https://github.com/adzialocha/it8951-video
Play videos on IT8951-controlled e-paper displays
https://github.com/adzialocha/it8951-video
epaper it8951 usb video waveshare-epaper
Last synced: 8 months ago
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Play videos on IT8951-controlled e-paper displays
- Host: GitHub
- URL: https://github.com/adzialocha/it8951-video
- Owner: adzialocha
- Created: 2022-11-14T17:32:11.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2023-06-02T15:11:40.000Z (about 3 years ago)
- Last Synced: 2025-07-01T15:12:52.374Z (11 months ago)
- Topics: epaper, it8951, usb, video, waveshare-epaper
- Language: Rust
- Homepage:
- Size: 4.2 MB
- Stars: 8
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# it8951-video
Play videos on IT8951-controlled e-paper displays via USB. This has been tested with a [Waveshare 7.8inch e-Paper HAT](https://www.waveshare.com/wiki/7.8inch_e-Paper_HAT) display.
## Design
This runs fairly smooth considering it is a e-Paper display (~5 fps) which has not been optimized for video usage. The following "tricks" have been used:
* Convert every video frame into an image which only contains black or white pixels (via dithering)
* Pack pixel information for every frame into 1bit (black = 0, white = 1) and store it in a file so it can be played later (don't do this on-the-fly as the dithering process takes too much time)
* Activate undocumented 1bpp (1 bit per pixel) and "pitch" mode on IT8951 by flipping the bits in the `0x1800_1138` register before displaying
* Store frame data via "fast write" (fw) `0xa5` command in memory
* Since the data is smaller now (322944 bytes) than grayscale images we can store up to 8 frames in the image buffer (which usually only has space for one image)
* Always write in `A2` mode since it is fast and does not cause any flashing with b/w-only data. Use `GL16` mode sometimes, just to make sure the ghosting does not minder the quality too much
## Requirements
* ffmpeg
* Rust
## Preparation
In order to make this work you need to create a udev rule that gives users permission to talk to this device. To this end add a file 60-it8951.rules to the `/etc/udev/rules.d` directory with the following contents:
```
SUBSYSTEM=="usb", ATTRS{idVendor}=="048d", MODE="0666"
```
This gives applications access to talk to devices by vendor "048d", which is the IT8951. You can then restart your system, or by write this to trigger without reboot:
```
udevadm control --reload-rules && udevadm trigger
```
## Usage
```
Play videos on IT8951-controlled e-paper displays
USAGE:
it8951-video [OPTIONS]
FLAGS:
--help Prints help information
-V, --version Prints version information
OPTIONS:
-v, --vcom VCOM value [default: -1.58]
-g, --ghost Paint in GL16 mode every nth frame [default: 32]
-t, --take Only take every nth frame from video [default: 5]
-w, --width Width of video on display [default: 1856]
-h, --height Height of video on display [default: 1392]
ARGS:
Video file which will be displayed
```
## Credits
* [@bspth](https://github.com/bspth) for finding almost every hack which made this work at all
* https://github.com/faassen/rust-it8951 for the SCSI over USB communication with IT8951