[FFmpeg-devel] [PATCH] avutil/hwcontext_cuda: check that the SDK defines cuCtxGetCurrent()

[Timo Rothenpieler]

On 01.10.2023 04:06, James Almer wrote:
> Fixes compilation after 05f8b2ca0f7e28775837a572c65ce9218f534ee2

It's expected behaviour to break compilation with random inter-release 
versions of ffnvcodec.
It's only reliable exactly on release versions.

I had planned to draw a release of the headers right after, but then my 
PC started to eat files for a yet unknown reason, and I need to figure 
that out first.

A workaround for this would be to check for the existence of 
cuCtxGetCurrent in configure. But there were multiple instances of this 
exact thing in the past, and everyone agreed that it's just expected 
behaviour with development versions of both parts.

> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
>   libavutil/hwcontext_cuda.c          | 4 ++++
>   libavutil/hwcontext_cuda_internal.h | 9 +++++++++
>   2 files changed, 13 insertions(+)
> 
> diff --git a/libavutil/hwcontext_cuda.c b/libavutil/hwcontext_cuda.c
> index 0312d3b9d7..4f55f6441d 100644
> --- a/libavutil/hwcontext_cuda.c
> +++ b/libavutil/hwcontext_cuda.c
> @@ -362,10 +362,14 @@ static int cuda_context_init(AVHWDeviceContext *device_ctx, int flags) {
>           if (ret < 0)
>               return ret;
>       } else if (flags & AV_CUDA_USE_CURRENT_CONTEXT) {
> +#if NVDECAPI_CHECK_VERSION(12, 1)
>           ret = CHECK_CU(cu->cuCtxGetCurrent(&hwctx->cuda_ctx));
>           if (ret < 0)
>               return ret;
>           av_log(device_ctx, AV_LOG_INFO, "Using current CUDA context.\n");
> +#else
> +        return AVERROR(ENOSYS);
> +#endif
>       } else {
>           ret = CHECK_CU(cu->cuCtxCreate(&hwctx->cuda_ctx, desired_flags,
>                                          hwctx->internal->cuda_device));
> diff --git a/libavutil/hwcontext_cuda_internal.h b/libavutil/hwcontext_cuda_internal.h
> index d5633c58d5..fe0963b4e5 100644
> --- a/libavutil/hwcontext_cuda_internal.h
> +++ b/libavutil/hwcontext_cuda_internal.h
> @@ -28,6 +28,15 @@
>    * FFmpeg internal API for CUDA.
>    */
>   
> +#if defined(NVDECAPI_MAJOR_VERSION) && defined(NVDECAPI_MINOR_VERSION)
> +# define NVDECAPI_CHECK_VERSION(major, minor) \
> +    ((major) < NVDECAPI_MAJOR_VERSION || ((major) == NVDECAPI_MAJOR_VERSION && (minor) <= NVDECAPI_MINOR_VERSION))
> +#else
> +/* version macros were added in SDK 8.1 ffnvcodec */
> +# define NVDECAPI_CHECK_VERSION(major, minor) \
> +    ((major) < 8 || ((major) == 8 && (minor) <= 0))
> +#endif
> +
>   struct AVCUDADeviceContextInternal {
>       CudaFunctions *cuda_dl;
>       int is_allocated;