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.