From 51f400f598631d9ba5b347dfa46292581494793e Mon Sep 17 00:00:00 2001
From: Gengshan Yang <luanyingjian@gmail.com>
Date: Mon, 16 Oct 2023 14:19:31 -0400
Subject: [PATCH] Update data_utils.py

---
 lab4d/dataloader/data_utils.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lab4d/dataloader/data_utils.py b/lab4d/dataloader/data_utils.py
index 33f7252..d56775e 100644
--- a/lab4d/dataloader/data_utils.py
+++ b/lab4d/dataloader/data_utils.py
@@ -24,8 +24,10 @@ class FrameInfo:
 
     def __init__(self, ref_list):
         self.num_frames = len(ref_list)
+        # need the raw frame index to apply Fourier time embedding
         raw_dir = ref_list[0].rsplit("/", 1)[0].replace("JPEGImages", "JPEGImagesRaw")
         self.num_frames_raw = len(glob.glob(raw_dir + "/*.jpg"))
+        assert self.num_frames_raw > 0 
         self.frame_map = [int(path.split("/")[-1].split(".")[0]) for path in ref_list]