bugs/ffmpeg-missing-in-docker.md

===== Application Startup at 2026-04-30 20:39:02 =====

INFO: Started server process [1]
INFO: Waiting for application startup.
INFO: Application startup complete.
INFO: Uvicorn running on http://0.0.0.0:7860 (Press CTRL+C to quit)
INFO: 10.16.29.229:48249 - "GET / HTTP/1.1" 200 OK
INFO: 10.16.29.229:48249 - "GET /style.css HTTP/1.1" 200 OK
INFO: 10.16.27.106:43311 - "GET /app.js HTTP/1.1" 200 OK
INFO: 10.16.1.210:19952 - "GET / HTTP/1.1" 200 OK
INFO: 10.16.27.106:32925 - "GET / HTTP/1.1" 200 OK
INFO: 10.16.1.210:19952 - "GET /app.js HTTP/1.1" 200 OK
INFO: 10.16.12.5:48186 - "GET /style.css HTTP/1.1" 200 OK
INFO: 10.16.29.229:21750 - "GET / HTTP/1.1" 304 Not Modified
INFO: 10.16.12.5:9327 - "GET /style.css HTTP/1.1" 304 Not Modified
INFO: 10.16.42.153:28833 - "GET /app.js HTTP/1.1" 304 Not Modified
Selected model is a bag of 4 models. You will see that many progress bars per track.
Separated tracks will be stored in /app/separated/mdx_extra
Separating track backend/uploads/95de5fce-3cb8-4cc9-b15b-66625179b0ac.mp3
Could not load file backend/uploads/95de5fce-3cb8-4cc9-b15b-66625179b0ac.mp3. Maybe it is not a supported file format?
When trying to load using ffmpeg, got the following error: FFmpeg is not installed.
When trying to load using torchaudio, got the following error: Could not load libtorchcodec. Likely causes: 1. FFmpeg is not properly installed in your environment. We support
versions 4, 5, 6, 7, and 8, and we attempt to load libtorchcodec
for each of those versions. Errors for versions not installed on
your system are expected; only the error for your installed FFmpeg
version is relevant. On Windows, ensure you've installed the
"full-shared" version which ships DLLs. 2. The PyTorch version (2.11.0+cu130) 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]
FFmpeg version 8:
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1503, in load_library
ctypes.CDLL(path)
File "/usr/local/lib/python3.11/ctypes/**init**.py", line 376, in **init**
self.\_handle = \_dlopen(self.\_name, mode)
^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libavutil.so.60: cannot open shared object file: No such file or directory

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torchcodec/\_internally_replaced_utils.py", line 93, in load_torchcodec_shared_libraries
torch.ops.load_library(core_library_path)
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1505, in load_library
raise OSError(f"Could not load this library: {path}") from e
OSError: Could not load this library: /usr/local/lib/python3.11/site-packages/torchcodec/libtorchcodec_core8.so

FFmpeg version 7:
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1503, in load_library
ctypes.CDLL(path)
File "/usr/local/lib/python3.11/ctypes/**init**.py", line 376, in **init**
self.\_handle = \_dlopen(self.\_name, mode)
^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libavutil.so.59: cannot open shared object file: No such file or directory

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torchcodec/\_internally_replaced_utils.py", line 93, in load_torchcodec_shared_libraries
torch.ops.load_library(core_library_path)
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1505, in load_library
raise OSError(f"Could not load this library: {path}") from e
OSError: Could not load this library: /usr/local/lib/python3.11/site-packages/torchcodec/libtorchcodec_core7.so

FFmpeg version 6:
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1503, in load_library
ctypes.CDLL(path)
File "/usr/local/lib/python3.11/ctypes/**init**.py", line 376, in **init**
self.\_handle = \_dlopen(self.\_name, mode)
^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libavutil.so.58: cannot open shared object file: No such file or directory

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torchcodec/\_internally_replaced_utils.py", line 93, in load_torchcodec_shared_libraries
torch.ops.load_library(core_library_path)
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1505, in load_library
raise OSError(f"Could not load this library: {path}") from e
OSError: Could not load this library: /usr/local/lib/python3.11/site-packages/torchcodec/libtorchcodec_core6.so

FFmpeg version 5:
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1503, in load_library
ctypes.CDLL(path)
File "/usr/local/lib/python3.11/ctypes/**init**.py", line 376, in **init**
self.\_handle = \_dlopen(self.\_name, mode)
^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libavutil.so.57: cannot open shared object file: No such file or directory

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torchcodec/\_internally_replaced_utils.py", line 93, in load_torchcodec_shared_libraries
torch.ops.load_library(core_library_path)
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1505, in load_library
raise OSError(f"Could not load this library: {path}") from e
OSError: Could not load this library: /usr/local/lib/python3.11/site-packages/torchcodec/libtorchcodec_core5.so

FFmpeg version 4:
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1503, in load_library
ctypes.CDLL(path)
File "/usr/local/lib/python3.11/ctypes/**init**.py", line 376, in **init**
self.\_handle = \_dlopen(self.\_name, mode)
^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libavutil.so.56: cannot open shared object file: No such file or directory

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torchcodec/\_internally_replaced_utils.py", line 93, in load_torchcodec_shared_libraries
torch.ops.load_library(core_library_path)
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1505, in load_library
raise OSError(f"Could not load this library: {path}") from e
OSError: Could not load this library: /usr/local/lib/python3.11/site-packages/torchcodec/libtorchcodec_core4.so
[end of libtorchcodec loading traceback].
INFO: 10.16.1.210:41571 - "POST /upload HTTP/1.1" 500 Internal Server Error
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/uvicorn/protocols/http/h11_impl.py", line 415, in run_asgi
result = await app( # type: ignore[func-returns-value]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/uvicorn/middleware/proxy_headers.py", line 56, in **call**
return await self.app(scope, receive, send)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/fastapi/applications.py", line 1159, in **call**
await super().**call**(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/applications.py", line 90, in **call**
await self.middleware_stack(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/middleware/errors.py", line 186, in **call**
raise exc
File "/usr/local/lib/python3.11/site-packages/starlette/middleware/errors.py", line 164, in **call**
await self.app(scope, receive, \_send)
File "/usr/local/lib/python3.11/site-packages/starlette/middleware/cors.py", line 96, in **call**
await self.simple_response(scope, receive, send, request_headers=headers)
File "/usr/local/lib/python3.11/site-packages/starlette/middleware/cors.py", line 154, in simple_response
await self.app(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/middleware/exceptions.py", line 63, in **call**
await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/\_exception_handler.py", line 53, in wrapped_app
raise exc
File "/usr/local/lib/python3.11/site-packages/starlette/\_exception_handler.py", line 42, in wrapped_app
await app(scope, receive, sender)
File "/usr/local/lib/python3.11/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in **call**
await self.app(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/routing.py", line 660, in **call**
await self.middleware_stack(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/routing.py", line 680, in app
await route.handle(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/routing.py", line 276, in handle
await self.app(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/fastapi/routing.py", line 134, in app
await wrap_app_handling_exceptions(app, request)(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/\_exception_handler.py", line 53, in wrapped_app
raise exc
File "/usr/local/lib/python3.11/site-packages/starlette/\_exception_handler.py", line 42, in wrapped_app
await app(scope, receive, sender)
File "/usr/local/lib/python3.11/site-packages/fastapi/routing.py", line 120, in app
response = await f(request)
^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/fastapi/routing.py", line 674, in app
raw_response = await run_endpoint_function(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/fastapi/routing.py", line 328, in run_endpoint_function
return await dependant.call(\*\*values)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/backend/main.py", line 33, in upload_audio
output_path = run_demucs(save_path)
^^^^^^^^^^^^^^^^^^^^^
File "/app/backend/demucs_runner.py", line 6, in run_demucs
subprocess.run(
File "/usr/local/lib/python3.11/subprocess.py", line 571, in run
raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['demucs', '--two-stems=vocals', '-n', 'mdx_extra', 'backend/uploads/95de5fce-3cb8-4cc9-b15b-66625179b0ac.mp3']' returned non-zero exit status 1.
Selected model is a bag of 4 models. You will see that many progress bars per track.
Separated tracks will be stored in /app/separated/mdx_extra
Separating track backend/uploads/1790a01f-024d-49ec-be3a-8ce76c16601a.mp3
Could not load file backend/uploads/1790a01f-024d-49ec-be3a-8ce76c16601a.mp3. Maybe it is not a supported file format?
When trying to load using ffmpeg, got the following error: FFmpeg is not installed.
When trying to load using torchaudio, got the following error: Could not load libtorchcodec. Likely causes: 1. FFmpeg is not properly installed in your environment. We support
versions 4, 5, 6, 7, and 8, and we attempt to load libtorchcodec
for each of those versions. Errors for versions not installed on
your system are expected; only the error for your installed FFmpeg
version is relevant. On Windows, ensure you've installed the
"full-shared" version which ships DLLs. 2. The PyTorch version (2.11.0+cu130) 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]
FFmpeg version 8:
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1503, in load_library
ctypes.CDLL(path)
File "/usr/local/lib/python3.11/ctypes/**init**.py", line 376, in **init**
self.\_handle = \_dlopen(self.\_name, mode)
^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libavutil.so.60: cannot open shared object file: No such file or directory

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torchcodec/\_internally_replaced_utils.py", line 93, in load_torchcodec_shared_libraries
torch.ops.load_library(core_library_path)
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1505, in load_library
raise OSError(f"Could not load this library: {path}") from e
OSError: Could not load this library: /usr/local/lib/python3.11/site-packages/torchcodec/libtorchcodec_core8.so

FFmpeg version 7:
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1503, in load_library
ctypes.CDLL(path)
File "/usr/local/lib/python3.11/ctypes/**init**.py", line 376, in **init**
self.\_handle = \_dlopen(self.\_name, mode)
^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libavutil.so.59: cannot open shared object file: No such file or directory

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torchcodec/\_internally_replaced_utils.py", line 93, in load_torchcodec_shared_libraries
torch.ops.load_library(core_library_path)
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1505, in load_library
raise OSError(f"Could not load this library: {path}") from e
OSError: Could not load this library: /usr/local/lib/python3.11/site-packages/torchcodec/libtorchcodec_core7.so

FFmpeg version 6:
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1503, in load_library
ctypes.CDLL(path)
File "/usr/local/lib/python3.11/ctypes/**init**.py", line 376, in **init**
self.\_handle = \_dlopen(self.\_name, mode)
^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libavutil.so.58: cannot open shared object file: No such file or directory

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torchcodec/\_internally_replaced_utils.py", line 93, in load_torchcodec_shared_libraries
torch.ops.load_library(core_library_path)
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1505, in load_library
raise OSError(f"Could not load this library: {path}") from e
OSError: Could not load this library: /usr/local/lib/python3.11/site-packages/torchcodec/libtorchcodec_core6.so

FFmpeg version 5:
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1503, in load_library
ctypes.CDLL(path)
File "/usr/local/lib/python3.11/ctypes/**init**.py", line 376, in **init**
self.\_handle = \_dlopen(self.\_name, mode)
^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libavutil.so.57: cannot open shared object file: No such file or directory

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torchcodec/\_internally_replaced_utils.py", line 93, in load_torchcodec_shared_libraries
torch.ops.load_library(core_library_path)
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1505, in load_library
raise OSError(f"Could not load this library: {path}") from e
OSError: Could not load this library: /usr/local/lib/python3.11/site-packages/torchcodec/libtorchcodec_core5.so

FFmpeg version 4:
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1503, in load_library
ctypes.CDLL(path)
File "/usr/local/lib/python3.11/ctypes/**init**.py", line 376, in **init**
self.\_handle = \_dlopen(self.\_name, mode)
^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libavutil.so.56: cannot open shared object file: No such file or directory

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/torchcodec/\_internally_replaced_utils.py", line 93, in load_torchcodec_shared_libraries
torch.ops.load_library(core_library_path)
File "/usr/local/lib/python3.11/site-packages/torch/\_ops.py", line 1505, in load_library
raise OSError(f"Could not load this library: {path}") from e
OSError: Could not load this library: /usr/local/lib/python3.11/site-packages/torchcodec/libtorchcodec_core4.so
[end of libtorchcodec loading traceback].
INFO: 10.16.12.5:6739 - "POST /upload HTTP/1.1" 500 Internal Server Error
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/uvicorn/protocols/http/h11_impl.py", line 415, in run_asgi
result = await app( # type: ignore[func-returns-value]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/uvicorn/middleware/proxy_headers.py", line 56, in **call**
return await self.app(scope, receive, send)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/fastapi/applications.py", line 1159, in **call**
await super().**call**(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/applications.py", line 90, in **call**
await self.middleware_stack(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/middleware/errors.py", line 186, in **call**
raise exc
File "/usr/local/lib/python3.11/site-packages/starlette/middleware/errors.py", line 164, in **call**
await self.app(scope, receive, \_send)
File "/usr/local/lib/python3.11/site-packages/starlette/middleware/cors.py", line 96, in **call**
await self.simple_response(scope, receive, send, request_headers=headers)
File "/usr/local/lib/python3.11/site-packages/starlette/middleware/cors.py", line 154, in simple_response
await self.app(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/middleware/exceptions.py", line 63, in **call**
await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/\_exception_handler.py", line 53, in wrapped_app
raise exc
File "/usr/local/lib/python3.11/site-packages/starlette/\_exception_handler.py", line 42, in wrapped_app
await app(scope, receive, sender)
File "/usr/local/lib/python3.11/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in **call**
await self.app(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/routing.py", line 660, in **call**
await self.middleware_stack(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/routing.py", line 680, in app
await route.handle(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/routing.py", line 276, in handle
await self.app(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/fastapi/routing.py", line 134, in app
await wrap_app_handling_exceptions(app, request)(scope, receive, send)
File "/usr/local/lib/python3.11/site-packages/starlette/\_exception_handler.py", line 53, in wrapped_app
raise exc
File "/usr/local/lib/python3.11/site-packages/starlette/\_exception_handler.py", line 42, in wrapped_app
await app(scope, receive, sender)
File "/usr/local/lib/python3.11/site-packages/fastapi/routing.py", line 120, in app
response = await f(request)
^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/fastapi/routing.py", line 674, in app
raw_response = await run_endpoint_function(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/fastapi/routing.py", line 328, in run_endpoint_function
return await dependant.call(\*\*values)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/backend/main.py", line 33, in upload_audio
output_path = run_demucs(save_path)
^^^^^^^^^^^^^^^^^^^^^
File "/app/backend/demucs_runner.py", line 6, in run_demucs
subprocess.run(
File "/usr/local/lib/python3.11/subprocess.py", line 571, in run
raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['demucs', '--two-stems=vocals', '-n', 'mdx_extra', 'backend/uploads/1790a01f-024d-49ec-be3a-8ce76c16601a.mp3']' returned non-zero exit status 1.
INFO: 10.16.29.229:14043 - "GET / HTTP/1.1" 304 Not Modified
INFO: 10.16.27.106:61337 - "GET / HTTP/1.1" 200 OK
INFO: 10.16.12.5:29961 - "GET /app.js HTTP/1.1" 304 Not Modified
INFO: 10.16.42.153:39129 - "GET /style.css HTTP/1.1" 304 Not Modified