dxva2: allow an empty array of ID3D11VideoDecoderOutputView

We can pick the correct slice index directly from the ID3D11VideoDecoderOutputView
casted from data[3].
Signed-off-by: Anton Khirnov <anton@khirnov.net>

libavcodec/dxva2_internal.h

@@ -73,7 +73,7 @@ typedef union {
 #define DXVA_CONTEXT_CFG_RESIDACCEL(avctx, ctx) (avctx->pix_fmt == AV_PIX_FMT_D3D11VA_VLD ? ctx->d3d11va.cfg->ConfigResidDiffAccelerator : ctx->dxva2.cfg->ConfigResidDiffAccelerator)
 #define DXVA_CONTEXT_VALID(avctx, ctx)          (DXVA_CONTEXT_DECODER(avctx, ctx) && \
                                                  DXVA_CONTEXT_CFG(avctx, ctx)     && \
-                                                 DXVA_CONTEXT_COUNT(avctx, ctx))
+                                                 (avctx->pix_fmt == AV_PIX_FMT_D3D11VA_VLD || ctx->dxva2.surface_count))
 #elif CONFIG_DXVA2
 #define DXVA_CONTEXT_WORKAROUND(avctx, ctx)     (ctx->dxva2.workaround)
 #define DXVA_CONTEXT_COUNT(avctx, ctx)          (ctx->dxva2.surface_count)
@@ -93,7 +93,7 @@ typedef union {
 #define DXVA_CONTEXT_CFG_BITSTREAM(avctx, ctx)  (ctx->d3d11va.cfg->ConfigBitstreamRaw)
 #define DXVA_CONTEXT_CFG_INTRARESID(avctx, ctx) (ctx->d3d11va.cfg->ConfigIntraResidUnsigned)
 #define DXVA_CONTEXT_CFG_RESIDACCEL(avctx, ctx) (ctx->d3d11va.cfg->ConfigResidDiffAccelerator)
-#define DXVA_CONTEXT_VALID(avctx, ctx)          (ctx->d3d11va.decoder && ctx->d3d11va.cfg && ctx->d3d11va.surface_count)
+#define DXVA_CONTEXT_VALID(avctx, ctx)          (ctx->d3d11va.decoder && ctx->d3d11va.cfg)
 #endif
 
 unsigned ff_dxva2_get_surface_index(const AVCodecContext *avctx,

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR 57
 #define LIBAVCODEC_VERSION_MINOR 30
-#define LIBAVCODEC_VERSION_MICRO  2
+#define LIBAVCODEC_VERSION_MICRO  3
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \