diff --git a/docs/api.rst b/docs/api.rst
index 03e453da3..8bc4bfc18 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -225,7 +225,7 @@ Methods for creating machine learning behavior classifiers
 .. toctree::
    :maxdepth: 2
 
-   simba.mixins.train_model_mixin
+   simba.mixins.train_model_mixin.TrainModelMixin
 
 
 
@@ -237,7 +237,7 @@ Methods for reading SimBA configparser.Configparser project config and associate
 .. toctree::
    :maxdepth: 2
 
-   simba.mixins.config_reader
+   simba.mixins.config_reader.ConfigReader
 
 
 Cue-light tools
diff --git a/simba/third_party_label_appenders/converters.py b/simba/third_party_label_appenders/converters.py
index 906dcce7e..5c8aba6e6 100644
--- a/simba/third_party_label_appenders/converters.py
+++ b/simba/third_party_label_appenders/converters.py
@@ -458,7 +458,7 @@ def scale_pose_img_sizes(pose_data: np.ndarray,
        :align: center
 
     :param pose_data: 3d MxNxR array of pose-estimation data where N is number of images, N the number of body-parts in each frame and R represents x,y coordinates of the body-parts.
-    :param imgs: Iteralble of images of same size as pose_data M dimension. Can be byte string representation of images of images as arrays.
+    :param imgs: Iteralble of images of same size as pose_data M dimension. Can be byte string representation of images, or images as arrays.
     :param size: The target size for the resizing operation. It can be: - `'min'`: Resize all images to the smallest height and width found among the input images. - `'max'`: Resize all images to the largest height and width found among the imgs.
     :param interpolation: Interpolation method to use for resizing. This can be one of OpenCV's interpolation methods.
     :return: The converted pose_data and converted images to align with the new size.
diff --git a/simba/utils/read_write.py b/simba/utils/read_write.py
index d0946a02b..91c96291a 100644
--- a/simba/utils/read_write.py
+++ b/simba/utils/read_write.py
@@ -546,7 +546,7 @@ def concatenate_videos_in_folder(in_folder: Union[str, os.PathLike],
 
     if check_nvidea_gpu_available() and gpu:
         if fps is None:
-            returned = os.system(f'ffmpeg -hwaccel auto -c:v h264_cuvid -f concat -safe 0 -i "{temp_txt_path}" -c copy -hide_banner -loglevel info "{save_path}" -y')
+            returned = os.system(f'ffmpeg -hwaccel auto -c:v h264_cuvid -f concat -safe 0 -i "{temp_txt_path}" -c:v h264_nvenc -c:a copy -hide_banner -loglevel info "{save_path}" -y')
         else:
             returned = os.system(f'ffmpeg -hwaccel auto -c:v h264_cuvid -f concat -safe 0 -i "{temp_txt_path}" -r {out_fps} -c:v h264_nvenc -c:a copy -hide_banner -loglevel info "{save_path}" -y')
     else:
diff --git a/simba/video_processors/video_processing.py b/simba/video_processors/video_processing.py
index d6dc6103a..6b65a7e6c 100644
--- a/simba/video_processors/video_processing.py
+++ b/simba/video_processors/video_processing.py
@@ -37,7 +37,7 @@
                                 check_valid_boolean, check_valid_lst,
                                 check_valid_tuple)
 from simba.utils.data import find_frame_numbers_from_time_stamp
-from simba.utils.enums import OS, ConfigKey, Formats, Options, Paths
+from simba.utils.enums import OS, ConfigKey, Formats, Options, Paths, Defaults
 from simba.utils.errors import (CountError, DirectoryExistError,
                                 FFMPEGCodecGPUError, FFMPEGNotFoundError,
                                 FileExistError, FrameRangeError,
@@ -3896,8 +3896,8 @@ def _bg_remover_mp(frm_range: Tuple[int, np.ndarray],
     save_path = os.path.join(temp_dir, f"{batch}.mp4")
     cap.set(1, start_frm)
     writer = cv2.VideoWriter(save_path, fourcc, video_meta_data['fps'], (video_meta_data['width'], video_meta_data['height']))
-    bg = np.full_like(bg_frm, bg_clr)
-    bg = bg[:, :, ::-1]
+
+    bg = np.full_like(bg_frm, bg_clr)[..., ::-1]  # Ensure RGB to BGR if needed
     dir, video_name, ext = get_fn_ext(filepath=video_path)
     while current_frm <= end_frm:
         ret, frm = cap.read()
@@ -3908,13 +3908,13 @@ def _bg_remover_mp(frm_range: Tuple[int, np.ndarray],
         gray_diff = 0.2989 * r + 0.5870 * g + 0.1140 * b
         gray_diff = gray_diff.astype(np.uint8)  # Ensure the type is uint8
         mask = np.where(gray_diff > 50, 255, 0).astype(np.uint8)
+        mask_inv = cv2.bitwise_not(mask)
         if fg_clr is None:
             fg = cv2.bitwise_and(frm, frm, mask=mask)
-            result = cv2.add(bg, fg)
+            result = cv2.bitwise_and(bg, bg, mask=mask_inv)
+            result = cv2.add(result, fg)
         else:
-            mask_inv = cv2.bitwise_not(mask)
-            fg_clr_img = np.full_like(frm, fg_clr)
-            fg_clr_img = fg_clr_img[:, :, ::-1]
+            fg_clr_img = np.full_like(frm, fg_clr)[..., ::-1]
             fg_clr_img = cv2.bitwise_and(fg_clr_img, fg_clr_img, mask=mask)
             result = cv2.bitwise_and(bg, bg, mask=mask_inv)
             result = cv2.add(result, fg_clr_img)
@@ -4007,7 +4007,7 @@ def video_bg_substraction_mp(video_path: Union[str, os.PathLike],
     frm_data = []
     for c, i in enumerate(frm_list):
         frm_data.append((c, i))
-    with multiprocessing.Pool(core_cnt, maxtasksperchild=9000) as pool:
+    with multiprocessing.Pool(core_cnt, maxtasksperchild=Defaults.MAXIMUM_MAX_TASK_PER_CHILD.value) as pool:
         constants = functools.partial(_bg_remover_mp,
                                       video_path=video_path,
                                       bg_frm=bg_frm,
@@ -4022,7 +4022,7 @@ def video_bg_substraction_mp(video_path: Union[str, os.PathLike],
         pool.join()
 
     print(f"Joining {video_name} multiprocessed video...")
-    concatenate_videos_in_folder(in_folder=temp_dir, save_path=save_path, video_format=ext[1:], remove_splits=True, gpu=gpu)
+    concatenate_videos_in_folder(in_folder=temp_dir, save_path=save_path, video_format=ext[1:], remove_splits=True, gpu=gpu, fps=video_meta_data['fps'])
     timer.stop_timer()
     stdout_success(msg=f'Video saved at {save_path}', elapsed_time=timer.elapsed_time_str)