lavc/vaapi_encode_h265: Add GPB frame support for hevc_vaapi

Use GPB frames to replace regular P/B frames if backend driver does not
support it.

- GPB:
    Generalized P and B picture. Regular P/B frames replaced by B
    frames with previous-predict only, L0 == L1. Normal B frames
    still have 2 different ref_lists and allow bi-prediction

Signed-off-by: Linjie Fu <linjie.fu@intel.com>
Signed-off-by: Fei Wang <fei.w.wang@intel.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/libavcodec/vaapi_encode_h265.c b/libavcodec/vaapi_encode_h265.c
index 0be32588c0..76d67237d2 100644
--- a/libavcodec/vaapi_encode_h265.c
+++ b/libavcodec/vaapi_encode_h265.c
@@ -886,6 +886,7 @@ static int vaapi_encode_h265_init_slice_params(AVCodecContext *avctx,
                                                VAAPIEncodePicture *pic,
                                                VAAPIEncodeSlice *slice)
 {
+    VAAPIEncodeContext                *ctx = avctx->priv_data;
     VAAPIEncodeH265Context           *priv = avctx->priv_data;
     VAAPIEncodeH265Picture           *hpic = pic->priv_data;
     const H265RawSPS                  *sps = &priv->raw_sps;
@@ -908,6 +909,9 @@ static int vaapi_encode_h265_init_slice_params(AVCodecContext *avctx,
 
     sh->slice_type = hpic->slice_type;
 
+    if (sh->slice_type == HEVC_SLICE_P && ctx->p_to_gpb)
+        sh->slice_type = HEVC_SLICE_B;
+
     sh->slice_pic_order_cnt_lsb = hpic->pic_order_cnt &
         (1 << (sps->log2_max_pic_order_cnt_lsb_minus4 + 4)) - 1;
 
@@ -1066,6 +1070,9 @@ static int vaapi_encode_h265_init_slice_params(AVCodecContext *avctx,
         av_assert0(pic->type == PICTURE_TYPE_P ||
                    pic->type == PICTURE_TYPE_B);
         vslice->ref_pic_list0[0] = vpic->reference_frames[0];
+        if (ctx->p_to_gpb && pic->type == PICTURE_TYPE_P)
+            // Reference for GPB B-frame, L0 == L1
+            vslice->ref_pic_list1[0] = vpic->reference_frames[0];
     }
     if (pic->nb_refs >= 2) {
         // Forward reference for B-frame.
@@ -1073,6 +1080,14 @@ static int vaapi_encode_h265_init_slice_params(AVCodecContext *avctx,
         vslice->ref_pic_list1[0] = vpic->reference_frames[1];
     }
 
+    if (pic->type == PICTURE_TYPE_P && ctx->p_to_gpb) {
+        vslice->slice_type = HEVC_SLICE_B;
+        for (i = 0; i < FF_ARRAY_ELEMS(vslice->ref_pic_list0); i++) {
+            vslice->ref_pic_list1[i].picture_id = vslice->ref_pic_list0[i].picture_id;
+            vslice->ref_pic_list1[i].flags      = vslice->ref_pic_list0[i].flags;
+        }
+    }
+
     return 0;
 }