On Thu, Sep 15, 2011 at 6:20 PM, Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > Hi Cliff, > > On Wednesday 14 September 2011 08:13:32 Cliff Cai wrote: >> Dear guys, >> >> I'm currently working on a camera/ISP Linux driver project.Of course,I >> want it to be a V4L2 driver,but I got a problem about how to design >> the driver framework. >> let me introduce the background of this ISP(Image signal processor) a >> little bit. >> 1.The ISP has two output paths,first one called main path which is >> used to transfer image data for taking picture and recording,the other >> one called preview path which is used to transfer image data for >> previewing. >> 2.the two paths have the same image data input from sensor,but their >> outputs are different,the output of main path is high quality and >> larger image,while the output of preview path is smaller image. >> 3.the two output paths have independent DMA engines used to move image >> data to system memory. >> >> The problem is currently, the V4L2 framework seems only support one >> buffer queue,and in my case,obviously,two buffer queues are required. >> Any idea/advice for implementing such kind of V4L2 driver? or any >> other better solutions? > > Your driver should create two video nodes, one for each stream. They will each > have their own buffers queue. > > The driver should also implement the media controller API to let applications > discover that the video nodes are related and how they interact with the ISP. Hi Laurent, As "Documentation/media-framework" says, one of the goals of media device model is "Discovering a device internal topology,and configuring it at runtime".I'm just a bit confused about how applications can discover the related video notes? Could you explain it a little more? Thanks a lot! Cliff -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
