Hi, I am going to start a new monitoring system, in which digital camera will be deplyed. I have very pretty good experience in term linux kernel, and device drivers and have developed a couple of drivers (char, and nic). Here are some domains that I need help, any comments will be appriciated:
1)How linux handle video devices; any special DMA practice involved, document, example etc.
2)The monitor sequences will be stored in a data base server; which kind server is appropriate for this kind app? why? any related development tool? Thanks in advance
Regarding the database server, we need more information about the embedded linux system and the data management requirements to provide any intelligent recommendations. For starters: How much memory does the system have? What CPU & clock speed? Is there any spinning media, or FLASH, or neither? What are the performance requirements?
BTW, generally speaking, storing digital images in a database is not generally done - a database adds little or no value compared to storing the images on the file system (assuming there is one) with a reference to the image in the database along with any other meta data (date, time, location, etc).
My first thought is that the monitors are controlled by individual embedded linux. The sequnces a re selectively transferred to a server. The server could be a super box, I mean I may assume that it have "sufficient" CPU power. The ideal case the files will be backed up on tapes. The reason to store the sequence in a database is to make search esier. A web server could be provided at the same time to allow a client to search the sequence data base on certain caracteristics.
...still don't have enough information to really make a recommendation.
What can be said is this: There are a wide variety of "embedded" database vendors that offer Linux solutions. The technology varies remarkably from multi-megabyte footprint client/server SQL disk-based solutions like Solid, MySQL, etc., to ultra small footprint (as little as 50K), truly embedded (i.e. linked with your application, not a client/server architecture) in-memory solutions.
The performance varies as widely as the footprint and architectures.
The choice for you will hinge on the capability of the embedded Linux hardware. If you've got the memory and CPU horsepower and a disk, and aren't concerned about very high performance, than a combination of MySQL and Apache could do.
On the other hand, if there is no disk, little memory, and/or a modest CPU and performance is a concern, then you'll want something light and fast and that can run in-memory (with the ability to stream the database image somewhere for backup) with an integrated embedded web server, such as my company's eXtremeDB.
And, of course, there is a whole range of possibilities in-between for which there are other suitable database solutions.
Without specific information about the hardware capabilities and what you want to do with the data, it is not possible to make a more specific recommendation.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.