hwdec: release images as soon as possible after mapping

We don't need to hold on to buffers longer than necessary. Doesn't
matter for vo_gpu but greatly matters for vo_gpu_next, since it persists
hwdec mapped textures for longer periods.

Unfortunately, only provides benefits for hwdecs which do explicit
copies in their decode path, which currently just means cuda and
d3d11va.

3 files changed, 15 insertions, 4 deletions

diff --git a/video/out/d3d11/hwdec_d3d11va.c b/video/out/d3d11/hwdec_d3d11va.c
index 02f796e003..3006e5c7d0 100644
--- a/video/out/d3d11/hwdec_d3d11va.c
+++ b/video/out/d3d11/hwdec_d3d11va.c
@@ -206,6 +206,9 @@ static int mapper_map(struct ra_hwdec_mapper *mapper)
                 .bottom = mapper->dst_params.h,
                 .back = 1,
             }), D3D11_COPY_DISCARD);
+
+        // We no longer need the original texture after copying it.
+        mp_image_unrefp(&mapper->src);
     } else {
         D3D11_TEXTURE2D_DESC desc2d;
         ID3D11Texture2D_GetDesc(tex, &desc2d);
diff --git a/video/out/gpu/hwdec.c b/video/out/gpu/hwdec.c
index 4fb6240651..dd2809f41e 100644
--- a/video/out/gpu/hwdec.c
+++ b/video/out/gpu/hwdec.c
@@ -186,6 +186,8 @@ void ra_hwdec_mapper_unmap(struct ra_hwdec_mapper *mapper)
 {
     if (mapper->driver->unmap)
         mapper->driver->unmap(mapper);
+
+    // Clean up after the image if the mapper didn't already
     mp_image_unrefp(&mapper->src);
 }
 
diff --git a/video/out/hwdec/hwdec_cuda.c b/video/out/hwdec/hwdec_cuda.c
index 895fb07d61..0fe0f7bda8 100644
--- a/video/out/hwdec/hwdec_cuda.c
+++ b/video/out/hwdec/hwdec_cuda.c
@@ -253,12 +253,18 @@ static int mapper_map(struct ra_hwdec_mapper *mapper)
     if (p_owner->do_full_sync)
         CHECK_CU(cu->cuStreamSynchronize(0));
 
+    // fall through
  error:
-   eret = CHECK_CU(cu->cuCtxPopCurrent(&dummy));
-   if (eret < 0)
-       return eret;
 
-   return ret;
+    // Regardless of success or failure, we no longer need the source image,
+    // because this hwdec makes an explicit memcpy into the mapper textures
+    mp_image_unrefp(&mapper->src);
+
+    eret = CHECK_CU(cu->cuCtxPopCurrent(&dummy));
+    if (eret < 0)
+        return eret;
+
+    return ret;
 }
 
 const struct ra_hwdec_driver ra_hwdec_cuda = {