From c6a4f5f1949dfcf4f9fe77e16de276504a8a60d4 Mon Sep 17 00:00:00 2001
From: dreamerlin <528557675@qq.com>
Date: Thu, 5 Nov 2020 16:16:08 +0800
Subject: [PATCH 1/2] fix a bug when data_prefix is None

---
 mmaction/datasets/base.py       | 5 +++--
 tests/test_data/test_dataset.py | 4 ++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/mmaction/datasets/base.py b/mmaction/datasets/base.py
index f526a00ace..99817d2dfb 100644
--- a/mmaction/datasets/base.py
+++ b/mmaction/datasets/base.py
@@ -67,8 +67,9 @@ def __init__(self,
         super().__init__()
 
         self.ann_file = ann_file
-        self.data_prefix = osp.realpath(data_prefix) if osp.isdir(
-            data_prefix) else data_prefix
+        self.data_prefix = osp.realpath(
+            data_prefix) if data_prefix is not None and osp.isdir(
+                data_prefix) else data_prefix
         self.test_mode = test_mode
         self.multi_class = multi_class
         self.num_classes = num_classes
diff --git a/tests/test_data/test_dataset.py b/tests/test_data/test_dataset.py
index e8698110f5..3b2a9d43bb 100644
--- a/tests/test_data/test_dataset.py
+++ b/tests/test_data/test_dataset.py
@@ -265,6 +265,10 @@ def test_dataset_realpath(self):
                                   's3://good')
         assert dataset.data_prefix == 's3://good'
 
+        dataset = RawframeDataset(self.frame_ann_file, self.frame_pipeline)
+        assert dataset.data_prefix is None
+        assert dataset.video_infos[0]['frame_dir'] == 'test_imgs'
+
     def test_video_dataset(self):
         video_dataset = VideoDataset(
             self.video_ann_file,

From a03cf14582f7fb1eb09d68ac6d6e4e0f135a7761 Mon Sep 17 00:00:00 2001
From: dreamerlin <528557675@qq.com>
Date: Thu, 5 Nov 2020 16:19:25 +0800
Subject: [PATCH 2/2] update changelog

---
 docs/changelog.md | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/docs/changelog.md b/docs/changelog.md
index bc44504e1b..844f678f31 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -1,5 +1,18 @@
 ## Changelog
 
+###v 0.9.0 (master)
+
+**Highlights**
+
+**New Features**
+
+**Improvements**
+
+**Bug Fixes**
+- Fix a bug in BaseDataset when `data_prefix` is None ([#314](https://github.com/open-mmlab/mmaction2/pull/314))
+
+**ModelZoo**
+
 ### v0.8.0 (31/10/2020)
 
 **Highlights**