diff --git a/biz/ffmpeg.py b/biz/ffmpeg.py
index 3d2f6e3..b8d22e0 100644
--- a/biz/ffmpeg.py
+++ b/biz/ffmpeg.py
@@ -36,7 +36,7 @@ def parse_ffmpeg_task(task_info, template_info):
             sub_ffmpeg_task = FfmpegTask(source)
             sub_ffmpeg_task.resolution = template_info.get("video_size", "")
             sub_ffmpeg_task.annexb = True
-            sub_ffmpeg_task.ext_data = find_placeholder_params(part.get('source'), task_params) or {}
+            sub_ffmpeg_task.ext_data = find_placeholder_params(part.get('source'), task_params_orig) or {}
             sub_ffmpeg_task.frame_rate = template_info.get("frame_rate", 25)
             sub_ffmpeg_task.center_cut = part.get("crop_mode", None)
             for effect in part.get('effects', []):