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View Full Version : Taking .mkv and putting into Apple TV compatible .mp4 with 5.1 .aac


AKarpo
26th February 2008, 06:38
Many people over at Macrumors.com http://forums.macrumors.com/showthread.php?p=5038247#post5038247 have been searching for a solution in order to get .mkv's with AC3 into an Apple TV compliant .mp4 container with 5.1 aac, along with Level 3.1 compliance.

Basically, after many hours of Googling and forum searching, this is the correct process as I understand it currently.

1) Demux .mkv into h.264 and .ac3 streams

2) In order to turn .ac3 into .aac, I was using Nero, however Nero spits out .mp4 instead of the raw .aac that I need. I tried using the Besweet guide here at Doom9 but I can't find the correct .dll's online (that work) anywhere after about a half hour of Googling.

3) Missing step that hasn't been covered yet: turning Level 5.1/4.1 video found in the .mkv into Level 3.1 that is compatible with an Apple TV. Do we do this before or after the demux in step 1? (I haven't figured this out yet) Maintaining full resolution of 1280x720 @ 23.967fps with a constant bitrate of around 5000-6000 would be nice too.

4) Remuxing everything back together with Yamb

If anyone could code something for this (Handbrake isn't quite there yet, Visualhub isn't getting the .ac3->.aac yet either) I feel that it would be a somewhat promising venture, financially. I think there are quite a few people out there sitting on these .mkv's, looking for a good solution to stream them to their AppleTV's that doesn't involve a full blown re-encode. (Yes I know about Popcornhour, their assembly and distribution channels are still way too in their infancy)

rebkell
26th February 2008, 06:53
It's convoluted, but you can drop the aac-mp4 into mkvmerge and create a mkv(a) file and then drop that into mkvextract and write out the raw aac file.

AKarpo
26th February 2008, 07:14
Okay so I guess I can use H264info to change the video level; I can just input "3.1" into Level field...Hopefully this is the only thing I need to change.

**Edit: Stayed up a little later. The quick fix I had for changing "levels" that were originally 5.1 or 4.1 in the .MKV's, with h264info, didn't quite work out; green frame all the way through..

So uh, unless the h.264 stream (found in the .mkv's) works with an Apple TV, I'm **** out of luck here. Reencoding only :(

Diveflo
28th February 2008, 19:11
Okay so I guess I can use H264info to change the video level; I can just input "3.1" into Level field...Hopefully this is the only thing I need to change.

**Edit: Stayed up a little later. The quick fix I had for changing "levels" that were originally 5.1 or 4.1 in the .MKV's, with h264info, didn't quite work out; green frame all the way through..

So uh, unless the h.264 stream (found in the .mkv's) works with an Apple TV, I'm **** out of luck here. Reencoding only :(

The problem is you do not just have to change the lvl, but also the profile from high to main. And there are main options, AppleTV just can't play...sadly, we have to reencode.
Even if you hack your AppleTV and install Perian as codec, which is able to play high profile, mkv etc, you still can't watch them because AppleTV just doesn't have the power. There is a Nvidia h264 acceleration chip inside the AppleTV, but the Perian codec can't access it.
There is been testing if it is possible to add the CoreCodec to the AppleTV which has been testen on a 800mhz mac. It was able to play 720p MKVs at ~16fps. Maybe if it gets implented into the AppleTV this could solve the problem.
Stay tuned...I will...

Brother John
1st March 2008, 15:38
An easier way to demux AAC from MP4 is MP4Box:
MP4Box.exe -raw 1 "audio.mp4"

burnsdg
3rd March 2008, 16:48
So uh, unless the h.264 stream (found in the .mkv's) works with an Apple TV, I'm **** out of luck here. Reencoding only :(
OR, use something OTHER than a restricted AppleTV?
Like this (http://www.mvixusa.com/product.php?product=mx780&page=specs) perhaps? Maybe it soon will support mkv's directly with enough user demand?

Atak_Snajpera
17th November 2009, 12:21
ffmpeg ripoff!!! remove link.