[mythtv-users] MythVideo DVD playback fault tolerance

[Ronald Frazier]

On Tue, May 10, 2011 at 4:13 PM, Scott Alfter <scott at alfter.us> wrote:
> On 5/7/2011 05:01, Chris Jewell wrote:
>> I have compared this . . .with VLC (running on the mythbuntu box) which
>> appears simply to skip a frame and carry on.
>
> I don't think you can rule out hardware.  I'm assuming that you're using
> different drives with your MythTV box and your Mac; what happens if you plug
> your MythTV box's optical drive into your Mac and play a disc from there (or
> the other way around: plug your Mac's optical drive into your MythTV box)?
> It's possible that one drive is less tolerant of scratches and other defects
> than the other.

I think that was his point of mentioning the VLC test. VLC handles it
perfectly fine, with just a small skip.

I used to experience a similar problem along these lines. In a
previous setup, I was having some odd issues where reading large files
would occasionally (not too often) result in a small block of the
large file being corrupt (but when you flush the cache and reread it,
it would work fine). I didn't know what was going on for the longest
time. However, what I did experience was, while TV playback never
really had any problems (other than the tiny glitches you get from an
imperfect signal), mythvideo would from time to time just completely
drop out of playback (ripped DVD iso and mkv files).

For many months, I had no idea why mythvideo would do that. Then one
day I moved all of my movies to a 2nd drive. In verifying that the
files were copied intact (md5sum comparison), I noticed that every now
and then I'd get a file that didn't match, but when I re-checksummed
it, it would suddenly be fine again. I think I tracked it down to a
driver incompatibility with a specific hard drive. Once eliminated,
the problem went away, and amazingly, so did my mysterious exiting out
of mythvideo.

In my case, yes it was the hardware/driver that was at fault, but the
point was that mythvideo was unable to cope with even these tiny
errors. In most of my other experiences, other systems have been able
to tolerate damaged DVDs with just some minor skips. Mythvideo seems
to demand perfection or it gives up

I'm not trying to rag on mythvideo, but rather just pointing out that
I've noticed a similar issue. And for the record, I'm still on 0.22
(and I think it may have even been 0.21 at the time I had those issues
before I fixed my system), so perhaps improvements have been made.
Just throwing in my 2 cents.

-- 
Ron