Re: [libreoffice-users] video issue -- thinking out loud and could do with help please

2017-11-09 10:02 GMT+01:00 Mike Scott <v.lo@scottsonline.org.uk>:

> OK. I'm well out of my depth, but this problem has been around too long
> unfixed and it needs fixing. If I 'think out loud' here, maybe others could
> chip in? Sorry this is a bit lengthy.
>
> The problem: a video on an Impress slide starts and finishes with an
> inappropriate frame displayed. I've made a series of test videos, the
> frames simply containing the frame number from 0....N-1, and in a selection
> of formats (.mp4, .flv and ".avi") using avconv. I then embed that video
> into a slide using Insert|Audio or Video.

> A placeholder frame from the video is displayed during editing. This is a
> frame from within the video, but it isn't always the same one.


> The big deal-breaker is that this placeholder frame is shown during the
> slide show when the slide appears and before the video plays (a long time
> if there's a slow transition), and also when the video has finished. This
> means at the very least an annoying flicker at the start, and a usually
> totally inappropriate ending.


> Sorry that's so long, but I think the symptoms need documenting somewhere.
> Any thoughts at all would be most welcome - thanks.


​Some thoughts about this.
Inserting video is finicky. At least your problem isn't that it randomly
stop working sometimes or that some formats are unsupported. These two
issues alone pushes a lot of people to simply have their video file at hand
during presentation, and switch to that instead of embeding it, which in
turns means that less people embed video, so issues are harder to diagnose,
etc.

About the thumbnail: on most of my (not so thorough) tests, LibreOffice
always showed the first frame as the preview, so it was not an issue. My
version is 5.3.1.2, but I'm afraid the preview picture is more a matter of
OS and media package than LibreOffice itself.
An "immediate" solution would be to surround your slides with video, with
slides with static images and no transition.

Here's what I did:
- Create a presentation with three slides: dummy1, video, dummy2
- Have long transitions on them. This shows that going from the video slide
to the dummy2 slide, the video preview image (in my case the first image of
the video) shows during the transition, which is not good
- Add a slide after the video with no transition. Place a capture of the
video's last frame at the exact same place the video should be (using
placement properties it's quite easy, even if tedious)

This way, when I move to the next slide after the video, the transition
looks smooth. I suppose the same thing could be done before the slide to
show the correct first frame in every case. One last issue I found there is
that the video flicker slightly when it starts playing; again, this is
probably OS/Library dependant.

This is obviously not an ideal solution. Ideally, you could specify on
which frame/timestamp the video should initially be, or simply just always
display the first frame one entering, and the current frame on exiting the
slide. Maybe there's even a suggestion about this, but obviously it' not
high priority since it's been around for so long.

-- 
To unsubscribe e-mail to: users+unsubscribe@global.libreoffice.org
Problems? https://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/
Posting guidelines + more: https://wiki.documentfoundation.org/Netiquette
List archive: https://listarchives.libreoffice.org/global/users/
All messages sent to this list will be publicly archived and cannot be deleted