diff --git a/render.py b/render.py
index 1452501..f783d8e 100644
--- a/render.py
+++ b/render.py
@@ -153,7 +153,7 @@ def compose(clips, fragment, target=150, base=1024, voice_over=None, options=Non
             }
         })
 
-        volume_front = '-15'
+        volume_front = '-13'
         if clip.get('volume') is not None:
             volume_front = '%0.2f' % (float(volume_front) + clip['volume'])
 
@@ -263,9 +263,9 @@ def compose(clips, fragment, target=150, base=1024, voice_over=None, options=Non
             print('%07.3f-%07.3f %07.3f' % (sub_offset, sub_offset+vo["duration"], vo["duration"]), vo["src"].split('/')[-1])
             voice_overs.append(vo)
             voc = vo.copy()
-            a, b = '5', '-1'
+            a, b = '6', '-1'
             if options.get('stereo_downmix'):
-                a, b = '5', '-1'
+                a, b = '6', '-1'
             voc['filter'] = {'volume': a}
             scene['audio-center']['A1'].append(voc)
             vo_low = vo.copy()
@@ -535,9 +535,17 @@ def render_all(options):
         timelines = render(prefix, scene, fragment_prefix[len(prefix) + 1:] + '/', options)
 
         scene_json = json.dumps(scene, indent=2, ensure_ascii=False)
-        write_if_new(os.path.join(fragment_prefix, 'scene.json'), scene_json)
+        scene_json_path = os.path.join(fragment_prefix, 'scene.json')
+        segment_path = os.path.join(fragment_prefix, 'segment.mp4')
+        is_new = write_if_new(scene_json_path, scene_json)
+        if not is_new:
+            if not os.path.exists(segment_path) or os.lstat(scene_json_path).st_mtime > os.lstat(segment_path).st_mtime:
+                is_new = True
+                print("%s needs update" % segment_path)
+        if not is_new:
+            print("%s did not change" % scene_json_path)
 
-        if not options['no_video'] and not options["single_file"]:
+        if is_new and not options['no_video'] and not options["single_file"]:
             for timeline in timelines:
                 print(timeline)
                 ext = '.mp4'
@@ -662,7 +670,7 @@ def render_all(options):
                 if os.path.exists(fn):
                     os.unlink(fn)
 
-    if options["single_file"]:
+    if is_new and options["single_file"]:
         cmds = []
         base_prefix = Path(base_prefix)
         for timeline in (
@@ -828,6 +836,11 @@ def scene_subtitles(scene, options):
     return subs
 
 
+DEFAULTS = {
+    "max-items": 10,
+    "no_video": False
+}
+
 def load_defaults(options):
     path = os.path.join(options["prefix"], "options.json")
     if os.path.exists(path):
@@ -836,8 +849,19 @@ def load_defaults(options):
         for key in defaults:
             if key not in options:
                 options[key] = defaults[key]
+        for key in DEFAULTS:
+            if key not in options:
+                options[key] = DEFAULTS[key]
     return options
 
+def reload_options(options):
+    path = os.path.join(options["prefix"], "options.json")
+    if os.path.exists(path):
+        with open(path) as fd:
+            defaults = json.load(fd)
+        for key in defaults:
+            options[key] = defaults[key]
+    return options
 
 def update_subtitles(options):
     import item.models
@@ -890,8 +914,6 @@ def render_infinity(options):
 
     defaults = {
         "offset": 100,
-        "max-items": 30,
-        "no_video": False,
     }
     state_f = os.path.join(prefix, "infinity.json")
     if os.path.exists(state_f):
@@ -899,7 +921,16 @@ def render_infinity(options):
             state = json.load(fd)
     else:
         state = {}
-    for key in ("prefix", "duration", "debug", "single_file", "keep_audio", "stereo_downmix"):
+
+    option_keys = (
+        "prefix",
+        "duration",
+        "debug",
+        "single_file",
+        "keep_audio",
+        "stereo_downmix"
+    )
+    for key in options_keys:
         state[key] = options[key]
 
     for key in defaults:
@@ -912,9 +943,9 @@ def render_infinity(options):
             f for f in os.listdir(render_prefix)
             if f.isdigit() and os.path.isdir(render_prefix + f) and state["offset"] > int(f) >= 100
         ]
-        if len(current) > state["max-items"]:
+        if len(current) > options["max-items"]:
             current = ox.sorted_strings(current)
-            remove = current[:-state["max-items"]]
+            remove = current[:-options["max-items"]]
             update_m3u(render_prefix, exclude=remove)
             for folder in remove:
                 folder = render_prefix + folder
@@ -926,6 +957,9 @@ def render_infinity(options):
         with open(state_f + "~", "w") as fd:
             json.dump(state, fd, indent=2)
         shutil.move(state_f + "~", state_f)
+        options = reload_options(options)
+        for key in options_keys:
+            state[key] = options[key]
 
 
 def join_subtitles(base_prefix, options):
diff --git a/render_sound.py b/render_sound.py
index 88e8340..4427b47 100644
--- a/render_sound.py
+++ b/render_sound.py
@@ -34,7 +34,7 @@ def render_music():
             "src": src,
             "duration": clip.sort.duration,
             "filter": {
-                'volume': '0',
+                'volume': '2',
             },
         })
 
@@ -112,7 +112,7 @@ def render_forest():
             "src": src,
             "duration": clip.sort.duration,
             "filter": {
-                'volume': '2',
+                'volume': '1',
             },
         })
 
diff --git a/utils.py b/utils.py
index 1cdd826..bd1cb21 100644
--- a/utils.py
+++ b/utils.py
@@ -56,6 +56,7 @@ def write_if_new(path, data, mode=''):
     if is_new:
         with open(path, write_mode) as fd:
             fd.write(data)
+    return is_new
 
 def format_duration(duration, fps, audio=False):
     if audio: