From a62c5ab691d409c69bd55ede8ae73aeef6d5d0f5 Mon Sep 17 00:00:00 2001
From: Oleg Dobkin <olegd@anyvision.co>
Date: Sun, 17 Nov 2019 16:32:45 +0200
Subject: [PATCH] Allow using primary CUDA device context
Add AVCUDADeviceContextFlags to control the creation of CUDA device
context for the hardware CUDA decoder.
The current values are 0 (default behavior) - new context will be
created for each decoder, and 1 - primary CUDA context will be used.
There are several reasons for using primary device context instead of
creating a new one:
- This is the recommended way to handle device contexts (see
https://docs.nvidia.com/cuda/cuda-driver-api/group__CUDA__CTX.html#group__CUDA__CTX_1g65dc0012348bc84810e2103a40d8e2cf)
- Memory allocations, kernels and other state are associated with the
current device context. Currently, the context is not accessible from
FFmpeg API, so, technically, the memory created by the hardware decoder
(the video frame) can't be safely read.
Signed-off-by: Oleg Dobkin <olegd@anyvision.co>
---
libavutil/hwcontext_cuda.c | 22 +++++++++++++++++-----
libavutil/hwcontext_cuda_internal.h | 2 ++
2 files changed, 19 insertions(+), 5 deletions(-)
@@ -29,6 +29,8 @@
#define CUDA_FRAME_ALIGNMENT 256
+#define USE_PRIMARY_CONTEXT 1
+
typedef struct CUDAFramesContext {
int shift_width, shift_height;
} CUDAFramesContext;
@@ -281,8 +283,12 @@ static void cuda_device_uninit(AVHWDeviceContext *device_ctx)
if (hwctx->internal) {
CudaFunctions *cu = hwctx->internal->cuda_dl;
if (hwctx->internal->is_allocated && hwctx->cuda_ctx) {
- CHECK_CU(cu->cuCtxDestroy(hwctx->cuda_ctx));
+ if (hwctx->internal->flags & USE_PRIMARY_CONTEXT)
+ CHECK_CU(cu->cuDevicePrimaryCtxRelease(hwctx->internal->cuda_device));
+ else
+ CHECK_CU(cu->cuCtxDestroy(hwctx->cuda_ctx));
hwctx->cuda_ctx = NULL;
+ hwctx->internal->cuda_device = NULL;
}
cuda_free_functions(&hwctx->internal->cuda_dl);
}
@@ -322,7 +328,6 @@ static int cuda_device_create(AVHWDeviceContext *device_ctx,
{
AVCUDADeviceContext *hwctx = device_ctx->hwctx;
CudaFunctions *cu;
- CUdevice cu_device;
CUcontext dummy;
int ret, device_idx = 0;
@@ -338,18 +343,25 @@ static int cuda_device_create(AVHWDeviceContext *device_ctx,
if (ret < 0)
goto error;
- ret = CHECK_CU(cu->cuDeviceGet(&cu_device, device_idx));
+ ret = CHECK_CU(cu->cuDeviceGet(&hwctx->internal->cuda_device, device_idx));
if (ret < 0)
goto error;
- ret = CHECK_CU(cu->cuCtxCreate(&hwctx->cuda_ctx, CU_CTX_SCHED_BLOCKING_SYNC, cu_device));
+ hwctx->internal->flags = flags;
+
+ if (flags & USE_PRIMARY_CONTEXT)
+ ret = CHECK_CU(cu->cuDevicePrimaryCtxRetain(&hwctx->cuda_ctx, hwctx->internal->cuda_device));
+ else
+ ret = CHECK_CU(cu->cuCtxCreate(&hwctx->cuda_ctx, CU_CTX_SCHED_BLOCKING_SYNC, hwctx->internal->cuda_device));
+
if (ret < 0)
goto error;
// Setting stream to NULL will make functions automatically use the default CUstream
hwctx->stream = NULL;
- CHECK_CU(cu->cuCtxPopCurrent(&dummy));
+ if (!(flags & USE_PRIMARY_CONTEXT))
+ CHECK_CU(cu->cuCtxPopCurrent(&dummy));
hwctx->internal->is_allocated = 1;
@@ -31,6 +31,8 @@
struct AVCUDADeviceContextInternal {
CudaFunctions *cuda_dl;
int is_allocated;
+ CUdevice cuda_device;
+ int flags;
};
#endif /* AVUTIL_HWCONTEXT_CUDA_INTERNAL_H */
--
2.17.1