diff --git a/video/decode/lavc.h b/video/decode/lavc.h
index d67292c4fd..14dc6dda4e 100644
--- a/video/decode/lavc.h
+++ b/video/decode/lavc.h
@@ -65,6 +65,7 @@ struct vd_lavc_hwdec {
 enum {
     HWDEC_ERR_NO_CTX = -2,
     HWDEC_ERR_NO_CODEC = -3,
+    HWDEC_ERR_EMULATED = -4,    // probing successful, but emulated API detected
 };
 
 struct hwdec_profile_entry {
diff --git a/video/decode/vaapi.c b/video/decode/vaapi.c
index d9267936d0..2b951fd1bb 100644
--- a/video/decode/vaapi.c
+++ b/video/decode/vaapi.c
@@ -409,6 +409,8 @@ static int probe(struct vd_lavc_hwdec *hwdec, struct mp_hwdec_info *info,
         return HWDEC_ERR_NO_CTX;
     if (!hwdec_check_codec_support(decoder, profiles))
         return HWDEC_ERR_NO_CODEC;
+    if (va_guess_if_emulated(info->vaapi_ctx))
+        return HWDEC_ERR_EMULATED;
     return 0;
 }
 
@@ -418,9 +420,12 @@ static int probe_copy(struct vd_lavc_hwdec *hwdec, struct mp_hwdec_info *info,
     struct priv dummy = {mp_null_log};
     if (!create_va_dummy_ctx(&dummy))
         return HWDEC_ERR_NO_CTX;
+    bool emulated = va_guess_if_emulated(dummy.ctx);
     destroy_va_dummy_ctx(&dummy);
     if (!hwdec_check_codec_support(decoder, profiles))
         return HWDEC_ERR_NO_CODEC;
+    if (emulated)
+        return HWDEC_ERR_EMULATED;
     return 0;
 }
 
diff --git a/video/decode/vd_lavc.c b/video/decode/vd_lavc.c
index 2593e50285..9ef49c25e1 100644
--- a/video/decode/vd_lavc.c
+++ b/video/decode/vd_lavc.c
@@ -200,19 +200,24 @@ static struct vd_lavc_hwdec *probe_hwdec(struct dec_video *vd, bool autoprobe,
 {
     struct vd_lavc_hwdec *hwdec = find_hwcodec(api);
     if (!hwdec) {
-        MP_VERBOSE(vd, "Requested hardware decoder not "
-                   "compiled.\n");
+        MP_VERBOSE(vd, "Requested hardware decoder not compiled.\n");
         return NULL;
     }
     int r = hwdec_probe(hwdec, &vd->hwdec_info, decoder);
+    if (r == HWDEC_ERR_EMULATED) {
+        if (autoprobe)
+            return NULL;
+        // User requested this explicitly.
+        MP_WARN(vd, "Using emulated hardware decoding API.\n");
+        r = 0;
+    }
     if (r >= 0) {
         return hwdec;
     } else if (r == HWDEC_ERR_NO_CODEC) {
         MP_VERBOSE(vd, "Hardware decoder '%s' not found in "
                    "libavcodec.\n", decoder);
     } else if (r == HWDEC_ERR_NO_CTX && !autoprobe) {
-        MP_WARN(vd, "VO does not support requested "
-                "hardware decoder.\n");
+        MP_WARN(vd, "VO does not support requested hardware decoder.\n");
     }
     return NULL;
 }
diff --git a/video/decode/vdpau.c b/video/decode/vdpau.c
index 4cd1eee531..44850dfaec 100644
--- a/video/decode/vdpau.c
+++ b/video/decode/vdpau.c
@@ -175,6 +175,8 @@ static int probe(struct vd_lavc_hwdec *hwdec, struct mp_hwdec_info *info,
         return HWDEC_ERR_NO_CTX;
     if (!hwdec_check_codec_support(decoder, profiles))
         return HWDEC_ERR_NO_CODEC;
+    if (mp_vdpau_guess_if_emulated(info->vdpau_ctx))
+        return HWDEC_ERR_EMULATED;
     return 0;
 }
 
diff --git a/video/out/vo_vaapi.c b/video/out/vo_vaapi.c
index 8fb863ece6..7d167ea82e 100644
--- a/video/out/vo_vaapi.c
+++ b/video/out/vo_vaapi.c
@@ -584,6 +584,11 @@ static int preinit(struct vo *vo)
         goto fail;
     }
 
+    if (va_guess_if_emulated(p->mpvaapi)) {
+        MP_WARN(vo, "VA-API is most likely emulated via VDPAU.\n"
+                    "It's better to use VDPAU directly with: --vo=vdpau\n");
+    }
+
     p->pool = mp_image_pool_new(MAX_OUTPUT_SURFACES + 3);
     va_pool_set_allocator(p->pool, p->mpvaapi, VA_RT_FORMAT_YUV420);
     p->va_image_formats = p->mpvaapi->image_formats;
diff --git a/video/out/vo_vdpau.c b/video/out/vo_vdpau.c
index b6728e79d8..3deac1724b 100644
--- a/video/out/vo_vdpau.c
+++ b/video/out/vo_vdpau.c
@@ -1005,6 +1005,11 @@ static int preinit(struct vo *vo)
 
     vc->video_mixer = mp_vdpau_mixer_create(vc->mpvdp, vo->log);
 
+    if (mp_vdpau_guess_if_emulated(vc->mpvdp)) {
+        MP_WARN(vo, "VDPAU is most likely emulated via VA-API.\n"
+                    "This is inefficient. Use --vo=opengl instead.\n");
+    }
+
     // Mark everything as invalid first so uninit() can tell what has been
     // allocated
     mark_vdpau_objects_uninitialized(vo);
diff --git a/video/vaapi.c b/video/vaapi.c
index 2b2b7819dd..56bffaa05f 100644
--- a/video/vaapi.c
+++ b/video/vaapi.c
@@ -448,3 +448,9 @@ void va_pool_set_allocator(struct mp_image_pool *pool, struct mp_vaapi_ctx *ctx,
     mp_image_pool_set_allocator(pool, alloc_pool, alloc_ctx);
     mp_image_pool_set_lru(pool);
 }
+
+bool va_guess_if_emulated(struct mp_vaapi_ctx *ctx)
+{
+    const char *s = vaQueryVendorString(ctx->display);
+    return s && strstr(s, "VDPAU backend");
+}
diff --git a/video/vaapi.h b/video/vaapi.h
index c555161999..8a96bb1347 100644
--- a/video/vaapi.h
+++ b/video/vaapi.h
@@ -109,4 +109,6 @@ struct mp_image *va_surface_download(struct mp_image *src,
 int va_surface_alloc_imgfmt(struct mp_image *img, int imgfmt);
 int va_surface_upload(struct mp_image *va_dst, struct mp_image *sw_src);
 
+bool va_guess_if_emulated(struct mp_vaapi_ctx *ctx);
+
 #endif
diff --git a/video/vdpau.c b/video/vdpau.c
index 20fbf2566f..0cf91ffe86 100644
--- a/video/vdpau.c
+++ b/video/vdpau.c
@@ -426,3 +426,13 @@ struct mp_image *mp_vdpau_upload_video_surface(struct mp_vdpau_ctx *ctx,
     mp_image_copy_attributes(hwmpi, mpi);
     return hwmpi;
 }
+
+bool mp_vdpau_guess_if_emulated(struct mp_vdpau_ctx *ctx)
+{
+    struct vdp_functions *vdp = &ctx->vdp;
+    VdpStatus vdp_st;
+    char const* info = NULL;
+    vdp_st = vdp->get_information_string(&info);
+    CHECK_VDP_WARNING(ctx, "Error when calling vdp_get_information_string");
+    return vdp_st == VDP_STATUS_OK && info && strstr(info, "VAAPI");
+}
diff --git a/video/vdpau.h b/video/vdpau.h
index 3aea414700..7fdbbf47bf 100644
--- a/video/vdpau.h
+++ b/video/vdpau.h
@@ -84,4 +84,6 @@ bool mp_vdpau_get_rgb_format(int imgfmt, VdpRGBAFormat *out_rgba_format);
 struct mp_image *mp_vdpau_upload_video_surface(struct mp_vdpau_ctx *ctx,
                                                struct mp_image *mpi);
 
+bool mp_vdpau_guess_if_emulated(struct mp_vdpau_ctx *ctx);
+
 #endif
diff --git a/video/vdpau_functions.inc b/video/vdpau_functions.inc
index 1789768c83..5604420f69 100644
--- a/video/vdpau_functions.inc
+++ b/video/vdpau_functions.inc
@@ -14,6 +14,7 @@ VDP_FUNCTION(VdpDecoderDestroy, VDP_FUNC_ID_DECODER_DESTROY, decoder_destroy)
 VDP_FUNCTION(VdpDecoderRender, VDP_FUNC_ID_DECODER_RENDER, decoder_render)
 VDP_FUNCTION(VdpDecoderQueryCapabilities, VDP_FUNC_ID_DECODER_QUERY_CAPABILITIES, decoder_query_capabilities)
 VDP_FUNCTION(VdpDeviceDestroy, VDP_FUNC_ID_DEVICE_DESTROY, device_destroy)
+VDP_FUNCTION(VdpGetInformationString, VDP_FUNC_ID_GET_INFORMATION_STRING, get_information_string)
 VDP_FUNCTION(VdpGenerateCSCMatrix, VDP_FUNC_ID_GENERATE_CSC_MATRIX, generate_csc_matrix)
 VDP_FUNCTION(VdpOutputSurfaceCreate, VDP_FUNC_ID_OUTPUT_SURFACE_CREATE, output_surface_create)
 VDP_FUNCTION(VdpOutputSurfaceDestroy, VDP_FUNC_ID_OUTPUT_SURFACE_DESTROY, output_surface_destroy)