MKV to MP4 for AppleTV

[chenks]

Originally Posted by Diode

Check out the latest beta of Subler (15 beta 3). He added support for 1080P tagging. It's also a pretty sweet tool that auto adds other meta tags (description, directors, etc).

yep, that now marks it as 1080P in iTunes.

[Adobe75]

It's not free, but I use iFlicks to automatically convert avi/mkv to iTunes and add metadata. I'm pretty sure it supports 1080p mkv files.

It is also very smart about audio tracks. It will automatically preserve AC3 audio and create a 2-ch AAC track. It will also convert DTS to AC3.

I use MP4tools also, but iFlicks is automatic when scripted and does a killer job on metadata.

[slothrob]

Originally Posted by Diode

You can turn off and on subs now with the ATV2 -it allows selection of multiple soft subs. Just hold down the select button while a movie is playing and you can change the subtitle track or the audio track selected.

Nice if you want to include a commentary track in your movie.

It depends on the type of soft subs. vobsubs cannot be turned on, but closed captions can. Other text subs, like .srt, can also be added and turned on and off, but closed captions are probably the only type you'll see commercially.

[khollister]

I have spent the last 3 evenings testing most of the tools for this. My conclusion is that iFlicks does a great job creating very high PQ H.264 High profile/L4.1 encodes, but has one fatal flaw for conversion of BD MKV's - no support for PGS subtitles.

iVI is unique at the moment in that it handles PGS subs and burns them into the encode (which is great for forced subs - the only type I care about), but currently does not create High Profile encodes. I emailed the dev and they are doing a ATV3 1080 preset with High/L4.1 encoding, so that will be my go-to solution.

Trying to dork around scripting command line tools to extract, convert and remix subs is way to much trouble for me.

[chenks]

Originally Posted by chenks

trying it just now, does this look correct?

Image

OK having converted a few 1080p rips, i'm noticing that some (but not all) end up with the audio slightly out of sync (5.1 track).

source files are 1080p MKV with DTS tracks, and being re-converted to AC3 5.1.

any ideas?

[Space Moose]

Originally Posted by chenks

OK having converted a few 1080p rips, i'm noticing that some (but not all) end up with the audio slightly out of sync (5.1 track).

source files are 1080p MKV with DTS tracks, and being re-converted to AC3 5.1.

any ideas?

The AppleTV doesn't play very well with AC3. Your best bet, if dealing with an MKV with AC3 is to convert just the audio to 5.1 channel AAC (which works a treat on the AppleTV).

For drag-and-drop simplicity, I use the MKV to AppleTV script here, which works great to repackage MKVs so they import into iTunes and play on ATV/iPhone/iPad, etc. The one thing it doesn't do is convert AC3 automatically (though there are good instructions on how to do that quicky).

Never reencode the video if you don't have to. A lot of the tools out there will reencode everything, even if just the audio is incompatible.

[Mackan]

Originally Posted by chenks

OK having converted a few 1080p rips, i'm noticing that some (but not all) end up with the audio slightly out of sync (5.1 track).

source files are 1080p MKV with DTS tracks, and being re-converted to AC3 5.1.

any ideas?

I have found MP4Tools to be a bit unreliable, when it comes to producing audio in sync.

Given a MKV file I have the following procedure:

1) Extract the h264 stream from the MKV with Subler or ffmpeg. Convert it via Handbrake using CRF 20 to reduce file size, and make it High Profile 3.1 for good compatibility. Quality degradation is visually minimal, but it takes a few hours...

2) Extract the audio stream from the MKV with ffmpeg into a CAF file, (supports larger than 4 GB stream file size). Convert to AC3 and Dolby Pro Logic II via a combination of Compressor/afconvert/sox. I then have total control over the quality and things like downmix matrix, normalization and dynamic range compression.

Handbrake does not give you good advanced audio conversion options so far. Otherwise I would have used Handbrake for the audio as well. If they introduce more advanced audio options, as well as video pass thru, it would be great. I guess that won't happen anytime soon though.

[chenks]

Originally Posted by Space Moose

The AppleTV doesn't play very well with AC3. Your best bet, if dealing with an MKV with AC3 is to convert just the audio to 5.1 channel AAC (which works a treat on the AppleTV).

i find that statement hard to believe, considering the default audio format for AppleTV files is AAC stereo and AC3 pass-thru 5.1

i've never had any issue with AC3 pass-thru until i've been using MP4Tools to remux an MKV DTS file to MP4.

----------

Originally Posted by Mackan

I have found MP4Tools to be a bit unreliable, when it comes to producing audio in sync.

Given a MKV file I have the following procedure:

1) Extract the h264 stream from the MKV with Subler or ffmpeg. Convert it via Handbrake using CRF 20 to reduce file size, and make it High Profile 3.1 for good compatibility. Quality degradation is visually minimal, but it takes a few hours...

2) Extract the audio stream from the MKV with ffmpeg into a CAF file, (supports larger than 4 GB stream file size). Convert to AC3 and Dolby Pro Logic II via a combination of Compressor/afconvert/sox. I then have total control over the quality and things like downmix matrix, normalization and dynamic range compression.

Handbrake does not give you good advanced audio conversion options so far. Otherwise I would have used Handbrake for the audio as well. If they introduce more advanced audio options, as well as video pass thru, it would be great. I guess that won't happen anytime soon though.

a few issue with that solution.

1) i don't want to re-convert the MKV file I have. I am simply remuxing it from MKV to MP4 and leaving the h264 file untouched.

2) i don't want to change the 5.1 audio track to DPLII

[Space Moose]

[QUOTE=chenks;14799657]i find that statement hard to believe, considering the default audio format for AppleTV files is AAC stereo and AC3 pass-thru 5.1

i've never had any issue with AC3 pass-thru until i've been using MP4Tools to remux an MKV DTS file to MP4.[COLOR="#808080"]

The AppleTV doesn't support AC3 audio according to its tech specs here, further I've never been able to get any file with AC3 audio to play on my AppleTV.

There's more information about that, including steps on how to tell what audio is *actually* in your file in this thread: AVI, MKV, h.264... WTF Does it All Mean?

I think whatever utility you're using is actually transcoding it into AAC (and perhaps leaving the AC3 as well, aka 'passing it through').

What's important to note though, is that the AppleTV isn't playing the AC3, and also there's no reason to transcode 5.1 AC3 all the way down to stereo, when 5.1 AAC works a treat.

[chenks]

Originally Posted by Space Moose

The AppleTV doesn't support AC3 audio according to its tech specs here, further I've never been able to get any file with AC3 audio to play on my AppleTV.

I think whatever utility you're using is actually transcoding it into AAC (and perhaps leaving the AC3 as well, aka 'passing it through').

What's important to note though, is that the AppleTV isn't playing the AC3, and also there's no reason to transcode 5.1 AC3 all the way down to stereo, when 5.1 AAC works a treat.

well i have stated AC3 pass-thru (a few times), so that clears up your mis-understanding.

the standard audio track layout for an AppleTV files is

track 1 - AAC stereo
track 2 - AC3 pass-thru 5.1

this is not an issue with the 400+ movies i have in itunes, except for a few with the issue i stated above.

[Space Moose]

Originally Posted by chenks

well i have stated AC3 pass-thru (a few times), so that clears up your mis-understanding.

From the pictures you posted, it looks like you're "Adding a 2-channel AAC", which means you're transcoding, which may not be necessary, and is definitely losing all the 5.1 goodness that the AppleTV can play.

When you pass through an AC3 5.1 and add an AAC 2-channel, then all the AppleTV sees is the AAC 2-channel. You're throwing away the surround sound needlessly, because the tool you're using is doing wonky stuff.

I'd recommend the link above so you'll have a very clear idea of what's happening to the file that goes through that utility.

[chenks]

Originally Posted by Space Moose

From the pictures you posted, it looks like you're "Adding a 2-channel AAC", which means you're transcoding, which may not be necessary, and is definitely losing all the 5.1 goodness that the AppleTV can play.

When you pass through an AC3 5.1 and add an AAC 2-channel, then all the AppleTV sees is the AAC 2-channel. You're throwing away the surround sound needlessly, because the tool you're using is doing wonky stuff.

sorry that's incorrect. if you don't understand this process then please don't try to advise on it.

i've created many files using this process and i know precisely what audio tracks are produced at the end.

the MKV only has a DTS track. i am using MP4Tools to create a 2 channel AAC stereo track as well a 5.1 AC3-pass-thru audio track.

this is what the resulting file looks like...

[Space Moose]

Originally Posted by chenks

sorry that's incorrect. if you don't understand this process then please don't try to advise on it.

i've created many files using this process and i know precisely what audio tracks are produced at the end.

the MKV only has a DTS track. i am using MP4Tools to create a 2 channel AAC stereo track as well a 5.1 AC3-pass-thru audio track.

this is what the resulting file looks like...

That's exactly as I suggested was happening in my last post.

The AppleTV is ignoring the AC3, so all it sees is the AAC 2-channel track.

You're throwing away the surround sound that could be played on the AppleTV.

You should be creating an AAC 5.1 audio track (if you want to also have a 5.1 AC3, that's fine, but for the tenth time, the AppleTV doesn't play it whatsoever).

Does that make sense?

[chenks]

Originally Posted by Space Moose

That's exactly as I suggested was happening in my last post.

The AppleTV is ignoring the AC3, so all it sees is the AAC 2-channel track.

You're throwing away the surround sound that could be played on the AppleTV.

You should be creating an AAC 5.1 audio track (if you want to also have a 5.1 AC3, that's fine, but for the tenth time, the AppleTV doesn't play it whatsoever).

Does that make sense?

sigh.. it's NOT ignoring the AC3 track.
my amp plays the 5.1 track very nicely thank you.

the appletv passes the AC3 track straight thru to the amp, hence the "pass-thru".

you clearly don't understand what is going on here, so please don't contribute any more mis-understanding to it.

[Space Moose]

Originally Posted by chenks

sigh.. it's NOT ignoring the AC3 track.
my amp plays the 5.1 track very nicely thank you.

Ah, I think my confusion is because I haven't tried getting AC3 to work since it was broken a while back. My mistake.

Although, it's still a valid question as to why you're even trying to get it to work, I see that there's a whole host of people having issues with time sync when using the AC3 passthrough (when it is working at all). Why not give the AAC 5.1 a shot, it's a more modern format and there aren't the same sync issues reported.

[Mackan]

Originally Posted by chenks

a few issue with that solution.

1) i don't want to re-convert the MKV file I have. I am simply remuxing it from MKV to MP4 and leaving the h264 file untouched.

2) i don't want to change the 5.1 audio track to DPLII

No problem, I understand what you want. I simply outlined my process for reference. I was in a similar situation as you, just wanting to remux the MKV files I have, and convert possible DTS track to AC3 5.1, together with a simple AAC stereo track. MP4Tools seemed to be the nice tool to achieve this.

But then I discovered that its remuxing process was not stable, giving audio out of sync, etc. Header stripping/compression may affect this. I use MKVToolnix to remove header stripping.

I also wanted the best quality for the stereo and AC3 track, so I took a different route. The file size saved from using Handbrake's constant quality setting made it worth for me to reconvert the h264 stream as well.

Good luck with your MKVs.

[dynaflash]

Originally Posted by khollister

iVI is unique at the moment in that it handles PGS subs and burns them into the encode (which is great for forced subs - the only type I care about),

PGS Subs added in HandBrake nightlies https://trac.handbrake.fr/changeset/4605

[chiefpavvy]

iVI is fantastic, I feel like a salesman, but it really is. I even ponied up the $10 for the "Pro" version because I want the capability to import DVDs if needed.

I really wish there were an iVI for Windows as well. Doesn't seem to be anything even remotely comparable. I don't want a bunch of open-source hack tools (no offense to Handbrake and such which I love and use all the time) I want a nice clean all-in-one that just works...iVI does that and does it very well.

[swindmiller]

Any programs that will do this for Windows. I am a slow convert over to the MAC side...everything but my desktop


Thanks,
Scott

[chiefpavvy]

Originally Posted by Space Moose

When you pass through an AC3 5.1 and add an AAC 2-channel, then all the AppleTV sees is the AAC 2-channel. You're throwing away the surround sound needlessly, because the tool you're using is doing wonky stuff.

That's just not correct. The Apple TV will see both tracks. It will default to the 2-channel AAC, that is standard operating procedure. But the 5.1 track is there and easily selected and used if wanted.

[mic j]

Originally Posted by chiefpavvy

That's just not correct. The Apple TV will see both tracks. It will default to the 2-channel AAC, that is standard operating procedure. But the 5.1 track is there and easily selected and used if wanted.

It defaults to the 5.1 track for me. Possibly because I have the aTV preference for audio set to Dolby Digital: On (as opposed to auto).

[chiefpavvy]

Originally Posted by mic j

It defaults to the 5.1 track for me. Possibly because I have the aTV preference for audio set to Dolby Digital: On (as opposed to auto).

Yes, if you have told it to prefer 5.1 it will. Default is the 2-channel AAC track however.

[dynaflash]

Originally Posted by Space Moose

Ah, I think my confusion is because I haven't tried getting AC3 to work since it was broken a while back. My mistake.

It was broken ?

Originally Posted by Space Moose

Why not give the AAC 5.1 a shot, it's a more modern format and there aren't the same sync issues reported.

The AppleTV will not playback AAC 5.1 properly at all. Only DPL2 which is actually a stereo track. AAC 5.1 would be six channels which is called oddly ... 6 channel discrete in HB. The AppleTV does not play this back properly and it ends up a 3.0 downmix. The AppleTV's best audio is from the 5.1 Dolby Digital AC3 track but it will of course require an audio device that can recognize and play it back.

That said at least HB' s 2 channel aac DPL 2 track is pretty decent if its all you can use.

[swindmiller]

But am I correct that in order for it to be able to be imported into iTunes you cannot just have an AC3 5.1 track. From what I understand you can have an AC3 5.1 track as long as you also have an AAC 2 channel track. Please correct me if I am wrong.

Most of mine have AC3 5.1 but I am trying to find a way to add the AAC in addition.
I can get it to convert the AC3 to AAC but I want the 5.1 option.

I am on windows.

Thanks,
Scott

[dynaflash]

Originally Posted by swindmiller

But am I correct that in order for it to be able to be imported into iTunes you cannot just have an AC3 5.1 track. From what I understand you can have an AC3 5.1 track as long as you also have an AAC 2 channel track. Please correct me if I am wrong.

For the AppleTv to work correctly it expects the first track to be AAC and the second track to be AC3. You can just have the AAC track, but you cannot just have the AC3 track.

iTunes *will* take it if it just has the AC3 track but no apple iOS devices or the AppleTV will play it.