[mythtv] Re:What is the recordedmarkup table for?

Geoffrey Hausheer ou401cru02 at sneakemail.com
Wed Jun 11 10:32:01 EDT 2003


Chris Pinkham wrote:
> The recordedmarkup table currently stores several 'type' records:

> -1 = flag to indicate file is currently being flagged for commercials
> 3 = blank frame in video
> 4 = commercial break start
> 5 = commercial break end
> 6 = offset of mpeg2 gop
> 7 = offset of rtjpeg/mpeg4 keyframe

> If you look at how the ProgramInfo::SetPositionMap function is
> used, then you should be able to easily update the recordedmarkup table
> after applying the cutlist while reencoding a file.

I guess my question is what are the type '6' and '7' records used for? 
During 'raw' encodings, I can easily update the fileposition (well it's
not that easy, but it can be done).  During full-transcoding (where I
don't preserve the sync-frames), I'd need to delete all type '6' and '7'
entries, and rebuild the table from scratch.  (Actually i would probably
do it this way in both cases as I mention below).

If the transcoder is using the cutlist, than I believe all the commercial
and blank frame entries in recordedmarkup can be deleted (In fact,
perhaps all entries for that program can be deleted).  If the cutlist is
not being used, then somehow the file-offsets need to be updated for all
of these entries (which is not very easy to do, since we don't store the
timestamp info, just the file offset)

This is further complicated by the fact that we don't want to modify the
recordedmarkup table until the file is actually switched (the user could
be watching the stream while we are transcoding it), which means that I
either need to regenerate the info after the transcoding is done, when
the files are being swapped, or create a new table while transcoding and
replace the recordedmarkup by that information when the files are
swapped.  I'd probably do the second (it is a lot more efficient), but I
need to understand what info needs to be preserved.  It may end up being
beneficial to store the timestamps along with the file-offsets in
recordedmarkup to make this process easier, but I don't think I need to
do that, and I'd prefer not to if I don't have to.

But before I get too far, I need to know what the type '6' and '7'
entires are needed for.

.Geoff

By the way, for some reason I'm receiving this mailing-list about 2 days
late.  dunno what is going on.  It's been happening since last friday. 
Anyhow, I'll keep up via the archives.
-- 
  Geoffrey Hausheer
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