torchcodec not compatible with brew-installed ffmpeg

[aliberts]

🐛 Describe the bug

Torchcodec doesn't work if ffmpeg was installed using brew.

Reproduction (on an ARM Mac):

# Setup
brew install ffmpeg
conda create -y -n torchcodec python=3.10 && conda activate torchcodec
pip install torch torchvision torchaudio torchcodec

# This will fail
python -c "import torchcodec;" 

Traceback

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/__init__.py", line 10, in <module>
    from . import decoders, samplers  # noqa
  File "/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/decoders/__init__.py", line 7, in <module>
    from ._core import VideoStreamMetadata
  File "/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/decoders/_core/__init__.py", line 8, in <module>
    from ._metadata import (
  File "/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/decoders/_core/_metadata.py", line 15, in <module>
    from torchcodec.decoders._core.video_decoder_ops import (
  File "/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/decoders/_core/video_decoder_ops.py", line 59, in <module>
    load_torchcodec_extension()
  File "/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/decoders/_core/video_decoder_ops.py", line 44, in load_torchcodec_extension
    raise RuntimeError(
RuntimeError: Could not load libtorchcodec. Likely causes:
          1. FFmpeg is not properly installed in your environment. We support
             versions 4, 5, 6 and 7.
          2. The PyTorch version (2.6.0) is not compatible with
             this version of TorchCodec. Refer to the version compatibility
             table:
             https://github.com/pytorch/torchcodec?tab=readme-ov-file#installing-torchcodec.
          3. Another runtime dependency; see exceptions below.
        The following exceptions were raised as we tried to load libtorchcodec:
        
[start of libtorchcodec loading traceback]
dlopen(/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/libtorchcodec7.dylib, 0x0006): Library not loaded: @rpath/libavutil.59.dylib
  Referenced from: <1066133A-B772-3E91-BB2F-2B124F1C5CC6> /opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/libtorchcodec7.dylib
  Reason: tried: '/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/lib-dynload/../../libavutil.59.dylib' (no such file), '/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/bin/../lib/libavutil.59.dylib' (no such file)
dlopen(/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/libtorchcodec6.dylib, 0x0006): Library not loaded: @rpath/libavutil.58.dylib
  Referenced from: <3DE0F4A5-8F38-3AD7-BB75-7BA53C57F543> /opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/libtorchcodec6.dylib
  Reason: tried: '/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/lib-dynload/../../libavutil.58.dylib' (no such file), '/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/bin/../lib/libavutil.58.dylib' (no such file)
dlopen(/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/libtorchcodec5.dylib, 0x0006): Library not loaded: @rpath/libavutil.57.dylib
  Referenced from: <E6431CF6-E34F-339E-BDB3-F660A1161AE7> /opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/libtorchcodec5.dylib
  Reason: tried: '/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/lib-dynload/../../libavutil.57.dylib' (no such file), '/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/bin/../lib/libavutil.57.dylib' (no such file)
dlopen(/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/libtorchcodec4.dylib, 0x0006): Library not loaded: @rpath/libavutil.56.dylib
  Referenced from: <45D49A90-22F9-3CBE-93E1-D1CB8E3E21E1> /opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/site-packages/torchcodec/libtorchcodec4.dylib
  Reason: tried: '/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/lib/python3.10/lib-dynload/../../libavutil.56.dylib' (no such file), '/opt/homebrew/Caskroom/miniconda/base/envs/torchcodec/bin/../lib/libavutil.56.dylib' (no such file)
[end of libtorchcodec loading traceback].

Since it doesn't appear in the specs below, I'll add that the version of ffmpeg installed by brew is 7.1.1.

Could be related to #265. Not super blocking as it does work normally if ffmpeg is installed with conda as instructed in the README.

In any case, thank you for this awesome work! 🙏

Versions

PyTorch version: 2.6.0
Is debug build: False
CUDA used to build PyTorch: None
ROCM used to build PyTorch: N/A

OS: macOS 15.3.1 (arm64)
GCC version: Could not collect
Clang version: 16.0.0 (clang-1600.0.26.6)
CMake version: version 3.31.4
Libc version: N/A

Python version: 3.10.16 (main, Dec 11 2024, 10:22:29) [Clang 14.0.6 ] (64-bit runtime)
Python platform: macOS-15.3.1-arm64-arm-64bit
Is CUDA available: False
CUDA runtime version: No CUDA
CUDA_MODULE_LOADING set to: N/A
GPU models and configuration: No CUDA
Nvidia driver version: No CUDA
cuDNN version: No CUDA
HIP runtime version: N/A
MIOpen runtime version: N/A
Is XNNPACK available: True

CPU:
Apple M3 Pro

Versions of relevant libraries:
[pip3] numpy==2.2.4
[pip3] torch==2.6.0
[pip3] torchaudio==2.6.0
[pip3] torchvision==0.21.0
[conda] numpy 2.2.4 pypi_0 pypi
[conda] torch 2.6.0 pypi_0 pypi
[conda] torchaudio 2.6.0 pypi_0 pypi
[conda] torchcodec 0.2.1 pypi_0 pypi
[conda] torchvision 0.21.0 pypi_0 pypi

[jrabary]

Same here. I'm using uv instead of conda and uv add ffmpeg doesn't solve the issue

[yongjincho]

Same error here. I'm also using uv.

[traversaro]

My guess is that due to rpath and dynamic loader settings, the loader only looks for ffmpeg in conda-related paths, not on homebrew. Just to understand, what is the use case of installing ffmpeg via homebrew while python via conda/conda-forge? I imagine that the python installed by homebrew has the rpath correctly set to find homebrew-installed libraries.

[c-salomonsen]

I had the same issue on similar specs. By setting DYLD_FALLBACK_LIBRARY_PATH to the homebrew library directory, you circumvent the issue.

export DYLD_FALLBACK_LIBRARY_PATH=/opt/homebrew/lib

Hope this helps!

[namgyaaal]

I had trouble getting the export DYLD_FALLBACK_LIBRARY_PATH solution to work with Jupyter notebook and found a hackish workaround to get it working on vscode jupyter:

On your uv project, go to .venv/lib/python<VERSION>/site-packages/torchcodec

Based on the number of libavutil.5X.dylib, match with the number in the error message and do the following:

install_name_tool -add_rpath /opt/homebrew/Cellar/ffmpeg/<VERSION>/lib libtorchcodec_decoder<NUMBER>.dylib
install_name_tool -add_rpath /opt/homebrew/Cellar/ffmpeg/<VERSION>/lib libtorchcodec_custom_ops<NUMBER>.dylib
install_name_tool -add_rpath /opt/homebrew/Cellar/ffmpeg/<VERSION>/lib libtorchcodec_pybind_ops<NUMBER>.so

codesign --force -s - libtorchcodec_decoder<NUMBER>.dylib
codesign --force -s - libtorchcodec_custom_ops<NUMBER>.dylib
codesign --force -s - libtorchcodec_pybind_ops<NUMBER>.so

it should work after this.

[enricd]

In my case, doing the export of the homebrew lib path didn't work and had to uninstall torchcodec to use torchaudio, and luckily the huggingface pipeline I'm trying to run works now with it

[guynich]

For the export DYLD_FALLBACK_LIBRARY_PATH workaround: this section describes a workflow to build the needed library of FFMPEG version 7 - tested on macOS.

[eduardobeattie]

I had trouble getting the export DYLD_FALLBACK_LIBRARY_PATH solution to work with Jupyter notebook and found a hackish workaround to get it working on vscode jupyter:

On your uv project, go to .venv/lib/python<VERSION>/site-packages/torchcodec

Based on the number of libavutil.5X.dylib, match with the number in the error message and do the following:

install_name_tool -add_rpath /opt/homebrew/Cellar/ffmpeg//lib libtorchcodec_decoder.dylib
install_name_tool -add_rpath /opt/homebrew/Cellar/ffmpeg//lib libtorchcodec_custom_ops.dylib
install_name_tool -add_rpath /opt/homebrew/Cellar/ffmpeg//lib libtorchcodec_pybind_ops.so

codesign --force -s - libtorchcodec_decoder.dylib
codesign --force -s - libtorchcodec_custom_ops.dylib
codesign --force -s - libtorchcodec_pybind_ops.so
it should work after this.

Thank you so much!!!! This fix worked for me after spending ages trying to get it to work.

[just-maiyak]

Hi !
I had the same problem with nix, using a nix development shell. Even though it's not the same package manager, I'm posting what helped me in case anyone else needs it. You should add the DYLD_FALLBACK_LIBRARY_PATH env variable, here what it looks like in my flake :

{
  ...
  outputs = { self, nixpkgs } : 
  {
    devShells.default = nixpkgs.mkShell {
      name = ...;
      buildInputs = with pkgs; [];
      DYLD_FALLBACK_LIBRARY_PATH = "${pkgs.ffmpeg.lib}/lib";
    }
  }
}