[Live-devel] LiveMedia in a Directshow Filter

[Yuri Timenkov]

BTW,

On 01.12.2010 7:18, Ross Finlayson wrote:
>> >while(true)
>> >{
>> >       fWatchVariable = 0;
>> >       dummyTask(NULL); // 100ms
>> >       env->taskScheduler().doEventLoop(&fWatchVariable);
>> >       if (fWatchVariable = 1)
This statement looks very strange: is it still assignment instead of 
comparison in your code? What is it supposed to be?
>> >       {
>> >             printf("\nIn While fWatchVariable=%d,",fWatchVariable);
>> >             if (!mP4LiveSms->mpeg4LiveSource != NULL)
>> >                               
>> mP4LiveSms->mpeg4LiveSource->deliverFrame();
>> >       }
>> >}
>
> [...]
>
>>  1)  How should I call deliverFrame() from the Main thread(DS Graph 
>> in a Filter) in order to signal my FramedSource that a new frame is 
>> arrived.
>
> You don't!  "deliverFrame()" - being a LIVE555 library operation - 
> should be called only from the LIVE555 event loop thread - not from 
> some other thread.
>
> However, what you *can* do in the non-LIVE555 thread (i.e., your 
> 'DirectShow' thread) is set "fWatchVariable" to 1.  If you do this, 
> then the LIVE555 event loop (your code above) will notice this, and do 
> the right thing, calling "deliverFrame()".
>
>
>> 3) Question about the parameters : fPresentationTime, 
>> fDurationInMicroseconds what exactly they mean.
>>   fPresentationTime Is the different between sample(frame) start and 
>> Stop - in my received filter -> pSample->GetTime(&tStart, &tStop);?
>
> In most situations, you can just set "fPresentationTime" by calling 
> "gettimeofday()".  You should do this inside your "deliverFrame()" 
> function (which is called from the LIVE555 event loop thread, of course).
>
>
>>   fDurationInMicroseconds - How do I set this parameter?
>
> In principle, it should be set to the duration between successive 
> frames (that you deliver using "deliverFrame()").
>
> However, because you are streaming from a live source, rather than 
> from a file, it's probably OK to leave this variable unset (in which 
> case, it'll get a default value of 0).