My approach to a custom, fully graphic OSD for analog video without using special hardware.
Some time ago I got annoyed by the available OSD solutions and I started to look for alternatives. Nowadays small micro controllers are fast enough and include fancy features like DMA so that the OSD generation can be handled in software. I selected a STM32F3 due to the availability in small packages and the necessary features I needed and got working.
The result:
- Fully opensource
- Very high update rates
- Full graphic overlays and animations
- Custom, nice font (can be changed)
- Currently showing 35 chars in 13 lines
- "Multi-color": up to eight levels of gray on the screen
- Configurable global brightness and "blackness" setting
In addition I also release the hardware design of a reference implementation that also includes a RTC6705 vide transmitter chip: see https://github.com/fishpepper/tinyFINITY
Please refer to my blogpost for more details: https://fishpepper.de/2019/03/11/tinyosd-tinyfinity-a-tiny-opensource-video-tx-with-full-graphic-osd