diff --git a/video/__init__.py b/video/__init__.py
new file mode 100644
index 0000000..b89740d
--- /dev/null
+++ b/video/__init__.py
@@ -0,0 +1,67 @@
+from exceptions import *
+from bilibili_api import video, sync, HEADERS
+import httpx
+
+
+class Video:
+    def __init__(self, video_number: str):
+        if len(video_number) <= 2:
+            raise InvalidVideoNumberException(
+                f"The video number {video_number} is too short!"
+            )
+        if video_number[:2].upper() == "AV":
+            if not video_number[2:].isnumeric():
+                raise InvalidVideoNumberException(
+                    f"Invalid AV video number {video_number}!"
+                )
+            else:
+                self.v = video.Video(aid="AV" + video_number[2:])
+        if video_number[:2].upper() != "BV":
+            raise InvalidVideoNumberException(f"Invalid video number {video_number}!")
+        else:
+            self.v = video.Video(bvid="BV" + video_number[2:])
+
+        try:
+            download_url_data = sync(self.v.get_download_url(0))
+            detecter = video.VideoDownloadURLDataDetecter(data=download_url_data)
+            streams = detecter.detect_best_streams()
+            self.url = streams[1].url
+        except:
+            raise BiliBiliAPIException("Error happens with bilibili-api-python.")
+        if detecter.check_flv_stream() == True:
+            raise BadVideoException(
+                f"This video ({self.title})) is only available in flv format."
+            )
+
+    def get_info(self):
+        try:
+            info = sync(self.v.get_info())
+        except:
+            raise BiliBiliAPIException("Error happens with bilibili-api-python.")
+        self.title = info["title"]
+        self.author = info["owner"]
+
+    def get_url(self):
+        try:
+            download_url_data = sync(self.v.get_download_url(0))
+            detecter = video.VideoDownloadURLDataDetecter(data=download_url_data)
+            streams = detecter.detect_best_streams()
+        except:
+            raise BiliBiliAPIException("Error happens with bilibili-api-python.")
+        if detecter.check_flv_stream() == True:
+            raise BadVideoException(
+                f"This video ({self.title})) is only available in flv format."
+            )
+        self.url = streams[1].url
+
+    def download_video(self):
+        with httpx.stream("GET", self.url, headers=HEADERS) as r:
+            self.length = int(r.headers["content-length"])
+            self.received_bytes = 0
+            with open("demo.m4a", "wb") as f:
+                for chunk in r.iter_bytes(1024):
+                    if not chunk:
+                        break
+                    self.received_bytes += len(chunk)
+                    f.write(chunk)
+                    print(f"downloaded {int(self.received_bytes / self.length * 100)}%")
diff --git a/video/exceptions.py b/video/exceptions.py
new file mode 100644
index 0000000..2283372
--- /dev/null
+++ b/video/exceptions.py
@@ -0,0 +1,10 @@
+class InvalidVideoNumberException(Exception):
+    pass
+
+
+class BiliBiliAPIException(Exception):
+    pass
+
+
+class BadVideoException(Exception):
+    pass