[libav-devel] [PATCH 2/2] vaapi_h265: Mark unused entries in RefPicList[01] as explicitly invalid

Mark Thompson sw at jkqxz.net
Sun Dec 17 21:05:43 CET 2017


The iHD driver looks at entries beyond num_ref_idx_l[01]_active_minus1
for unknown reasons.
---
This still isn't enough to actually work for encoding H.265 with the iHD driver on Skylake.  It can generate output with this rather than crashing, but the output is still wrong (though it does resemble the input somewhat).

It also seems to like inserting emulation prevention bytes everywhere in slice headers after the first, so it breaks totally if AUDs are present.


 libavcodec/vaapi_encode_h265.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/libavcodec/vaapi_encode_h265.c b/libavcodec/vaapi_encode_h265.c
index a9853a3aa..813d4f944 100644
--- a/libavcodec/vaapi_encode_h265.c
+++ b/libavcodec/vaapi_encode_h265.c
@@ -767,8 +767,6 @@ static int vaapi_encode_h265_init_slice_params(AVCodecContext *avctx,
 
         .num_ref_idx_l0_active_minus1 = sh->num_ref_idx_l0_active_minus1,
         .num_ref_idx_l1_active_minus1 = sh->num_ref_idx_l1_active_minus1,
-        .ref_pic_list0[0]             = vpic->reference_frames[0],
-        .ref_pic_list1[0]             = vpic->reference_frames[1],
 
         .luma_log2_weight_denom         = sh->luma_log2_weight_denom,
         .delta_chroma_log2_weight_denom = sh->delta_chroma_log2_weight_denom,
@@ -802,6 +800,25 @@ static int vaapi_encode_h265_init_slice_params(AVCodecContext *avctx,
         },
     };
 
+    for (i = 0; i < FF_ARRAY_ELEMS(vslice->ref_pic_list0); i++) {
+        vslice->ref_pic_list0[i].picture_id = VA_INVALID_ID;
+        vslice->ref_pic_list0[i].flags      = VA_PICTURE_HEVC_INVALID;
+        vslice->ref_pic_list1[i].picture_id = VA_INVALID_ID;
+        vslice->ref_pic_list1[i].flags      = VA_PICTURE_HEVC_INVALID;
+    }
+
+    av_assert0(pic->nb_refs <= 2);
+    if (pic->nb_refs >= 1) {
+        // Backward reference for P- or B-frame.
+        av_assert0(pic->type == PICTURE_TYPE_P ||
+                   pic->type == PICTURE_TYPE_B);
+        vslice->ref_pic_list0[0] = vpic->reference_frames[0];
+    }
+    if (pic->nb_refs >= 2) {
+        // Forward reference for B-frame.
+        av_assert0(pic->type == PICTURE_TYPE_B);
+        vslice->ref_pic_list1[0] = vpic->reference_frames[1];
+    }
 
     return 0;
 }
-- 
2.11.0


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