[Kdenlive-devel] Progress updates (was Re: GUI)

[Jason Wood]

On Wednesday 08 Jan 2003 11:15 pm, Rolf Dubitzky wrote:
>
> BTW, another thing I'm going to add the next revision is a reply to <play>
>
>   <reply command="play" status="playing"/>

Ok.

> Every frame piave will send:
>
>   <playing time="123.456"/>
>
> or
>
>  <reply command="play" status="playing" time="123.456"/>

Definitely the shorter one is better, because we are no longer "replying" to 
the play command - this is piave alerting kdenlive to it's current status.

However, I am not sure if perhaps <playing> is too specific a command. For 
example, we will need another command for <rendering> at least, but I am not 
sure if we will ever expect piave to play and render at the same time - I am 
suspecting that we won't. So perhaps a more general <position time=""/> 
command would be better? I am unsure.

> and after the scene is played, I'll send:
>
>  <reply command="play" status="stopped" time="123.456"/>

Here, I think it is more clear-cut. If you can consider that piave can be 
"playing", it can be "rendering", and it can be "stopped", I think a more 
general   <currentStatus status="stopped"/> might make sense. 

But maybe not, since I cannot think of a reason why piave might start playing 
or rendering without kdenlive telling it to.

Perhaps the best reason for having a seperate statusChanged command is that 
the communication on the client side becomes cleaner - Instead of having to 
code "this is a reply to a play command, telling me it has finished", and 
"this is a reply to a render command, telling me it has finished", I would 
just have to code "Piave has finished whatever it was doing".

What do you think?

>
> Also play will start playing at a start point and till a stop:
>
>  <play speed="1.0" start="12.34" stop="23.45"/>

Ok, a few default values that I think make sense :

- If no start time is specified, piave should play from it's current seek 
position.

- If no stop time is specified, piave should play until the end of it's 
scenelist.

And keep in mind these use-cases that we might want to add later (I don't 
think they matter yet, but making sure that the VEML can handle them now 
means less work later):

* The user wishes to play in a loop the entire scenelist, starting from the 
beginning.
* The user wishes to play in a loop the entire scenelist, but starts playing 
somewhere in the middle of the loop.
* The user wishes to play some section of the scenelist, starting from an 
arbitrary location (which may start before the looped section)

For example on that last point : You have some intro footage before the main 
loop of footage. You want to check that the intro links seamlessly into the 
loop, and that the loop is seamless within itself. You haven't yet set this 
up on the timeline (I'm not sure how the looping of clips will work on the 
timeline yet, but it is planned functionality)

Cheers,
Jason

-- 
Jason Wood
Homepage : www.uchian.pwp.blueyonder.co.uk