ * 或任何其更新的版本条款重新分发或修改它
+ * libmedia is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3.1 of the License, or (at your option) any later version.
+ * 
+ * libmedia 希望能够为您提供帮助，但不提供任何明示或暗示的担保，包括但不限于适销性或特定用途的保证
+ * 您应自行承担使用 libmedia 的风险，并且需要遵守 GNU Lesser General Public License 中的条款和条件。
+ * libmedia is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ */
+
 import { SessionDescription, Media } from './type'
 import { grammars, SdpGrammar } from './grammars'
 import { Data } from 'common/types/type'
diff --git a/src/avprotocol/libsdp/type.ts b/src/avprotocol/libsdp/type.ts
index 8f6a9904..3a0b7c57 100644
--- a/src/avprotocol/libsdp/type.ts
+++ b/src/avprotocol/libsdp/type.ts
@@ -1,3 +1,28 @@
+/*
+ * libmedia sdp type defined
+ *
+ * 版权所有 (C) 2024 赵高兴
+ * Copyright (C) 2024 Gaoxing Zhao
+ *
+ * 此文件是 libmedia 的一部分
+ * This file is part of libmedia.
+ * 
+ * libmedia 是自由软件；您可以根据 GNU Lesser General Public License（GNU LGPL）3.1
+ * 或任何其更新的版本条款重新分发或修改它
+ * libmedia is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3.1 of the License, or (at your option) any later version.
+ * 
+ * libmedia 希望能够为您提供帮助，但不提供任何明示或暗示的担保，包括但不限于适销性或特定用途的保证
+ * 您应自行承担使用 libmedia 的风险，并且需要遵守 GNU Lesser General Public License 中的条款和条件。
+ * libmedia is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ */
+
 export interface MediaDescription extends SharedDescriptionFields, MediaAttributes {}
 
 export type Media = {