[FFmpeg-devel] [PATCH] lavc/vaapi_encode: Convert P to B-frames if driver doesn't support

Linjie Fu linjie.fu at intel.com
Mon Jun 1 16:49:44 EEST 2020


Automatically convert P-frames to B-frames according to the query
results of VAConfigAttribPredictionDirection.

If P-frames is not supported by driver, convert P-frames to B-frames
with 2 same ref_lists(forward-prediction only, low delay B-frames).

If query is not supported with current VAAPI version, convert P to B
by default for low power mode to avoid unexpected errors.

Signed-off-by: Linjie Fu <linjie.fu at intel.com>
---
Since the query support is ready in LIBVA and media-driver, this patch
is now ready for upstream:
https://github.com/intel/libva/commit/0014ada0eb0fd09a0dd928e5a132ecf12ed85c2e
https://github.com/intel/media-driver/commit/d7061b608ad4d55fccab00f8d80b852f20eab1d7

 libavcodec/vaapi_encode.c      | 61 +++++++++++++++++++++++++++++++++++-------
 libavcodec/vaapi_encode.h      |  2 ++
 libavcodec/vaapi_encode_h265.c |  7 +++++
 3 files changed, 60 insertions(+), 10 deletions(-)

diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c
index cb05ebd..0710be7 100644
--- a/libavcodec/vaapi_encode.c
+++ b/libavcodec/vaapi_encode.c
@@ -1768,26 +1768,57 @@ static av_cold int vaapi_encode_init_gop_structure(AVCodecContext *avctx)
 {
     VAAPIEncodeContext *ctx = avctx->priv_data;
     VAStatus vas;
-    VAConfigAttrib attr = { VAConfigAttribEncMaxRefFrames };
-    uint32_t ref_l0, ref_l1;
+    VAConfigAttrib attr[2] = { { VAConfigAttribEncMaxRefFrames },
+#if VA_CHECK_VERSION(1, 8, 0)
+                               { VAConfigAttribPredictionDirection }
+#else
+                               { 0 }
+#endif
+                             };
+    uint32_t ref_l0, ref_l1, b_predict_direction;
 
     vas = vaGetConfigAttributes(ctx->hwctx->display,
                                 ctx->va_profile,
                                 ctx->va_entrypoint,
-                                &attr, 1);
+                                attr, FF_ARRAY_ELEMS(attr));
     if (vas != VA_STATUS_SUCCESS) {
         av_log(avctx, AV_LOG_ERROR, "Failed to query reference frames "
                "attribute: %d (%s).\n", vas, vaErrorStr(vas));
         return AVERROR_EXTERNAL;
     }
 
-    if (attr.value == VA_ATTRIB_NOT_SUPPORTED) {
+    if (attr[0].value == VA_ATTRIB_NOT_SUPPORTED) {
         ref_l0 = ref_l1 = 0;
     } else {
-        ref_l0 = attr.value       & 0xffff;
-        ref_l1 = attr.value >> 16 & 0xffff;
+        ref_l0 = attr[0].value       & 0xffff;
+        ref_l1 = attr[0].value >> 16 & 0xffff;
     }
+#if VA_CHECK_VERSION(1, 8, 0)
+    if (attr[1].value != VA_ATTRIB_NOT_SUPPORTED)
+        b_predict_direction =  attr[1].value;
+    else
+        b_predict_direction = 0;
 
+    if (b_predict_direction & VA_PREDICTION_DIRECTION_BI_NOT_EMPTY) {
+        av_log(avctx, AV_LOG_WARNING, "Driver does not support P "
+               "reference frames.\n");
+        if (!ref_l0 || !ref_l1) {
+            av_log(avctx, AV_LOG_ERROR, "Query result conflicts.\n");
+            return AVERROR_EXTERNAL;
+        }
+        ctx->p_to_b = 1;
+        av_log(avctx, AV_LOG_WARNING, "Convert P-frames to low delay "
+               "B frames.\n");
+    }
+#else
+    av_log(avctx, AV_LOG_WARNING, "B-frame prediction direction query "
+           "is not supported with this VAAPI version.\n");
+    // P frames is not supported in low power encoding for HEVC,hence
+    // we convert P-frames to low delay B-frames if query is not
+    // available with this VAAPI version.
+    if (ctx->low_power)
+        ctx->p_to_b = 1;
+#endif
     if (ctx->codec->flags & FLAG_INTRA_ONLY ||
         avctx->gop_size <= 1) {
         av_log(avctx, AV_LOG_VERBOSE, "Using intra frames only.\n");
@@ -1798,14 +1829,24 @@ static av_cold int vaapi_encode_init_gop_structure(AVCodecContext *avctx)
         return AVERROR(EINVAL);
     } else if (!(ctx->codec->flags & FLAG_B_PICTURES) ||
                ref_l1 < 1 || avctx->max_b_frames < 1) {
-        av_log(avctx, AV_LOG_VERBOSE, "Using intra and P-frames "
-               "(supported references: %d / %d).\n", ref_l0, ref_l1);
+        if (ctx->p_to_b)
+            av_log(avctx, AV_LOG_VERBOSE, "Using intra and low delay "
+                   "B-frames (supported references: %d / %d).\n",
+                   ref_l0, ref_l1);
+        else
+            av_log(avctx, AV_LOG_VERBOSE, "Using intra and P-frames "
+                   "(supported references: %d / %d).\n", ref_l0, ref_l1);
         ctx->gop_size = avctx->gop_size;
         ctx->p_per_i  = INT_MAX;
         ctx->b_per_p  = 0;
     } else {
-        av_log(avctx, AV_LOG_VERBOSE, "Using intra, P- and B-frames "
-               "(supported references: %d / %d).\n", ref_l0, ref_l1);
+        if (ctx->p_to_b)
+            av_log(avctx, AV_LOG_VERBOSE, "Using intra, low delay B- and "
+                   "B-frames (supported references: %d / %d).\n",
+                   ref_l0, ref_l1);
+        else
+            av_log(avctx, AV_LOG_VERBOSE, "Using intra, P- and B-frames "
+                   "(supported references: %d / %d).\n", ref_l0, ref_l1);
         ctx->gop_size = avctx->gop_size;
         ctx->p_per_i  = INT_MAX;
         ctx->b_per_p  = avctx->max_b_frames;
diff --git a/libavcodec/vaapi_encode.h b/libavcodec/vaapi_encode.h
index 1329f64..69dd9b3 100644
--- a/libavcodec/vaapi_encode.h
+++ b/libavcodec/vaapi_encode.h
@@ -313,6 +313,8 @@ typedef struct VAAPIEncodeContext {
     int idr_counter;
     int gop_counter;
     int end_of_stream;
+    // Convert P-frames to B-frames with forward reference only
+    int p_to_b;
 
     // Whether the driver supports ROI at all.
     int             roi_allowed;
diff --git a/libavcodec/vaapi_encode_h265.c b/libavcodec/vaapi_encode_h265.c
index 92e0510..bc7626b 100644
--- a/libavcodec/vaapi_encode_h265.c
+++ b/libavcodec/vaapi_encode_h265.c
@@ -872,6 +872,7 @@ 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;
@@ -894,6 +895,9 @@ 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_b)
+        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;
 
@@ -1052,6 +1056,9 @@ 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_b && pic->type == PICTURE_TYPE_P)
+            // Reference for low delay B-frame, L0 == L1
+            vslice->ref_pic_list1[0] = vpic->reference_frames[0];
     }
     if (pic->nb_refs >= 2) {
         // Forward reference for B-frame.
-- 
2.7.4



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