Neucrack

It'a bug in V4 kmodel, I'll fix tomorrow

fixed at https://github.com/sipeed/MaixPy/commit/20c776d8f13b50309af0af7f4fe47920d64e844a thanks~

```python success = kpu.set_outputs(kput_net, out_idx, width, height, channel) ``` maybe you should call `kpu.set_outputs(task, 0, 1,1,2)` ? Which means first output layer has two node

- [x] bug: can not play record avi video, solved - [x] bug: some player can not play video recorded by maixpy, resolved, for no audio data but audio header...

https://dl.sipeed.com/MAIX/MaixPy/release/master/maixpy_v0.5.0_124_g92d9c04 

@zyx-dev upload failed, but you can customize your firmware here: https://www.maixhub.com/compile.html

compile your firmware follow the build.md, remove the module you don't need, and try to reduce the lcd resolution  and if you can kmodel V3, just use V3, and...

 

you can set rgb_gain_db mannually by `sensor.set_auto_whitebal(False, rgb_gain_db=(0x52,0x40,0x4d))`

but it's better done in firmware with proper values, we havent dig into it