[mythtv] [mythtv-firehose] mythtv/master commit: 3870b0777 by Daniel Thor Kristjansson (daniel-kristjansson)

James Courtier-Dutton james.dutton at gmail.com
Mon Sep 26 12:04:59 UTC 2011

On 26 September 2011 12:29, Stuart Morgan <stuart at tase.co.uk> wrote:
> On Sunday 25 Sep 2011 14:45:42 Gavin Hurlbut wrote:
>> On Sun, Sep 25, 2011 at 2:06 PM, MythTV <noreply at mythtv.org> wrote:
>> > I've also added a small hack for NTSC and PAL video, if the number
>> > of lines in the video is 480 or 576 we assume the video is interlaced.
>> > After watching a poorly mastered DVD one too many times I decided
>> > this hack was necessary. The DVD override for still frames will
>> > still ensure that those are not deinterlaced, this is just for the
>> > autodetection in the video.
>> This would force 480p recordings to be treated as 480i, would it not?  I
>> guess it's only the *auto*deinterlace, but still, that could be annoying for
>> those few recordings.  Just a thought.
> I was actually pretty close to implementing this myself, for PAL DVDs at a
> bare minimum. Like Daniel I've got some badly mastered DVDs and it's not an
> acceptable solution to require users to force de-interlacing from the menu for
> these. It's pretty certain that commercial DVD players assume all content is
> interlaced since the spec (as I read it) doesn't allow for 480p or 576p.
> --

What are these badly mastered DVDs, and how does myth determine what
the format of the video is?
I helped write libdvdnav, so I understand DVD playing, and in that
whole time, incorrect interlace detection was not reported.  (When
using xine to play DVDs)
The media stream itself contains some information regarding the media
format, and so does the .ifo files.
If these disagree, the .ifo file setting should be used.

Detection of hints is also much easier in NTSC DVDs by looking at the
rff flags.  rff set =  non-interlaced, rff not-set = probably
There are hints for PAL with the camera/film attribute.
camera = interlaced, film = non-interlaced.

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