Handbreak AAC vs. AAC+AC3

Discussion in 'Apple TV and Home Theater' started by d21mike, Oct 8, 2008.

  1. d21mike macrumors 68040

    d21mike

    Joined:
    Jul 11, 2007
    Location:
    Torrance, CA
    #1
    Handbreak iPOD Preset has AAC Audio Encoder and AppleTV has AAC+AC3 Encoder. I am thinking of using the iPOD (HiRes) Preset for my iPhone.

    I believe I can also use the AAC+AC3 with the iPOD Preset and the file is a little larger but I don't know if there is an advantage.

    Can someone explain the difference and if it is worth using?
     
  2. mrgreen4242 macrumors 601

    mrgreen4242

    Joined:
    Feb 10, 2004
    #2
    AC3 is "true" 5.1 surround sound ripped directly from the DVD and not re-encoded. It gets passed through to a 5.1 reciever via the optical audio on an ATV but is otherwise ignored.

    It's good if you have or think you will have an ATV (or Mac mini) based home theatre system with 5.1 surround. Otherwise it's just a waste of space.
     
  3. d21mike thread starter macrumors 68040

    d21mike

    Joined:
    Jul 11, 2007
    Location:
    Torrance, CA
    #3
    Sorry. I meant to say I do also have a AppleTV (just got it). I was hoping to be able to use the same M4V File for both. I noticed the iPOD HiRes has a default bit rate of 1500. But I can (if I want) increase it to 2500 (like the AppleTV Preset) and the file sizes are about the same as AppleTV Preset. However, unlike the AppleTV Preset created file I can play all of the iPod Preset Created files on my iPhone and my AppleTV which is a bit confusing.

    So are you saying if I want to use for both iPod and AppleTV I should use the iPOD Preset with 1500 - 2500 (based on file size vs. quality consideration) and also use ACC+AC3 (which is a little bigger file size)?

    Also (since you mentioned Mac Mini), a Mac Mini "appears" to be the same size as a AppleTV. I normally use Windows but would like to have a Mac Mini for some new things I may be doing. Would a Mac Mini be a better AppleTV? Or just overkill if it is really only doing AppleTV Stuff? I could move my AppleTV to the bedroom. My AppleTV is current connected to my Windows iTunes.
     
  4. Mr Kram macrumors 68000

    Mr Kram

    Joined:
    Oct 1, 2008
    #4
    there's a thread around somewhere that discusses the best hybrid file out there. it seems that the consensus is to use the ipod hi-res setting with acc+ac3 and the bitrate set to 2000-3000 depending on quality. i personally use this setting with strict anamorphic and 2200 bitrate. i've been very pleased with the general results.

    as for the mac mini question. i suppose if cost was not an issue that mac mini would serve as a more robust and versatile media server.
     
  5. mrgreen4242 macrumors 601

    mrgreen4242

    Joined:
    Feb 10, 2004
    #5
    Using the mini on your TV involves a little work getting it setup, the ATV just works. The mini has more options, of course, but for a just plug it in and go the ATV can't be beat. I'd say use the ATV for awhile and if you decide to get another one look at a mini then and see if you'd use the extra features.

    If you have an ATV and there's even a chance of you having 5.1 hooked up to it in the next 4 years or so, I'd rip with the AC3 track, personally. It adds about 3mb per minute to the file, so ~300mb per file, not HUGE.

    As for rip settings, I use a custom setting for my ATV and iPod touch (and hopefully decent forward and sideways compatibility). I use a 64% CRQ h264 encode with some advanced flag set. I use the maximum non-anamorphic resolution for the movie. I also use a weak denoise filter which helps lower the overall size of the file and can add a slight improved perceived image on some older or poorly transferred films. For audio, I do keep the AC3 track and also a 160kbps AAC DPLII track with 1.50 dynamic range settings (helps keep the voice track clear on stereo setups, imo).

    The result plays on my ATV, looks DVD quality on my 30" HDTV from my normal 8-9' viewing distance. It plays fine on my iPod touch and, of course, looks fantastic there. It looks lower than DVD quality on my iMac, as it's a very high res display and you are sitting very close to it. That said, it's about as good as non-HD iTunes downloads. Because I use CRQ the file size varies quite a bit, but I average about 1.5gb per movie (including the AC3 soundtrack). I've had some shorter movies that happen to compress well for whatever reasons go down as far as 900mb, and some longer movies that don't compress as well up to 2.5gb. But, 1.5gb is pretty typical.

    I've ripped about 100 movies this way, so far, and 40 or 50 episodes of TV shows. I'm quite happy with the compromise of space vs. quality and haven't felt the need to tweak anything in my settings since I started using this custom preset. The encode time is decent as well. On my 2.4ghz C2D iMac I'm averaging just below realtime encoding (it's single pass since it's CRQ, plus a fast scanning pass for subtitles, but I don't know if that's used for the video encoding at all). Some are a little over realtime, some are ~60% realtime, but I'm very close to realtime, maybe 92% realtime speed, when you average all the movies I've ripped together.

    Hope that helps. If you want the exact settings I use send me a PM to remind me to check it when I get home from work.

    Rob
     
  6. d21mike thread starter macrumors 68040

    d21mike

    Joined:
    Jul 11, 2007
    Location:
    Torrance, CA
    #6
    Thanks, that was very helpful.

    You said "strict anamorphic". I am use release 9.2 under windows and the setting is a check box for "Anamorphic PAR". Is that the same? The default is not checked. Also, there is another check box (to the right) that says "Loose Anamorphic" which is also not checked.
     
  7. dynaflash macrumors 68020

    Joined:
    Mar 27, 2003
    #7
    Use loose anamorphic.

    The aac + ac3 soundtrack(s) makes you future proof (sort of) for new or future apple devices, (ie. if playing on something besides an appletv like an ipod, etc you will hear the aac soundtrack since thats all it's capable of playing). If you use the same file on an atv connected to a Dolby Digital capable device you will get the AC3 track (at the expense of file size since typical ac3 5.1 surround tracks eat up 448 kbps/sec).

    Your choice.
     
  8. d21mike thread starter macrumors 68040

    d21mike

    Joined:
    Jul 11, 2007
    Location:
    Torrance, CA
    #8
    Thanks. I believe I will follow your recommendations.
     

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