H264 + AC3 in MKV - Ultimate solution but no support?

[DigitalWarrior]

I would like to get some discussion going here with regards to the MKV container and using it to hold H264 video streams and AC3 audio streams.

I have been encoding/transcoding video for years now and playing with TVersity and various other media servers for equally long.

One of my long term goals has always been to find a suitable combination of Container, Video encoder and Audio encoder to facilitate effective backup of my DVD collection.

To that end I have spent many, many hours experimenting with different combinations and what I have discovered is that within my list of acceptable parameters, the combination of MKV, H264 and AC3 is really by far the best option.

The reason for this is primarily because I want the audio stream to remain as AC3. What I just CANNOT understand is why there does not seem to be a much bigger push for this in the community as a whole.

It seems to me that everybody has a home theater amp these days capable of AC3 (Dolby Digital) decoding, and every single DVD
released (just about) has a Dolby 5.1 AC3 soundtrack. It is therefore only logical that if you are backing up your DVDs and looking to retain maximum quality, you would want to keep the AC3 surround sound intact. There are 2 reasons for that, first because compared to the video stream, the audio is relatively small, and 2nd because you then have the original audio track that can still be handed off to your HT amp and play correctly as 5.1 discrete channels.

When I backup DVDs, my real issue is with the encoding of the video stream, that's where I save major space, and with H264 I'm getting massive space savings at truly excellent quality.

So, logically then, I would want to combine H264 video with AC3 audio. Fine. Problem is I then need a container that supports that!

MP4 does NOT support that, not properly. You can only embed an AC3 audio stream in an MP4 as a private stream, which is dodgy at best. So MP4 is out (which blows my mind actually, I can't believe the MPEG standards body made the decision to NOT support AC3, but I digress).

AVI is no good for H264 for various reasons, so that's out.

Which leaves us with MKV, which works like a charm and plays perfectly on a PC with the appropriate codecs etc. The problem however is when you want to STREAM the MKV to an extender of some sort, that's when it all falls down, horribly.

I have a DSM-320 and an XBox360. I use TVersity to stream to the DSM-320, with great success for years now (in terms of AVI/XVID/DIVX material, even with AC3 soundtracks), and I use Transcode360 to stream to my Xbox360.

I have had marginal success streaming MKVs with AC3 audio to the XBox360 via Transcode360, using the Mencoder engine. It works, but there is still a slight framerate issue and, more importantly, the playback is unreliable in that videos tend to stop playing at random points or suddenly skip ahead (an XBox360 thing). But, at least the video plays, and is very high quality. The AC3 soundtrack is presumably being compressed to WMA however, which is no good to me.

So, I went back to my trusty DSM-320 / TVeristy combination and tried to get it working there. But as yet, I have had no success.

What I cannot understand is why it is such a big deal to demux an MKV file, transcode the video, and simply hand the AC3 audio stream through untouched. If it would just do that with MKV files, all my problems would be solved. I've tried tweaking all kinds of things but it just will not do it, it keeps wanting to transcode the audio too.

The bottom line is that MKV is the ONLY container out there that allows you to effectively combine H264 and AC3, and the tools available to do it for you, like StaxRip, AutoMKV and meGUI are superb. StaxRip is my weapon of choice and it does a phenomenal job of taking one of my original DVDs and turning it into an MKV with H264 compressed video and the original AC3 audio track at about 1/5 to 1/6 the size of the original DVD with virtually NO discernable loss of video quality.

Given that, why is support for playing back this format on anything other than an a PC so poor? And why aren't more people pushing for it?

I see so much talk about the new AAC audio codecs and how they can compress audio more efficiently than AC3 and that's why MP4 only supports AAC and not AC3. But practically speaking, NOBODY owns an HT amp that has any clue what to do with an AAC surround sound track, but just about EVERYBODY owns an amp that knows EXACTLY what to do with AC3, AND DVDs are shipping with AC3 and DTS soundtracks, not AAC, so it makes NO sense to me that a mainstream digital container does NOT support AC3, it's just ridiculous. And yes, I know you can feed a 6 channel AAC audio track into your amp via analog input with a separate
cable for EACH channel, but come on, seriously, anybody with a half decent system uses SPDIF for their audio transport, or maybe Analog Digital, or maybe now HDMI. All single cable solutions.

MKV is out there doing what needs to be done. And it's doing it well. The tools are out there for creating MKV and they work, very well.

All that is required is for one Media Server to offer decent support for the container and we have a huge winner on our hands.

I'm really hoping TVersity is going to be it.

[KamoKarzi]

I will second this !
should have posted this in a main part of the forum though would get more eposure.

[carhur61]

I enjoyed your posting, very educational. Have your concerns already been answered, I mean, is your DSM320 working now with the MKV, H264 and AC3 combination?

Question for you. What do you think is the best application available to convert my video media to MKV+H264+AC3?

Thank you very much.

Carlos

PS: Do you have a blog or a place where you are sharing your experiences?

[theedudenator]

Good topic also..

Is there any updates??

What is the best way to play a DVD with AC3 on the DSM 320??

[dloneranger]

Interesting post
Trouble with this is mkv's are nice on the pc, but nothing else supports them decently or at all, same for H264 and ac3 have a bit more success
As you're posting in the dsm320 forum, you're especially outta luck with some luck with your requirements as the dsm does none of them, no h264, no ac3, no multi channel audio while streaming (at least as far as I remember)
So, your videos will always be transcoded, like you mention, even in transcod360 as the dsm, just can't play back those formats - it just ain't gonna happen sorry


It's not a good answer, but you picked possibly the worst format for portablity that you could, even if it's the best quality
For Ac3 - make sure that ffdshow isn't decoding it and get the ac3 filter off the main download page - set it to stereo and that might help with ac3

I'm just going to give my 2 cents here about storing videos on your pc for use on the dsm

First off
Hard drives are stupidly cheap now, so frankly I don't really care if one format is slightly smaller than the other - if I run out of space, get another hard drive

Second
Encoded videos to what your player will play back natively - if you don't then you'll be stuck in a 'always transcode' ' hell

Third
If all you media is on your pc then, at least check out divx properly
Get a license, they do give away freebies now and then, but it's not hard to figure out how to get a serial
Then, forget about multi pass encoding totally, that's only for making sure a vid fits a cd perfectly

Instead pick,
home theater profile
1-pass quality based (the smaller the number the better the image) - I just use 4
On the Codec tab, pick 'insane', that will give you the smallest file sizes

Depending on the video - the sizes will vary wildly, but 'usually' you'll get a better picture and a smaller file size - mine vary between between 300-800 Mb and most are on the 300-500ish side - it does take longer, but give a few a try and see how you go

[jackmeat]

the dsm will play ac3 fine with the crappy dlink media server it comes with but won't touch mkv container with h264 video. with traversity i get the video just fine when transcoding, but no audio at all. i seem to be stuck at a crossroad here that seems everyone is stuck at, but there has to be someway to get both to work, since one or the other work. anyone have some creative ideas? i have tried all methods of codec combos and the like that i can think of, along with the suggestions from here. nothing seems to do it.

[HTEnthusiast]

trying to get xvid to work with either dts or ac3 5.1 audio, also going to try wmv container with vc-1 and wma, but seeing if I can get tversity to transcode the wma in to something my receiver can work with

[jwdaigle]

So the original poster posted the article well over a year ago. And it still has a lot of relevance today.

I own a DSM-510, and a DVD player that can play divx and mp4 files.

Neither of which does me any good for downloading a high definition (>= 720p) from the net. It seems like everything comes as x264 along with AC3 sound. Inside an mkv container.

Why is this so popular to rip things this way?

Divx converter looks at mkv files and says "what the heck is this"?. The DVD player wont even list the mkv files, much less try to decode them.

I am thinking that in the future, more hardware devices will support something sane (read: has a lot of instances of that combination out there).

But for now, i am stuck with my dreams of download and watch.

I am hoping that tversity might help out with this? Does anyone have a working model for what seems to be the most popular download combination around - mkv/264/ac3 to be played on a dsm510 and/or dvd player?

Thanks in advance for any insight,

Joe
ps thank you original poster - you more or less took the words right out of my mouth. Very well said!

[invar]

*bump* because this would be a really nice feature... (transcoding audio/video separately.)

Is there some reason why both have to be transcoded? I love being able to watch HD content streamed from my computer to my Xbox 360, but the fact that the audio is downconverted to stereo really annoys me...

[invar]

Another bump because I really don't understand why this can't be done.

[Team503]

I'm going to bump this, because the OP echoes my thoughts perfectly. My DSM-520HD and my Xbox360 are almost never used for media anymore; I just watch on my computer.

Two years ago, when MKV was new and rare, this problem was of little consequences. Nowdays, EVERYTHING HD going around the net is x/h264, AC3, MKV.

Why does TVersity, the package that prides itself on supporting everything, not support what is surely the most popular HD rip format on the 'net?

[chefMedia]

Its funny no matter how hard you try to get a clean stream of your mkv files to your dlink DSM product it will never work..
read the product specs of the hardware before you expect something to work.. The entire DSM line does not support the MKV container!!
(with possibly the exception of the DSM 720) The DSM-720 supports H.264 but im not sure it has the ability to play the AC3 format.

Scream at dLink for a firmware update for our underachieving DSM 320/520 "HD" products!
.. maybe they will come to terms that h264 is the most popular format out there at the moment..

Sorry for the rant.. but its funny to see how people struggle to understand that the hardware (PS3, DSM's) just lacks the MKV container.. this limitation is crucial in what you want we all want.. a clean method to play mkv's on our media devices.. no messy transcoding!!

unfortunatly the only solution for our hardware is to transcode mkv's file on the fly with tVersity.. this changes the file format from mkv to mpg! in which the video isnt all that bad but the audio is diminished to 2 channels of wretched crap! those of us with a decent DD/DTS receiver dont want that garbage! We want to stream 5.1 surround with a nice crisp image! not too hard to ask.. right?

The only real solution i found to this whole mess is something like what dLink is now offering..
you can skip the whole tVersity thing all together with one of these:
http://www.dlink.com/products/?sec=0&pid=655
this thing will let you designate a pc on your network to be a pseudo server of sorts.. instead of streaming/transcoding, you basically get a remote desktop feature on your HDTV.. then get yourself a copy of coreAVC **which is hands down THE best HD codecs on the market atm!!! **
you can forget about ffdshow (most of which is extremely outdated by todays standards anyhow!!!) With this solution, if you have a smooth running MKV on your pc then you should see exactly the same thing on your TV.. the hardware itself does not process any video/audio meaning its not bias to any elite Matroska containers..

The only reason I play with tVersity these days is to share my media with the rest of the house.. which includes a PS3 and a DSM 520..
other then that I run my Vista MediaBox running VMC for all my goodies.. i literally get a 5-10% cpu load running the coreAVC pro codec while running a 1080p.mkv file.. its a beautiful thing.. a tremendous difference compared to transcoding with tVersity from MKV -> mpeg @ ~ 50% on my quad core

ok ok.. enough whining.. I have a successful solution to stream the mkv format.. Keep in mind this isnt the perfect H264+AC3 solution.. it is just a bearable one imo.. check out the post i reference for my solution http://forums.tversity.com/viewtopic.php?f=28&t=23314 the only thing I did different was limited ffdshow to load only with tVersity (in the whitelist).. i have yet to experiment with CCCP in place of the recommended downloads in the post.. it should work hand and hand considering CCCP is based off ffdshow, I believe it has a more updated build of ffdshow.. I personally try to do my best to stay away from huge codec packs.. but I would have to say CCCP is one of the better ones out there.. once again keep in mind that this isn't the perfect solution as it will simply take your mkv file and transcode it to an mpeg format.. removing the nice sound quality as well as changing the video quality a bit.. it also bogs down the pc as tVersity needs to stress the resources of your machine while doing all this work..

I know most of my post kind of degrades the whole streaming/transcoded media idea.. I am NOT here to knock tVersity.. They have been a saving grace for me for many years now.. they have made an excellent program for what its worth! well I shouldnt say that either since they dont actually ask for money.. but really, for the majority of people out there this program is an excellent alternative to an HTPC..

thats my two cents.. and i dont care if you think im wrong!

thanks out to kaitoudark for posting the write up on the PS3 boards!

[mikepaul]

I'm not sure TVersity could get free 5.1 surround support added in to help everyone looking to maintain the good audio they had in the original. Transcoding is the big reason to pick TVersity over another server, but it is still a kludge compared to hand-crafting a new streamable version of the video. For the most part, people who intend to keep a video should do that...

[chefMedia]

I'm not sure TVersity could get free 5.1 surround support

Thats not entirely true.. with the ac3filter you can carry the 5.1 surround to an external receiver..
you just cant do this with the mkv container if the receiving device doesnt support the format.. I have successfully gotten avi/divx/mp4 encoded with ac3 out to my ps3 with 5.1 channels (sry untested with the DSM520).. The only problem with the mkv container is that it needs to be transcoded during the transcode process.. essentially removing your audio channels and replacing it with stereo

Ive been playing with win7 on my media machine recently.. seems the mkv container, while native to the system, still encounters some problems.. according to many articles it seems a good solution is to mux the file..
check this out http://www.edandersen.com/2009/01/05/native-hd-mkv-playback-in-windows-7/

In theory I believe you can apply the same sort of concept to this problem.. im not 100% on this though as the receiving devices are still limited to certain file formats.. yes mux'ng a file will still change the original file format.. so tVersity might just go ahead and transcode even after the mux.. but quality is what we are after.. aigh lol just trying to throw some ideas out there

I dont have the time to really test this idea out.. if there are any guinea pigs out there willing to give it a go.. let me know if it works out

[mikepaul]

I'm not sure TVersity could get free 5.1 surround support

Thats not entirely true.. with the ac3filter you can carry the 5.1 surround to an external receiver..
you just cant do this with the mkv container if the receiving device doesnt support the format.. I have successfully gotten avi/divx/mp4 encoded with ac3 out to my ps3 with 5.1 channels (sry untested with the DSM520).. The only problem with the mkv container is that it needs to be transcoded during the transcode process.. essentially removing your audio channels and replacing it with stereo

While you might have sent AC3-laden AVI/divx/MP4 to the PS3 and had them play, I guess that's because the TVersity profile for the PS3 isn't forcing transcoding when the audio is AC3. I believe the Xbox 360 profile isn't going to let that happen, but the audio codecs the 360 supports is probably a much shorter list than the PS3.

If the MKV contained exactly what the PS3 could play as-is, and a MKV splitter existed that transparently opened the MKV and presented it as if it was just another AVI, then you might get what you want without Sony supporting MKV. My feeling is that MKV has become too much of a 'pirate' tool for companies like MIcrosoft and Sony to welcome it with open arms, but divx started that way too so there's always hope...