Adding 5.1 AC3 Track to 720p 2.0 Mp4?

Discussion in 'Apple TV and Home Theater' started by brobins, Nov 29, 2008.

  1. brobins macrumors member

    Joined:
    Nov 27, 2008
    #1
    Hi there,

    I have a great movie trilogy in full 1080p with 5.1 - I have transcoded this down to 720p for the AppleTV and it plays fine, files are a little large but thats ok as they seem to play and the quality is great.

    Now the files I transcoded ended up with 2 ch sound which is fine - What I am wondering is can I take the original AC3 5.1 from the 1080p files and merge it into the 720p files as a separate sound track for use with a amp via optical out on the AppleTV?

    What is the best way to do this and will it have any effect on the compatibility of the files for AppleTV use?

    Many Thanks
     
  2. Cave Man macrumors 604

    Cave Man

    #2
    How did you transcode it? If you used Handbrake, it becomes quite easy. Click on the ATV preset, change the quality to 6,000 kps, under Pictures change to 720p (1280 x whatever, preserving aspect), then under the Audio tabs make sure the first 5.1 source is for Dolby Pro Logic II and the second is for AC3 passthrough. That makes it work for the ATV and gives both two-channel analog and six-channel digital audio.
     
  3. brobins thread starter macrumors member

    Joined:
    Nov 27, 2008
    #3
    Thanks for your reply.

    What you suggest would work yep but as I have already transcoded the video with 2-ch I do not want to spend another week having to do it again!

    All I want to do is add a 5.1 track to the already transcoded 720p files - If at all possible?

    Many Thanks
     
  4. Thomss macrumors member

    Joined:
    Oct 2, 2008
    #4
    Have you tried playing with yamb? I'm sure you can split / add files in mp4 containers.
     
  5. brobins thread starter macrumors member

    Joined:
    Nov 27, 2008
    #5
    Hi there.

    No I haven't, I am on a Apple Mac with OS X. I do have and use Quicktime Pro however, You can extract and copy paste in that etc.

    Could I do that? Paste the 5.1 track in Quicktime Pro and export as a Mp4? Do you think that would work?

    Many Thanks
     
  6. kolax macrumors G3

    Joined:
    Mar 20, 2007
    #6
    I think QuickTime would make it a .mov container - which can cause problems.
     
  7. brobins thread starter macrumors member

    Joined:
    Nov 27, 2008
    #7
    I have gone ahead and done it! :)

    Used Quicktime Pro, Saved as Mov, now the file contains the 2ch sound and the AC3 surround which is unticked!

    I now plan on running it through Visual Hub or Handbrake using pass-through back into an mp4 without touching the video or sound tracks.

    I will report back once its done and let you all know if it worked.
     
  8. brobins thread starter macrumors member

    Joined:
    Nov 27, 2008
    #9
    An Update:

    Instead of running the .mov through handbrake to remux back into an mp4 I decided to just try the actual .mov file first. Copys into itunes and plays fine, synced it to the appletv - plays video fine but no sound BUT I have not yet connected my AppleTV to an AV Reciever to check if the 5.1 gets picked up..
     
  9. kolax macrumors G3

    Joined:
    Mar 20, 2007
    #10
    Avoid .mov at all costs ;)

    Run it through HandBrake and see what audio files it pulls out in the audio tab.
     
  10. brobins thread starter macrumors member

    Joined:
    Nov 27, 2008
    #11
    What is the problem with .mov files? I have a few and they all seem ok?!

    I will try the handbrake passthrough once I have tried connecting it to an Av Reciever..

    Many Thanks
     
  11. kolax macrumors G3

    Joined:
    Mar 20, 2007
    #12
    When using audio pass through (i.e. your stereo/5.1) there is issues.
     
  12. brobins thread starter macrumors member

    Joined:
    Nov 27, 2008
    #13
    Ah that might explain it as my other Movs are only Stereo!

    I shall try handbrake passthrough into a Mp4 container and see what that throws out!

    Cheers
     

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