Then again AVStream has lots of stuff implemented already there is less writing, but yes more thinking (read breaking your head). BUT when you figure it out everything looks very clean and simple. Anyway if you'll write AVStream driver you'll have to read older drivers docs also (well not everything) as some things are just upgrades. In short: AVStream hides a lot of stuff from you, so you don't need to bother with them. Waldemar MG> This is exactly what I've been doing. MG> If you want to talk to a 1394 device, you have to make your own IRPsand send them to the MG> 1394 stack. You will find examples on how to dothis in the 1394 samples. Compuware's MG> DriverWorks also has usefulsample code for talking to 1394. MG> To expose your hardware as an audio device, you need to create a kernelstreaming filter. MG> You can try using portclass miniports (like MSVAD)or AVStream. There's also the older stream MG> class stuff, but you'd bebetter off with AVStream. MG> Portclass is an older model and doesn't handle surprise removal aswell. AVStream is MG> cleaner, but there is no good example code forbuilding an audio driver. Portclass is perhaps MG> quirkier, but muchbetter documented. MG> Both AVC.sys and 61883.sys weren't useful for our purposes. AVC.sysdoesn't support audio MG> formats. 61883.sys didn't give me enoughcontrol over the streaming. MG> Matt MG> John D. Farmer wrote: MG> Greetings, MG> MG> I'm new to Audio driver developmentand still pretty new to driver development in MG> general. I am working ona project that needs to stream audio data down to the 1394 Bus, MG> viaAVC.sys and 61883.sys. The overall propose of my project is to supportFirewire hardware that MG> will implement the IEC-61883-6 standard (whichMicrosoft says they were going to support, but MG> which I have yet to seesupported). I am guessing I am in need of a upper filter driver totake MG> care of the passing down audio data through the AV/C stack (inplace of the avcaudio.sys which I MG> cannot find on my system but found inthe documentation as: Kernel-Mode WDM Audio Components MG> subsection:AVCAudio Class System Driver) and another driver below avc.sys to beable to package MG> the audio data up into the 61883-6 standard format onits way down to the 1394 bus (since I do MG> not believe that 61883.sysdoes not yet support the 61883-6 standard). MG> MG> I have been perusing thedocumentation and this list and there seems to be alot of MG> confusion tome on which way would be best to do this. I started by trying to useMSVAD (which I MG> believe is a Port Class driver), but then I noticed thatMSVAD does not seem to handle IRPs or MG> anything else that would allow meto send data down to the 1394 bus. I looked at the MSDN docs MG> and theysaid that Port Class drivers could not be used for this purpose. I tooka look at MG> this list, and it seems a number of people have been able todo this by implementing their own MG> IRPs and URBs (in the case of USB). I've taken note of this and noticed that it seems to be MG> extremelydifficult to do, and probably not the best way to handle this problem. MG> MG> I then started to lookat the AVStream and Stream class drivers. The AVStream overview MG> onMSDN that it is a: "multimediaclass driver that supports video-only streaming and MG> integratedaudio/video streaming." So does this mean that I cannot use AVStreamto stream MG> audio-only? My last option was the Stream class driver whichthe MSDN docs seem to suggest that MG> these driver are almost if nottotally deprecated. MG> MG> I also looked at AV/C Client driver(which I think is a Stream Minidriver) as a option, MG> and it seemed to bealmost what I wanted, but the documentation says that the avcstream.sysplays MG> a part in the AV/C stack, my big problem with this is: I can'tfind avcstream.sys on my system MG> (I'm running Windows XP) see: IEC-61883Protocol Driver in a Client Driver Stack in the MSDN MG> documentation. AmI correct in assuming that avcstream.sys handles the AV/C Audio subunit? MG> MG> So as you can probably tell, I am alittle lost and confused on this subject. If there is MG> anyone out therewho could give this newbie a little guidance, I would be in youreternal debt. MG> MG> Thanks, MG> MG> John Farmer MG> ******************WDMAUDIODEV addresses:Post message: MG> mailto:wdmaudiodev@xxxxxxxxxxxxxxxxxxxxxx: MG> mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribeUnsubscribe: MG> mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribeModerator: MG> mailto:wdmaudiodev-moderators@xxxxxxxxxxxxxxxx to WDMAUDIODEV page:http://www.wdmaudiodev.de/ ****************** 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/