| --- |
| license: mit |
| library_name: dempeg2 |
| pipeline_tag: image-to-image |
| tags: |
| - video-restoration |
| - mpeg2 |
| - dvd |
| - compression-artifact-removal |
| --- |
| |
| # dempeg2 weights for Avatar: The Last Airbender |
|
|
| Weights for [dempeg2](https://github.com/seproDev/dempeg2), which removes MPEG-2 artefacts. |
| Besides the decoded picture, it reads what the MPEG-2 stream says about how each frame was compressed: the quantiser of |
| every macroblock, the macroblock types, and the frame type. |
|
|
| **These weights are only for the NTSC DVDs of Avatar: The Last Airbender.** |
| They were trained to undo two encoders: the one used for most NA discs (probably a Sony hardware encoder), and Cinema |
| Craft Encoder (used for the Book 1 Vol 1 reissue and Book 3 Vol 3-4). |
| On anything else (other shows, other encoders, PAL, live action) they are untested and probably wrong. |
|
|
| Comparisons: [slow.pics](https://slow.pics/c/aC8xE9pb) |
|
|
| ## What they do |
|
|
| The model only aims to remove MPEG-2 artefacts: ringing, mosquito noise, block edges, and colour blotches. |
| Film grain that the encoder dropped in P and B frames is restored, so the grain no longer pulses with every GOP. |
|
|
| There is no sharpening and no invented detail. |
| Problems that come from the master, such as halos and the chroma shift of the NA discs, are kept on purpose. |
| The training taught the model to leave these alone, so they can be fixed separately. |
|
|
| ## Model |
|
|
| A NAFNet-style U-Net with 27M parameters. |
| Each frame is processed on its own, together with 15 planes of side information and a noise input for grain. |
|
|
| Training started with an MSE loss on clean Blu-ray animation, encoded to look like the ATLA DVDs. |
| A GAN fine-tune of 16k steps followed. |
| During the fine-tune, a penalty stopped the model from adding a block pattern, without punishing random grain. |
|
|
| `model.safetensors` holds the weights in fp16. The model config is stored in the file's metadata. |
|
|
| More details, measurements, and limits: [docs/model.md](https://github.com/seproDev/dempeg2/blob/main/docs/model.md). |
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|
