[linux-dvb] Re: How to build a DSM-CC objectcarousel with a predefined moduleorganization?

[Marek Pikarski <mass@linuxtv.org>]

Hi!

TRAN THUONG Tien wrote:

> Dear Marek Pikarski,
> I’m a newbie iTV application developer based on DVB-MHP. I have 
> developed some application MHP in the mode “resident application”. I’d 
> like now to test my application in the mode of “downloaded 
> application”. So I’m finding now the tools to encode my applications 
> and theirs resources in DSM-CC Objectcarousel for broadcasting. I have 
> found then your tools, and have compiled successfully. I’m very glad 
> and am studying your tools. Thank you very much!
> In fact, I’d like to build the DSM-CC objectcarousels following the 
> predefined module organizations that allow to create the DSM-CC 
> objectcarousels more effective for transporting the resources and 
> using the resources in application. Does your dsmcc-oc tool allow 
> doing that?
Well, here some basic explanations:
The ServiceGateway module of the ObjectCarousel only includes the whole 
directory structure of the broadcasted filesystem,
so that all objects are known and can be requested by the client, i.e. a 
client can mount the ObjectCarousel as fast as possible.
Then, all other modules include files and other objects. These objects 
are put into modules as long as the module's size does
not exceed 64kb, i.e. these modules include multiple objects. Objects 
with a size >64kb are put into single modules.

> I see with the command “dsmcc-oc.exe –help” the tool will accept only 
> a directory as an input.
Yes, basically it encodes a filesystem hierarchy.
But, for more performance, I recently added the '-exp' option which 
allow people to build ObjectCarousels consisting of
multiple DataCarousels. Since each generated DataCarousel gets 
broadcasted on its own PID, each one can be broadcasted
with a different rate.
For example, you can generate a seperate DataCarousel from a 'pictures' 
subdirectory of the ObjectCarousel's root, which
only includes pictures. And you can broadcast this DataCarousel with 
whatever rate you want to do.

> Thank you in advance for your replies,
> Best regards,
> Tien
Cheers, Marek