Dear David! 1) correct, The App does not do that. 2) True; DSound can ( and in some cases will ) insert "silence pack" ( buffer with 0's ) into stream, so, driver may receive such 0 packs from "nowhere". Wave driver will never do that. It should not be a problem for you, just ignore this packs and continue search for the spdif header key-word. Microsoft is slowly going to the idea with never stopping audio on PC; that means, they will never fix this for you (I mean silence insertion) Nick Gorokhov --- david lee <davidlioncity@xxxxxxxxxxxx> wrote: > Dear Nick, > > Yes, I do agree with what you said. Okay, It is better to give an example to > > clarify the situation what I met. Basically, I get one SPDIF package, for > example, 6144bytes for AC3 data, by call GetMapping. However, by following > GetMapping call, I get all zero data and there is no any SPDIF header for > these data. Thus: > 1) These data are sent by Applications. But it looks like impossible because > all data sent by application will be packaged, which means that I will get > SPDIF Header. > Either, > 2) DSound insert these data. But I really cannot understand why DSound will > insert these data. According to DDK documents, if portclass do not have > enough data send to miniport driver, it will > repeat the buffer which it holds. Therefore, I should not get all these zero > data while the repeated buffer. > > BTW Can any application guys or Microsfot guys give comments? > > David > > Nick Gorohov <engkosha2001@xxxxxxxxx> wrote: > Dear David! > > I am Audio Filter designer at Sonic ( www.sonic.com ). > Yes, we do that with SPDIF: the beginning is real portion > of the spdif data ( the real amount is in data header), > the rest filled with 0's. The trick is that a whole pack > of data has the same number of audiosamples that > unencrypted ( PCM ) pack will have. So, can ignore all > these 0's. > > Regards, > > Nick Gorokhov > > > --- david lee wrote: > > > Dear Stephan, > > > > In fact, I set theConnectionInterface.Id =NULL, then what is the default > > value. > > > > According to what you say, as long as I update the position, the port class > > will send more valid data to me. Am I correct? > > > > Thanks > > Stephan Kappertz wrote: > > You should check the pins ConnectionInterface.Id when the pin is created. > > Most likely the ConnectionInterface is > KSINTERFACE_STANDARD_LOOPED_STREAMING. > > This means that your driver receives just one valid circular buffer when > > playback starts. It is supposed to loop through this buffer until playback > > stops. The current DMA position that your driver reports will be used to > > update the portion of the circular buffer with new data that is currently > NOT > > played. > > > > Stephan > > > > > > > > -----Ursprüngliche Nachricht----- > > Von: wdmaudiodev-bounce@xxxxxxxxxxxxx > > [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] Im Auftrag von david lee > > Gesendet: Monday, October 11, 2004 11:35 AM > > An: wdmaudiodev@xxxxxxxxxxxxx > > Betreff: [wdmaudiodev] DirectSound and PowerDVD/WinDVD Strange behavior > > > > > > Dear all, > > > > When I use PowerDVD/WinDVD SPDIF pass through and select direct sound audio > > render, I always get a lot of zero data with a few valid data in the > > beginning of playback. Due to use driver to decode the AC3/DTS data, I am > not > > sure how to handle these zero data. Any suggestion? (Treat them as data > need > > to be decoded or as rubbish and discarded) > > > > BTW, if I select waveout audio render, All the data at the beginning are > > useful valid data,which I can decode. > > > > Thanks in advance > > > > David > > > > Yahoo! Mobile > > - Download the latest ringtones, games, and more! > > > > Yahoo! Mobile > > - Download the latest ringtones, games, and more! > > > > > _______________________________ > Do you Yahoo!? > Declare Yourself - Register online to vote today! > http://vote.yahoo.com > ****************** > > WDMAUDIODEV addresses: > Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx > Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe > Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe > Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx > > URL to WDMAUDIODEV page: > http://www.wdmaudiodev.de/ > > > Yahoo! Mobile > - Download the latest ringtones, games, and more! _______________________________ Do you Yahoo!? Declare Yourself - Register online to vote today! http://vote.yahoo.com ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.de/