libavcodec/qsvenc: Add gop_size reset support to qsvenc

Signed-off-by: Wenbin Chen <wenbin.chen@intel.com>

doc/encoders.texi

@@ -3335,6 +3335,9 @@ Change these value to reset qsv codec's qp configuration.
 @item @var{max_frame_size}
 Supported in h264_qsv and hevc_qsv.
 Change this value to reset qsv codec's MaxFrameSize configuration.
+
+@item @var{gop_size}
+Change this value to reset qsv codec's gop configuration.
 @end table
 
 @subsection H264 options

libavcodec/qsvenc.c

@@ -639,6 +639,7 @@ static int init_video_param(AVCodecContext *avctx, QSVEncContext *q)
     q->param.mfx.CodecProfile       = q->profile;
     q->param.mfx.TargetUsage        = avctx->compression_level;
     q->param.mfx.GopPicSize         = FFMAX(0, avctx->gop_size);
+    q->old_gop_size                 = avctx->gop_size;
     q->param.mfx.GopRefDist         = FFMAX(-1, avctx->max_b_frames) + 1;
     q->param.mfx.GopOptFlag         = avctx->flags & AV_CODEC_FLAG_CLOSED_GOP ?
                                       MFX_GOP_CLOSED : MFX_GOP_STRICT;
@@ -1697,6 +1698,20 @@ static int update_max_frame_size(AVCodecContext *avctx, QSVEncContext *q)
     return updated;
 }
 
+static int update_gop_size(AVCodecContext *avctx, QSVEncContext *q)
+{
+    int updated = 0;
+    UPDATE_PARAM(q->old_gop_size, avctx->gop_size);
+    if (!updated)
+        return 0;
+
+    q->param.mfx.GopPicSize = FFMAX(0, avctx->gop_size);
+    av_log(avctx, AV_LOG_DEBUG, "reset GopPicSize to %d\n",
+           q->param.mfx.GopPicSize);
+
+    return updated;
+}
+
 static int update_parameters(AVCodecContext *avctx, QSVEncContext *q,
                              const AVFrame *frame)
 {
@@ -1707,6 +1722,7 @@ static int update_parameters(AVCodecContext *avctx, QSVEncContext *q,
 
     needReset = update_qp(avctx, q);
     needReset |= update_max_frame_size(avctx, q);
+    needReset |= update_gop_size(avctx, q);
     if (!needReset)
         return 0;
 

libavcodec/qsvenc.h

@@ -253,6 +253,8 @@ typedef struct QSVEncContext {
     float old_b_quant_offset;
     // This is used for max_frame_size reset
     int old_max_frame_size;
+    // This is used for gop reset
+    int old_gop_size;
 } QSVEncContext;
 
 int ff_qsv_enc_init(AVCodecContext *avctx, QSVEncContext *q);