[osg-users] ImageStream current frame

Robert Osfield robert.osfield at gmail.com
Tue Sep 23 01:27:39 PDT 2008


Hi Richard,

Chasing after PixelBufferObject usage will just waste your time on
something that really won't lead to much benefit.  What you are after
is a value that the OSG doesn't at present provide, but the OSG is
open source, so you can take the source extended it to do what you
need to do and then get these changes make into the main trunk.   The
changes will need to be to base class and the ImageStream
implementations.

Robert.

On Tue, Sep 23, 2008 at 1:28 AM, Richard Baron Penman
<richardbp+osg at gmail.com> wrote:
> thanks for the clarification about ImageStream Robert.
>
> If I understand right ImageStream buffers the frames in a PixelBufferObject
> and switches the frames in the compileBuffer() function. So if I could get
> feedback from this function then I could determine the frame count. Possibly
> the _compiledList[contextID] variable might help with this.
> Am I on the right track? Can you offer any advice?
>
> Richard
>
>
>> Hi Richard,
>>
>> These methods are virtual methods, and ImageStream is a base class...
>> that implementations subclass from, so the fact a header doesn't
>> implement something doesn't say anything about the actual
>> implementations that are meant to implement it.
>>
>> Secondly the getReferenceTime() and TimeMultiplier are an time offset
>> and multiple, that is used by the ImageStream implementations to
>> compute the current time, and not the current time of the movie.
>>
>> The actual time of the movie is something that would have to added to
>> ImageStream and its implementations, it should be possible to do this,
>> something like a getMovieTime().
>>
>> Robert.
>>
>> On Fri, Sep 19, 2008 at 6:52 AM, Richard Baron Penman
>>
>> <richardbp+... at gmail.com> wrote:
>> > hello,
>>
>> > I would like to display what percentage of a video has been played. I'm
>> > using the ImageStream class and I thought getReferenceTime() or
>> > getTimeMultiplier() might help me, but they always return 0.
>>
>> > Examining the header file I found this:
>> > 72             virtual double getLength() const { return 0.0; }
>> > 73
>> > 74             virtual void setReferenceTime(double) {}
>> > 75             virtual double getReferenceTime() const { return 0.0; }
>> > 76
>> > 77             virtual void setTimeMultiplier(double) {}
>> > 78             virtual double getTimeMultiplier() const { return 0.0; }
>>
>> > So it seems this functionality is not ready yet. Does anyone have an
>> > alternative way to determine the current playing video frame?
>>
>> > regards,
>> > Richard
>>
>> > _______________________________________________
>> > osg-users mailing list
>> > osg-us... at lists.openscenegraph.org
>> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph...
>
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