View topic - MultiMedia Interface (6.2.1) questions

MultiMedia Interface (6.2.1) questions

Read-only archive of qnx.rtos (Writing resources managers, and general discussion around the QNX Neutrino RTOS) at inn.qnx.com

MultiMedia Interface (6.2.1) questions

Postby phearbear » Sun Jan 11, 2004 3:49 am

Hi everyone

I'm developing a filter for the MultiMedia interface (6.2.1) and I have
a few questions:

1) In AOStreamInspector 'RateStream', am I allowed to call 'Sniff' more
then once? I want to do this as a small hack to minimize my changes to
the mediaparsing library i'm using...

2) In AOExtInspector, what format does the extension come in?
(.myext or myext?)

Also,there seems to be a bug in the documentation,
AOAudioFormat_t->depth seems to be in BYTES, not BITS as the
documentation claim.

I also tried to write a small utility that printed out the resources of
every availible plugin, not sure if I did it the right way, attached my
program, any comments on that one would be great.
It results in FPE for several plugins when I call their GetResources()
function. And the window_writer.so crash my test utility unless I
PtInit()'ed.

Thanks in advance

/Johan Björk
phearbear
QNX Master
 
Posts: 110
Joined: Fri Jul 05, 2002 11:44 pm

Re: MultiMedia Interface (6.2.1) questions

Postby Angelo Pennacchioli » Thu Jan 15, 2004 5:57 pm

Hi, Johan


"Johan Björk" <phearbear@home.se> wrote in message
news:btqfp8$sbs$1@inn.qnx.com...
Hi everyone

I'm developing a filter for the MultiMedia interface (6.2.1) and I have
a few questions:

1) In AOStreamInspector 'RateStream', am I allowed to call 'Sniff' more
then once? I want to do this as a small hack to minimize my changes to
the mediaparsing library i'm using...

As long as you don't call streamer->read(),
you can call streamer->Sniff() as many times as you want.




2) In AOExtInspector, what format does the extension come in?
(.myext or myext?)
..myext


Also,there seems to be a bug in the documentation,
AOAudioFormat_t->depth seems to be in BYTES, not BITS as the
documentation claim.

You are right.
the docs will be corrected.

I also tried to write a small utility that printed out the resources of
every availible plugin, not sure if I did it the right way, attached my
program, any comments on that one would be great.
It results in FPE for several plugins when I call their GetResources()
function. And the window_writer.so crash my test utility unless I
PtInit()'ed.

the window_writer.so filter has a photon dependency and
needs the widget library initialized.

Your program is OK.
Your use of the api is correct.
I have to check why some of the filters are FPE ing.

Regards,
Angelo.


Thanks in advance

/Johan Björk



----------------------------------------------------------------------------
----


#include <stdio.h
#include <mmedia/mmedia.h


int main()
{
int32_t cookie=0;
AOResourceAccess *ras;
AOResource_t *res;
AODeConstructor *constructor;
AOICtrl_t *ctrl;
void *ctx;
int n=0;

PtInit(NULL);
MmInitialize(NULL);

while(ctrl = AoIterate(NULL,0,&cookie)) {
AoHold(ctrl);

constructor =
AoGetInterface(ctrl,"AODeConstructor",AODECONSTRUCTOR_VERSION,0);
if(constructor)
ctx = constructor->Create(NULL);
else
ctx=NULL;

if(ras =
AoGetInterface(ctrl,"AOResourceAccess",AORESOURCEACCESS_VERSION,0))
{
if(res=ras->GetResources(ctx))
{
for(;res->name;res++)
{
fprintf(stderr,"%s\n",res->name);
}
}
n++;
}
AoRelease(ctrl);
}


}
Angelo Pennacchioli
 

Re: MultiMedia Interface (6.2.1) questions

Postby phearbear » Fri Jan 16, 2004 8:28 am

Hi

"Angelo Pennacchioli" <apennacchioli@qnx.com> skrev i meddelandet
news:bu6ivf$5a2$1@inn.qnx.com...
Hi, Johan


"Johan Björk" <phearbear@home.se> wrote in message
news:btqfp8$sbs$1@inn.qnx.com...
Hi everyone

I'm developing a filter for the MultiMedia interface (6.2.1) and I have
a few questions:

1) In AOStreamInspector 'RateStream', am I allowed to call 'Sniff' more
then once? I want to do this as a small hack to minimize my changes to
the mediaparsing library i'm using...

As long as you don't call streamer->read(),
you can call streamer->Sniff() as many times as you want.

Excellent!





2) In AOExtInspector, what format does the extension come in?
(.myext or myext?)
.myext
Oups, great to know that, It'd be neat if the docs would mention this!



Also,there seems to be a bug in the documentation,
AOAudioFormat_t->depth seems to be in BYTES, not BITS as the
documentation claim.

You are right.
the docs will be corrected.
Neato


I also tried to write a small utility that printed out the resources of
every availible plugin, not sure if I did it the right way, attached my
program, any comments on that one would be great.
It results in FPE for several plugins when I call their GetResources()
function. And the window_writer.so crash my test utility unless I
PtInit()'ed.

the window_writer.so filter has a photon dependency and
needs the widget library initialized.

Your program is OK.
Your use of the api is correct.
I have to check why some of the filters are FPE ing.

Great! Please keep me updated on this if possible.
phearbear
QNX Master
 
Posts: 110
Joined: Fri Jul 05, 2002 11:44 pm


Return to qnx.rtos

Who is online

Users browsing this forum: No registered users and 1 guest