notes.txt

# GPU acceleration for moviepy

1. Modify env\Lib\site-packages\moviepy\video\tools\drawing.py by adding:

import torch


def blit_gpu(im1, im2, pos=None, mask=None, ismask=False):
    device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")

    if pos is None:
        pos = [0, 0]

    xp, yp = pos
    x1 = max(0, -xp)
    y1 = max(0, -yp)
    h1, w1 = im1.shape[:2]
    h2, w2 = im2.shape[:2]
    xp2 = min(w2, xp + w1)
    yp2 = min(h2, yp + h1)
    x2 = min(w1, w2 - xp)
    y2 = min(h1, h2 - yp)
    xp1 = max(0, xp)
    yp1 = max(0, yp)

    if (xp1 >= xp2) or (yp1 >= yp2):
        return im2

    if not isinstance(im1, torch.Tensor):               # 5.43 ms per loop / 100 loops
        im1 = torch.tensor(im1, device=device)
    if not isinstance(im2, torch.Tensor):
        im2 = torch.tensor(im2, device=device)

    blitted = im1[y1:y2, x1:x2]

    new_im2 = im2.clone()

    if mask is None:
        new_im2[yp1:yp2, xp1:xp2] = blitted
    else:
        if not isinstance(mask, torch.Tensor):          # 2.71 ms per loop / 10 loops
            mask = torch.tensor(mask[y1:y2, x1:x2], device=device)  # 1.45 ms / 100 loops
        else:
            mask = mask[y1:y2, x1:x2]
        if len(im1.shape) == 3:
            mask = mask.unsqueeze(-1).repeat(1, 1, 3)
        blit_region = new_im2[yp1:yp2, xp1:xp2]
        new_im2[yp1:yp2, xp1:xp2] = (1.0 * mask * blitted + (1.0 - mask) * blit_region)

    return new_im2.cpu().numpy().astype("uint8") if not ismask else new_im2.cpu().numpy()   # 6.13 ms / 100 loops
    #return new_im2 if not ismask else new_im2



2. Modify  of env\Lib\site-packages\moviepy\video\VideoClip.py 

Add to the beginning of file:
from .tools.drawing import blit, blit_gpu


Replace line 565:
return blit_gpu(img, picture, pos, mask=mask, ismask=self.ismask)