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Convert to ATV & 5.1 sound ?

Discussion in 'Apple TV and Home Theater' started by NullMind, May 4, 2010.

  1. macrumors newbie

    I need to convert a movie to ATV, I was trying Video Monkey but it seems it makes the audio 2 channel only ? so surround only I assume, how can i convert a movie to ATV and keep the 5.1 sound ? I dont mind paying for software to do it.
  2. macrumors member

    HandBrake, available at handbrake.fr, is capable of doing this quite easily.
  3. macrumors 6502a

    Handbrake is probably the most popular app for converting files for the AppleTV. And it is completely free.
  4. macrumors newbie

    i tried handbrake, I choose AAC (coreaudio) and 256kb (if i select AC3 sends me to aac(faac) , but then i take the resulting file and put it on video monkey to check the input stats and shows as only having 2 channels ?
  5. macrumors 6502a

    Using Handbrake for AppleTV, just use the AppleTV preset. By default, it will do 5.1 passthrough and a 2.0 track.
  6. macrumors newbie

    i tried doing that on a quick test, the resulting file shows 2 tracks only on the info panel

  7. macrumors member

    Is that screenshot taken from videomonkey? If so, ignore it. All my DVD rips have both aac and AC3 5.1 passthrough, but videomonkey doesn't show this. Even QuickTime doesn't see the AC3 track. I recommend you import that video into iTunes and then use the get info function. The box that shows up should show the following "Stereo, Dolby Digital 5.1". VLC should also be able to tell you if you have AC3 passthrough.
  8. macrumors regular

    Not familiar with that program, but two audio channels might mean two audio tracks -- one stereo and one 5.1.

    The AppleTV preset on handbrake will give you two audio tracks -- one a stereo mix down and one a passthrough of the surround sound. Unless of course you are talking about DTS. That is another ball of wax. Then you will only get a stereo mix down.
  9. macrumors newbie

    alright, i tried the ATV setting in handbrake


    i then imported the file to itunes and checked the info


    says "stereo" :(

    I am converting from a MKV with 6-channel DTS
  10. macrumors member

    Well, there is your problem. Handbrake doesn't currently support converting DTS to AC3. The only solution is to use a program to extract the dts from the mkv, convert it to AC3 and then remux it back into the MKV.
  11. macrumors newbie

    any advise on a program to extract the dts ? (for osx)
  12. macrumors regular

    There is a process but it involves the terminal, multiple programs, and will probably not work for you. It did not work for me. If you have VMware Fusion or Parallels running Windows there are some one stop shops. I just used a program called Popcorn audio converter on windows to convert the DTS track on Gladiator MKV made from BluRay. It worked great.
  13. macrumors member

    Hopefully one of the handbrake developers will want this for their own use soner or later, and therefore add it to the program. You have to remember, as Handbrake is open-source, everything that gets done is in the develoers spare time. DTS-HD seems to be the prefered format for new Blu-Ray releases, so I guess we will probably see it sooner or later as blu-ray becomes more and more popular.
  14. macrumors member

    Well you can try the latest beta of MKVtools found here. The latest version will convert 5.1 AC3 and 5.1 DTS to 5.1 AAC, so it should do exactly what you're looking for. Just use the "Apple TV" preset under quick conversions and MKVtools should take care of the rest. Note I wrote "should" because it still is a beta. I've tested it on a limited number of files for the PS3 and it worked great. Since I don't have an ATV your mileage will vary and I'd like to hear feedback. At the very least, it will let you extract the tracks from your MKV file.
  15. macrumors 68020

    Um, 5.1 AAC is the same as six channel discreet AAC in HB, not the same as DTS 5.1 to AC3 5.1 which I *think* is what is being requested.

    Fwiw, the atv will take a 5.1 AAC track (six channel discreet aac in HB parlance) and downmix that to a kind of funky dolby 3.0 stereo track. Far and away worse than using DPL2 mixdown and certainly worse than the AC3 5.1 Pass through track desired.
  16. macrumors member

    My bad. Since I have a PS3, I've been focused on getting 5.1 AAC, so somewhere along the line I got the impression that the ATV also supported 5.1 AAC. That's why it's helpful to post and ask questions in these forums :). So, just for my clarification, for the ATV, the you want to pass through 5.1 AC3, and if the original has either 5.1 DTS or 5.1 AAC you want to convert to 5.1 AC3 in a .m4v container file. Is that right?
  17. macrumors 68020

    Agreed and there is no "bad" only info. It is cool that thePS3 supports six channel aac, sometimes I wish the atv did.

    Yes, Ideally you want to pass thru an ac3 track since the atv can pass it thru to a Dolby 5.1 ac3 capable receiver unmodified from the source.

    Well, if you can convert 5.1 dts to ac3 that is the bomb. because of the atv's ac3 pass thru capability.

    Now I am not so sure the benefit of taking aac compressed six channel audio and going to AC3 with it ( or whats involved). Seems pretty lossy to me.

    Currently in HB we would take an aac 5.1 source and downmix it to dpl2 for the atv. No conversion from aac to ac3 which as I said seems like lossy to really lossy.

    By and large the atv is a strange animal when it comes to audio.

    A. just any aac track (though of course the six channel gets downmixed as I said above)
    or B. An aac track first (set to enabled) and an AC3 5.1 Passthru track second (set to disabled).

    The atv will sense if the audio is hooked up to a 5.1 capable audio device and use the second track (yes, even though its disabled in the output file) otherwise if its hooked up say to a stereo tv via hdmi it will use the first aac dpl2 track.

    So that should be about as clear as mud ;)
  18. macrumors 68020

    If in quicktime you go to the Movie Properties inspector you should see a "Surround" track, click on it and at the bottom you will see all six channel assignments. That is your AC3 pass thru track. The aac dpl2 track will be labeled stereo at the top.
  19. macrumors member

    Hi Dynaflash,
    Maybe not mud, but more like a pond full of muck and scum :). You'd think apple could simplify the audio, but such is life. I'd look into DTS to AC3 converion, but I'd like to have some confidence that the resulting file will work for ATV users. The current version of MKVtools (2.2.6) will take an MKV file with AVC and 5.1 AC3 and pass thru both tracks, assuming the video doesn't have to be downsized, to a .m4v container. Have you tried it? Because if passed through AC3 video output from MKVtools works on the ATV, then it stands to reason that a file with audio converted to AC3 should also work. Can you or anyone else confirm that MKVtools .m4v files with AC3 audio plays on the ATV?
  20. macrumors 68020

    Yes, ac3 pass thru from MKV tools does work on atv ....

    Now for the *but*. That is with current atv os. There was a previous version (2.4.1 iirc) which required that there be an aac track. In other words just one AC3 passthru track would not work. That was corrected in atv 3.0. So in the future ymmv. ... and you thought the mud was thick before ;)

    My sense is if you just want mvktools to pass thru you would probably alright with just the dts ->AC3 track in future revs. Though of course reading the tea leaves with apple is a fools game. ;)

    On a related note, if you can get dts ->ac3 working inside the mkv tools ui that would be shiny ... something we have had on the shelf at hb for quite some time.

    As you know no small chore.
  21. macrumors regular

    Here is a link to the ad hoc Mac OS X method of DTS to AC3 conversion that involves the terminal and that I could not get to work:
    Here is the link for the windows program that I did get to work through VMware Fusion running Windows XP on my iMac.

    I have only used it once, but it worked as advertised. My Gladiator MKV only had 5.1 DTS audio. Handbrake would only give me a stereo mix down. So, I ran the MKV through PopCorn and it added a 5.1 AC3 track. The 5.1 DTS track was still there and not altered. When I put the new MKV through handbrake, I had a choice of both the DTS and the AC3 tracks as the source audio. With the AC3 track selected, passthrough was an option. The resulting file sounded fine and in sync. Mission accomplished.
  22. macrumors member

    It's especially difficult without an apple TV to test on :(. So, for anyone out there who wants to give the latest beta of MKVtools a try (v2.3.b5), if you use the Apple TV preset in the quick convert box on 5.1 DTS mkv files, it hopefully will now convert the 5.1 DTS to 5.1 AC3 and put the video in an .m4v file playable on an ATV. I think I got the channel mapping correct, but as mentioned previously, I can't verify for an ATV. Any feedback would be useful.
  23. macrumors 68020

    Channel mapping looks correct. But I ended up with only a 364 kbps AC3 track which seems a bit low. However it does work when run back through hb.

    Any thought to having this dts > ac3 as simply a remux option instead of using MKVTools Apple TV preset only? Just a thought.

    Note: The ATV observes quicktimes channel mapping in the movie properties inspector.
  24. macrumors member

    Good to know that the channel mapping is correct. The bit rate is low and will be fixed. It 's supposed to be 448 but I think it was left at 384 from AAC conversions, though it looks like some of the AAC bitrates were left at 2-channel numbers. Sometimes when programming late at night, intentions don't translate into results :). I'm curious why you ran the video back through hb. Does the .m4v video created by MKVtools not play properly on the ATV?
    I'm looking for suggestions and requests, but I'm not sure what you're asking for.
  25. macrumors member

    Two things

    1) What dynaflash was try to ask (I think) was the ability to just transcode the DTS to AC3 and leave it in either a new MKV file or replacing the DTS audio in the original mkv file. This would keep a great MKV file and give users the ability to put the file into handbrake and alter the settings more.

    2) on the topic of mkvtools. With the appletv settings this will give the new file the 5.1 surround sound correct? I am running Avatar right now but it is only a test

    Ps a nice suggestion would be a ETA along with the parentage completed

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