Why convert m2ts to mkv?

Mkv has less overhead than m2ts so a 1:1 copy would be a little smaller.

Most of the time.

Nobody bothers to change the container when ripping the BD as-is.
MKV usually means all but one audio stream is dumped and the video re-encoded so the resulting movie fits a SL or DL DVD (4.37GB or 8GB).

1080P DTS fits well enough on a DL DVD. Its hard to send 50GB "backups" to your hundreds of "friends" across the world.

Pull up your favorite torrent tracker site and search for a movie in 1080P. You'll get a bunch of ~8GB mkvs unless its long movie which are usually ~12GBs(DVD9+DVD5).

The question of re-encoding the video/audio stream is beside the point. .m2ts and .mkv are both containers; they have no bearing on the amount of compression used. An mkv could be a crappy 1 GB re-encode of a Blu-ray, or a 50 GB complete rip of a Blu-ray.

That being said, I believe an m2ts taken from a Blu-ray or AVCHD disk is going to be a bit bigger than an mkv with the same contents, because the m2ts contains extra file structure information that you don't need. Additionally, as diogen pointed out, when repacking an m2ts into an mkv, people usually remove any audio streams they don't want. There's no point in keeping a French dub of an American film if you can't speak French (although, AFAIK, most studios don't really include foreign tracks as much anymore).

But the biggest consideration is the software or hardware you're using to watch the movies on.

If you plan on watching the rips using software like XBMC, VLC, etc., you should be fine either way.

If you plan on using PowerDVD, or another Blu-ray player software, you should stick to m2ts.

If, as you mentioned, you use a stand-alone device like a Popcorn Hour or a Western Digital player, you'll probably have better compatibility with the mkv container.

You are entirely correct.

The issue is, probably 99.99% of Blu-ray-to-MKV "backups" are really just ripped off copies of rented or borrowed movies, or done by people who actually will buy them but then make copies to share on the Internet.

When you change the container and get rid of stuff you don't want, you can save a few GBs of space. Plus, not all software can play the subtitles straight from an m2ts, nor change audio streams.

For my media server, I convert the m2ts to mkv, pick the audio stream and subtitle if necessary, and usually end up saving a few GBs per movie. That adds over of time.

I think Matroska is simply a more flexible and compatible format. It's also easier to handle than m2ts files thanks to the MKVToolnix utilities. Also, MKV supports chapters which M2TS doesn't.

I currently use it to archive part of my HD-DVD collection on the HTPC (of course without reencoding the video). Works well for those too.

There is (at least) one advantage M2TS has: Windows 7 plays it (when DRM free) out of the box...
For MKV you need Haali installed.

My own experience has been that reencoding formats employing the splendid H264 technology do effectively shrink the file sizes ofterribly large .m2ts movie files. With as much as 50gb of storage capacity to play with, on a dual layer Blu-ray disc, there's no need for the video disc producers to work at keeping file sizes down, nor should they.

Like several others here, whether it's a case of using Popcorn Hour's hard drive video streaming interface, or any of the growing number of streaming media boxes that plug into HDTV's, or external hard drive storage played through a HTPC, storage space quickly becomes, in fact, a critical concern, if you see yourself as a "movie collector". On our 1080p 65" HDTV, my 66 year old eyes find little to discern, qualitatively, between 1080p pictures and 720p pictures, converted with H264, at a somewhat lower bitrate, as well as the lower 720p screen resolution (same framerate). That quality tradeoff is one I'm willing to make, to cut a 20gb movie to perhaps 5gb's, for the sake of extending my hard drives' storage capacity!

I am having one huge problem, however. None of the commercial, "one click" reencoding programs seem to offer a feature that enables you to select the audio track among those several which may be offered in the .m2ts video file. The reencoding programs default the selection to the first of the audio tracks, which may or may not be the English track, or may be the track which has Director's comments, if available. Does anyone here know of an .m2ts capable reencoding program, which can reencode to .mkv, and which ALLOWS SELECTION OF THE AUDIO TRACK WANTED?

heh

"re-encodes"

Just buy a bigger hard drive. Less than 10 cents a gig nowadays.

Uhhh, yes, "re-encodes". What was there in my query that suggested I was a newbie clown, incapable of doing the math, and that I had not already purchased several 1tb SATA drives, at less than "10 cents a gig nowadays"? I suppose your simplistic, all-too-obvious reply was well intentioned, but it does NOTHING to address my basic question, concerning what I consider to be a consistent shortcoming in the commercially available, Hi-Def video conversion engines.

My collection of films now numbers in excess of 5,000 titles, all on DVD's, of which I'd like to transfer as many as 1,500 to hard drives, for the sake of immediacy and enormous cataloging convenience. Even at less that "less than "10 cents a gig", it adds up fast! More to the point, when you fail to see much difference, on screen, between 1080p and carefully encoded 720p material, my question is why pay for hard drive space, and storage racks, that you need not employ, and where does the space come from to rack mount those extra 8 - 10 SATA drives?

It should not be THAT difficult for one software designer to detect the multiple tracks that many of the main movie .m2ts files contain, and offer a selection among those tracks for the conversion. They seem quite content to take your $30 to $40, only for the customer to learn after the fact that as much as 25% of the time, you're going to get the Director's comments, or even stranger, on US releases, a German or French track, for the program's default, first track selection. After an eight hour reencode, it's no fun to run the file in your player and hear "Wie geht es ihnen..." as the first audio you hear!

I've had little success learning to use the complexities of the various freeware GUI's that are designed to help walk the user through the use of the Haali Splitter, tsMuxeR, etc., so I keep coming back to the "one click" approach... yes, this is one case where I like things "dumbed down" for me. So, again I ask if anyone here is aware of a program that allows the user to select from among the audio tracks in .m2ts videos? If not, should it be that difficult for some software designer to include that feature? It seems like a stunning omission to me... lazy software design...

I'm against re-encodes, and when I convert m2ts to mkv, it's NOT a re-encode, as the video is not touched. What I do is merely leave some "options" out, like audio tracks and various subtitles, and change the container.

That's fine; I certainly respect that point of view. If I had unlimited financial resources, such as the bankers, oil companies, and pharmaceutical manufacturers paying off Congress, I'd probably feel differently about the sacrilege of diminishing video quality to save on drive space. But, I have a LOT of movies to archive, and can't afford the luxury of buying many, many more hard drives in order to do it.

And, I still insist... I can't SEE enough of a qualitative difference between 1080p and 720p to agonize over my choice. This thread started as a question about converting from m2ts to mkv, my favorite H264 conversion format, so I doubt that I'm the only one who makes this choice... and then gets hit with the audio track issue. Any solutions, any programs that enable this choice?

Use "eac3to" to demux the m2ts (it lists what audio track is what, and makes the video track a MKV file). It can also transcode audio if you want, to dts, ac3, FLAC.

Transcode your video to 720p H.264.

Mux the final video and audio via MKVMerge.

Thanks to all

...whew, that sounds so straightforward and east to follow, to those who have figured out all the settings, and now understand the methodologies! But, I still prefer the well laid out, easy-to-use, "one click" graphic interfaces fronting the few major conversion engines commercially available. And, in my quest to solve this riddle of the missing audio track choices, I think I've found a winner. I don't have anything to gain by promoting one particular company's product, but so far, so good, with AVS Video Converter 6, available at AVS4U.com. When you click the "Advanced" button, among the features in the drop down window is the heretofore missing Audio "Track" selection feature... per this company screen capture. It's a fast conversion engine, and has a "Pause" feature, also missing from most of the competing software. It's been exactly what I was looking in vain for. Only one problem... this puppy ain't cheap, at $59!

My primary reason is because MKV can hold FLAC, m2ts can't.

According to the specs of that software, it can read mkv, but cannot write/create a mkv, which is what this thread is about. Also don't see FLAC support listed either:

http://onlinehelp.avs4you.com/AVS-Vi...edFormats.aspx

I'll stick to the free software. Typing one line in CMD is worth saving $60.

Before using my HTPC, I used to stream .m2ts wirelessly via PS3 Media Server. I would run into trouble wirelessly steaming MKV files, but M2TS files would work much better than MKV files for me. But now since I have a dedicated computer, I can run wither MVK or m2ts wirelessly with not issues at all.

The m2ts format has one huge advantage over the mkv: it can be splitted and then played from any point you want. The mkv file can become unplayable or simply useless even if only header or few kbytes are corrupted. As for me, this certainty of usability is worth a few megabytes bigger filesize.

If you have a A110 - why not use ToNMT? You use it to rip just the movie and you can select any/all audio streams; and it's free. If you want to rip just the movie and select a specific audio track/s then use ClownBD - it's also free. Both are easy easy to use (did I stress easy?). I use both in conjunction with AnyDVD HD (requirement to rip BDs). I find that even ripping just the movie and one audio stream (the HD one) ends up over 25GBs for most of the new releases (Transformers 2 is the largest rip yet at over 30GB). I've never tried MKV nor have the desire - if the movie is under 25GB - I rip to a 25GB disc (that cost @$3) - if it's over that size and if I want a copy I rip the entire image using AnyDVD's "rip to image" feature and then use ImgBurn to burn it to the BD-R DL disc (@$9). And yes, ImgBurn is free!

If just backing up (1:1) your BD discs, I really do not see much point in remuxing to mkv...you can easily remove unwanted audio or other tracks and still have the original BD subtitles after remuxing to m2ts by using TSmuxer...this is especially convenient if you have a media player - m2ts demuxing is done in hardware and is thus less demanding than mkv demuxing which needs to be programmed and is done in emulation and sometimes just plain has bugs or becomes a strain on the processor due to otheh tasks it needs to perform in parallel like rendering srt subtitles...m2ts and BD subtitles are handled entirely by hardware's internal routines and are smooth and trouble-free..IMHO of course

I want to put some of my bluray movies on my server but don't want the complete disc because of storage. Putting up to 50gb for each movie will fill up even a moderate size server. So my question is, can I put the movie file only and keep chapters in the file (not menu) so I can jump forward or backward. And if so, how?

Thanks

I should mention, I know how to recognize and extract the file but how do i keep chapters embedded in it.

I dont' use chapters but I have a PCH-A110, AnyDVD HD, and us ToNMT to rip just the movie and chosen audio/s. On the PCH you can fast frd or 'jump' by percentage of the movie. It works fine for me though I don't know what system you're using to watch.

I have a PCH-100, C-200 and can do that but also the Mvix Ultio which I can't. I would like to reduce the size of these too but haven't figured out what is the best way to do that.

Go read the MKV topic in the HTPC area, it has all the info you need.