Andrey, > the most likely reason (proved by the steady fps regardless of the frame > size) is the exposure time. Obviously the frame rate can not be higher > than 1/exposure time, so please check that - in the camera GUI the frame
makes sense > rate (the rate sensor currently operates at) is shown in different > colors, depending on the source of the limitation. You may slightly > decrease the required exposure time by increasing analog gain(s) I see. is there a non-HTML-UI way to set these values? > Potentially there can be several bottlenecks in the camera: > > 1 - exposure time makes sense, and obvious to understand. > 2 - sensor limitations - for each frame dimensions, decimation and > binning and operation mode (free running/ triggered) there is a certain > minimal frame period. sure, this is something beyond my control I guess > 3 - camera FPGA - in JPEG mode it can compress 53MPix/sec (average, peak > can go higher), in JP4 mode - 80MPix/sec. Sensor gets up to ~75MPix sec > (average) at the full frame, lower at smaller ones. So in JPEG mode only > with the largest frames it can be an issue, in JP4 - never. thanks for the info. I'll try to play around with these modes. BTW, what is JP4 mode? :) > 4 - bandwidth of the network - up to full 10 megabytes/second over > 100mbps network, when you hit that limit you can try lowering the > compression quality with the same frame size/rate. the camera is connected directly to my laptop, so I guess I'm doing 100mb/s. but yes, this can already be a bottleneck. (BTW, wouldn't it be better if the camera came with a gigabit ethernet port?) > 5 - similarly - HDD bandwidth, it is approximately 16MB/sec, limited by > the ETRAX FS CPU, improving results when lowering compression quality > can be an indicator. Additionally if the HDD has large directory with > files (best performance is achieved with simple *.mov files and large > limits on the file segment) there could be frame drops when opening a > new file segment - the camera videobuffer fro the compressed frames is > 19MB, so you can calculate the time that the file system has to > close/open file. I don't have an HDD attached. I'll try to play around these, as soon as I can de-brick my camera (see my latest e-mail) Akos _______________________________________________ Support-list mailing list [email protected] http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com
