Understanding Handbrake

Discussion in 'Mac Basics and Help' started by StephenCampbell, Sep 15, 2014.

  1. StephenCampbell macrumors 65816

    Joined:
    Sep 21, 2009
    #1
    I'm using Handbrake to rip some DVDs to my 2013 iMac.

    From what I've read, I gain nothing by putting the Constant Quality RF to lower than 18.

    I set it to "High Profile" and change the default RF 20 to RF 18, increase the audio bit-rate to the max, and hit Start.

    Sometimes the picture quality looks the same as the DVD, but sometimes I feel like it's ~95% of the quality. I've been doing mostly films from the 1930s, and when I tried a modern DVD like Munich, I thought there was a slight noticeable difference.

    What would be causing the difference? Going below RF 18 can't increase the picture quality because it goes beyond the point to which the DVD is already compressed itself.

    I'm extremely, extremely picky and I'm probably analyzing and comparing too closely.. I can't say for certain if there actually is any quality difference in most cases, but what else could I do to guarantee the same quality as the Apple DVD Player playback?

    Thanks!
     
  2. StephenCampbell, Oct 5, 2014
    Last edited: Oct 5, 2014

    StephenCampbell thread starter macrumors 65816

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    Sep 21, 2009
    #2
    Sorry to bump the thread, but I resolved my first question and have another.

    What kind of audio codec should I be using to watch the movies on my Mac in QuickTime or VLC?

    The default setting of "high profile" is to have two tracks, one which encodes with AAC (CoreAudio) and the other which is an AC3 Passthru. I normally increase the bitrate on the AAC track to the max allowed (either 256 or 320 usually), and the AC3 passthru track is unmodifiable.

    By default the files play using the AAC audio track, and I'm not sure how to hear the AC3 passthru track. But it is there I believe.. it shows those two audio tracks in Handbrake.

    In VLC I can see Stream 0, Stream 1 and Stream 2 under "media information" and streams 1 and 2 are two audio tracks, but there are two (a stereo and a surround) even for movies that I encoded in the "normal" setting that didn't have two audio tracks. So I'm confused about that. There were a few that I encoded with just an AAC track, and then I began doing the "high profile" with the second AC3 passthru track, but they all appear the same in the VLC media information.

    I'm using Logitech Z-2300 2.1 speakers, by the way.

    How do I best preserve the audio from the film?
     
  3. Alrescha macrumors 68020

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    #3
    In VLC you should be able to go to the menu and select Audio/Audio Track. Since you do not (I think) have a Dolby Digital capable device, VLC should downmix that audio to stereo on-the-fly for you.

    If you connect up a Dolby Digital receiver and speakers using an optical out (if you have one), you will hear all the channels as intended. iTunes will also play the Dolby Digital track if you have the appropriate equipment (but it will not downmix for you).

    A.
     
  4. StephenCampbell, Oct 5, 2014
    Last edited: Oct 5, 2014

    StephenCampbell thread starter macrumors 65816

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    #4
    Yes, I see "Stereo" and "Surround" options in VLC. But what do those correspond to? Both options are there on all videos, even those that I didn't rip with the two audio tracks.

    In QuickTime 7, under 'movie properties' I can see an AAC track and an AC3 track as well... even for those that I didn't encode with the AC3 passthru track. ?? And the AAC track is called a stereo track, while the AC3 is called a surround track.
     
  5. Alrescha macrumors 68020

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    #5
    I am pretty sure that my copy of VLC (2.1.5) only shows me tracks that exist, same for QuickTime (I suppose *everything* could be lying, but I do not think so).

    It may be the best option if you have no external audio hardware - but in the external realm there are lots of options (USB, Optical, Thunderbolt). It is worth exploring.

    If you might upgrade in the future (whether Mac-attached or Apple TV) then I recommend including/keeping the surround track.

    A.
     
  6. StephenCampbell thread starter macrumors 65816

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    Sep 21, 2009
    #6
    Well this is what happens in Handbrake:

    Under "Normal" preset:

    One audio track titled "0: English (AC3) (1.0 ch)" Codec "AAC (CoreAudio)"

    When I switch it to "High Profile" there is a second audio track beneath that, titled the same (0: English (AC3) (1.0 ch)", but the codec is AC3 Passthru.

    Only the first few rips I did were in Normal, and all the others have been in High Profile (both tracks) and the Bitrate turned up for the AAC track.

    Is AC3 Passthru synonymous with "surround"? Why can't my Mac play the original audio from the DVD unaltered, even if it's not surround?

    I still don't quite get what's what here. Thank you so much for your help!

    Edit: By the way, I don't know if it's weird that it says the tracks are "1.0 ch" but keep in mind these are all 1930s films I've been ripping so far.
     
  7. Alrescha, Oct 5, 2014
    Last edited: Oct 5, 2014

    Alrescha macrumors 68020

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    #7
    Right, I use the Apple TV3 preset, which also generates two audio tracks.

    Well, I would choose "DVD compatible audio". It does not have to be surround sound, but it could be. As you have seen, it could be a single monaural track.

    It can - plug in a DVD drive, pop in a DVD and DVD Player should start right up. :) Alternatively, point DVD Player at one of your ripped VIDEO_TS folders and it will play that too.

    Handbrake converts files for many purposes. I use it exclusively to backup/compress/convert my DVDs so I can store them in iTunes as m4v files and play them on my Apple TV. This may be the most common use of Handbrake.

    As such, it helps to know that Apple has a format it uses for such files, and Handbrake outputs to match. An Apple movie file has a video track, an AAC audio track, and <all optionally> an AC3 track, subtitle tracks, and chapter track. So, in lots of presets Handbrake creates two audio tracks by default. Happily, iTunes can play those same files, as can VLC and probably many other programs. It is my format of choice, for good or bad.

    The two audio tracks means that devices without an Dolby Digital decoder can play the AAC track. Over time, more and more devices have such a decoder - maybe someday we will not need the extra track at all.

    You are most welcome. Enjoy those movies!

    A.

    Addendum:

    I mention external receivers and decoders and speakers because if you do end up with a Dolby Digital 5.1 track, you will need 6 speakers to listen to it as intended. As far as I know, your iMac does not have that many... :) --A
     
  8. StephenCampbell thread starter macrumors 65816

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    Sep 21, 2009
    #8
    Thank you very much. I admit I still haven't wrapped my head around all this fully, but that's okay!

    I had originally been under the impression that AC3 was the format that the audio was on on the DVD, and that it was an equivalent to something like AIFF in terms of being full and uncompressed. And then compared to that AAC would be the same as AAC vs. AIFF, i.e. much more compressed and losing a lot of data. Is this not the case in this situation? What is the nature of the audio on the DVD? What is it?

    Does Apple DVD player have a Dolby Digital decoder? But QuickTime/iTunes/etc do not?

    What is an "apple movie file"? I don't necessarily want to mimic what they provide on Apple TV. I want the best possible.
     
  9. Alrescha, Oct 5, 2014
    Last edited: Oct 5, 2014

    Alrescha macrumors 68020

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    #9
    AC3 is a compressed (lossy) format. I think the compression is why folks with an audio bent like DTS better as it can support lossless compression. There may be some DVDs created with PCM (lossless, same as a CD), but I think those are limited to music DVDs. The lossy/lossless compression applies only to the medium of course, we do not know what happened to the audio before it got stamped on the DVD.

    Yes. I would speculate that just a few years ago, DVD Player is the only place where anyone expected to need to decode Dolby Digital audio. If you are using conventional speakers, DVD Player will mix down the audio for stereo like I described earlier with VLC.

    That was just my choice to refer to the file format that Apple uses for the Apple TV. Someone else may have a better name.

    In that case you will want to keep those VIDEO_TS folders from your DVD rips :)

    But if you are referring to audio quality only, then just keep that AC3 track around. VLC will play it for you just fine - I do not know that DVD Player would do any better.

    A.
     
  10. StephenCampbell thread starter macrumors 65816

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    Sep 21, 2009
    #10
    So VLC just 'knows' to use the AC3 track? Whereas QuickTime will use AAC? What's the difference in quality between AC3 and AAC usually?

    My initial plan was to just copy VIDEO_TS folders to my hard drive, but sometimes it wouldn't work, yet a handbrake rip would work with the same disc. And the handbrake rips take less space and look basically the same as the DVD with RF 18 and "slow" H.264 preset.
     
  11. Alrescha macrumors 68020

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    #11
    VLC will play whichever track you tell it, defaulting to the first one (probably: VLC's choice of tracks - especially subtitles - is sometimes a mystery to me). QuickTime is going to use the AAC track.

    Quality? As you rightly said earlier, AAC means an (undesirable) extra step. Given the high bit rate you use, the difference may not be meaningful. I think you will have to listen to them. Alas, I am not aware of a hotkey to switch audio tracks in VLC.

    If you are keeping the AC3 track you will have the best audio available, regardless of where you go with it in the future. I use the Apple TV3 preset, with RF 18.

    A.
     
  12. StephenCampbell thread starter macrumors 65816

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    Sep 21, 2009
    #12
    How do I tell VLC to use AC3? All I see is "stereo" and "surround."

    Also, the AC3 Passthru track is often locked at 192kbps or something, whereas I put the AAC at 256 or 320, whichever the higher option is for the given DVD. Is the AC3 still better? I thought the kbps is all that's relevant in terms of quality. Lower bitrate is lower quality. Is that wrong?
     
  13. Alrescha macrumors 68020

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    #13
    Pick the track from the menu. Track one is AAC and track two is AC3. "Stereo" and "Surround" are just text labels (which you could edit with something like Subler). You can verify the contents in the Media Info (Command-I) window in VLC.

    Alternatively, do not even generate the AAC track. It does not look like you require it for anything at the moment. I generate it only for compatibility purposes. Do whatever fits your usage - just keep that AC3 track around.

    The AC3 track is your source - it is the best you have. Converting it to AAC will not create any more information. Using a high bit rate on the AAC conversion might help better preserve what you have, but at some point (like RF numbers below 18) you are just wasting bits.

    A.
     
  14. StephenCampbell, Oct 6, 2014
    Last edited: Oct 6, 2014

    StephenCampbell thread starter macrumors 65816

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    Sep 21, 2009
    #14
    But I'm seeing "Stereo" and "Surround" for all my rips, including the ones I did with only an AAC audio track. How do I know that "Surround" means AC3 for the rips that have both?

    And as I said before, even rips that only had the AAC track have an AAC and an AC3 track displayed under "Media Information" in VLC. I don't get it. I could rip another one with just AAC to test, but I know these rips only had AAC.
     
  15. Alrescha macrumors 68020

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    #15
    You are asking me to convince you of the contents of files that you created. I am not sure I am really qualified to do that.

    You said you used Handbrake to create these files, and I am trusting that Handbrake is telling the truth. I do not know what presets you used or anything else about your process. You say you created only an AAC track, but VLC says you have two tracks. Be it far from me to take sides :)

    In VLC, the Media Info window will display the contents of the file: video, audio, etc. Alternatively, the Subler program will not only show you, but will let you create or delete tracks as may suit your needs. MP4Tools is also useful for viewing, converting, and extracting tracks from files.

    A.
     
  16. StephenCampbell thread starter macrumors 65816

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    Sep 21, 2009
    #16
    Yes, I can see Stream 0, 1 and 2 in the Media Info window, but I don't know how to tell if it's using Stream 1 or Stream 2 for audio. How do I tell it to use Stream 2?
     
  17. Alrescha macrumors 68020

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    #17
    I am pretty confident that if you go to the menu and choose the first audio track (regardless of its name), you will get the first audio track listed in the Media Info window. Likewise, if you pick the second track I am pretty sure that is the second audio track in Media Info. Anything else violates the Rule of Least Astonishment.

    Now, if you want to complain that there is little commonality between what VLC shows you in the menu under Audio and what it shows you in Media Info, I am in complete agreement. Alas, there is not much I can do about that, not being a VLC developer.

    A.
     
  18. StephenCampbell thread starter macrumors 65816

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    Sep 21, 2009
    #18
    I see. My only concern with selecting "Surround" in the menu is the possibility of losing big chunks of the audio that I'm supposed to be hearing, since I don't have a surround system. But I'll do some more experimenting.

    Thanks again for all your help. You have been utterly invaluable!
     
  19. CrashCocoB macrumors newbie

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    Mar 15, 2015
    #19
    Hi,

    I've a question regarding Handbrake.

    I'm ripping my DVD collection into Apple TV 3 and iPad friendly format files.

    I use the ATV3 preset and have a question.
    I use to keep for the audio 2 tracks :
    - AAC Dolby Pro Logiciel
    - AC3 Passthru

    My question is :

    I've DVD of old movies / TV Shows for which on the DVD there is only 2.0 or 1.0 audio.

    In this case, does it worth to keep the AC3 Passthru track ?

    Currently I've a 2.1 system but will upgrade to 5.1 later. So for DVD with AC3 5.1 it definitly worths it. But for 2.0 or 1.0 I don't know.

    I raise the question in Digital Audio forum but since there is here a post about Handbrake maybe better to ask here.

    Cheers.
     

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18 September 15, 2014