mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2026-08-10 17:14:41 +00:00
a234fc1130
When loading a TorchScript model that does not contain any learnable
parameters (e.g., a purely functional model), the Torch backend would
crash during inference. This occurred because the code attempted to
dereference the first iterator of the model's parameter list
`parameters().begin()` to determine the device, which results in
Undefined Behavior when the parameter list is empty.
This commit fixes the issue by determining the inference device directly
from the user-configured `ctx->device` string instead of probing the
model parameters, allowing parameterless models to execute safely.
Testing:
1. Generate a parameterless model:
cat << 'EOF' > generate_model.py
import torch
class DummyModel(torch.nn.Module):
def forward(self, x):
return x
scripted_model = torch.jit.script(DummyModel())
scripted_model.save("dummy_model.pt")
EOF
python3 generate_model.py
2. Run inference (previously crashed, now succeeds):
./ffmpeg -y -i input.mp4 -vf 'format=rgb24,dnn_processing=dnn_backend=torch:model=dummy_model.pt' -frames:v 5 -f null -
Signed-off-by: Raja Rathour <imraja729@gmail.com>