iTunes can't play .mp4/.m4v, but Quicktime can?

Discussion in 'Apple TV and Home Theater' started by troy14, May 1, 2013.

  1. troy14 macrumors 6502a

    Mar 25, 2008
    Las Vegas (Summerlin), NV
    Hi everyone,

    Hoping someone can shed some light for me. I have a bunch of movies in .mp4 format.

    My problem is this: I can right click the file and view in Quicktime. Everything plays fine. As soon as I copy them into iTunes, this is where the problem occurs. I can double click it and when it goes to play, a black screen comes up and it does not advance the movie. If I scroll to a different part of the movie (say, 1 hr in), it will display the picture at that time, but will not continue playing and there is no audio.

    When I try to watch these movies on my Apple TV (2nd gen), they will play but there will be NO sound.

    Is there anything I am doing wrong? I have tried changing the audio options on my Apple TV to disable dolby digital, 16bit etc, and nothing works!

    I originally thought it was something weird because my iTunes library is on an external drive (WD MyBook 3tb connected FW 800) but then I made a new library on my actual Mac Mini and the same thing happens.

    FWIW I also ran a video through iFlicks and it "optimized for iTunes" which took 6 minutes and it still had the same issue, and it was a .m4v file when it came out of iflicks.

    This is the video specs:
    Codec -- H.264
    Resolution -- 1080p (1920 x 804)
    Bitrate -- 4 565 Kbps (Avg)
    Frame Rate -- 23.976 fps
    Audio -- AC3 (640 Kbps) 6 channels (Front: L C R, Side: L R, LFE)
    Language -- English
    Subtitles -- English (Hardcoded when necessary)
    Extension -- MP4
    Source -- BluRay
  2. mic j macrumors 68030

    Mar 15, 2012
    So only a few of your movies are doing this...correct? Are these downloaded files?
  3. stuckwithme247 macrumors regular

    Jan 14, 2003
    Have you tried simply using QuickTime to convert it. File -> iTunes -> Apple TV? I know you can use the open source HandBrake to make videos with subtitles. They have a few presets for iTunes and Apple TV. Where does the video file originate from?
  4. troy14, May 1, 2013
    Last edited: May 1, 2013

    troy14 thread starter macrumors 6502a

    Mar 25, 2008
    Las Vegas (Summerlin), NV
    Correct and correct.

    Figured out the Apple TV can't play 5.1 audio, which is why it never worked.

    What a bummer. Was hoping I could dump my ATV 2 / Plex for an aTV 3 with 1080p.
  5. soulsteelgray macrumors regular

    Mar 20, 2012
    FWIW, I can get 5.1 audio to work on my Apple TV 3, and the following is the report on the audio streams in my encode of one movie (Zero Dark Thirty). I encoded it using the Apple TV 3 preset in HandBrake. Not sure if this'll help you any but I just wanted to give my 2 cents.

    Audio #1
    ID                               : 2
    Format                           : AAC
    Format/Info                      : Advanced Audio Codec
    Format profile                   : LC
    Codec ID                         : 40
    Duration                         : 2h 36mn
    Bit rate mode                    : Variable
    Bit rate                         : 163 Kbps
    Maximum bit rate                 : 276 Kbps
    Channel(s)                       : 2 channels
    Channel positions                : Front: L R
    Sampling rate                    : 48.0 KHz
    Compression mode                 : Lossy
    Stream size                      : 183 MiB (3%)
    Language                         : English
    Encoded date                     : UTC 2013-03-19 09:45:49
    Tagged date                      : UTC 2013-03-19 13:20:18
    Audio #2
    ID                               : 3
    Format                           : AC-3
    Format/Info                      : Audio Coding 3
    Mode extension                   : CM (complete main)
    Codec ID                         : ac-3
    Duration                         : 2h 36mn
    Bit rate mode                    : Constant
    Bit rate                         : 640 Kbps
    Channel(s)                       : 6 channels
    Channel positions                : Front: L C R, Side: L R, LFE
    Sampling rate                    : 48.0 KHz
    Bit depth                        : 16 bits
    Compression mode                 : Lossy
    Stream size                      : 719 MiB (13%)
    Language                         : English
    Encoded date                     : UTC 2013-03-19 09:45:49
    Tagged date                      : UTC 2013-03-19 13:20:18
  6. Toubro macrumors newbie

    May 4, 2013
    iTunes cannot play the video, because it doesn't support AC-3.
    The AppleTV cannot process the AC-3 signal, but it can pass on the signal to an external surround decoder. If no other soundtracks are present, the ATV will play the movie without sound. The ATV does however support other types of surround, AAC for example.

    In the situation where a movie has 2 soundtracks, like in soulsteelgrays example, the ATV will choose the stereo AAC output for systems that does not support AC-3. It will also play the stereo AAC track in iTunes and on iDevices, (notice that you can't transfer videos with only an AC-3 soundtrack to iDevices).

    Subler is a fantastic little program, which can convert the soundtrack without reencoding the movie track.
  7. Mrbobb macrumors 601

    Aug 27, 2012
    Kinda weird that QT can but iTunes can't, because iTunes CALLS QT to play video.
  8. Nermal Moderator


    Staff Member

    Dec 7, 2002
    New Zealand
    I suspect that the OP has an AC3 QuickTime component installed (Perian?). As far as I know, iTunes runs at a slightly lower level and doesn't make use of third-party components.
  9. Toubro macrumors newbie

    May 4, 2013
    My thoughts exactly.
  10. Ritsuka macrumors 6502a

    Sep 3, 2006
    QuickTime Player on Mountain Lion can play ac3 because Apple added a decoder, but the decoder is in the Player app, not a system component, so iTunes can't use it.

    Perian ac3 decoder is still broken on Mountain Lion.
  11. Nermal Moderator


    Staff Member

    Dec 7, 2002
    New Zealand
    Huh. You learn something every day; I had no idea that there's a built-in decoder now. I also didn't know that Perian doesn't work because I no longer use it (I've had too many problems with it over the years).
  12. mtbdudex macrumors 68000


    Aug 28, 2007
    SE Michigan
    iTunes can't play .mp4/.m4v, but Quicktime can?

    Simply the whole digital lifestyle is a bag of hurt.
    Way to much "stuff" to move content you create or own to other devices.

    Really, to move something to ATV you need to re-code it? Why? My friends rip blurays full lossless and stream those to their devices.
    I love and hate Apple TV.
  13. thirdeyeopen666 macrumors 6502


    Sep 16, 2007
    iTunes can play the file without issue... but you have to have at least one stereo track. Using handbrake, add an audio track that is Stereo or Pro Logic, and then one that is AC3 pass-thru. This way you'll be able to play it on either device, AND keep your 5.1 sound.
  14. priitv8 macrumors 68040

    Jan 13, 2011
    If your original source already contains AVC video track with suitable bitrate and only AC3 audio, I would not waste time on HandBrake (because it always reencodes the movie).
    I use just the MP4Tools to repackage the movie and add AAC stereo track, which takes considerably less time. Plus it leaves the video and AC3 surround tracks intact - no change in quality.
  15. orestes1984, Nov 15, 2014
    Last edited: Nov 15, 2014

    orestes1984 macrumors 65816

    Jun 10, 2005
    An Apple TV can play multichannel audio by either one of two means:

    • Having your audio down converted to multichannel AAC.
    • Having a second AC3 channel set as pass through.

    You will need a primary stereo track with the first method and to have the secondary AC3 channel. It will play just fine as a pass through and your receiver should automatically detect it. There's no need to reencode anything you can just change the container using Subler.

    Perian is not broken on Mountain Lion or Mavericks, you just need to download an additional audio library then enable multichannel output in Perian, then Subler and everything else will work correctly.
  16. se419 macrumors newbie

    Feb 7, 2008
    SF, CA / NY, NY
    Export from QT in AppleTV format if iTunes import/copy does not play

    I had the same issue where an iTunes import/copy of an M4P file did not play. I exported from the QuickTime Player, using the "iPad, iPhone 4 & Apple TV" setting, and it successfully created a file that would play through Apple TV. (The estimated file size was way off however, actual export was much smaller and similar in size to the source, and the higher quality export option, "iPad2, iPhone 5 & Apple TV" was grayed out and not available.)

    Not sure what the conversion did to the audio, but I assume the conversion was lossy. See below for file info, original and conversions:

    Major difference is that the original and iTunes converted files were .mp4, but the QT Player output a .m4v file that played in iTunes and my AppleTV.

    All files (using get info) said they were: 720 × 404; AAC, H.264; 2 audio channels and 42:44 duration. Both MP4s (original and itunes import) were exactly the same byte count so it looks like iTunes copied and did not recompress the file, however the QT Player exported M4V file was slightly smaller in size, by about 100KB (for a 425MB file).

    I don't know where/how to view the deeper audio format information to find if any of the files had surround encoding.

    MacOS X 10.9.5
    AppleTV V 3
    QT V. 10.3
    iTunes V.

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