And finally, I think it will be a dual processor.... but I am wondering if the time has come for one processor to be optimized for stills and the other processor optimized for video.
That's an interesting thought. I guess it depends on the frame rate. If they only bump up to 10fps, I think a single DIGIC7 could handle it (easily...with room to spare for a whole ton of other stuff). That would be ESPECIALLY if they move the ADC onto the sensor die and make it column parallel. They do have a patent for CP-ADC with a Dual-Scale Ramp ADC (the dual-scale just allows the ADC to operate at different rates based on some trigger factor...say sensor heat...more heat, higher noise, slower readout, less noise...switch from high speed readout to low speed readout when possible under higher heat, and you could counteract the increase in dark current noise...I have no idea what the trigger factor would be to switch from the higher speed to the lower speed or vice versa in an actual product, though.) Parallelizing ADC and putting that logic on the die also reduces load in the DIGIC itself...it would then solely be responsible for digital pixel processing, in which case a DIGIC 7 that has no ADC units could theoretically have even more processing power than a DIGIC 7 that did include the ADC units. So instead of being 7x faster than a DIGIC 6, it might end up being 12x or 14x faster.
If you had one of those dedicated to stills/af/metering, and one dedicated to video, you could really do a hell of a lot with the video. Canon should be able to surpass what the Bionz X in the A7s does easily, achieving ultra low noise ISO 400k, maybe even 800k.
Every so often there needs to be a "reset"
It happened in lenses when AF started to come out. Canon took the brave step of completely redesigning the interface to handle the requirements of digital communication between lens and body and we jumped from FD to EOS... this might be the time for a similar jump on the inside of the camera.
15 years ago, the innards of digital cameras were a collection of ic's with specific functions and the communication between them was both complex and at the same time, fairly limited. At the moment, Canon is doing a major redesign to fit DPAF onto it's sensors and presumably, onto a smaller fabrication technique. This gives us four big possibilities on the sensors. First, with less wasted surface area, the amount of captured light goes up and with that, so does the performance. The second one is with smaller fabrication comes smaller transistors and that means shorter electrical paths and that gives us higher speed. Third is that with smaller transistors and lower voltages, we get less heat, and that means lower noise and longer battery life. Fourth is that with smaller transistors the a/d can be integrated into the sensor and that gives us less noise and a cleaner design.
With all the analog confined to the sensor, one can now communicate digitally between the sensor, processor(s), display devices, and storage medium(s). Gigabyte per second transfer rates are easy to achieve.
15 years ago, there was no video on DSLRs.... now it is a standard feature.... yet we have the same general purpose DIGIC doing both..... it might be time for a split into a dedicated stills processor and a dedicated video processor.
This could be the time for a "reset" of the internal architecture of the Canon DSLRs.....