Hello! I just recently found this forum in my search for people trying to convert mkv videos for use on Apple TV (or PS3 or Xbox 360 for that matter). I have an application called MKVtools that I know some here have used, and I'm looking for feedback on the latest beta. There is a video related forum that I frequent, but there doesn't seem to be much interest in converting MKV files there, and the feedback I've gotten via e-mail, though very useful, has been limited. So when I saw an 11 page (at last count) post on converting mkv movies into mp4, I thought that this might be a good place to post. I'm not sure how to do this without coming across as trying to pimp my software, because that is not my intention, so please let me know if I've crossed any boundaries. I'm just trying to finish a project that I naively started as something fun to try, but which has reached a kind of state of limbo, though I think it would of interest to many people here. Specifically, after receiving numerous requests, I started working on expanding the capabilities of MKVtools (it originally had the awful name of MoKgVm2DVD) to include the ability to convert MKV to MP4 for various devices like the iPhone, Apple TV, PS3 and Xbox 360. The problem is that, other than the iPhone/iPod, I don't have the other devices to test with, and so conversion presets for Apple TV, PS3 and Xbox 360 are still very much beta. So if you have one of these devices, and if you're interested in giving the most recent beta of MKVtools a try, it can be found at http://www.emmgunn.com/betadownload.html. Note you'll get a nag screen when you run the software, but it is fully functional without registering. You can post comments here or you can e-mail me at firstname.lastname@example.org and I'll try to incorporate the feedback into a working final release. You should know that MKVtools is an application that controls a number of UNIX command line applications (the "tools") like mencoder and the suite of tools from mkvtoolnix. This means that its capabilities and limitations are directly related to the UNIX applications it controls. Also, I'm not enough of a UNIX expert to build distributable binaries from source, so MKVtools is limited to using UNIX applications that have pre-compiled binaries available for Mac OS X. Some of the known issues/limitations inlude: The "tool" mp4box has issues with muxing large files (2GB seems to be the magic number). Apparently there is a patch to fix this issue, but I can't find a pre-compiled Mac OS X version of mp4box with this patch. The current work around would be to split the mkv file, process the parts, and then join the resulting mp4 files (all new capabilities of the MKVtools beta). Mp4box can't mux AC3 audio into an mp4 file. I don't know of any command line application that will do this. If you know of one, and pre-compiled binaries are available, let me know and I can probably add it to the tools controlled by MKVtools. The "tool" mencoder can't decode DTS. This is one of many limitations of the version of mencoder used by MKVtools. It's about two years old and I'd love to use a newer pre-compiled version of both mencoder and mplayer. 5.1 audio is converted to stereo. If anyone knows of a pre-compiled command line tool that will convert 5.1 audio into 5.1 aac, it could be incorporated into MKVtools. Can only mux one video track and one audio track into the mp4 file. This should be expanded in the next release, and will probably be in an upcoming beta. Thanks in advance for any feedback/comments!