Datamosh: MPEG Compression Artifacts Shader

Datamosh is a post-processing shader that recreates the visual artifacts associated with corrupted MPEG-style video compression. Instead of traditional visual enhancement, the shader deliberately introduces macroblock displacement, color quantization, chroma reconstruction errors, and edge artifacts to emulate the appearance of damaged or mispredicted P-frames. The result is a constantly shifting image where sections of the scene appear to borrow data from the wrong locations, producing a convincing datamosh-inspired aesthetic during gameplay.

This shader solves a specific creative problem: how to bring the signature look of corrupted digital video into a real-time 3D environment. It is not intended for players who want clean graphics or improved performance. Rather, it serves content creators, glitch art enthusiasts, and anyone seeking a surreal, cursed visual experience. The shader works best for making Minecraft footage look like a corrupted VHS tape or a broken streaming feed, giving builds and scenes an unnatural, unstable feel.

Key features include:

• Macroblock Motion Corruption – The image is divided into 8x8 pixel blocks that periodically drift or jump to incorrect screen positions, mimicking misplaced I-frame data.
• Color Quantization – Reduces the color palette in certain areas to create banding and false contours, typical of low-bitrate compression.
• Chroma Reconstruction Errors – Shifts color information out of alignment with brightness data, causing rainbow fringes and bleeding edges.
• Delta-Frame Prediction Artifacts – Simulates faulty motion vectors that leave ghost trails or torn geometry behind moving objects.
• Edge Artifacts – Introduces blocky ringing and mosquito noise around high-contrast borders, especially on text and item frames.

Requirements: Datamosh requires OptiFine (with shader support) or an Iris-compatible mod loader for Minecraft 1.17+. It runs on integrated graphics but may drop below 30 FPS on low-end hardware due to the extra per-pixel calculations. The shader is not suitable for players with photosensitive epilepsy, as the rapid block shifts can trigger flickering. It is also incompatible with other post-processing shaders and will override existing compositing effects. Note that the visual distortion is intentional and permanent while active; this is not a debugging tool or a temporary glitch effect.