Tech Tip Tuesday: Troublesome MKV files Work Around

So yesterday's blog posting was on
MKV (Mastroka) Video files, and
using my friend emmgunn's MKV Tools
to create a usable format (.avi or .mp4)
file that used less system resources,
so that you could easily edit in
MpegStreamclip, (avi) or just drag
and drop to your iPod or Apple Tv.
(.mp4)

But this assumes that the video can be
transcoded, and isn't using a properitary
codec ( audio or video) that would prevent it
from being transcoded into a useable format.

Let's say for the sake of this post you have an
.mkv file, that for audio has standard AAC
audio, but for the video has a weird variant of
.h264 for the Video portion of the file.

You try to process it with MKV Tools, but
it is having a hard time trying to process the
video, transcoding it to XVID. You already
tried to open it Quicktime Pro Player, and
it opens, but scrubbing through to
edit it causes nothing but spinning beachballs,
and the same is true for MpegStreamclip.

To add insult to injury, it is only 30mins in length,
and MKV Tools is taking at least twice that in
just getting to 50% of the file transcoded!

Well, there is another option you can try to get
something useable at this point.

First, let's stop everything and start simply.
First let's see if we can play it without
it stuttering or giving any beachaballs.
For that, we'll use VLC Player.

So we open VLC Player, and we try and open our
troublesome MKV file. Success it opens,
and we can play it start to finish.
We also notice while in VLC, it has English
subtitles turned on, and they display
while playing. Perfect!

So we know we can view our video intact using VLC.
Armed with that, we know we can capture it.
So for that we'll use my favorite app,
iShowU.

Launch iShowU, and set it to a capture window
as large as Normal size in VLC. For instance,
if the normal playing window of the file is
640 x 480 pixels, we'll set it to that in
iShowU.

Next, we set iShowU to capture system audio,
and to capture the video as a DV Stream file
to our disc destination ( the Desktop is fine).
Set it to not follow the mouse cursor,
and click record.

Play the video again in VLC, and let it play
for the entire length of 30 minutes.

When it is done, stop VLC, and stop recording in
iShowU. A few minutes later, iShowU will have
a complete version of the mkv file,
subtitles hard encoded, as a DV Stream file.

This file is now ready for you to use in MpegStreamclip,
or iMovie, FCE, and FCP, and to edit to your
heart's content.

But let's say for a moment, that back when we
tried to play it in Quicktime Pro Player, that
it actually did not give us beachballs, and that
we could scrub through without much hassle.

You could then try something much easier:
Try exporting from Quicktime Pro Player
as a DV Stream file, and let it make the attempt.
The file should be intact audio and video wise,
but may or may not embed the subtitles
if they are present.

So I would recommend first the option of "capturing"
the playback of the .mkv through iShowU to
get the fast, most usable file (with hard coded
subtitles if present) into your NLE.

But if you have time, you can try the Quicktime Pro Player
option, which may take up to double the amount of
runtime of the file ( 1 hour for a 30min file) and
may or may not embed the subtitles.

Monday Mac App Toolbox: MKVTools

MKV, or Mastroka Video, is a pain for Mac users.
Although the adoption of it has merit :
open-source, ability to contain within it
HD (High Definition) Video and Audio, as well
as subtitles, it is often a piece of work to get it
into a usuable format if you want to use part of it
in an Final Cut Pro or iMovie sequence.
Tried and true converters such as MpegStreamclip
and Quicktime Player often choke
( even with Perian installed on the system),
usually on trying to decode everything that is in the container,
instead of just focusing on what is needed.

Rather than go through the hassle of trying to use MKV as it is,
I find that I'd rather get the video into a format that I use,
and then go from there. To facilitate that, I often turn to
MKVTools.

MKVTools is developed by my good friend
emmgunn, enables you to drag and drop a MKV file onto it,
and from there, you are presented with options to flatten the
file down by embedding subtitles, and even
transcoding the file into another format,
such as XVID for video and mp3 for audio.

This is what I tend to do, by transcoding it to another file,
I get it into a more compatible format like XVID
and the audio into mp3, which makes it less labor
intensive to decode and enable playback in
Quicktime and MpegStreamclip ( but not VLC,
which handles mkvs much easier for playback, but not editing).

Once it is in an .avi container ( or .mp4),
I can then open this file in MpegStreamclip,
and scrub through it pretty easily, getting the
pieces I want here or there, and exporting them
from there to DV stream, for ingestion into iMovie,
FCE or FCP.

Or if I happen to have a file that I'd rather just be able to watch
at my leisure, I'll keep the .avi ( or .mp4) file that is generated
by MKVTools, and watch that on my HTMac, or encode it
for direct watching on my iPod ( or an Apple TV).

It is the #1 tool I turn to for getting mkv files into easier
to handle formats.
But what if you have an .mkv that is stubborn and chokes
MKVTools ability to transcode it into something useful?

Tune in to tomorrow's Tech Tip Tuesday, where I'll talk about
two ways to get around heavy problem mkv's to get something
useful for your video productions.