[mythtv] New idea for commercial flagging...
Ed Wildgoose
lists at wildgooses.com
Wed Dec 22 23:13:03 UTC 2004
Do you guys in the States have these lead in and lead out clips on all
your shows? In the UK all the advert breaks have a short burst of
either a static frame saying some jazzed up version of the program name,
or sometimes an animated version.
By "hashing" all frames in some sensible way (and ignoring blank frames)
it should be possible to find a series of repeated frames that are near
identical for a second or so. These blocks of identical frames would
then be our commercial lead in and our markers (perhaps optionally
looking for a scene or blank frame afterwards to find the exact end of
the commercial break.
Any thoughts on a sensible hashing function? Might be almost a perfect
identical frame for DVB users, but for analogue users there is going to
be sufficient "noise" to make the detection of identical frames tricky.
My first thought would be to break the frame up into, say, 8x8 pixel
blocks, average the colour and then quantise this colour to a smaller
range (say 1-8 instead of 1-256 for each colour). Does this sound
"fuzzy" enough to spot identical frames? Anyone read any research
papers on doing this that might have some better ideas..? Anyone got a
couple of hours free to try coding this up...?
Ed W
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