[Luke Pearson]

This is assuming you already have your video exported as a single clip and just want to repurpose it to iTunes spec.

I find the easiest way to work with audio is to mimic an FCP type of setup;

1. Make a timeline with a multi-channel master track and set it to have 8 channels. Obviously make sure the video settings match up with your source.
2. Add 8 adaptive tracks.
3. Use the mapping option to map track 1, input 1 to output 1. Map track 2, input 1 to output 2. Map track 3, input 1 to output 3 and so on. Make sure you set you set inputs 2-8 to none.]
4. On your clip, modify the audio channels and set the preset to Mono, Number of Audio Tracks to 8 and Channel Format to Mono. Make sure the Source and Channel mapping maps Source Channel 1-8 to Tracks 1-8.
5. Drop the clip onto your timeline and you’ll be good to go. When you do your export, in the Export Settings, set the Basic Audio Settings to 8 channel, Track Layout to 8 Mono Pairs and Channel Layout can be left on Mono (make sure you change the channel assignments in QuickTime Pro once exported).

[Luke Pearson]

If you aren’t going encode to ProRes get a PC, you could spend under $2k on a top of the range Intel i7 with plenty of RAM, storage and a GPU or 2.

edit/ this would obviously involve using Adobe CC.

[Luke Pearson]

The iTunes spec is the same globally.

[Luke Pearson]

Hi Jon,

iTunes will accept 29.97 progressive content.

[Luke Pearson]

If you want to stick with ProRes your only option is a Mac, a PC can decode but not encode unless Apple ever license the encode part to Adobe (they have done this with non competitors so very unlikely they’ll allow Adobe to license it.)

This is the only thing stopping me from ditching Mac at my facility.

[Luke Pearson]

Thanks Tom, I got your email, thanks for the work around.

[Luke Pearson]

Good news, the latest 7.1 update has seriously improved AVC Intra encoding, I’m seeing an improvement of around 150% on this system.

[Luke Pearson]

It’s not that difficult to do, AS-11 is the delivery file format, you can work however you want before getting to the final step. You can export using Media Encoder/Premiere to an OP1a and then use the DPP app available at https://www.digitalproductionpartnership.co.uk/downloads/metadata-application/ to re-wrap to AS-11 and add the required metadata.

[Luke Pearson]

Just an update, still experiencing slow export speeds but a 45 minute export is actually taking around 90 minutes to export as opposed to my earlier timings.

I’ve been monitoring the CPU, GPU and RAM use extensively, CPU use by Premiere or AME is only at around 4%, RAM use is at around 1.5GB and the GPU is not being used during the export.

Exporting the same timeline to DNxHD (matching settings) takes around 15 minutes, RAM use hits around 12GB and the CPU ramps up to around 50%.

I’ve sent a bug report off to Adobe, I haven’t yet tried going from a different codec to AVC Intra so that’ll be my next test.

[Luke Pearson]

After some more research and going from the same project to other codecs it looks like the problem lies with the AVC Intra encoder. I can go to DNxHD, XDCAM, Uncompressed and others at about 3-4 times faster than run time coming from the same ProRes source file. These codecs also max out the ram usage and the CPU runs at around 50%.