qsvdec: Relax the surface vs coded dimension check

Fix a common vp8 decoding failure.

Many vp8 clips cannot decode if hw_frames_ctx is enabled, reporting
"Error during QSV decoding.: incompatible video parameters (-14)".

It is due to mfx.FrameInfo.Width/Height not matching coded_w/coded_h.

See: avconv -hwaccel qsv -init_hw_device qsv -c:v vp8_qsv -i vp8-test-vectors-r1/vp80-00-comprehensive-001.ivf
-vf "hwdownload,format=nv12" -pix_fmt yuv420p -f md5 -
Signed-off-by: Zhong Li <zhong.li@intel.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

libavcodec/qsv.c

@@ -389,7 +389,7 @@ static mfxStatus qsv_frame_alloc(mfxHDL pthis, mfxFrameAllocRequest *req,
         mfxFrameInfo      *i  = &req->Info;
         mfxFrameInfo      *i1 = &frames_hwctx->surfaces[0].Info;
 
-        if (i->Width  != i1->Width  || i->Height != i1->Height ||
+        if (i->Width  > i1->Width  || i->Height > i1->Height ||
             i->FourCC != i1->FourCC || i->ChromaFormat != i1->ChromaFormat) {
             av_log(ctx->logctx, AV_LOG_ERROR, "Mismatching surface properties in an "
                    "allocation request: %dx%d %d %d vs %dx%d %d %d\n",

libavcodec/qsvdec.c

@@ -149,9 +149,6 @@ static int qsv_decode_init(AVCodecContext *avctx, QSVContext *q)
             else if (frames_hwctx->frame_type & MFX_MEMTYPE_VIDEO_MEMORY_DECODER_TARGET)
                 iopattern = MFX_IOPATTERN_OUT_VIDEO_MEMORY;
         }
-
-        frame_width  = frames_hwctx->surfaces[0].Info.Width;
-        frame_height = frames_hwctx->surfaces[0].Info.Height;
     }
 
     if (!iopattern)