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by AceJohnny2 4111 days ago
I worked on camera drivers for mobile phone SoCs 5 years ago. Back then a strong constraint that separated "video" from "picture" was that we didn't have enough memory bandwidth to stream uncompressed "picture"-sized frames at "video" framerate.

Google's Camera2 API no longer presents that distinction.

Funny how things change, that's my personal experience with Moore's law.

Another problem we had is that we'd developed flexible OpenMAX-compliant modules to expose the hardware's capabilities, following Nokia's requirements. We tried pushing those to Google whose APIs back then were much more limited. They (as far as I knew back then) didn't care.

Again, funny how things change...
1 comments
supercurio 4111 days ago
Yes with devices implementing fully Camera2, the rule is that you can stream full resolution sensor data to buffers that you can capture and save either for processing (like HDR & superresolution) or video recording :)

At that time, was the viewfinder preview built on full sensor readout or line-skipped/binned sensor readout?

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AceJohnny2 4111 days ago
Yes, the new API makes much more sense. I'm just surprised and a bit disappointed it took so long to come about :(. I was always disappointed by the capabilities of production phones compared to what we could do in dev, but of course, in dev we didn't have all the constraints of running alongside the rest of the OS and only using the vendor's APIs!

As for your question, I'm rusty on the details. I definitely remember binning was used for some use-cases. For viewfinder, our hardware pipeline would generate a lower-resolution stream from the full-resolution stream used for encoding.

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supercurio 4111 days ago
Yes and one reason it took so much time might be the same reason why there's the risk Camera2 might stay a Nexus-only thing.

Manufacturers like keeping camera features, UI and processing exclusive to their devices, which is one thing encourages brand loyalty. The most users will rely on a favorite third party app, the more likely they might switch to another brand on their next device.

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