[mythtv-users] "Perfect" DVD Rip -> small picture

[Rod Smith]

On Friday 19 December 2008 12:16:49 am Bob Sully wrote:
>
> Pardon the question if the answer's obvious, but I didn't find a quick fix
> in the list archives.
>
> I just ran a "perfect" rip on a letterboxed DVD.  The job ran cleanly
> (6.6GB file).  When I play back the resultant .vob file, however, the
> picture is significantly smaller than when playing the DVD, with a thick
> black box around the whole picture rather than just the typical
> letterboxed black bars above and below.

What's your TV (or monitor's) aspect ratio? If you've got a letterboxed 4:3 
DVD and a 16:9 TV/monitor, the "natural" result will be as you describe -- 
you'll get bars on the side from the attempt to play a 4:3 video on a 16:9 
device, and the bars on the top and bottom are actually part of the 
recording. To get around this, you'll need to use a zoom function to 
eliminate the black bars. It could be that the player for your DVD is doing 
this automatically, but it's not doing it on the "raw" VOB file. If you want 
to transcode the recording to another format, you can use crop functions of 
mencoder to do this, for instance. (I think ffmpeg has similar options.) 
AFAIK, there's no way to tell MythTV to do this.

Another possibility is that your player is confused about the aspect ratio. 
Does the image appear "squashed" in any dimension? If so, this is probably 
what's going on. If you've got a 16:9  recording and the player thinks it's 
4:3, or vice-versa, then the player will squash or stretch the image 
inappropriately. You can overcome this with command-line players like mplayer 
by using appropriate command-line switches, such as mplayer's -monitoraspect 
and -aspect, which set the monitor's and recording's aspect ratios, 
respectively. In my experience, MythTV's internal player does a much better 
job of getting the aspect ratio right than does mplayer.

As an unrelated suggestion, you could try using non-Myth tools to do the 
extraction. I'm not positive, but I think that the dvdunauthor program will 
extract the individual recordings. The dvdbackup program backs up a DVD to 
your hard disk, but it keeps the DVD's structure, which means that you won't 
have easy access to individual items; they'll be glommed together in a way 
that may be hard to extricate just one item.

-- 
Rod Smith