From ec0abd190273b7b636c7085d7caed8220ab09172 Mon Sep 17 00:00:00 2001
From: tassaron
Date: Sun, 16 Jul 2017 14:06:11 -0400
Subject: apply complex filters to audio streams from components

tons of sound options could be given now, + installation using setup.py
---
 src/core.py | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 86 insertions(+), 17 deletions(-)

(limited to 'src/core.py')

diff --git a/src/core.py b/src/core.py
index 4c12209..324b04f 100644
--- a/src/core.py
+++ b/src/core.py
@@ -468,7 +468,8 @@ class Core:
         '''
             Constructs the major ffmpeg command used to export the video
         '''
-        duration = str(duration)
+        safeDuration = "{0:.3f}".format(duration - 0.05)  # used by filters
+        duration = "{0:.3f}".format(duration + 0.1)  # used by input sources
 
         # Test if user has libfdk_aac
         encoders = toolkit.checkOutput(
@@ -526,35 +527,99 @@ class Core:
             '-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 self.selectedComponents
             if 'audio' in comp.properties()
         ]
-        if extraAudio:
-            unwantedVideoStreams = []
-            for streamNo, params in enumerate(extraAudio):
+        if extraAudio or globalFilters > 0:
+            # Add -i options for extra input files
+            extraFilters = {}
+            for streamNo, params in enumerate(reversed(extraAudio)):
                 extraInputFile, params = params
                 ffmpegCommand.extend([
-                    '-t', duration,
+                    '-t', safeDuration,
                     '-i', extraInputFile
                 ])
-                if 'map' in params and params['map'] == '-v':
-                    # a video stream to remove
-                    unwantedVideoStreams.append(streamNo + 1)
+                # Construct dataset of extra filters we'll need to add later
+                for ffmpegFilter in params:
+                    if streamNo + 2 not in extraFilters:
+                        extraFilters[streamNo + 2] = []
+                    extraFilters[streamNo + 2].append((
+                        ffmpegFilter, params[ffmpegFilter]
+                    ))
+
+            # Start creating avfilters!
+            extraFilterCommand = []
+
+            if globalFilters <= 0:
+                # Dictionary of last-used tmp labels for a given stream number
+                tmpInputs = {streamNo: -1 for streamNo in extraFilters}
+            else:
+                # Insert blank entries for global filters into extraFilters
+                # so the per-stream filters know what input to source later
+                for streamNo in range(len(extraAudio), 0, -1):
+                    if streamNo + 1 not in extraFilters:
+                        extraFilters[streamNo + 1] = []
+                # Also filter the primary audio track
+                extraFilters[1] = []
+                tmpInputs = {
+                    streamNo: globalFilters - 1
+                    for streamNo in extraFilters
+                }
+
+                # Add the global filters!
+                # NOTE: list length must = globalFilters, currently hardcoded
+                if tmpInputs:
+                    extraFilterCommand.extend([
+                        '[%s:a] ashowinfo [%stmp0]' % (
+                            str(streamNo),
+                            str(streamNo)
+                        )
+                        for streamNo in tmpInputs
+                    ])
+
+            # Now add the per-stream filters!
+            for streamNo, paramList in extraFilters.items():
+                for param in paramList:
+                    source = '[%s:a]' % str(streamNo) \
+                        if tmpInputs[streamNo] == -1 else \
+                        '[%stmp%s]' % (
+                            str(streamNo), str(tmpInputs[streamNo])
+                        )
+                    tmpInputs[streamNo] = tmpInputs[streamNo] + 1
+                    extraFilterCommand.append(
+                        '%s %s%s [%stmp%s]' % (
+                            source, param[0], param[1], str(streamNo),
+                            str(tmpInputs[streamNo])
+                        )
+                    )
 
-            if unwantedVideoStreams:
-                ffmpegCommand.extend(['-map', '0'])
-            for streamNo in unwantedVideoStreams:
-                ffmpegCommand.extend([
-                    '-map', '-%s:v' % str(streamNo)
-                ])
+            # Join all the filters together and combine into 1 stream
+            extraFilterCommand = "; ".join(extraFilterCommand) + '; ' \
+                if tmpInputs else ''
             ffmpegCommand.extend([
                 '-filter_complex',
-                'amix=inputs=%s:duration=first:dropout_transition=3' % str(
-                    len(extraAudio) + 1
+                extraFilterCommand +
+                '%s amix=inputs=%s:duration=first [a]'
+                % (
+                    "".join([
+                        '[%stmp%s]' % (str(i), tmpInputs[i])
+                        if i in extraFilters else '[%s:a]' % str(i)
+                        for i in range(1, len(extraAudio) + 2)
+                    ]),
+                    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,
@@ -573,7 +638,7 @@ class Core:
         ffmpegCommand.append(outputFile)
         return ffmpegCommand
 
-    def readAudioFile(self, filename, parent):
+    def getAudioDuration(self, filename):
         command = [self.FFMPEG_BIN, '-i', filename]
 
         try:
@@ -588,6 +653,10 @@ class Core:
                 d = d.split(' ')[3]
                 d = d.split(':')
                 duration = float(d[0])*3600 + float(d[1])*60 + float(d[2])
+        return duration
+
+    def readAudioFile(self, filename, parent):
+        duration = self.getAudioDuration(filename)
 
         command = [
             self.FFMPEG_BIN,
-- 
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