avfilter/vpp_qsv: fix regression on older api versions (e.g. 1.11)

Commit 8b83dad introduced a
regression in a way that scaling via vpp_qsv doesn't work any longer
for devices with an MSDK runtime version lower than 1.19. This is true
for older CPUs which are stuck at 1.11.
The commit added checks for the compile-sdk version but it didn't test
for the runtime version.

Signed-off-by: softworkz <softworkz@hotmail.com>

libavfilter/vf_vpp_qsv.c

@@ -26,6 +26,7 @@
 #include "libavutil/opt.h"
 #include "libavutil/eval.h"
 #include "libavutil/hwcontext.h"
+#include "libavutil/hwcontext_qsv.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/mathematics.h"
 
@@ -139,8 +140,9 @@ static const AVOption options[] = {
     { "height", "Output video height", OFFSET(oh), AV_OPT_TYPE_STRING, { .str="w*ch/cw" }, 0, 255, .flags = FLAGS },
     { "format", "Output pixel format", OFFSET(output_format_str), AV_OPT_TYPE_STRING, { .str = "same" }, .flags = FLAGS },
     { "async_depth", "Internal parallelization depth, the higher the value the higher the latency.", OFFSET(async_depth), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, .flags = FLAGS },
+#ifdef QSV_HAVE_SCALING_CONFIG
     { "scale_mode", "scale mode: 0=auto, 1=low power, 2=high quality", OFFSET(scale_mode), AV_OPT_TYPE_INT, { .i64 = MFX_SCALING_MODE_DEFAULT }, MFX_SCALING_MODE_DEFAULT, MFX_SCALING_MODE_QUALITY, .flags = FLAGS, "scale mode" },
-
+#endif
     { NULL }
 };
 
@@ -297,13 +299,40 @@ static int config_input(AVFilterLink *inlink)
     return 0;
 }
 
+static mfxStatus get_mfx_version(const AVFilterContext *ctx, mfxVersion *mfx_version)
+{
+    const AVFilterLink *inlink = ctx->inputs[0];
+    AVBufferRef *device_ref;
+    AVHWDeviceContext *device_ctx;
+    AVQSVDeviceContext *device_hwctx;
+
+    if (inlink->hw_frames_ctx) {
+        AVHWFramesContext *frames_ctx = (AVHWFramesContext *)inlink->hw_frames_ctx->data;
+        device_ref = frames_ctx->device_ref;
+    } else if (ctx->hw_device_ctx) {
+        device_ref = ctx->hw_device_ctx;
+    } else {
+        // Unavailable hw context doesn't matter in pass-through mode,
+        // so don't error here but let runtime version checks fail by setting to 0.0
+        mfx_version->Major = 0;
+        mfx_version->Minor = 0;
+        return MFX_ERR_NONE;
+    }
+
+    device_ctx   = (AVHWDeviceContext *)device_ref->data;
+    device_hwctx = device_ctx->hwctx;
+
+    return MFXQueryVersion(device_hwctx->session, mfx_version);
+}
+
 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     VPPContext      *vpp = ctx->priv;
     QSVVPPParam     param = { NULL };
     QSVVPPCrop      crop  = { 0 };
     mfxExtBuffer    *ext_buf[ENH_FILTERS_COUNT];
+    mfxVersion      mfx_version;
     AVFilterLink    *inlink = ctx->inputs[0];
     enum AVPixelFormat in_format;
 
@@ -317,6 +346,11 @@ static int config_output(AVFilterLink *outlink)
     param.ext_buf       = ext_buf;
     param.async_depth   = vpp->async_depth;
 
+    if (get_mfx_version(ctx, &mfx_version) != MFX_ERR_NONE) {
+        av_log(ctx, AV_LOG_ERROR, "Failed to query mfx version.\n");
+        return AVERROR(EINVAL);
+    }
+
     if (inlink->format == AV_PIX_FMT_QSV) {
          if (!inlink->hw_frames_ctx || !inlink->hw_frames_ctx->data)
              return AVERROR(EINVAL);
@@ -467,19 +501,20 @@ static int config_output(AVFilterLink *outlink)
 #endif
     }
 
-    if (inlink->w != outlink->w || inlink->h != outlink->h) {
 #ifdef QSV_HAVE_SCALING_CONFIG
-        memset(&vpp->scale_conf, 0, sizeof(mfxExtVPPScaling));
-        vpp->scale_conf.Header.BufferId    = MFX_EXTBUFF_VPP_SCALING;
-        vpp->scale_conf.Header.BufferSz    = sizeof(mfxExtVPPScaling);
-        vpp->scale_conf.ScalingMode        = vpp->scale_mode;
-
-        param.ext_buf[param.num_ext_buf++] = (mfxExtBuffer*)&vpp->scale_conf;
-#else
-        av_log(ctx, AV_LOG_WARNING, "The QSV VPP Scale option is "
-            "not supported with this MSDK version.\n");
-#endif
+    if (inlink->w != outlink->w || inlink->h != outlink->h) {
+        if (QSV_RUNTIME_VERSION_ATLEAST(mfx_version, 1, 19)) {
+            memset(&vpp->scale_conf, 0, sizeof(mfxExtVPPScaling));
+            vpp->scale_conf.Header.BufferId    = MFX_EXTBUFF_VPP_SCALING;
+            vpp->scale_conf.Header.BufferSz    = sizeof(mfxExtVPPScaling);
+            vpp->scale_conf.ScalingMode        = vpp->scale_mode;
+
+            param.ext_buf[param.num_ext_buf++] = (mfxExtBuffer*)&vpp->scale_conf;
+        } else
+            av_log(ctx, AV_LOG_WARNING, "The QSV VPP Scale option is "
+                "not supported with this MSDK version.\n");
     }
+#endif
 
     if (vpp->use_frc || vpp->use_crop || vpp->deinterlace || vpp->denoise ||
         vpp->detail || vpp->procamp || vpp->rotate || vpp->hflip ||