Change API output to gr.File for proper file serving

app.py

@@ -204,23 +204,23 @@ def _process_video_api_impl(
     file_path, gazing_ratio, task_loss_requirement, output_fps, progress=None
 ):
     """API-friendly endpoint that takes a file path string instead of gr.File.
-    Returns only the gazing video path for programmatic use."""
+    Returns the gazing video as a gr.File output for proper file serving."""
     if not file_path or not os.path.exists(file_path):
-        return "Error: file not found"
+        raise gr.Error("file not found")
 
     metadata = extract_metadata(file_path)
     if metadata[1] is None:
-        return "Error: could not read file"
+        raise gr.Error("could not read file")
 
     _, tmp_path, total_frames, fps, _, _ = metadata
 
-    yield "Loading model..."
+    yield gr.update()
 
     if progress:
         progress(0.0, desc="Loading model...")
     setup = get_model(device)
 
-    yield "Processing video..."
+    yield gr.update()
 
     if progress:
         progress(0.1, desc="Processing video...")
@@ -239,9 +239,7 @@ def _process_video_api_impl(
         progress_callback=update_progress,
         spatial_batch_size=2,
     ):
-        yield "Processing..."
-
-    yield "Saving output..."
+        yield gr.update()
 
     fps_to_use = output_fps if output_fps is not None else results["fps"]
 
@@ -249,7 +247,7 @@ def _process_video_api_impl(
     save_video(results["gazing_frames"], gazing_file.name, fps_to_use)
     gazing_file.close()
 
-    yield gazing_file.name
+    yield gr.File(value=gazing_file.name)
 
 
 if ZEROGPU_AVAILABLE:
@@ -461,7 +459,7 @@ with gr.Blocks(title="AutoGaze Demo", delete_cache=(86400, 86400)) as demo:
         )
         api_output_fps = gr.Number(label="Output FPS", value=None)
         api_button = gr.Button("Process (API)")
-        api_result = gr.Textbox(label="Result Path")
+        api_result = gr.File(label="Result")
         api_button.click(
             fn=process_video_api,
             inputs=[api_file_path, api_gazing_ratio, api_task_loss, api_output_fps],