diff --git a/comfy_api/latest/_input/video_types.py b/comfy_api/latest/_input/video_types.py
index 451e9526e..8fff52c16 100644
--- a/comfy_api/latest/_input/video_types.py
+++ b/comfy_api/latest/_input/video_types.py
@@ -65,6 +65,12 @@ class VideoInput(ABC):
         buffer.seek(0)
         return buffer
 
+    def get_active_trim_window(self) -> tuple[float, float]:
+        """Return the active trim as ``(start_time, duration)`` in seconds (start_time normalized
+        to ``>= 0``; ``duration == 0`` means "until the end"). Default: no trim; trimmable subclasses override.
+        """
+        return 0.0, 0.0
+
     # Provide a default implementation, but subclasses can provide optimized versions
     # if possible.
     def get_dimensions(self) -> tuple[int, int]:
diff --git a/comfy_api/latest/_input_impl/video_types.py b/comfy_api/latest/_input_impl/video_types.py
index 99e67d363..4a12ff9c1 100644
--- a/comfy_api/latest/_input_impl/video_types.py
+++ b/comfy_api/latest/_input_impl/video_types.py
@@ -75,6 +75,12 @@ class VideoFromFile(VideoInput):
             self.__file.seek(0)
         return self.__file
 
+    def get_active_trim_window(self) -> tuple[float, float]:
+        start_time = self.__start_time
+        if start_time < 0:
+            start_time = max(self._get_raw_duration() + start_time, 0.0)
+        return float(start_time), float(self.__duration)
+
     def get_dimensions(self) -> tuple[int, int]:
         """
         Returns the dimensions of the video input.
diff --git a/comfy_api_nodes/util/conversions.py b/comfy_api_nodes/util/conversions.py
index 5738df57f..a1b5d599c 100644
--- a/comfy_api_nodes/util/conversions.py
+++ b/comfy_api_nodes/util/conversions.py
@@ -469,6 +469,11 @@ def _apply_video_scale(video: Input.Video, scale_dims: tuple[int, int]) -> Input
     input_container = None
     output_container = None
 
+    # get_stream_source() is untrimmed, so apply the trim window in this same pass.
+    # start_time is normalized (>= 0); duration == 0 means "until the end".
+    start_time, duration = video.get_active_trim_window()
+    trimming = bool(start_time or duration)
+
     try:
         input_source = video.get_stream_source()
         input_container = av.open(input_source, mode="r")
@@ -487,16 +492,45 @@ def _apply_video_scale(video: Input.Video, scale_dims: tuple[int, int]) -> Input
                 audio_stream.layout = stream.layout
                 break
 
+        in_video = input_container.streams.video[0]
+        start_pts = int(start_time / in_video.time_base) if trimming else 0
+        end_pts = int((start_time + duration) / in_video.time_base) if duration else None
+        if start_pts:
+            input_container.seek(start_pts, stream=in_video)
+
+        encoded = 0
         for frame in input_container.decode(video=0):
+            if trimming:
+                if frame.pts is None or frame.pts < start_pts:
+                    continue
+                if end_pts is not None and frame.pts >= end_pts:
+                    break
             frame = frame.reformat(width=out_w, height=out_h, format="yuv420p")
+            # Re-wrap as a fresh frame: dropping irregular source timestamps (VFR/AVI/GIF/...)
+            # lets the encoder assign clean ones and avoids mp4 muxer errors.
+            frame = av.VideoFrame.from_ndarray(frame.to_ndarray(format="yuv420p"), format="yuv420p")
             for packet in video_stream.encode(frame):
                 output_container.mux(packet)
+            encoded += 1
         for packet in video_stream.encode():
             output_container.mux(packet)
 
+        if encoded == 0:
+            raise ValueError(
+                f"resize produced no frames (start_time={start_time}, duration={duration} "
+                "selected nothing from the source)"
+            )
+
         if audio_stream is not None:
             input_container.seek(0)
             for audio_frame in input_container.decode(audio=0):
+                if trimming:
+                    if audio_frame.time is None or audio_frame.time < start_time:
+                        continue
+                    if duration and audio_frame.time > start_time + duration:
+                        break
+                # Carry odd audio time bases the mp4 muxer rejects; reset pts, encoder assigns clean ones (MP3-in-AVI)
+                audio_frame.pts = None
                 for packet in audio_stream.encode(audio_frame):
                     output_container.mux(packet)
             for packet in audio_stream.encode():