Hi Bastian, On Monday 30 May 2011 23:39:13 Bastian Hecht wrote: > 2011/5/30 Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>: > > On Sunday 29 May 2011 15:27:23 Bastian Hecht wrote: > >> Hello Laurent, > >> > >> I'm on to a project that needs two synced separate small cameras for > >> stereovision. > >> > >> I was thinking about realizing this on an DM3730 with 2 aptina csi2 > >> cameras that are used in snapshot mode. > > > > As far as I know, the DM3730 doesn't have CSI2 interfaces. > > If I don't mix up datasheets, it is stated very clearly that 2 csi2 > interfaces are supported. I took the datasheet at > http://www.ti.com/litv/pdf/sprugn4k declared as AM/DM37x Multimedia > Device Technical Reference Manual (Silicon Revision 1.x) (Rev. K) > (PDF 26851 KB). > "The camera ISP implements three receivers which are named CSI2A, > CSI1/CCP2B, and CSI2C. The CSI2A and CSI2C are MIPI D-PHY CSI2 > compatible." on page 1070. Chapter 6 starts with the following disclaimer: "NOTE: This chapter gives information about all modules and features in the high-tier device. To check availability of modules and features, see Section 1.5, AM/DM37x Family, and the device-specific data manual. In unavailable modules and features, the memory area is reserved, read is undefined, and write can lead to unpredictable behavior." And if you look at table 1-3 on page 195, the CSI2 receivers are not supported. > >> The questions that arise are: > >> > >> - is the ISP driver capable of running 2 concurrent cameras? > > > > Yes it can, but only one of them can use the CCDC, preview engine and > > resizer. The other will be captured directly to memory as raw data. You > > could capture both raw streams to memory, and then feed them > > alternatively through the rest of the pipeline. Whether this can work > > will depend on the image size and frame rate. > > Ok I will check if it is sufficient to do any conversions on the cpu. > > >> - is it possible to simulate a kind of video stream that is externally > >> triggered (I would use a gpio line that simply triggers 10 times a > >> sec) or would there arise problems with the csi2 protocoll (timeouts > >> or similar)? > > > > I don't think there will be CSI2 issues (although I'm not an expert > > there) if you trigger the sensors externally. > > Nice, when the ISP side is probably no problem - do you have any > experience with snapshot mode and know if cameras are capable of doing > it at framerates about 10fps? It is just because snapshot mode sounds > like taking 1 frame every now and then... can't they call it "trigger > mode"? :) I haven't personally tried it, but 10fps doesn't sound impossible to reach with external triggers. -- Regards, Laurent Pinchart -- 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
