This will be a short post, and here I will show you how to fix cropped PAL video on the Eachine ProDVR. The ProDVR is probably the cheapest DVR on the market and works very well. However, it has for a long time had an issue where the bottom few lines would be removed from the picture if your system was using PAL. This is especially an issue if you have an OSD and want it to show up in your recordings. However, a new firmware has been released which fixes this issue, and this is how you use it.
Warning: Flashing new firmware risks bricking your DVR and I am not aware of any method to recover bricked DVRs. This process worked perfectly for me but I am not responsible if you brick your DVR attempting this.