slacha1
Level 1 (1 points)

Q: H264 with AC3

Hi,

 

I would like to export my FCPX HD videos using H264 video and AC3 5.1 multichannel audio in an appropriate container.

The reason why I am not using AAC multichannel audio is because:

- AppleTV does not support true multichannel AAC decoding (or transcoding to DTS, as recommended by the DVB);

- DVD or BlueRay burning software do as well not support multichannel AAC (just performing downmixes);

 

I made tests on Compressor doing seperate H264 and AC3 encodes, then mux'ing both components into one MP4 stream. Unfortunately, although QT, VLC as well as ATV can decode the stream, no disc burning software will accept this 'non-standard' component combination.

 

My questions:

- Is there a possibility within compressor to combine H264 video with AC3 audio in a appropriate container ?

- Is anybody aware of a DVD or BlueRay burning software capable to handle multichannel AAC as true multichannel (whether as discrete PCM channels or as an AC3 transcode) ?

- Are there plans that ATV4 will properly support AAC multichannel (whether as discrete PCM channels via HDMI or as a DTS or AC3 transcode via optical audio interface) ?

 

Thank you

Posted on Dec 16, 2012 12:56 PM

by slacha1,Solvedanswer
slacha1 slacha1
Level 1 (1 points)
A:

I think I found the solution:

 

I inspired myself on the iTunes format .m4v which allows the combination of H264 video with AC3 audio.

Consequently there are several ways to proceed:

- export via FCPX using ProRes 422 and 5.1 PCM linear audio, then ecoding to H264 and AC3 using e.g. handbrake;

- export via FCPX trhough Compressor using seperate encodes for H264 and AC3, then muxing both compoents into a .m4v file using a mux tool such as Subler.

 

.m4v is indeed recognized by ATV, as well as by DVD/BD bruning software such as Toast.

 

a few points thought which I would recommend Apple to considered:

- Compressor should allow to directly create a .m4v file with H264 video and AC3 audio (currently not possible)

- Quicktime should be updated to correctly display within inspector the status of the AC3 decode. Indeed, presently quicktime will decode a 5.1 AC3 but will display it as a 'stereo' audio, which is not correct and misleading. VLC shows for instance the correct Dolby format...

- it's a pitty that iDVD does not support AC-3 passthough or a transcode for AAC to DTS or AC3, because multichannel audio is quite standard for DVD's and most MAC users will have video files with multichannel audio.

- ATV should support multichannel decoding of .mov files using multichannel AAC, whether via discrete PCM channels on the HDMI interface or via a DTS (or AC3) transcode via the optical audio interface.

 

Thx and best regards

 

Steve

Posted on Dec 18, 2012 2:18 AM

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slacha1

Q: H264 with AC3

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  • Helpful answers

  • by Russ H,

    Russ H Russ H Dec 17, 2012 4:55 AM in response to slacha1
    Level 7 (21,820 points)
    Quicktime
    Dec 17, 2012 4:55 AM in response to slacha1

    My 5.1 experience is limited so I'm hoping someone who routinely works in 5.1 will jump into this discussion. (You might consider posting this question on the Logic Pro boards.)

     

    But a couple of comments: iDVD will take a muxed h.264 and AC3, and encode it to MPEG2 DVD standards, but won't keep the surround sound. DVD Studio Pro will not take the muxed h.264 file, but will preserve the surround sound. DVDSP will take a ProRes file muxed file, although it works best by having a compression program do the DVD encoding and providing it with elementary streams. Neither authoring program will do Blu Ray.

     

    AFAIK, Adobe Premier and Encore can produce both DVD and Blu Ray with 5.1. I don't believe that Encore will preserve the surround sound if you give it a muxed file, but will if you give it elementary streams. Whether it would take AAC, I don't know.

     

    We can't specullate about Apple plans – even if we knew (which I don't).

     

    Question: How did you mux your files?

     

    Russ

  • by slacha1,Solvedanswer

    slacha1 slacha1 Dec 18, 2012 2:18 AM in response to Russ H
    Level 1 (1 points)
    Dec 18, 2012 2:18 AM in response to Russ H

    I think I found the solution:

     

    I inspired myself on the iTunes format .m4v which allows the combination of H264 video with AC3 audio.

    Consequently there are several ways to proceed:

    - export via FCPX using ProRes 422 and 5.1 PCM linear audio, then ecoding to H264 and AC3 using e.g. handbrake;

    - export via FCPX trhough Compressor using seperate encodes for H264 and AC3, then muxing both compoents into a .m4v file using a mux tool such as Subler.

     

    .m4v is indeed recognized by ATV, as well as by DVD/BD bruning software such as Toast.

     

    a few points thought which I would recommend Apple to considered:

    - Compressor should allow to directly create a .m4v file with H264 video and AC3 audio (currently not possible)

    - Quicktime should be updated to correctly display within inspector the status of the AC3 decode. Indeed, presently quicktime will decode a 5.1 AC3 but will display it as a 'stereo' audio, which is not correct and misleading. VLC shows for instance the correct Dolby format...

    - it's a pitty that iDVD does not support AC-3 passthough or a transcode for AAC to DTS or AC3, because multichannel audio is quite standard for DVD's and most MAC users will have video files with multichannel audio.

    - ATV should support multichannel decoding of .mov files using multichannel AAC, whether via discrete PCM channels on the HDMI interface or via a DTS (or AC3) transcode via the optical audio interface.

     

    Thx and best regards

     

    Steve

  • by DaveF,

    DaveF DaveF Sep 8, 2016 11:07 AM in response to slacha1
    Level 3 (683 points)
    Video
    Sep 8, 2016 11:07 AM in response to slacha1

    I hope this finding is just my inexperience with these tools, and I'd be very happy to eat my words and find out that Compressor 4 can do this now.  I work professionally in sound for film, but only dabble with video.  I have needs both professionally and personally to be able to embed 5.1 AC3 files to video but so far find no solutions using Apple's "pro" tools.

     

    After much searching across the internet (finding very little actually), the only Apple solution I found was to copy the AC3 file using Quicktime Pro 7 and paste it into the movie file which was also opened in Quicktime.  I've done this with other types of audio before in Quicktime to add or replace audio tracks, but I can't do this with AC3 files anymore as I can't find any way to get Quicktime 7 Pro to open the AC3 file.  Everything to do with this solution seems to have fallen out of support (if we want to call it supported to start with).

     

    In this and other threads, the ONLY solution I found that worked now (Sept 2016) was to use a free app called "Subler".  All these powerful Apple tools and we have to rely on a free app that might fall out of support at any time to mux? Surely there must be others, but after searching the net for several hours, and asking my audio peers, I still find myself with extremely limited options.

     

    I can make 5.1 AC3 files easily with Compressor, and convert video, but what good are the AC3 files to me if I can't combine them into a video file to play over my Apple TV? The combo of FCPX and Compressor 4, (both of which I own) certainly ought to be able to mux 5.1 AC3 to a video file .  One of the big draws to an Apple TV is the ability to play AC3 files where other media plays cannot.

     

    I really hope I'm wrong and just don't know how to use the tools, but reading through the manual I find no way yet to do this seemingly simple and obvious task.

  • by Ardpatrick,

    Ardpatrick Ardpatrick Sep 17, 2016 4:45 PM in response to DaveF
    Level 1 (8 points)
    Video
    Sep 17, 2016 4:45 PM in response to DaveF

    Just posted the same question on here elsewhere! Combining AC3 and .mov files used to work in QT pro 7. Quite incredible that its so difficult to do now, even with 'Pro" applications. I won't even begin...

  • by DaveF,

    DaveF DaveF Sep 18, 2016 9:21 AM in response to Ardpatrick
    Level 3 (683 points)
    Video
    Sep 18, 2016 9:21 AM in response to Ardpatrick

    I found a half-way solution.

     

    Inside Compressor 4, go to file and "Add Surround Sound Group", and add the 5.1 audio files one by one, as well as the video.  This only works if you have the audio in separate mono files to start with though.  Then there is a box to tick in the audio pane (after you've selected your output type) to "Include Dolby 5.1 Audio Track".

     

    The BAD side of this, is I can't find a way to make ANY adjustments to the AC3 encoding, so I assume they're using their default AC3 settings which I really don't like.  If they do, they flip the phase on the surrounds, and apply film compression, neither of which I want.

     

    In any case I got this to work over my Apple TV, but with no control over the AC3 encode, so I can't send mixes made for client review like this.

     

    "Pro" tools.... not.

     

    Apple, in the  surround sound group WHY oh WHY can't one of the options be an AC3 file instead of the raw audio files/???

  • by Ardpatrick,

    Ardpatrick Ardpatrick Sep 18, 2016 7:46 PM in response to DaveF
    Level 1 (8 points)
    Video
    Sep 18, 2016 7:46 PM in response to DaveF

    Hi Dave,

     

    Thanks. My problem is I don't want to use Compressor for video. But I do use Compressor to make AC3 files. The problem is combining them with the H.264 files made elsewhere. I have found a workaround which is to open the AC3 files in QT Player 10.3 (on another machine in my case) and save them as QT movies. Then they can be copied and pasted into H.264 files on a machine running 10.8.5, an QT Pro 7.

     

    With a workflow like that I feel like I must be doing something illegal! But its my content, edited on my machines, using "Pro" software I've bought and paid for! Pathetic really.

  • by DaveF,

    DaveF DaveF Sep 18, 2016 8:34 PM in response to Ardpatrick
    Level 3 (683 points)
    Video
    Sep 18, 2016 8:34 PM in response to Ardpatrick

    Interesting solution there.  I hadn't tried opening the AC3 files with Quicktime 10.x (only QT 7 which would NOT open them), but I was able to do what you mentioned there.  Then using Quicktime Pro 7.6.6 I was then able to open the "AC3 as .mov" file and add it to the video.

     

    I'm certainly with you, this is a real hack-around having to do it this way. The "Pro" apps should certainly be doing this instead of us having to use an old and unsupported version of QT.

     

    But thanks for that tip!

     

    (on further inspection - my ATV 4 doesn't see that saved file as having an AC3 stream.... sigh....  I'll have to look at this further when I get some time)