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  1. Member
    Join Date
    Nov 2013
    Location
    Western Australia
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    (Not sure if I've put this in the right area, was gonna put it in Audio)

    Alright so basically I use avspmod / avisynth + megui to encode videos. I ran into a strange problem where when I would preview a video in avspmod, it would show the video but it wouldn't have any audio.

    Playing this particular video on its own in any video player works fine and the audio is recognized as aac. As soon as I preview the avspmod script I don't get any audio and it sees the audio as PCM. Its not just a problem with the preview because if I actually encode the video I end up with no audio either.

    My brother has created a script that makes avisynth encoding much easier. It's a script he calls DSS3 (combines video and audio). When using this script but without trimming the video (my intended encode of the video is a trimmed section of it) I will have audio, but it will be distorted and sound like it's sped up. Interestingly if I change it to FFaudiosource, it previews the audio fine, of course there's no video because there's not meant to be. My brother said this might be the key to fixing it. Here's an screenshot of what I mean by changing it to FFaudiosource. http://img18.imageshack.us/img18/9618/kbkt.png

    Installed I have:
    Latest 32bit ffdshow from the official website http://ffdshow-tryout.sourceforge.net/download.php
    Latest Haali Media Splitter from the official website http://haali.su/mkv/
    32bit and 64bit versions of the AAC and AC3 ACM codecs (I was told by my brother this should fix it but it didn't)
    AC3 Filter 2.6.0b

    I normally preview the script in daum potplayer (latest version), but when I previewed it in MPC-HC (latest version) I would get an error saying something like "ACM Wrapper: Output". Once again, the video would play but the audio wouldn't. The error no longer comes up but I still don't have audio. I googled the problem and found some people say that you can fix it by enabling raw audio in ffdshow, I tried this and it didn't work. I'm not sure if this is word for word the exact same problem I have but yeah http://www.cccp-project.net/forums/index.php?topic=3903.0

    I've tried fresh installs of ffdshow and haali with reboots after installing them but no luck.

    My brother is quite the encoder and on his computer he does not have this issue with this video. I've tried everything he's said and nothing has worked. Tried replicating the settings he has in his ffdshow audio decoder area, no luck.

    If you require any screenshots or further information please let me know. Any help is greatly appreciated because this is really frustrating for me.
    Last edited by WAusJackBauer; 27th Nov 2013 at 19:41.
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  2. avisynth frameserves uncompressed audio & video . So the audio will appear as PCM if you are previewing a scropt

    avspmod doesn't play audio ; if you want to see if audio is present and frameserved check by adding info() to the script

    If you want audio & video, use FFMpegSource2("video.mp4", atrack=-1) . You need ffms2.avsi in the plugins folder

    It's essentially the same thing as

    aud=FFAudioSource()
    vid=FFVideoSource()
    AudioDub(vid,aud)

    Then you can trim() audio & video together (use the same script to encode video and audio)
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  3. Member
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    Location
    Western Australia
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    Originally Posted by poisondeathray View Post
    avisynth frameserves uncompressed audio & video . So the audio will appear as PCM if you are previewing a scropt

    avspmod doesn't play audio ; if you want to see if audio is present and frameserved check by adding info() to the script

    If you want audio & video, use FFMpegSource2("video.mp4", atrack=-1) . You need ffms2.avsi in the plugins folder

    It's essentially the same thing as

    aud=FFAudioSource()
    vid=FFVideoSource()
    AudioDub(vid,aud)

    Then you can trim() audio & video together (use the same script to encode video and audio)
    Confusing as to why it works fine on my brothers computer, but nonetheless thank you very much for this work around
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  4. Post the "DSS3" script

    It's sounds like it's probably a directshow based function (thus not necessarily frame accurate) . If so, I would avoid it , especially if using temporal filters or Trim() to make edits . You get mixed up frames and unpredictable results. Directshow is very unreliable for encoding under those conditions

    "DSS2" is supposedly frame accurate, but depends on container timestamps, and has a last frame bug (It skips the last frame)

    If you still want to debug the issue, you need to figure out your directshow filters. If you render the video file in graphstudio you will see what decoders and splitters current have the highest merits . You may have to make some adjustments, disabling or enabling others - another reason why directshow is a big PITA . Directshow is very inconsistent because it's dependent on that specific system's configuration

    FFMS2 also has some "quirks", for example you might have to adjust the framerate with AssumeFPS() ,sometimes it's fractionally off . But it's much more reliable than directshow methods, and frame accurate because it indexes the file
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