0015712: [Core] Never black stills

[admin]

Would like to see video thumbnail generation so it won't take 'black frames' of video and will try to find a 'good' thumbnail

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 http://mantis.kennisnet.nl/view.php?id=15712
0015712: 8 [Core] Nooit meer zwarte stills genereren. -- nice to have

feature: nooit zwarte stills genereren.
Ofwel, bedenk een methode om de kwaliteit van een stil te bepalen. Wanneer de gegenereerde stil onder dit kwaliteitsnivo komt, genereer dan een nieuwe.

[MC-arjen]

Choosen algorithm: we take 5 samples around 30 seconds or 50 procent of the video in the case of a smaller video. The image with the best contrast is chosen.

[forgacs]

We take 5 samples. First is from the given frametime, and the others from the frametime +- 1 and 3 seconds (eg. 10, 11, 9, 13, 7).
The image with the most colours is chosen.

[MC-arjen]

released in 1.7.0.1

[Michiel.Schok]

Please document this behaviour in the relevant section on mediamosa.org/api.
In discussion on VP-tech maillist, the following comments have been made by Arjen:

Momenteel werkt deze functie alleen bij de enkelvoudige still. Ik zie
wel wat uitdagingen als je deze functionaliteit ook bij de
interval/scene overgangen zou willen.

So this is only for still_type=NORMAL

page to update: http://mediamosa.org/node/3649

[forgacs]

The documentation was updated.

[Frans]

[Core] #18 Stills generation: added a remark on de api documentation
about the algoritme of generating black stills. see
http://mediamosa.org/node/3649

[Michiel.Schok]

Approved the update of the documentation.
The versioning of the documentation is not correct (just mentioned it on issue #158, but it's uniformly wrong....) Won't say it again, but will try to contact via mail to see if it's easy to straighten it.