6.0.0 video thumbnailer...

[Gilles Caulier]

Hi Maik,

Definitively no, because we need to limit the dependencies puzzle
definitively. Look well, this thumbnailer use KIO in background, and you
know what i mean about the portability of KIO...

The DK thumbnailer architecture is based on QThread, and we can use here
ActionThreadBase/ActionJob instead QObject/Qthread.

But you can include your patch in future internal digiKam core video
thumbnailer based on this kind of code (:=)))

Gilles

2018-03-04 18:10 GMT+01:00 Maik Qualmann <metzpinguin at gmail.com>:

> Do we want to use libffmpegthumbnailer as additional dependencies? Also
> used
> by Dolphin here. For that I already have a nearly finished patch, because I
> tested it some time ago and it worked very well and fast. I will reactivate
> the patch to test...
>
> Maik
>
> Am Sonntag, 4. März 2018, 17:49:39 CET schrieb Gilles Caulier:
> > Hi all,
> >
> > Since i written the FFMPEG video metadata parser in 6.0.0 branch, i'm
> > trying to register a huge video collection from my host computer.
> >
> > Here, more than 2500 MKV files are present, plus a lots of MP4, MOV, and
> > another media taken with cellular and camera.
> >
> > The registration have been very fast. 2500 file parsed in 2 minutes and
> > ready to use. System has SSD, Sqlite, 8 cores, and 32Gb of RAM. No crash
> > all work fine... excepted... the video thumbnails.
> >
> > I facing random dysfunctions with video files. Sometime thumbs are there,
> > sometime not. Using F5 always give a different results until i try to
> > insist and i can see the DB locked and revival...
> >
> > The video thumbnailer is based on QtAV frame extractor. My QtAV is last
> > stable 1.12.0. I suspect a bug somewhere in QtAV, as i can see
> thumbnailer
> > code including a lots of mutex to prevent concurrency.
> >
> > This is typically abnormal. FFMPEG API is re-entrant as i checked with
> the
> > multi-threaded metadata parser unit test.
> >
> > As we depend now directly of FFMPEG API, I propose to rewrite the video
> > thumbnailer with libav C function.
> >
> > We have code ready to use with ffmpeg API here :
> >
> > https://cgit.kde.org/ffmpegthumbs.git/tree/
> >
> > Your viewpoint ?
> >
> > Gilles
>
>
>
>
>
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