OverflowError: value too large to convert to int8_t about chaquopy HOT 7 CLOSED

I gather from the ftrobopy examples that getCameraFrame returns a list of integers ranging from 0 to 255. Unfortunately, Java represents bytes using the range -128 to 127 instead.

You can work around this by replacing frame in the decodeByteArray call with:

[(x if x < 128 else x - 256) for x in frame]

Chaquopy should really be able to deal with this when converting a bytes or bytearray object to a Java byte[], so I'll make sure that's fixed in a future version. Then you'll be able to just do bytes(frame), which should have much better performance.

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That fixed the error! Thanks so much for the quick answer!
By the way, I am now getting a black screen once camera data comes in. Any fix for that (I presume it has to do with my while true loop)?

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Unfortunately I'm not familiar with either ftrobopy or BitmapFactory. But perhaps you could try narrowing the problem down by trying to load and display a known image from a file?

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The problem is the loop IMO, is there a known way to do a "main loop" with chaquopy?
EDIT: Confirmed, it works with a normal image outside the loop, if I insert the "while true", I also get a black screen.

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Oh right, I see what you mean. This issue isn't specific to Chaquopy, you've just got to fit into Android's event-driven model, and not block the main thread.

Try using Handler.postDelayed to schedule a callback. There's an example of how to create a Runnable in the Python API documentation. Then every time it calls you back, you can call it again to schedule the next update.

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Works like a charm! Thanks!

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Continued in #41.

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