Questions about converting mkv's to mp4

Discussion in 'Apple TV and Home Theater' started by mic j, Aug 3, 2012.

  1. mic j macrumors 68030

    Mar 15, 2012
    So I have a bunch of blu-ray mkv containing the h.264 codec. Some have DTS-HD, many have subtitles and/or forced subtitles. In order get these files compatible with the aTV, the DTS-MA needs to be converted to AC3, correct? Also, how do you take the PGS subs from the BR and get them in mp4 container, i.e. soft subs. What apps can do do one or both of these things and how forced subtitles that are not "burned in" work when changing the container from mkv to mp4?

    I hear a lot of people saying just convert your h.264 base mkv to mp4 using various software, but how easy and effective is that if you are not just dealing with torrents that have no subtitles and only AC3 audio?
  2. tbayrgs macrumors 603


    Jul 5, 2009
    I've seen detailed and what appear to be time consuming ways to convert subtitles around the forum here but I personally didn't want to spend the time or effort so if the non-English speaking parts weren't burned in, I'd find a .srt version online and mix it into the .m4v container using Subler. If you you want the subs to look exactly as they do in the film, you won't be satisfied with this method (i.e. the yellow scripted subs in Avatar will now be white text at the bottom of the screen) but I was more concerned with just having the subs.

    Software like MP4Tools will allow you to just pass through the native h.264 video will converting the audio to an Apple TV friendly format but the problem I encountered was that converting to both 5.1 ac3 and a stereo AAC resulted in the stereo being the second audio file and I would always have to manually change the audio stream when viewing (no 6 channel setups in our house at the moment :(). The other problem with passing through the native video is that the video bitrate of blu ray rips is too much for the Apple TV to handle. If you encode with Handbrake, the default Apple TV preset has the stereo file first. You can also take that .srt subs file and add it right into the encoding process (though muxing later is just as easy, IMO).
  3. MightyWhite macrumors member

    Feb 29, 2012
    Oxford UK
    I have the same problem at the moment and I found that handbrake nightly build version ( kind of beta) have the option to include subtitles for bluray mkv files..

    At the moment I have just set off Salt with forced subtitles only using the apple tv3 setting so I will post back later how that went...

    Will take a while though as the hamsters in my old dell laptop can't turn the wheel so fast anymore... Roll on iMac update....
  4. mic j thread starter macrumors 68030

    Mar 15, 2012
    I have been considering trying to take some of my mkv bluray rips (because they use the h.264 codec) and convert them to m4v without compression but it's not worth the effort if you are trading one set of issues(slight loss of quality, long transcode times, etc) for a different set of issues. So it occurred to me some of the issues might be subtitle support and need to convert dts audio, high bitrates not being able to be handled by the aTV or possibly even my home network. I have also since read that there are possibly problems with FF/REV, skipping to chapters, etc. If these were torrent downloads I think it might be a different situation.

    As my m4v's are working just fine, think I will just take it's few weaknesses and stick with that method.

    Thanks for your replies.

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