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  • Adobe Premiere CC Multichannel 5.1 Quicktime to 640kbps Dolby Digital AC3

    Posted by Gary Huff on July 17, 2016 at 3:37 am

    I have a QuickTime master render which has a multichannel audio of a 5.1 surround mix that was done in ProTools (exported via Final Cut Pro 7). The tracks are in this particular order:

    1 – Left
    2 – Right
    3 – Center
    4 – LFE
    5 – Left Surround
    6 – Right Surround

    I have setup the sequence with the 5.1 mix track option, but everything I have seen seems to be geared towards mixing the audio within Premiere. The mix has already been done and all I want to do is to export out for a Blu-ray and have Media Encoder take these six channels and create a compliant AC3 Dolby Digital encode.

    I have used the track mixer to assign the tracks to their “pots” for each of the channels, then left the LFE positioned in the center and turned the LFE knob up to 100%, but I’m still iffy on whether this is going to mess with the mix in the resulting file, as I don’t want that, I just want each track properly encoded and assigned and left untouched otherwise.

    I also have mono WAV exports from ProTools of this mix as well if that is any better.

    Anyone have any experience with this workflow and can help me out? Thanks!

    Ben Cohen replied 7 years, 10 months ago 3 Members · 3 Replies
  • 3 Replies
  • Ht Davis

    July 19, 2016 at 8:28 am

    1. NEVER TURN LFE ALL THE WAY UP!!!!! Unless of course, you plan to kill somebody when you light their whole house on fire when the SubWoofer explodes… …In that case, you know, sure.
    2. You don’t want to go changing encoders back and forth. Output your video, send it to final cut, and mix it in there. You can get great quality video encoding from Compressor, and it will mix the streams as you see fit. Finally, when you want to encode the audio for stereo output as well, the dolby from your final cut will mix down for a standard mixed stereo if you tell it to encode that way. In stereo, the LSRS will be delayed and phased, so they create dimension, and the LFE will be fed much the same by delays to all speakers, both in phase and out, so it will play normal on stereo. The Stereo channels will be WAV encoded, but compressed data, and the rest will be the differential analysis of the delays, Phase and db drops from those channels. That’s why the files are kept so small. The compression is just the mathematical representation of the differential from the main speakers. Fun in’t it?
    3. If you can only use PREMIERE, then you’ll be in a mess. You’ll have to strike a balance. I’d dump the wavs into premiere, then start LFE at 15% and play with it there, watching it close. Don’t let it go above about 1\3 of the phase meter when you set it for 94-96db width. That will allow you to get the full safe range. At about 1\3 of the meter, you’re at 30dbu (sound pressure), which is enough to feel an earthquake in your calves. Try staying below the 1\3. If you can keep it to that, you shouldn’t have a problem with general use. -6dbV on that meter is a max value for other speakers. It gives you enough headroom to allow them to attenuate their own volume levels.

    Good luck.

    Also, In light of recent problems found with audition, consider the following:
    Make a Batch file in windows that will
    1. take a dropped file as input(your session file will do)
    2. get the parent folder (the whole structure is important)–this is the folder where your session is, along with the folder containing your audio files that you record.
    3. periodically non-destructively (as in not deleting files that are no longer in the first folder) Mirror the contents of the parent folder to another location anywhere on any drive (every 2-5 minutes works) and make sure you set this folder, or you can simply use the parent folder of the original file and add a Backup folder inside,
    4. then just continually make backups using a forever loop (Condition is always true like While 1==1). You can close it when you close audition by simply closing the Command prompt window. You won\’t lose everything even if you crash, after all, audition cannot delete what it knows nothing about.

    On mac open automator:
    start by making an application–call it BackupStart. create 2 Path variables: SessionFile, ParentFolder. These will be what you use to grab your files. Create more Path variables with names similar to BackupFolder#, where # is the number of which backup folder. You can now Set Variable Value (in actions library) for the path Session file as your first action (this will catch the path of the file you drop on the app). Next, run a shell script in Bash (an action in utilities or system), and set STDIN to Arguments. Clear everything in the shell, and type: dirname \”$1\” Exactly as shown (don\’t replace dirname, it\’s a command that grabs the name of the parent folder of the file you just dropped in. Add another Set Variable action for ParentFolder. Now use an ASK for finder items action, and look in it\’s options to \”Ignore this items input\” and check the box. Add a Set Variable for BackupFolder1. Repeat for each BackupFolder variable you have (ask for folder, set variable). Now add a GET VARIABLE action, go to options and select \”Ignore input\” again, make sure you are GETting the ParentFolder variable. Now another GET Variable for Backupfolder1, but DONT ignore input (you want the two to pass into one another and continue on). Repeat this last op for each BackupFolder variable, leaving the ignore input unchecked to group them all together. Now add a RUN WORKFLOW action and turn off \”Wait for workflow to finish\”. Save this file, leave it open, and go to file Duplicate. Rename the duplicate BackupLoop1. File >Convert this doc to a Workflow. Delete the variable SessionFile from this document and all but the very last of the actions(Run Workflow). The other variables are still necessary. Everything we add should be above the RUN WorkFlow action. Use a Get Variable on your ParentFolder, and as before, do not check ignore input. You need this to run straight through from the first document. Add the GET Variable for your backups. Add a Shell Script in Bash, with STDIN set to Arguments. Clear the script box, and type:
    rsync -vau \”$1/\” \”$2/\” (enter)
    rsync -vau \”$2/\” \”$3/\” (enter)
    The first line copies your parent folder\’s contents, the second copies the first backup to the second. You can continue this until you have handled every backup in the script. Apply a PAUSE action for a few seconds. Now add a Loop Action, and set it to run 50 or more times (applies a wait time until finish) and set it to use the same input. This will continually backup all your data as you record, and when you hit stop, you should get a copy of your audio almost immediately after, done by your system, and making the RAW file data into a finished file set. Now add the GET VARIABLE set again for all your variables, ignoring the input of the first one, but keeping it for the others. Point them into the last action of RUN WorkFlow. Again, Duplicate the document, call it BackupLoop2. Change the Run Workflow in this file so it points to where you saved BackupLoop1. Change the RUN WorkFlow in BackupLoop1 to point to BackupLoop2. Change the Run Workflow in BackupStart to point to BackupLoop1 and place BackupStart in your DOCK. When you get ready to record, drop the session file onto your dock icon, pick your backup folder(s), and then let it go. Hit record, and when you hit stop, wait a few seconds for it to end the raw file tags. Now check your backup folder. You should have a perfect WAV capture there.

    IF audition crashes, you can drag the files in your backup folder to the original place and continue.

  • Gary Huff

    July 21, 2016 at 12:45 am

    [Ht Davis] “You don’t want to go changing encoders back and forth. Output your video, send it to final cut, and mix it in there”

    For reasons I won’t get into, that’s not going to happen. Final Cut Pro 7 is now out of the equation.

    [Ht Davis] “you can get great quality video encoding from Compressor,”

    Not in my experience, and I have made some decent extra cash by providing a service of not using Compressor to make the masters for physical media delivery. Like people come to me because they had tried to use Compressor and were not happy with the output.

    The rest of your advice involves mixing the audio. The audio is already mixed from ProTools. Everything is done and as it should be. All I want to do is turn it into a .AC3 without altering the mix that the client paid for. And then the automator workflow, I have no idea what you are talking about there.

  • Ben Cohen

    August 2, 2016 at 3:19 am

    Hi Gary, I’m interested in figuring this out with you – I need to tackle this exact same workflow.

    What I am planning to do is map the audio channels in Premiere by right clicking the video in the project browser, and choosing “Modify>Audio Channels” – then I will set the audio for the video as 5.1 and assign L,R,C,Lfe,Ls,Rs to the correct channels in their respective order based on the original file.

    After I have done this mapping for the clip, I will bring the clip into a sequence that is 5.1 (the easiest way to do this is to directly drag the footage/clip from the project browser onto the “new item” icon at the bottom of the project browser window. This creates a sequence with audio settings to match the clip settings. Or, if needed, I can create a 5.1 sequence manually.

    From there, I can adjust things, but assuming there is no editing or mixing to be done I can simply send the sequence to media encoder and encode based on whatever settings I think are best.

    As far as I can tell, this workflow should not affect the original mix in any way. I’m still in the process of getting familiar with all the various Blu-Ray encoding settings at my disposal (MPEG-2 vs. H264, and all the audio options under Dolby Digital), so if you have any thoughts on that front I would appreciate some discussion on those best practics. But the above is my inclination of how to get your original media into Premiere, map your channels and get it to Media Encoder without impacting the original mix as provided.

    What do you think?

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