[mythtv-users] dvd iso playback problem

[Richard]

On 28/04/13 20:49, Dan Littlejohn wrote:
>
<snip>

> Now most of my dvd isos will play, I still have 1/2 dozen that won't
> although the failure is different (these play fine in xine).  I wonder
> if it is related.  This is the log from trying to play one of those
> (with the loopback MTU set to 16k)

<snip>

Hi Dan,

> 2013-04-28 13:33:03.765665 E [2698/2894] Decoder
> DVD/dvdringbuffer.cpp:521 (safe_read) - DVDRB: Failed to read block:
> Error reading NAV packet.

This error seems to indicate that there was an issue with the data from 
the image.  The library MythTV uses (libdvdnav) to parse the DVD data is 
reporting that a data structure it was expecting wasn't found (or was 
corrupt).  One reason for this could be using encrypted ISOs in storage 
groups across the network, but you said your images were all decrypted 
so unless one has slipped through the net, it shouldn't be that.

If the data has been corrupted, it poses the question why the image 
plays in other applications (to my knowledge, most use the same library, 
although possibly with their own modifications).  One reason may be that 
some applications attempt to skip the menu and jump straight to the main 
feature.  That could well mean that they're not seeing the corrupted 
data if it's part of the menu.

You could try starting the frontend with '-v playback --loglevel=debug'. 
  That will certainly give more data (although not from libdvdnav).

Are you getting the same problem from the other images that won't play?

Richard.