Low 1080p bit rates - 720p files bigger than 1080p files on iTunes

Discussion in 'Apple TV and Home Theater' started by AwesomeD, Mar 8, 2012.

  1. AwesomeD, Mar 8, 2012
    Last edited: Mar 8, 2012

    AwesomeD macrumors newbie

    Joined:
    Jan 15, 2009
    #1
    I'm glad Apple finally got around to adding 1080p movies to iTunes and that they aren't charging extra for them for people who already have the 720p versions.

    I love the quality of the 1080p trailers from Apple trailers and was hoping for that, but I don't think we will be getting that. The 1080p files on iTunes don't appear to have nearly the same bit rate as the trailers which is making me second guess building a digital movie library using iTunes.

    Here is why:

    Downloaded The Hunger Games 1080p trailer from Apple Trailers was 2mins and 35 seconds long and was 191.90 mbs

    So that would mean it's roughly 100 mbs for every 1min and 18seconds. Going to round down to easy math. So let's say 100 mbs for every minute. You would get the following video sizes

    60 min movie - 6GB (1080p)
    90 min movie - 9GB (1080p)
    120 min movie - 12GB (1080p)

    Iron Man on the iTunes store is showing the following:
    SD 1.74 GB
    720p 4.03 GB
    1080p 3.84 GB (Iron Man is over two hours and should be over 12 GB)

    WAIT WHAT the 1080p encode is smaller than the 720p encode.
    See it for yourself here if you don't believe me:
    http://itunes.apple.com/us/movie/iron-man/id289156796

    NOTE: Go to Preferences > Store > 720p or 1080p to see the different file sizes on the page.

    Let's try one more

    Star Trek
    SD 1.83 GB
    720p 4.08 GB
    1080p 4.30 GB

    At least this time the 1080p file is bigger, but not by much only 220 MB.

    I think I'm going to wait until Apple starts requesting proper 1080p encodes like they already do with their movie trailers.

    With that said I have no issue with the size of the 720p encodes. The 720p Hunger Game Trailer was 50mb per minute which is more inline with the file sizes on the iTunes store than the 1080p encodes.

    60 min movie - 3GB (720p)
    90 min movie - 4.5GB (720p)
    120 min movie - 6GB (720p)

    There is no way the 1080p file sizes are correct IMO
     
  2. MacinJosh macrumors 6502a

    Joined:
    Jan 29, 2006
    Location:
    Finland
    #2
    I think it's because the new ATV uses a more efficient encoding method utilising High Profile level 4 as opposed to Baseline.

    H.264 video up to 1080p, 30 frames per second, High or Main Profile level 4.0 or lower, Baseline profile level 3.0 or lower with AAC-LC audio up to 160 Kbps per channel, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats
     
  3. AwesomeD thread starter macrumors newbie

    Joined:
    Jan 15, 2009
    #3
    Looks like Apple Trailers are using AVC Main@L4.0 and the iTunes content is using AVC High@L4.0.

    Apple Trailer was 9,785 Kbps Bitrate
    iTunes content was 5,013 Kbps Bitrate
     
  4. ftaok macrumors 601

    ftaok

    Joined:
    Jan 23, 2002
    Location:
    East Coast
    #4
    OK, but what are the "specs" for the 720p and 1080p versions of Iron Man. It's weird that the 1080p file is smaller than the 720p one. Are there some differences between the profile used?
     
  5. Scarpad macrumors 68000

    Scarpad

    Joined:
    Jan 13, 2005
    Location:
    Ma
    #5
    I saw that too, I Redownloaded a 1080p version of a breaking bad ep but I havent tried watching it yet, I'm wondering if these are just upconverts on the old stuff re-encoded.

    ----------

    Well that's why still at 1080p, these versions are no replacement for a blu ray. OK For smaller screens thou
     
  6. BarkingGhost macrumors regular

    BarkingGhost

    Joined:
    Oct 18, 2011
    Location:
    Atlanta+35 miles
    #6
    If the bitrates (or even file sizes) are significantly smaller than the movie Blu-ray counterparts then I would say Apple is taking lessons from U-Verse and its abomination of video transport.

    It is interesting comparing the two Fantastic Four movies on BD. The second movie was shorter in run time, but used dual-layer with H.264 and the first one single-layer with H.264. Made a difference visually (and in player load times).

    But, if you're blind then ignorance is bliss. :)
     
  7. thenaes macrumors member

    Joined:
    Nov 20, 2011
    #7
    Does anyone know if the new ATV still only has 8GB of storage space? Maybe that's why these bitrates are so low? That doesn't explain the lower file size than 720p though, at all.
     
  8. NightStorm macrumors 68000

    Joined:
    Jan 26, 2006
    Location:
    Whitehouse, OH
    #8
    Baseline vs. Main profile can (somewhat) explain this.

    I'm more interested in doing some testing to see just how large/complex of a 1080p encode the AppleTV v2 can play without issue. If the results are acceptable, it might just convince me to go back and re-encode my Bluray/HDDVD collection. Otherwise, I'll stick with my custom anamorphic 1280x720p encodes.
     
  9. iBug2 macrumors 68040

    Joined:
    Jun 12, 2005
    #9
    They won't be until they get along the lines of 20mbit or so. After that it's diminishing returns.
     
  10. rayyu882 macrumors member

    Joined:
    Jan 18, 2010
    #10
  11. OptyCT macrumors 6502

    Joined:
    Nov 9, 2008
    #11
    This entire issue is the reason I'm not pulling the trigger on the new ATV and waiting to see how this all plays out. I've spent a lot of time encoding movies in high-quality 720p. I have a feeling that Apple's idea of 1080p isn't going to look a lot better (if any) than my 720p rips. I think the people on this message board equate 1080p to something that you'd see on a blu-ray. I don't like when a company advertises "1080p" and it doesn't look anywhere near blu-ray quality (i.e. Netflix, etc.).
     
  12. Scarpad macrumors 68000

    Scarpad

    Joined:
    Jan 13, 2005
    Location:
    Ma
    #12
    1080p is just resolution and level of detail, bit starved 1080p is no better than and probably worse than 720p, but why does this surprise anyone, Apple feels Music at 256k is fine , then it probably feels 1080p at 8 mpps is fine too.
     
  13. CptnJustc macrumors 6502

    Joined:
    Jan 19, 2007
    #13
    My tiny HD iTunes movie collection:

    Iron Man (HD).m4v
    3.97 GB, 1280x532, 4391 kbps

    Iron Man (1080p HD).m4v
    3.84 GB, 1920x800, 4250 kbps

    Religulous (HD).m4v
    3.40 GB, 1280x720, 4688 kbps

    Religulous (1080p HD).m4v
    3.94 GB, 1920x1080, 5444 kbps

    Iron Man is 2:06 while Religulous is 1:41. Maybe there's a rough inverse correlation between length and difference in bit rates, with them trying to stay within 4 GB?

    May be old news, but I was pleasantly surprised to see that some of my SD movies had seen their bit rates upgraded significantly at some point, with some of those seeing upgraded resolutions.
     
  14. dynaflash macrumors 68020

    Joined:
    Mar 27, 2003
  15. idunn macrumors 6502

    Joined:
    Jan 12, 2008
    #15
    1080p, where?

    When referring to iTunes, do you mean Apple TV?

    In checking, and downloading the latest version of iTunes, I see no mention from there on a computer of 1080p content. As this was cited, 'Iron Man' is shown offered in either SD or HD content, two options, with, I believe, HD still referring to 720p.

    Any thoughts on this?
     
  16. jlasoon macrumors 6502

    Joined:
    Jun 1, 2006
    Location:
    Orlando, FL
    #16
    iTunes preference -> Store -> When downloading HD videos, prefer 1080p
     
  17. CptnJustc macrumors 6502

    Joined:
    Jan 19, 2007
    #17
    Under Preferences -> Store, you can change whether you prefer 720p or 1080p when downloading videos. When you visit an HD movie's page in the iTunes store, the info on the left side, including file size, will be for whichever version you 'prefer'.

    It will also say "HD: Includes 720p, 1080p (Downloading 720p)", and clicking on the "(Downloading 720p)" text will take you to your preferences. If you change them, the info on the left will auto-update.
     
  18. Icaras macrumors 603

    Icaras

    Joined:
    Mar 18, 2008
    Location:
    California, United States
    #18
    Also, not everything HD in the iTunes store is available in 1080p. Check the movie details on the left hand side.

    OP: I have Iron man too but trashed the 720p version before redownloading the 1080p version so I couldn't compare file sizes. However, that said, I find your claim to be strange because I'm currently in the process of replacing all my TV Shows on my Mac now with 1080p copies and I went ahead and checked file sizes and sure enough every 1080p file I came across with were larger than my existing 720p files, which they should be. So I don't know whats going on with that...
     
  19. CptnJustc macrumors 6502

    Joined:
    Jan 19, 2007
    #19
    Iron Man appears to be an unusual case, but you can verify it for yourself:

    http://itunes.apple.com/us/movie/iron-man/id289156796

    Toggle between 720p and 1080p downloads and watch the info on the left change between 4.03 GB (720p) and 3.84 GB (1080p).
     
  20. Icaras macrumors 603

    Icaras

    Joined:
    Mar 18, 2008
    Location:
    California, United States
    #20
    Strange indeed. I also found another strange case in my library: Gladiator 720p is 5.38GB and the 1080p version is 5.04GB. Wow, what the heck.

    But so far, these two titles seem to be the only ones that are abnormal in my library. I've gone through and already replaced about a couple dozen of my iTunes HD movies so far and they all had larger file sizes at 1080p. And with my TV Show library, I've found nothing like this yet. Still strange though for sure.
     
  21. chiefpavvy macrumors 6502a

    Joined:
    Feb 23, 2008
    #21
    Exactly. Too many people get caught up in bitrates.

    It would absolutely be possible to create a 1080p encode at a smaller file size which looked 'better' than a 720p version done with a crap encoder or poor settings etc.

    Also remember iTunes Store starts with a version of the film at a quality we do not have access to. It's better than Blu Ray. Better source, better results, at lower bitrates. Pretty simple.
     
  22. MovieCutter macrumors 68040

    MovieCutter

    Joined:
    May 3, 2005
    Location:
    Washington, DC
    #22
    Also remember that a lot of these encodes were done a couple years ago. I'm pretty sure H264 encoding has evolved pretty significantly since then.
     
  23. Icaras macrumors 603

    Icaras

    Joined:
    Mar 18, 2008
    Location:
    California, United States
    #23
    Ah, that would make sense. So basically take these file size comparisons with a grain of salt then.
     
  24. MovieCutter macrumors 68040

    MovieCutter

    Joined:
    May 3, 2005
    Location:
    Washington, DC
    #24
    Not a grain of salt...just with an educated perspective.
     
  25. Icaras macrumors 603

    Icaras

    Joined:
    Mar 18, 2008
    Location:
    California, United States
    #25

Share This Page