[mythtv-users] Mencoder magic for Internal player

[Paul Mason]

On 11/12/2007, Neil Dunbar <neil.dunbar at pobox.com> wrote:
>
> All,
>
> Not a question to burn any brainpower over, since I have a working
> solution
> anyway, but it might be nice to see if I can improve it.
>
> Problem: I've got a fair number of Matroska rips from HD-DVD, transcoded
> via
> x264 down to 720p from 1080p. Since I've got a 720p LCD HDTV, leaving it
> in
> 1080p is silly, to say nothing of a CPU-hog.
>
> Now, I know that the MythVideo Internal player (version 0.20.2) doesn't
> really
> like Matroska that much. It plays, but fast forwarding and rewinding is a
> bit
> of a dead loss. So I transcode them into MPEG-2 files via mencoder - takes
> more space, but I can deal with that, and I can fast forward, remember
> position, all that stuff. Problem solved.
>
> So now I thought I'd transcode to MPEG-4 (DX50) via mencoder to get
> smaller
> file sizes, while not beating up too much on the frontend CPU. The files
> play
> fine in mplayer, but when imported I sometimes get framedrops, and fast
> forwarding/rewind tends to be a bit of a disaster. Picture gets corrupted
> until the next keyframe, audio doesn't silence when FF goes past x3. Lots
> of
> people have described these problems - so nothing new here.
>
> But since recordings transcoded via Mythtranscode into MPEG-4
> play/rewind/fast
> forward just fine, there must be a set of parameters for mencoder/ffmpeg
> which will produce Internal-friendly files. Does anyone have experience
> that
> could bring to bear here?
>
> I know I could also use Xine and Mplayer, but the integration of theme and
> control from the Internal player is just too nice (and has significant WAF
> correlation).
>
> All ideas happily entertained,
>
>
I can't give you a precise answer but I've seen something similar. I wanted
to rip a set of DVDs of TV shows and I didn't have the discspace for ISOs. I
initially used the Import function in Mythtv but I couldn't get a
combination of time taken:quality I was happy with with the defaults. I then
tried to define my own transcoder but found it didn't get called so to cut a
long story short I ended up ripping and transcoding them outside of Myth
with a few scripts.

I used avidemux2_cli to transcode using ffmpeg4. Once I'd settled on this
process I went ahead and ripped/transcoded 250+ episodes of TV from DVDs. I
was checking them using mplayer. When I came to view them in Mythtv I found
the same sorts of problems you reported - especially the fact that the
picture gets corrupted until the next keyframe (sometimes this happens in
normal play, not just in fastforward). So I changed the default player to
mplayer. As you say the lack of consistency with the rest of Myth is
irritating but it would take too long to re-encode them (and if I was to
invest that kind of time, I'd want to go back to the DVDs).

However now that I've done my "big push" when I want to do any new rips -
I've done a couple of discs since - I use the same process but set
avidemux2_cli to xvid4 instead. This takes about twice as long on my machine
but the results are a little better and they play fine with the internal
player.

I have a feeling that mythtrancode uses ffmpeg as well so maybe that's the
common factor here?

-- 
Paul Mason
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