On Thu, 7 Sep 2000, Alex Holden wrote: > the image and use the hardware JPEG compression. One possibility I was > wondering about was whether it might be possible to loop the internal > video output back to the internal video input, send the captions to the > video output, and use the overlay features of the 7110A to superimpose the > captions on the captured image? To reply to myself, it seems that while the 7110A and 36060 support the multiplexing of a second video source into a rectangular area within the primary capture area, the 36067 doesn't appear to have any way to generate the second source and spit it onto the video bus in sync with the capture of the primary source. Using a completely seperate encoder probably wouldn't work as the 71110A can't switch between two inputs rapidly enough to multiplex between two inputs within one frame (two seperate 7110A's on the same bus could do it though). However, I have discovered that the 36067 has support for DMAing RGB data from system RAM and filtering it through the 36060- using it as a hardware JPEG accelerator. So what I could do, and admittedly this isn't an ideal solution but it should be faster than doing the compression in software, is to capture in RGB format to a contigous buffer, draw the captions to the buffer (a user space program could mmap() the buffer to get to it and orchestrate the process using ioctl()s), then feed the data back through the 36067 and 36060 to compress it. Are there any obvious flaws I've missed? Any suggestions on a suitable API? -- --------------- Linux- the choice of a GNU generation. -------------- : Alex Holden (M1CJD)- Caver, Programmer, Land Rover nut, Radio Ham : -------------------- http://www.linuxhacker.org/ --------------------
