Audio Downmix for AviSynth?

[Vlcek]

Is there any plugin able to do automatical downmix (to stereo) for audio from unspecified number of channels?
Im batch-converting more MOV files and getting sometimes 3-6 sound channels and need result in stereo. There is default converttomono, need something like converttostereo but with full downmix, not just separating left/right channels...

[check]

I assume you are loading the file with directshowsource? Why not simply configure the decoder in use to output stereo?

[Vlcek]

Im loading them with QTinput, got some problems with framerate after using directshowsource...

[Mr_Odwin]

In the FAVC package there's a FAVCStereo.avsi that can be imported into a script and then FAVCStereoDSS(VideoClip,AudioClip) can be called. Note that you should maybe tweak it to your liking - there's normalisation, conversion to 48000 hz and 16 bit in there, that maybe you don't like?

Example use:

QTInput(Path\Video.mov)
FAVCStereoDSS(Last,Last)


Here it is for convenience:


Function FAVCStereo(clip Video, clip Audio) {

Dubbed = Video

Chan0 = (HasAudio(Audio)==False) ? AudioDub(Video, BlankClip(Video, audio_rate=48000, stereo=true)) : nop()
Dubbed = (HasAudio(Audio)==False) ? Chan0 : Dubbed

Audio = (HasAudio(Audio)==True) ? ConvertAudioToFloat(Audio) : Audio

Chan1 = (AudioChannels(Audio)==1) ? Audiodub(Video, GetChannel(Audio, 1, 1)) : nop()
Dubbed = (AudioChannels(Audio)==1) ? Chan1 : Dubbed

Chan2 = (AudioChannels(Audio)==2) ? Audiodub(Video, Audio) : nop()
Dubbed = (AudioChannels(Audio)==2) ? Chan2 : Dubbed

FrontLeft = (AudioChannels(Audio)==3) ? MixAudio(GetChannel(Audio, 1), GetChannel(Audio, 2), 0.5, 0.5) : nop()
FrontRight = (AudioChannels(Audio)==3) ? MixAudio(GetChannel(Audio, 3), GetChannel(Audio, 2), 0.5, 0.5) : nop()
Chan3 = (AudioChannels(Audio)==3) ? Audiodub(Video, MergeChannels(FrontLeft, FrontRight)) : nop()
Dubbed = (AudioChannels(Audio)==3) ? Chan3 : Dubbed

TotalLeft = (AudioChannels(Audio)==4) ? MixAudio(GetChannel(Audio, 1), GetChannel(Audio, 3), 0.5, 0.5) : nop()
TotalRight = (AudioChannels(Audio)==4) ? MixAudio(GetChannel(Audio, 2), GetChannel(Audio, 4), 0.5, 0.5) : nop()
Chan4 = (AudioChannels(Audio)==4) ? Audiodub(Video, MergeChannels(TotalLeft, TotalRight)) : nop()
Dubbed = (AudioChannels(Audio)==4) ? Chan4 : Dubbed

FrontLeft = (AudioChannels(Audio)==5) ? MixAudio(GetChannel(Audio, 1), GetChannel(Audio, 2), 0.3694, 0.2612) : nop()
FrontRight = (AudioChannels(Audio)==5) ? MixAudio(GetChannel(Audio, 3), GetChannel(Audio, 2), 0.3694, 0.2612) : nop()
TotalLeft = (AudioChannels(Audio)==5) ? MixAudio(FrontLeft, GetChannel(Audio, 4), 1, 0.3694) : nop()
TotalRight = (AudioChannels(Audio)==5) ? MixAudio(FrontRight, GetChannel(Audio, 5), 1, 0.3694) : nop()
Chan5 = (AudioChannels(Audio)==5) ? Audiodub(Video, MergeChannels(TotalLeft, TotalRight)) : nop()
Dubbed = (AudioChannels(Audio)==5) ? Chan5 : Dubbed

BackLeft = (AudioChannels(Audio)>=6) ? MixAudio(GetChannel(Audio, 4), GetChannel(Audio, 6), 0.2698, 0.2698) : nop()
BackRight = (AudioChannels(Audio)>=6) ? MixAudio(GetChannel(Audio, 5), GetChannel(Audio, 6), 0.2698, 0.2698) : nop()
FrontLeft = (AudioChannels(Audio)>=6) ? MixAudio(GetChannel(Audio, 1), GetChannel(Audio, 2), 0.2698, 0.1906) : nop()
FrontRight = (AudioChannels(Audio)>=6) ? MixAudio(GetChannel(Audio, 3), GetChannel(Audio, 2), 0.2698, 0.1906) : nop()
TotalLeft = (AudioChannels(Audio)>=6) ? MixAudio(FrontLeft, BackLeft, 1, 1) : nop()
TotalRight = (AudioChannels(Audio)>=6) ? MixAudio(FrontRight, BackRight, 1, 1) : nop()
Chan6 = (AudioChannels(Audio)>=6) ? Audiodub(Video, MergeChannels(TotalLeft, TotalRight)) : nop()
Dubbed = (AudioChannels(Audio)>=6) ? Chan6 : Dubbed


Dubbed = (HasAudio(Audio)==True) ? Normalize(Dubbed) : Dubbed
Dubbed = (HasAudio(Audio)==True) ? SSRC(Dubbed, 48000) : Dubbed
Dubbed = (HasAudio(Audio)==True) ? ConvertAudioTo16bit(Dubbed) : Dubbed

return(Dubbed)
}

Function FAVCStereoDSS(clip Video, clip Audio) {

Dubbed = Video

Chan0 = (HasAudio(Audio)==False) ? AudioDub(Video, BlankClip(Video, audio_rate=48000, stereo=true)) : nop()
Dubbed = (HasAudio(Audio)==False) ? Chan0 : Dubbed

Audio = (HasAudio(Audio)==True) ? ConvertAudioToFloat(Audio) : Audio

Chan1 = (AudioChannels(Audio)==1) ? Audiodub(Video, GetChannel(Audio, 1, 1)) : nop()
Dubbed = (AudioChannels(Audio)==1) ? Chan1 : Dubbed

Chan2 = (AudioChannels(Audio)==2) ? Audiodub(Video, Audio) : nop()
Dubbed = (AudioChannels(Audio)==2) ? Chan2 : Dubbed

FrontLeft = (AudioChannels(Audio)==3) ? MixAudio(GetChannel(Audio, 1), GetChannel(Audio, 3), 0.5, 0.5) : nop()
FrontRight = (AudioChannels(Audio)==3) ? MixAudio(GetChannel(Audio, 2), GetChannel(Audio, 3), 0.5, 0.5) : nop()
Chan3 = (AudioChannels(Audio)==3) ? Audiodub(Video, MergeChannels(FrontLeft, FrontRight)) : nop()
Dubbed = (AudioChannels(Audio)==3) ? Chan3 : Dubbed

TotalLeft = (AudioChannels(Audio)==4) ? MixAudio(GetChannel(Audio, 1), GetChannel(Audio, 3), 0.5, 0.5) : nop()
TotalRight = (AudioChannels(Audio)==4) ? MixAudio(GetChannel(Audio, 2), GetChannel(Audio, 4), 0.5, 0.5) : nop()
Chan4 = (AudioChannels(Audio)==4) ? Audiodub(Video, MergeChannels(TotalLeft, TotalRight)) : nop()
Dubbed = (AudioChannels(Audio)==4) ? Chan4 : Dubbed

FrontLeft = (AudioChannels(Audio)==5) ? MixAudio(GetChannel(Audio, 1), GetChannel(Audio, 3), 0.3694, 0.2612) : nop()
FrontRight = (AudioChannels(Audio)==5) ? MixAudio(GetChannel(Audio, 2), GetChannel(Audio, 3), 0.3694, 0.2612) : nop()
TotalLeft = (AudioChannels(Audio)==5) ? MixAudio(FrontLeft, GetChannel(Audio, 4), 1, 0.3694) : nop()
TotalRight = (AudioChannels(Audio)==5) ? MixAudio(FrontRight, GetChannel(Audio, 5), 1, 0.3694) : nop()
Chan5 = (AudioChannels(Audio)==5) ? Audiodub(Video, MergeChannels(TotalLeft, TotalRight)) : nop()
Dubbed = (AudioChannels(Audio)==5) ? Chan5 : Dubbed

BackLeft = (AudioChannels(Audio)>=6) ? MixAudio(GetChannel(Audio, 5), GetChannel(Audio, 4), 0.2698, 0.2698) : nop()
BackRight = (AudioChannels(Audio)>=6) ? MixAudio(GetChannel(Audio, 6), GetChannel(Audio, 4), 0.2698, 0.2698) : nop()
FrontLeft = (AudioChannels(Audio)>=6) ? MixAudio(GetChannel(Audio, 1), GetChannel(Audio, 3), 0.2698, 0.1906) : nop()
FrontRight = (AudioChannels(Audio)>=6) ? MixAudio(GetChannel(Audio, 2), GetChannel(Audio, 3), 0.2698, 0.1906) : nop()
TotalLeft = (AudioChannels(Audio)>=6) ? MixAudio(FrontLeft, BackLeft, 1, 1) : nop()
TotalRight = (AudioChannels(Audio)>=6) ? MixAudio(FrontRight, BackRight, 1, 1) : nop()
Chan6 = (AudioChannels(Audio)>=6) ? Audiodub(Video, MergeChannels(TotalLeft, TotalRight)) : nop()
Dubbed = (AudioChannels(Audio)>=6) ? Chan6 : Dubbed


Dubbed = (HasAudio(Audio)==True) ? Normalize(Dubbed) : Dubbed
Dubbed = (HasAudio(Audio)==True) ? SSRC(Dubbed, 48000) : Dubbed
Dubbed = (HasAudio(Audio)==True) ? ConvertAudioTo16bit(Dubbed) : Dubbed

return(Dubbed)
}