Try to build with CUDA support and FFmpeg4

Author: NicolasHug

.github/workflows/linux_cuda_wheel.yaml

@@ -68,7 +68,7 @@ jobs:
         python-version: ['3.9']
         cuda-version: ['11.8', '12.4', '12.6']
         # TODO: put back ffmpeg 5 https://github.com/pytorch/torchcodec/issues/325
-        ffmpeg-version-for-tests: ['6', '7']
+        ffmpeg-version-for-tests: ['4.4.2', '6', '7']
     container:
       image: "pytorch/manylinux2_28-builder:cuda${{ matrix.cuda-version }}"
       options: "--gpus all -e NVIDIA_DRIVER_CAPABILITIES=video,compute,utility"

src/torchcodec/decoders/_core/CMakeLists.txt

@@ -77,10 +77,7 @@ if(DEFINED ENV{BUILD_AGAINST_ALL_FFMPEG_FROM_S3})
     )
 
 
-    if(NOT ENABLE_CUDA)
-	    # TODO: Enable more ffmpeg versions for cuda.
-	    make_torchcodec_library(libtorchcodec4 ffmpeg4)
-	endif()
+	make_torchcodec_library(libtorchcodec4 ffmpeg4)
 	make_torchcodec_library(libtorchcodec7 ffmpeg7)
 	make_torchcodec_library(libtorchcodec6 ffmpeg6)
 	make_torchcodec_library(libtorchcodec5 ffmpeg5)