make logo scale optional

ffplayout.yml

@@ -34,7 +34,9 @@ logging:
 pre_compress:
     helptext: Settings for the pre-compression. All clips get prepared in that way,
         so the input for the final compression is unique. 'aspect' must be a float
-        number. 'logo' is only used if the path exist. With 'logo_opacity' logo can
+        number. 'logo' is only used if the path exist. 'logo_scale' scale the logo to
+        target size, leave it blank when no scaling is needed, format is 'number:number',
+        for example '100:-1' for proportional scaling. With 'logo_opacity' logo can
         become transparent. With 'logo_filter' 'overlay=W-w-12:12' you can modify
         the logo position. With 'use_loudnorm' you can activate single pass EBU R128
         loudness normalization. 'loud_*' can adjust the loudnorm filter. [Output is
@@ -45,7 +47,7 @@ pre_compress:
     fps: 25
     add_logo: True
     logo: "docs/logo.png"
-    logo_scale: "100:-1"
+    logo_scale:
     logo_opacity: 0.7
     logo_filter: "overlay=W-w-12:12"
     add_loudnorm: False

ffplayout/filters.py

@@ -19,10 +19,10 @@
 
 import math
 import os
+import re
 
 from .utils import _pre_comp
 
-
 # ------------------------------------------------------------------------------
 # building filters,
 # when is needed add individuell filters to match output format
@@ -116,14 +116,18 @@ def overlay_filter(duration, ad, ad_last, ad_next):
     when clip before was an ad fade logo in
     """
     logo_filter = '[v]null[logo]'
+    scale_filter = ''
 
     if _pre_comp.add_logo and os.path.isfile(_pre_comp.logo) and not ad:
         logo_chain = []
-        opacity = 'format=rgba,scale={},colorchannelmixer=aa={}'.format(
-            _pre_comp.logo_scale, _pre_comp.logo_opacity)
+        if _pre_comp.logo_scale and \
+                re.match(r'\d+:-?\d+', _pre_comp.logo_scale):
+            scale_filter = 'scale={},'.format(_pre_comp.logo_scale)
+        logo_extras = 'format=rgba,{}colorchannelmixer=aa={}'.format(
+            scale_filter, _pre_comp.logo_opacity)
         loop = 'loop=loop=-1:size=1:start=0'
         logo_chain.append(
-            'movie={},{},{}'.format(_pre_comp.logo, loop, opacity))
+            'movie={},{},{}'.format(_pre_comp.logo, loop, logo_extras))
         if ad_last:
             logo_chain.append('fade=in:st=0:d=1.0:alpha=1')
         if ad_next: