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  1. Member midders's Avatar
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    I'm using FAVC to re-encode a PAL 4:3 letterbox DVD to 16:9 (trying to get best possible quality) and the video is fine, but the audio output only shows 2 channels, despite using the AC3 and "Retain if present" audio options.

    Any ideas how to keep the 6 channel audio? I've tried both Aften and QuEnc as audio encoders with the same result.

    Details below:

    Input filmclip.avs (MediaInfo):
    Audio
    Format : AC-3
    Format/Info : Audio Coding 3
    Duration : 9s 920ms
    Bit rate mode : Constant
    Bit rate : 384 Kbps
    Channel(s) : 6 channels
    Channel positions : Front: L C R, Rear: L R, LFE
    Sampling rate : 48.0 KHz

    Output filmclip.vob (MediaInfo):
    Audio
    Format : AC-3
    Format/Info : Audio Coding 3
    Duration : 9s 632ms
    Bit rate mode : Constant
    Bit rate : 384 Kbps
    Channel(s) : 2 channels
    Channel positions : L R
    Sampling rate : 48.0 KHz

    The process I'm trying is:
    1 - rip to HDD with DVD Fab
    2 - demux with ProjectX
    3 - mux to mpg with ImagoMPEG-Muxer
    4 - write AVS script to crop the black bars leaving just the 2.35:1 video
    5 - use the AVS script as input to FAVC

    Any help appreciated

    Sláinte

    midders
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  2. Always Watching guns1inger's Avatar
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    How are you passing the audio back into FAVC ? I believe that FAVC needs to see a 6 channel AC3 audio track in order to keep it. If you pass through a 6 channel PCM track from Avisynth, FAVC will re-encode it down to 2 channels.

    You do realise that FAVC is putting black bars back on the video, because 2.35 is wider than 16:9 ?

    Did you know that DVD Rebuilder can do all of this, and preserve the entire disc structure (menus etc) ?
    Read my blog here.
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  3. Member midders's Avatar
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    Originally Posted by guns1inger
    How are you passing the audio back into FAVC? I believe that FAVC needs to see a 6 channel AC3 audio track in order to keep it. If you pass through a 6 channel PCM track from Avisynth, FAVC will re-encode it down to 2 channels.
    Thanks; that seems to be the problem. I didn't realise that using AVISynth to crop the video would have an affect on the audio as well.

    Originally Posted by guns1inger
    You do realise that FAVC is putting black bars back on the video, because 2.35 is wider than 16:9 ?
    Yes, just did the cropping to force it to recognize a 2.35:1 source

    Originally Posted by guns1inger
    Did you know that DVD Rebuilder can do all of this, and preserve the entire disc structure (menus etc) ?
    Yes, I tried this first; I'm trying to see if I can improve on the quality at all.

    Thanks for your help

    Sláinte

    midders
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  4. Always Watching guns1inger's Avatar
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    Generally Avisynth outputs uncompressed video and audio, however mediainfo seems to think the AVS script is outputting AC3, so perhaps the issue is with FAVC after all.

    I stopped using FAVC much a while back, as the last release seemed to have issues which have not been addressed. I seem to remember that one of them was a problem with the Retain AC3 if Present function. It might be worth reverting back a version to see if you have better luck.

    However if your script is not doing anything more than cropping (i.e. no other filtering is being performed) then it is very unlikely that your results will be any better than DVD Rebuilder's.
    Read my blog here.
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