Reducing Framerate Below 24, and iTunes file size cap.

Discussion in 'Apple TV and Home Theater' started by TheCheapGeek, Jan 26, 2009.

  1. TheCheapGeek macrumors 6502

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    #1
    Ok i have to main questions. I have a 720p movie that was mkv and i encoded it by passing through the video to mp4 in quicktime, the frame rate is 24 so that's not the issue. The file size is about 5 gigs and it wont import into iTunes. I have heard that there is a file size cap of 4 gigs, Is this true? Also i recently purchased an eyetv and i am trying to properly encode the HD content for the Apple TV. What is the proper way to reduce the frame rate to 24 without creating a jerky picture. Encoding it via handbreak did not work, choosing 24 fps created a jerky although beautiful hi def picture. Any Help?
     
  2. Diveflo macrumors regular

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    Mar 12, 2008
    #2
    I have movies as big as 9GB and it works perfectly. No such thing as a file size cap.
     
  3. TheCheapGeek thread starter macrumors 6502

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    #3
    Humm ok, well i think i may have traced it down to the audio. Will a file fail to import or just refuse to play the audio? Does the apple tv have any file size cas on streaming a movie?
     
  4. downinitjr macrumors member

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    May 17, 2007
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    Minnesota
    #4
    Those .mkv files coming from the internet in all but the rarest of cases will need to have the video/audio re-encoded to play on the TV. Although the video track is h.264 they have been encoded with a different profile level and will need to be re-encoded. Just passing through the video and or audio to a new container will not work, this has been tried to death. If you install a program like boxee on your TV it may give you more lee-way, but I assume your talking about a TV not hacked. Handbrake is going to be your best option for re-encoding, but even with the fastest of machines, its going to take hours per movie.
     
  5. dynaflash macrumors 68020

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    #5
    720p has to be at no more than actually 25 fps. even though you are showing your movie source as 24, I wager not. If cutting it to 24 fps in hb created a movie that worked on your atv but was jerky, that means the source was not truly 24fps and hb dropped frames to get what you wanted, hence the "jerkiness". as far as greater than 4GB, that is a limation of 32bit mp4's ... has nothing to do with iTunes or the atv. HB has a setting to enable 64 bit mp4's (which is turned on with the appleTV preset) which can be as big as you want file size wise and iTunes/ATV play them just fine.
     
  6. TheCheapGeek thread starter macrumors 6502

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    #6
    Ok well the frame-rate issue is from recorded content from over the air digital broadcasting. The playing frame-rate of this content is around 26 i believe. I simply dropped the mpeg file into handbreak, selected the apple tv preset, selecting 24 fps rather than same as source, and finally changing the resolution to 720p. This produced a jerky picture. How can i encode this file in 720p at 24 fps and have smooth playback?

    THe mkv source is a download of Indiana Jones last crusade witch i own in two other formats so dont lecture me on piracy. Ok how can one identify if the correct h.264 profile was used in the encoding?
     
  7. dynaflash macrumors 68020

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    #7
    In HB you can't. video frames will be dropped in order to maintain audio sync.

    One of the reasons I am very much hoping for 720p at 30 fps asap for the atv.
     
  8. TheCheapGeek thread starter macrumors 6502

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    #8
    I guess this is the required h.264 profile

    Progressive Main Profile (CAVLC)
     
  9. TheCheapGeek thread starter macrumors 6502

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    #9
    Can Quicktime Pro reduce the frame rate properly?
     
  10. dynaflash macrumors 68020

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    #10
    No, not properly. Unless you reduce the pitch of the audio track the same, you will get de-sync on the audio.
     
  11. spacepower7 macrumors 68000

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    #11
    You can find out info about your file with the free app MediaInfo Mac.

    Many of those internet mkv files are High Profile 5.1 which the AppleTV can't play without being hacked with Boxee or XBMC. You can re-encode the video to a lower profile with Handbrake.
     
  12. Diveflo macrumors regular

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    Mar 12, 2008
    #12
    Can Boxee play these? I thought the AppleTV was just not powerful enough?
     
  13. TheCheapGeek thread starter macrumors 6502

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    #13
    I just re-encoded a high profile mkv back to a low profile h.264 .mp4 and it works flawlessly. Also using visual hub i encoded eye tv recordings, 1920 x 1080 at 30 fps to 1280 x 720 at 24 fps. This seemed to work very well using two pass encoding, but i notice that i cannot force visual hub to use quick time. Any help on that?
     
  14. downinitjr macrumors member

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    Minnesota
    #14
    For what reason are you trying to force it to use quicktime encoding? Quicktime in general is going to give you a slower encode time with less encoding options. Can't say it enough, if your re-encoding video, get to know handbrake, its in general going to give you faster re-encode times, as well as quality, and maintain compatibility with current standards.
     
  15. TheCheapGeek thread starter macrumors 6502

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    #15
    I have used handbreak and it spent provide the highest quality. In fact I did some testing and handbreak had the poorest quality. QuickTime in my experiance provides the best quality but the worst time frame.
     
  16. dynaflash macrumors 68020

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    #16
    ... and your tests were using the *exact* same options, etc. and source between HB and QT ?
     
  17. TheCheapGeek thread starter macrumors 6502

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    #17
    Yes i had a 45 second clip of a tv recording of of NBC who's resolution was 1920 x 1080, frame rate was around 30, and it was a .mpg file. I encoded in handbrake using the apple tv preset, then upped the resolution to 1280 x 720, dropped the fps to 24 and selected de interlace. Visual hub I set the quality to go nuts and h.264, in the advanced window I specified the resolution to the same 1280 x 720 and the frame rate and began. Because quicktime would not oped a mpeg file, i did a simple encode in visual hub to .mp4 passing through the resolution and fps, then openeing that file in quicktime pro and exporting using the same resolution 1280 x 720 and 24 fps.

    Comparing all three resulting files. Quicktimes encode was easily the best, but the two step process and quicktimes encode time make it a very time consuming process. Visual hub was the best of both worlds it was a very fast encode and had great quality, there were slight areas where there was evidence of stuttering but it was hardly noticeable. Handbrake took longer than visual hub and had enough stuttering to make the video unwatchable.

    So if i am doing something incorrectly please let me know, i would like to consolidate my efforts into one program?
     
  18. NightStorm macrumors 68000

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    #18
    Which deinterlacing selection did you use in Handbrake? My guess would be fast.

    Now, the correct way to convert this content would be to use the deteleceine + decomb filters. Everything else identical, I'm almost certain the HB encode will look better and finish quicker.
     
  19. TheCheapGeek thread starter macrumors 6502

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    #19
    Ok what does the decomb filter add to the mix, i have never used that. I will have to do some more test encodes tonight.
     
  20. dynaflash macrumors 68020

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    #20

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