move code into a new function for future expansion

src/toolkit/ffmpeg.py

@@ -98,20 +98,53 @@ def createFfmpegCommand(inputFile, outputFile, components, duration=-1):
         '-i', inputFile
     ]
 
-    # Add extra audio inputs and any needed avfilters
-    # NOTE: Global filters are currently hard-coded here for debugging use
-    globalFilters = 0  # increase to add global filters
     extraAudio = [
         comp.audio for comp in components
         if 'audio' in comp.properties()
     ]
-    if extraAudio or globalFilters > 0:
+    segment = createAudioFilterCommand(extraAudio, safeDuration)
+    ffmpegCommand.extend(segment)
+    if segment:
+        # Only map audio from the filters, and video from the pipe
+        ffmpegCommand.extend([
+            '-map', '0:v',
+            '-map', '[a]',
+        ])
+
+    ffmpegCommand.extend([
+        # OUTPUT
+        '-vcodec', vencoder,
+        '-acodec', aencoder,
+        '-b:v', vbitrate,
+        '-b:a', abitrate,
+        '-pix_fmt', Core.settings.value('outputVideoFormat'),
+        '-preset', Core.settings.value('outputPreset'),
+        '-f', container
+    ])
+
+    if acodec == 'aac':
+        ffmpegCommand.append('-strict')
+        ffmpegCommand.append('-2')
+
+    ffmpegCommand.append(outputFile)
+    return ffmpegCommand
+
+
+def createAudioFilterCommand(extraAudio, duration):
+    '''Add extra inputs and any needed filters to the main ffmpeg command.'''
+    # NOTE: Global filters are currently hard-coded here for debugging use
+    globalFilters = 0  # increase to add global filters
+
+    if not extraAudio and not globalFilters:
+        return []
+
+    ffmpegCommand = []
     # Add -i options for extra input files
     extraFilters = {}
     for streamNo, params in enumerate(reversed(extraAudio)):
         extraInputFile, params = params
         ffmpegCommand.extend([
-                '-t', safeDuration,
+            '-t', duration,
             # Tell ffmpeg about shorter clips (seemingly not needed)
             #   streamDuration = getAudioDuration(extraInputFile)
             #   if streamDuration and streamDuration > float(safeDuration)
@@ -188,29 +221,6 @@ def createFfmpegCommand(inputFile, outputFile, components, duration=-1):
             str(len(extraAudio) + 1)
         ),
     ])
-
-        # Only map audio from the filters, and video from the pipe
-        ffmpegCommand.extend([
-            '-map', '0:v',
-            '-map', '[a]',
-        ])
-
-    ffmpegCommand.extend([
-        # OUTPUT
-        '-vcodec', vencoder,
-        '-acodec', aencoder,
-        '-b:v', vbitrate,
-        '-b:a', abitrate,
-        '-pix_fmt', Core.settings.value('outputVideoFormat'),
-        '-preset', Core.settings.value('outputPreset'),
-        '-f', container
-    ])
-
-    if acodec == 'aac':
-        ffmpegCommand.append('-strict')
-        ffmpegCommand.append('-2')
-
-    ffmpegCommand.append(outputFile)
     return ffmpegCommand