lavc/qsvenc_hevc: add qmax/qmin support for HEVC encoding

Add qmax/qmin support for HEVC software bitrate control(SWBRC).

Limitations:
    - RateControlMethod != MFX_RATECONTROL_CQP
    - with EXTBRC ON

Signed-off-by: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Signed-off-by: Linjie Fu <linjie.fu@intel.com>
Signed-off-by: Zhong Li <zhongli_dev@126.com>

libavcodec/qsvenc.c

@@ -735,6 +735,11 @@ FF_ENABLE_DEPRECATION_WARNINGS
             if (q->adaptive_b >= 0)
                 q->extco2.AdaptiveB = q->adaptive_b ? MFX_CODINGOPTION_ON : MFX_CODINGOPTION_OFF;
 #endif
+        }
+
+        if (avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == AV_CODEC_ID_HEVC) {
+            if (q->extbrc >= 0)
+                q->extco2.ExtBRC = q->extbrc ? MFX_CODINGOPTION_ON : MFX_CODINGOPTION_OFF;
 
 #if QSV_VERSION_ATLEAST(1, 9)
             if (avctx->qmin >= 0 && avctx->qmax >= 0 && avctx->qmin > avctx->qmax) {
@@ -750,12 +755,6 @@ FF_ENABLE_DEPRECATION_WARNINGS
                 q->extco2.MaxQPP = q->extco2.MaxQPB = q->extco2.MaxQPI;
             }
 #endif
-        }
-
-        if (avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == AV_CODEC_ID_HEVC) {
-            if (q->extbrc >= 0)
-                q->extco2.ExtBRC = q->extbrc ? MFX_CODINGOPTION_ON : MFX_CODINGOPTION_OFF;
-
             q->extco2.Header.BufferId = MFX_EXTBUFF_CODING_OPTION2;
             q->extco2.Header.BufferSz = sizeof(q->extco2);
 

libavcodec/qsvenc_hevc.c

@@ -263,6 +263,8 @@ static const AVCodecDefault qsv_enc_defaults[] = {
     // same as the x264 default
     { "g",         "248"   },
     { "bf",        "8"     },
+    { "qmin",      "-1"    },
+    { "qmax",      "-1"    },
     { "trellis",   "-1"    },
     { "flags",     "+cgop" },
 #if FF_API_PRIVATE_OPT