Forum archive - A reliable method to convert MKV to MP4

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A reliable method to convert MKV to MP4

Alphonse55 posted 2009 Mar 04 12:06

Ok, I have a bunch of HD quality MKVs that I am trying to convert to MP4 for playback on an AppleTV. I use handbrake for most conversions but on this it just does not work right. Either the program quits unexpectedly or if I get a file it plays back with choppy video. Visualhub works but I have noticed that the quality is not the best (always too dark). MKVtools always hits me with an error before it can finish. Quicktime takes about 45 hours to complete (on a mac pro). I am just looking for a reliable method of converting 1080p and 720p MKV files to 720p MP4s. I searched through the board but couldn't find anything that seems to really work. Any help on this would be greatly appreciated. Thanks

terryj posted 2009 Mar 04 14:26

What happens if you add a step in your workflow? Your workflow is now: 1. HD MKV file ( i assume h.264 with acc audio?) 2. drag and drop into VisualHub or Quicktime Pro to MP4. 45 hours to complete and the resulting video is too dark or choppy. My guess is because of decoding h.264, and then reencoding it to mp4 ( crunching and uncrunching and crunching again). So if you make the file an intermediate file, like DV Stream, and then go to mpeg-4, what happens then: Your new workflow is now: 1. HD MKV file ( i assume h.264 with acc audio?) 2. Export out of Quicktime Pro ( w/Perian) to DV Stream format. 2. drag and drop into VisualHub to MP4. Your audio and video is flattened, which means you require more space to (temp) store the DV Stream file, but it goes in cleaner ( less decode/code) into VisualHub, so it should come out cleaner? just a thought.

emmgunn posted 2009 Mar 04 14:45

Alphonse55 : MKVtools always hits me with an error before it can finish. Quicktime takes about 45 hours to complete (on a mac pro). I am just looking for a reliable method of converting 1080p and 720p MKV files to 720p MP4s. I searched through the board but couldn't find anything that seems to really work. Any help on this would be greatly appreciated. Thanks Howdy, In case your interested, after a bit of a hiatus, I've had a little bit of time to return to working on an update for MKVtools. The error your getting with MKVtools at the end of processing is probably due to a bug in the version of mp4box used by MKVtools. For the latest beta, I was able to track down a much newer version of mp4box with the following improvements (untested) for apple TV, ps3 and xbox360 users: AC3 audio can now be muxed into mp4 files. This means that mkv files with avc video and ac3 audio can be converted to mp4 files in minutes. The resulting file only plays in VLC unless the extension is changed from .mp4 to .m4v in which case quicktime (w/ perian for the AC3) and itunes will play the video. However, since I don't have a appleTV (or xbox or PS3) I don't know if this will work on other devices so your mileage may vary. You may have to fall back on AAC encoding. Mp4box can now mux files larger than 2GB. I converted a 3GB file to mp4 with the PS3 preset, video passthru and aac encoding in about 5 minutes on a macbook pro. I've had reports that these files will successfully play on PS3's, but I've heard nothing about other devices. The downside is that I could only track down an intel binary of mp4box (and Mac OS X 10.5 only????) with this capability so though MKVtools is still universal binary, this one feature is intel only, at least for now. If you want to give it a try, the newest beta can be found here. It's fully functional though you'll get the annoying nag screen and you can't queue jobs. If you've already registered for older versions of MKVtools, your registration code will work for this version. I've been hoping for feedback regarding the playability of these files on the various devices but I haven't had much luck. Also, if needed, MKVtools does some hex editing to change the video track's profile level to 4.1. MKVtools can do this for the most commonly encoded videos, but if you get a "hex not found error" that means that MKVtools couldn't find the hex string to edit. If that's the case, I'd like to hear about it to see if I can expand the profile levels that MKVtools can handle. Good luck and thanks in advance if you are able to supply feedback.

Poopshute posted 2009 Nov 13 19:58

I've been having the hugest headache trying to get various apps to convert a MKV with 5.1 DTS to an MP4 so that's it's playable on my AppleTV (while preserving the 5.1 DTS sound). So far the latest MKVtools seems to be doing the trick (at 14% which is much better than any of the other apps I've tried including Handbrake, FilmRedux, and Video Monkey... all failed with one getting as far as 5%). If this works, you'll have one more Big Mac for the day!

hashshashin1212 posted 2010 Jan 18 20:06

I'm having the exact same problem. I have some large 1080p and 720p mkv files. Visualhub will convert them with the Apple TV present, but the end result (mp4 file) comes out choppy (dropping frames) on both ATV and Quicktime. I'm not changing the frame rate on the source files since they are already set at 24fps (23.976). I've also tried Handbrake, I found that it will lower thet resolution much lower than 720p and if I used the ATV legacy present it will keep it at 1080p for those 1080p mkvs (no problems with the 720p files). My question is: Has anybody found a one stop solution to this problem with Visualhub with dropping frames?? Is there a way I can drop both my 1080p and 720p mkv files and convert them to ATV HD friendly files without any choppy end result? Thanks in advance. Output settings used in Visualhub: Apple TV present Quality: Go nuts Frame rate: same as source Dimesions: 1280x720 or 1280x544 (if differen from source: auto) Other: best quality mp4 Audio: AAC 160, 192, 320 (depending on source) Am I doing something wrong?

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