[FFmpeg-devel] lavc/vaapi_encode_h264: respect "slices" option in h264 vaapi encoder

[Jun Zhao]

From f9b42385faedd64dacf613785c393c7b025237c9 Mon Sep 17 00:00:00 2001
From: Jun Zhao <jun.zhao at intel.com>
Date: Tue, 1 Aug 2017 23:05:44 -0400
Subject: [PATCH V2 3/4] lavc/vaapi_encode_h264: respect "slices" option in
 h264 vaapi encoder

Enable multi-slice support in AVC/H.264 vaapi encoder.

Signed-off-by: Wang, Yi A <yi.a.wang at intel.com>
Signed-off-by: Jun Zhao <jun.zhao at intel.com>
---
 libavcodec/vaapi_encode_h264.c | 38 +++++++++++++++++++++++++++++++++-----
 1 file changed, 33 insertions(+), 5 deletions(-)

diff --git a/libavcodec/vaapi_encode_h264.c b/libavcodec/vaapi_encode_h264.c
index f9fcd805a4..5dad6d10a5 100644
--- a/libavcodec/vaapi_encode_h264.c
+++ b/libavcodec/vaapi_encode_h264.c
@@ -141,6 +141,10 @@ typedef struct VAAPIEncodeH264Context {
     int mb_width;
     int mb_height;
 
+    int slice_of_mbs;
+    int slice_mod_mbs;
+    int last_mb_index;
+
     int fixed_qp_idr;
     int fixed_qp_p;
     int fixed_qp_b;
@@ -957,6 +961,7 @@ static int vaapi_encode_h264_init_picture_params(AVCodecContext *avctx,
     VAEncPictureParameterBufferH264  *vpic = pic->codec_picture_params;
     VAAPIEncodeH264Context           *priv = ctx->priv_data;
     int i;
+    int max_slices;
 
     if (pic->type == PICTURE_TYPE_IDR) {
         av_assert0(pic->display_order == pic->encode_order);
@@ -1002,7 +1007,22 @@ static int vaapi_encode_h264_init_picture_params(AVCodecContext *avctx,
     vpic->pic_fields.bits.idr_pic_flag = (pic->type == PICTURE_TYPE_IDR);
     vpic->pic_fields.bits.reference_pic_flag = (pic->type != PICTURE_TYPE_B);
 
-    pic->nb_slices = 1;
+    max_slices = 1;
+    if (ctx->max_slices) {
+        max_slices = FFMIN(priv->mb_height, ctx->max_slices);
+        if (avctx->slices > max_slices) {
+            av_log(avctx, AV_LOG_WARNING, "The max slices number per frame "
+                   "cannot more than %d.\n", max_slices);
+        } else {
+            max_slices = avctx->slices;
+        }
+    }
+
+    pic->nb_slices = max_slices;
+
+    priv->slice_of_mbs  = (priv->mb_width * priv->mb_height) / pic->nb_slices;
+    priv->slice_mod_mbs = (priv->mb_width * priv->mb_height) % pic->nb_slices;
+    priv->last_mb_index = 0;
 
     return 0;
 }
@@ -1052,14 +1072,18 @@ static int vaapi_encode_h264_init_slice_params(AVCodecContext *avctx,
         av_assert0(0 && "invalid picture type");
     }
 
-    // Only one slice per frame.
-    vslice->macroblock_address = 0;
-    vslice->num_macroblocks = priv->mb_width * priv->mb_height;
+    vslice->macroblock_address = priv->last_mb_index;
+    vslice->num_macroblocks = priv->slice_of_mbs + (priv->slice_mod_mbs > 0 ? 1 : 0);
+    if (priv->slice_mod_mbs > 0)
+        priv->slice_mod_mbs--;
+    priv->last_mb_index += vslice->num_macroblocks;
 
     vslice->macroblock_info = VA_INVALID_ID;
 
     vslice->pic_parameter_set_id = vpic->pic_parameter_set_id;
-    vslice->idr_pic_id = priv->idr_pic_count++;
+    vslice->idr_pic_id = priv->idr_pic_count;
+    if (priv->last_mb_index == priv->mb_width * priv->mb_height)
+        priv->idr_pic_count++;
 
     vslice->pic_order_cnt_lsb = (pic->display_order - priv->last_idr_frame) &
         ((1 << (4 + vseq->seq_fields.bits.log2_max_pic_order_cnt_lsb_minus4)) - 1);
@@ -1157,6 +1181,10 @@ static av_cold int vaapi_encode_h264_configure(AVCodecContext *avctx)
 #endif
     }
 
+    if (!ctx->max_slices && avctx->slices > 0)
+        av_log(avctx, AV_LOG_WARNING, "The encode slice option is not "
+               "supported with this VAAPI version.\n");
+
     return 0;
 }
 
-- 
2.11.0