Re: QTMovieLayer and renderInContext:

FROM : John Clayton
DATE : Fri Nov 23 16:14:15 2007

OK,

Thanks for trying anyway Bill.  I do appreciate it.

Just one part of the sentence below I didn't understand.  You said 
'...and what I get is every few frames rendered...', can you please 
explain in more detail what you did exactly, and whether or not you 
had the QTMovie playing or static?

thanks

--
John Clayton
http://www.coderage-software.com/



On 23/11/2007, at 2:41 PM, Bill Dudney wrote:

> Ah,
>
> Sorry no enlightenment here...
>
> But my curiosity was piqued so I had to spend some time messing with 
> it. I'm not surethis will help you but figured I'd share what I 
> found in case it does.
>
> I tried setting the beginTime on my QTMovieLayer and what I get is 
> every few frames are rendered (looks like ever beginTime'th frame) 
> and all the audio is played. timeOffset does not appear to affect my 
> video at all.
>
> HTH,
>
> -bd-
> http://bill.dudney.net/roller/objc
>
> On Nov 22, 2007, at 7:24 AM, John Clayton wrote:
>

>> Hi Bill, thanks for the input... buuuuuut:
>>
>> Nope, my aim is somewhat different.
>>
>> I need a movie in a view.  I want the frames of the movie to be in 
>> a layer.  I do *not* want it to autoplay, and I *do* want to tell 
>> the layer that the beginTime and duration are X and Y respectively, 
>> and I do want to be able to control the specific frame that is 
>> represented on the layer from that movie.
>>
>> Try thinking about putting a few movies across a timeline, and 
>> telling them to start/end at a particular time along that 
>> timeline.  This is what I'm trying to do.
>>
>> What I've got going so far:
>> a) a QTMovieLayer (with INF/default duration), rendering a movie 
>> (NOT autoplay on construction)
>> b) a slider on a view that tells the NSMovie what render time is, 
>> via the setCurrentTime:(QTTime) method.
>>
>> this works.  and I gotta say, beautifully.
>>
>> where it all breaks down is in the following:
>> c) set the QTMovieLayers beginTime to something (anything)
>>
>> now nothing is rendered at all.
>>
>> So far, my belief/understanding is as follows - but please do feel 
>> free to enlighten me:
>>
>> When using (a) and (b), the Core Anim engine sees that the 
>> QTMovieLayer has an infinite duration, and thus, the movie is a 
>> valid candidate to be rendered by the Core Anim system.  Every time 
>> the 'rendering time' is modified by the slider, the currentTime of 
>> the NSMovie is changed - and QTMovieLayer (being async in nature) 
>> renders the new frame properly.
>>
>> I'm still not clear why settings a beginTime (as in (c) above)) 
>> causes the animation to do nothing.
>>
>> --
>> john
>>
>>
>> On 22/11/2007, at 1:27 PM, Bill Dudney wrote:
>>

>>> Hi John,
>>>
>>> I'm not sure that I understand the question but if all you want to 
>>> do is put a movie layer into a view I have a simple example here 
>>> that works for me;
>>>
>>> - (void)awakeFromNib {
>>>    NSString *moviePath = @"your path here";
>>>    NSError *error = nil;
>>>    movie = [QTMovie movieWithFile:moviePath error:&error];
>>>    [movie autoplay];
>>>    QTMovieLayer *layer = [QTMovieLayer layerWithMovie:movie];
>>>    [self setLayer:layer];
>>>    [self setWantsLayer:YES];
>>> }
>>>
>>> This awakeFromNib is from my view class that takes up the whole 
>>> window. The movie plays when the app starts.
>>>
>>> In the example (that I've not posted yet but will soon) on my blog 
>>> I have a 'play' button that sits in the view that the movie plays 
>>> on and it works like a champ.
>>>
>>> HTH,
>>>
>>> -bd-
>>> http://bill.dudney.net/roller/objc
>>>
>>> On Nov 21, 2007, at 11:47 PM, John Clayton wrote:
>>>

>>>> Hi All,
>>>>
>>>> I am trying to use the CALayer renderInContext: call to put the 
>>>> contents of a QTMovieLayer instance onto a view, but I get a 
>>>> blank view - nothing renders.
>>>>
>>>> Is this call supposed to work for a QTMovieLayer?  I suppose the 
>>>> question could be expanded to: is the renderInContext: method 
>>>> supposed to work for any type of open-gl based layer class?
>>>>
>>>> Thanks,
>>>> --
>>>> John Clayton
>>>> http://www.coderage-software.com/
>>>>
>>>>
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>>>

>>

>