Converting or demuxing MKV's to another container using x264 or vc-1

[dm_0001]

My goal is to watch my existing MKV collection of videos using GPU hardware acceleration of my 8500gt video card by either converting/demuxing the files into another container that supports hardware acceleration. I'm looking for the fastest solution while keeping quality the SAME.

I've read through a bunch of threads and this is what I understand there is no GPU HW acceleration available for MKV containers. I've tried the alternative of using CoreAVC but my AMD x2 4000 CPU doesn't have the horsepower for 1080p videos (720p is working OK).

The latest thread I read was to use alltoavi but it converts at 5fps and would take forever from what I've seen.

Does anyone have any suggestions? I think alot of people are in the same boat so if there's already a thread that you think achieves what I want, please send it my way.

I'd like to ideally convert/demux the MKV container into an mp4 file.

[poisondeathray]

My understanding is that:

1) Nvidia's Purevideo only supports h.264, not vc-1
2) You also need to checkoff "enable hardware acceleration" in you video player
3) Haali splitter has problems with hardware accelerated MKV's in its current revision, but even remuxing your streams into an AVI or MP4 will not necessarily get you much more fps

Anyhow,

1) Demux you MKV into individual streams by using MKVextractGUI

2) You may have to rename the video & audio streams so the names are identical (except for extension, like .mp3, etc..)

3) If you have subtitles, attach them separately (you may want to convert them to a more common format like .srt using subtitle workshop)

4) If you prefer mp4, use avidemux to remux audio & video. (open the video file, and set video to "copy"; but for audio you have to use audio=> main track => external track => browse). Select MP4 as your output container and save as. Note you have to type your final output WITH extension (e.g. finalvideo.mp4). Note you can also select AVI or some other container as your output with avidemux.

5) If this process doesn't work, you may have to encode your audio to something more familiar like mp3 if your audio is a bizarre format (AVI doesn't like some of the weirder ones found in some MKVs)

There should be no re-encoding (i.e. not 5fps), only a stream copy into a new container. With avidemux the process should take only a few minutes.

[dm_0001]

Thank you!

I tried avidemux on my laptop and got it working. I'll verify the GPU acceleration this weekend. And just like you mentioned in point #5 the sound wasn't working at first until I picked MP3.

Is there anyway to keep the 6-channel AC3?? I'd like to keep audio quality too

[poisondeathray]

I think AC3 has compatibilty problems in mp4, but the standard audio format for mp4 is AAC anyway. You can convert to 6-channel AAC using avidemux (on the sidebar, select AAC and configure your options instead of "copy")

Alternatively, you can use AVI container with 5.1 AC3

[dm_0001]

I converted as you suggested using AAC (sidebar) but when I have a look at the details in VLC it says its using AAC with 2-channels. I went back into avidemux and tried using different combinations in the filter/mixer but that doesn't help.

I'm testing this on a laptop and I'm looking at the advanced media information in VLC media player to tell how many audio channels are being used. The audio codec is mp4a which looks right.

I also tried using an AVI container and I get 6 channel audio but no video when played in a few different type of players. The properties on VLC says its using codec AVC1 but no image appears.

[poisondeathray]

1) Open your original MKV with avidemux
2) Audio => Main track => select external AC3 => browse and point to the demuxed AC3 audio track
3) In the audio sidebar, select AAC (FAAC), configure the bitrate you want, mixer should be "5.1"
4) In the video sidebar, select copy as per usual
5) In the output sidebar, select MP4
6) Save "filename.mp4"

This worked for me; but note it takes a bit longer because the audio is re-encoded (but video stream is conserved)
You can also check video/audio characteristics with mediainfo or gspot

Cheers

[dm_0001]

Thanks again.

It was working earlier but when I checked the media properties with VLC it showed 2-channel audio for some reason. Now I downloaded mediainfo and it shows it correctly as 6-channel audio.