hi developers I am working on an android program to control an external hardware and process camera images in the real time. The hardware interface is an IOIO (http://www.sparkfun.com/products/10585). It controls an LED array to turn on and off. The software captures images from the camera using setPreviewCallbackWithBuffer() and store a few image frames per LED state. The camera thread and IOIO thread communicate by wait/notify.
Unfortunately, I found that the saved camera frames are not synchronized with the IOIO pin status; I can only get synchronized images when I insert a Thread.sleep(delay>250) between toggling the IOIO pins and signaling camera to start saving data. At first, I suspected that this was caused by the communication latency on the IOIO side. But per IOIO's author, Ytai Ben-Tsvi, this is way too long compared to the expected latency (1~4ms), see http://groups.google.com/group/ioio-users/browse_thread/thread/f81f057bda73c525?hl=en If IOIO is ruled out, I now start questioning if there is a delay when the onPreviewFrame() is triggered. Is there a way to quantify the latency of the onPreviewFrame callbacks? The surfaceview seems to get updated very quickly, but I don't know how fast a displayed frame can be passed to onPreviewFrame() for processing. Any android documents discuss about this? Qianqian -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
