[mythtv] Re: [mythtv-commits] mythtv commits (top_field_first)

Daniel Thor Kristjansson danielk at cat.nyu.edu
Sun Aug 15 14:01:12 EDT 2004

I did not find it to be reliable at all. I think it's supposed to be set
when the film is transferred to video, so it doesn't get set if you
encode an NTSC transmission, or if the stream wasn't initially tagged
when recording ATSC. My hope initially was that top_field_first, and the
other flag that controls this could be used, but it didn't even work on
many things I knew were transfered from film.

transcode has filters that will detect a film transfer however, maybe
they could be used on recorded video to flag them appropriately? Of
course, if it is from film the best thing to do might be to transcode it
to 24 fps progressive...

-- Daniel

On Sun, 15 Aug 2004, Doug Larrick wrote:

]mythtv at cvs.mythtv.org wrote:
]> ----------------------------------------------------------------------------
]> Changes committed by ijr on Sun Aug 15 05:36:31 2004
]> Modified Files:
]>    in mythtv/libs/libmythtv:
]>         avformatdecoder.cpp frame.h videoout_xv.cpp videooutbase.cpp
]>         videooutbase.h
]> Log Message:
]> - Pay attention to the top_field_first flag from avcodec when doing bob.
]How reliable is avcodec's interlace detection?  Would it make sense to
]replace the rules-based (frame size & rate-based) detection in
]NuppelVideoPlayer with just looking at this flag?  Would it make sense
]to make the decision of which field to send there rather than in (each)
]videoout class?

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