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4th July 2019, 20:58 | #162 | Link | |
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5th July 2019, 00:47 | #163 | Link |
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I supose from 6.1 or 7.1 to 5.1
The first four channels (FL,FR,FC,LFE) must remain the same to avoid changes in volume, I can't recommend a Normalize like after a down2. Only the Side and Back channels must be used to obtain 2 Surround channels. 6.1 to 5.1 SL' = BL + 0.7071 x BC SR' = BR + 0.7071 x BC Normalized to avoid clip: SL' = 0.5879 x BL + 0.4142 x BC SR' = 0.5879 x BR + 0.4142 x BC Or best option with BeHappy or MeGUI and AviSynth plugin AudioLimiter: SL' = MixAudio(BL, BC, 1, 0.7071).SoftClipperFromAudX(0.0) SR' = MixAudio(BR, BC, 1, 0.7071).SoftClipperFromAudX(0.0) 7.1 to 5.1 SL' = BL + SL SR' = BR + SR Normalized to avoid clip: SL' = 0.5 x BL + 0.5 x SL SR' = 0.5 x BR + 0.5 x SR Or best option with BeHappy or MeGUI and AviSynth: SL' = MixAudio(BL, SL, 1, 1).SoftClipperFromAudX(0.0) SR' = MixAudio(BR, SR, 1, 1).SoftClipperFromAudX(0.0) With the AudioLimiter plugin we obtain the same volume, most the time, with 2 surround speakers in 5.1 than 4 speakers in 7.1. Only moments with high volume we can't preserve the volume balance between front and surround channels.
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6th July 2019, 21:44 | #166 | Link |
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When converting a 5.1 or 7.1 audio to stereo WAV, is there a way to equalize loudness during conversion,
so that the normal parts remain unchanged, and loud parts get decreased in volume? Can this be done in ffmpeg or avisynth? Some filter, maybe? |
6th July 2019, 23:25 | #167 | Link |
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This is the purpose of SoftClipperFromAudX().
I think is safe to use it to mix surround channels first (7.1 -> 5.1), maybe can be used also to mix front with surround (5.1 -> 3.1) and after to 2.0: FL' = FL + 0.7071 x FC FR' = FR + 0.7071 x FC and Normalize.
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