lavc/qsvenc: add forced_idr option

This option can be used to repect original input I/IDR frame type.
Reviewed-by: Mark Thompson <sw@jkqxz.net>
Signed-off-by: Zhong Li <zhong.li@intel.com>

libavcodec/qsvenc.c

@@ -1192,6 +1192,13 @@ static int encode_frame(AVCodecContext *avctx, QSVEncContext *q,
     if (qsv_frame) {
         surf = &qsv_frame->surface;
         enc_ctrl = &qsv_frame->enc_ctrl;
+        memset(enc_ctrl, 0, sizeof(mfxEncodeCtrl));
+
+        if (frame->pict_type == AV_PICTURE_TYPE_I) {
+            enc_ctrl->FrameType = MFX_FRAMETYPE_I | MFX_FRAMETYPE_REF;
+            if (q->forced_idr)
+                enc_ctrl->FrameType |= MFX_FRAMETYPE_IDR;
+        }
     }
 
     ret = av_new_packet(&new_pkt, q->packet_size);

libavcodec/qsvenc.h

@@ -87,6 +87,7 @@
 { "adaptive_i",     "Adaptive I-frame placement",             OFFSET(qsv.adaptive_i),     AV_OPT_TYPE_INT, { .i64 = -1 }, -1,          1, VE },                         \
 { "adaptive_b",     "Adaptive B-frame placement",             OFFSET(qsv.adaptive_b),     AV_OPT_TYPE_INT, { .i64 = -1 }, -1,          1, VE },                         \
 { "b_strategy",     "Strategy to choose between I/P/B-frames", OFFSET(qsv.b_strategy),    AV_OPT_TYPE_INT, { .i64 = -1 }, -1,          1, VE },                         \
+{ "forced_idr",     "Forcing I frames as IDR frames",         OFFSET(qsv.forced_idr),     AV_OPT_TYPE_BOOL,{ .i64 = 0  },  0,          1, VE },                         \
 
 typedef int SetEncodeCtrlCB (AVCodecContext *avctx,
                              const AVFrame *frame, mfxEncodeCtrl* enc_ctrl);
@@ -168,6 +169,7 @@ typedef struct QSVEncContext {
 #endif
     char *load_plugins;
     SetEncodeCtrlCB *set_encode_ctrl_cb;
+    int forced_idr;
 } QSVEncContext;
 
 int ff_qsv_enc_init(AVCodecContext *avctx, QSVEncContext *q);