docs/anime_video_model.md

# Anime Video Models

:white_check_mark: We add small models that are optimized for anime videos :-)<br>
More comparisons can be found in [anime_comparisons.md](anime_comparisons.md)

- [How to Use](#how-to-use)
- [PyTorch Inference](#pytorch-inference)
- [ncnn Executable File](#ncnn-executable-file)
  - [Step 1: Use ffmpeg to extract frames from video](#step-1-use-ffmpeg-to-extract-frames-from-video)
  - [Step 2: Inference with Real-ESRGAN executable file](#step-2-inference-with-real-esrgan-executable-file)
  - [Step 3: Merge the enhanced frames back into a video](#step-3-merge-the-enhanced-frames-back-into-a-video)
- [More Demos](#more-demos)

| Models                                                                                                                             | Scale | Description                    |
| ---------------------------------------------------------------------------------------------------------------------------------- | :---- | :----------------------------- |
| [realesr-animevideov3](https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.5.0/realesr-animevideov3.pth) | X4 <sup>1</sup>   | Anime video model with XS size |

Note: <br>
<sup>1</sup> This model can also be used for X1, X2, X3.

---

The following are some demos (best view in the full screen mode).

<https://user-images.githubusercontent.com/17445847/145706977-98bc64a4-af27-481c-8abe-c475e15db7ff.MP4>

<https://user-images.githubusercontent.com/17445847/145707055-6a4b79cb-3d9d-477f-8610-c6be43797133.MP4>

<https://user-images.githubusercontent.com/17445847/145783523-f4553729-9f03-44a8-a7cc-782aadf67b50.MP4>

## How to Use

### PyTorch Inference

```bash
# download model
wget https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.5.0/realesr-animevideov3.pth -P weights
# single gpu and single process inference
CUDA_VISIBLE_DEVICES=0 python inference_realesrgan_video.py -i inputs/video/onepiece_demo.mp4 -n realesr-animevideov3 -s 2 --suffix outx2
# single gpu and multi process inference (you can use multi-processing to improve GPU utilization)
CUDA_VISIBLE_DEVICES=0 python inference_realesrgan_video.py -i inputs/video/onepiece_demo.mp4 -n realesr-animevideov3 -s 2 --suffix outx2 --num_process_per_gpu 2
# multi gpu and multi process inference
CUDA_VISIBLE_DEVICES=0,1,2,3 python inference_realesrgan_video.py -i inputs/video/onepiece_demo.mp4 -n realesr-animevideov3 -s 2 --suffix outx2 --num_process_per_gpu 2
```

```console
Usage:
--num_process_per_gpu    The total number of process is num_gpu * num_process_per_gpu. The bottleneck of
                         the program lies on the IO, so the GPUs are usually not fully utilized. To alleviate
                         this issue, you can use multi-processing by setting this parameter. As long as it
                         does not exceed the CUDA memory
--extract_frame_first    If you encounter ffmpeg error when using multi-processing, you can turn this option on.
```

### NCNN Executable File

#### Step 1: Use ffmpeg to extract frames from video

```bash
ffmpeg -i onepiece_demo.mp4 -qscale:v 1 -qmin 1 -qmax 1 -vsync 0 tmp_frames/frame%08d.png
```

- Remember to create the folder `tmp_frames` ahead

#### Step 2: Inference with Real-ESRGAN executable file

1. Download the latest portable [Windows](https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.5.0/realesrgan-ncnn-vulkan-20220424-windows.zip) / [Linux](https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.5.0/realesrgan-ncnn-vulkan-20220424-ubuntu.zip) / [MacOS](https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.5.0/realesrgan-ncnn-vulkan-20220424-macos.zip) **executable files for Intel/AMD/Nvidia GPU**

1. Taking the Windows as example, run:

    ```bash
    ./realesrgan-ncnn-vulkan.exe -i tmp_frames -o out_frames -n realesr-animevideov3 -s 2 -f jpg
    ```

    - Remember to create the folder `out_frames` ahead

#### Step 3: Merge the enhanced frames back into a video

1. First obtain fps from input videos by

    ```bash
    ffmpeg -i onepiece_demo.mp4
    ```

    ```console
    Usage:
    -i                   input video path
    ```

    You will get the output similar to the following screenshot.

    <p align="center">
        <img src="https://user-images.githubusercontent.com/17445847/145710145-c4f3accf-b82f-4307-9f20-3803a2c73f57.png">
    </p>

2. Merge frames

    ```bash
    ffmpeg -r 23.98 -i out_frames/frame%08d.jpg -c:v libx264 -r 23.98 -pix_fmt yuv420p output.mp4
    ```

    ```console
    Usage:
    -i                   input video path
    -c:v                 video encoder (usually we use libx264)
    -r                   fps, remember to modify it to meet your needs
    -pix_fmt             pixel format in video
    ```

    If you also want to copy audio from the input videos, run:

     ```bash
    ffmpeg -r 23.98 -i out_frames/frame%08d.jpg -i onepiece_demo.mp4 -map 0:v:0 -map 1:a:0 -c:a copy -c:v libx264 -r 23.98 -pix_fmt yuv420p output_w_audio.mp4
    ```

    ```console
    Usage:
    -i                   input video path, here we use two input streams
    -c:v                 video encoder (usually we use libx264)
    -r                   fps, remember to modify it to meet your needs
    -pix_fmt             pixel format in video
    ```

## More Demos

- Input video for One Piece:

    <https://user-images.githubusercontent.com/17445847/145706822-0e83d9c4-78ef-40ee-b2a4-d8b8c3692d17.mp4>

- Out video for One Piece

    <https://user-images.githubusercontent.com/17445847/164960481-759658cf-fcb8-480c-b888-cecb606e8744.mp4>

**More comparisons**

<https://user-images.githubusercontent.com/17445847/145707458-04a5e9b9-2edd-4d1f-b400-380a72e5f5e6.MP4>