lavc/qsvenc: use VBR if maxrate is not specified on Windows

Currently AVBR is disabled and VBR is the default method if maxrate is
not specified on Linux, but AVBR is the default one if maxrate is not
specified on Windows. In order to make user experience better accross
Linux and Windows, use VBR by default on Windows if maxrate is not
specified. User need to set both avbr_accuracy and avbr_convergence to
non-zero explicitly and not to specify maxrate if AVBR is expected.

In addition, AVBR works for H264 and HEVC only in the SDK.

$ ffmpeg.exe -v verbose -f lavfi -i yuvtestsrc -vf "format=nv12" -c:v
vp9_qsv -f null -

4 files changed, 10 insertions, 3 deletions

diff --git a/libavcodec/qsvenc.c b/libavcodec/qsvenc.c
index 7ac5390f10..31ff3b76ed 100644
--- a/libavcodec/qsvenc.c
+++ b/libavcodec/qsvenc.c
@@ -479,7 +479,10 @@ static int select_rc_mode(AVCodecContext *avctx, QSVEncContext *q)
         rc_desc = "constant bitrate (CBR)";
     }
 #if QSV_HAVE_AVBR
-    else if (!avctx->rc_max_rate) {
+    else if (!avctx->rc_max_rate &&
+             (avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == AV_CODEC_ID_HEVC) &&
+             q->avbr_accuracy &&
+             q->avbr_convergence) {
         rc_mode = MFX_RATECONTROL_AVBR;
         rc_desc = "average variable bitrate (AVBR)";
     }
diff --git a/libavcodec/qsvenc.h b/libavcodec/qsvenc.h
index a983651dda..ff859f2a7e 100644
--- a/libavcodec/qsvenc.h
+++ b/libavcodec/qsvenc.h
@@ -52,8 +52,6 @@
 
 #define QSV_COMMON_OPTS \
 { "async_depth", "Maximum processing parallelism", OFFSET(qsv.async_depth), AV_OPT_TYPE_INT, { .i64 = ASYNC_DEPTH_DEFAULT }, 1, INT_MAX, VE },                          \
-{ "avbr_accuracy",    "Accuracy of the AVBR ratecontrol (unit of tenth of percent)",    OFFSET(qsv.avbr_accuracy),    AV_OPT_TYPE_INT, { .i64 = 1 }, 1, UINT16_MAX, VE }, \
-{ "avbr_convergence", "Convergence of the AVBR ratecontrol (unit of 100 frames)", OFFSET(qsv.avbr_convergence), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, UINT16_MAX, VE },     \
 { "preset", NULL, OFFSET(qsv.preset), AV_OPT_TYPE_INT, { .i64 = MFX_TARGETUSAGE_BALANCED }, MFX_TARGETUSAGE_BEST_QUALITY, MFX_TARGETUSAGE_BEST_SPEED,   VE, "preset" }, \
 { "veryfast",    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = MFX_TARGETUSAGE_BEST_SPEED  },   INT_MIN, INT_MAX, VE, "preset" },                                                \
 { "faster",      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = MFX_TARGETUSAGE_6  },            INT_MIN, INT_MAX, VE, "preset" },                                                \
@@ -124,6 +122,10 @@
 { "gamestreaming",      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = MFX_SCENARIO_GAME_STREAMING },     .flags = VE, "scenario" },                                      \
 { "remotegaming",       NULL, 0, AV_OPT_TYPE_CONST, { .i64 = MFX_SCENARIO_REMOTE_GAMING },      .flags = VE, "scenario" },
 
+#define QSV_OPTION_AVBR \
+{ "avbr_accuracy",    "Accuracy of the AVBR ratecontrol (unit of tenth of percent)",    OFFSET(qsv.avbr_accuracy),    AV_OPT_TYPE_INT, { .i64 = 0 }, 0, UINT16_MAX, VE }, \
+{ "avbr_convergence", "Convergence of the AVBR ratecontrol (unit of 100 frames)", OFFSET(qsv.avbr_convergence), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, UINT16_MAX, VE },
+
 extern const AVCodecHWConfigInternal *const ff_qsv_enc_hw_configs[];
 
 typedef int SetEncodeCtrlCB (AVCodecContext *avctx,
diff --git a/libavcodec/qsvenc_h264.c b/libavcodec/qsvenc_h264.c
index 1bbdc45203..3fae8f0200 100644
--- a/libavcodec/qsvenc_h264.c
+++ b/libavcodec/qsvenc_h264.c
@@ -115,6 +115,7 @@ static const AVOption options[] = {
     QSV_OPTION_LOW_DELAY_BRC
     QSV_OPTION_MAX_MIN_QP
     QSV_OPTION_SCENARIO
+    QSV_OPTION_AVBR
 
     { "cavlc",          "Enable CAVLC",                           OFFSET(qsv.cavlc),          AV_OPT_TYPE_BOOL, { .i64 = 0 },   0,          1, VE },
 #if QSV_HAVE_VCM
diff --git a/libavcodec/qsvenc_hevc.c b/libavcodec/qsvenc_hevc.c
index 5986c3f1a6..98e002a305 100644
--- a/libavcodec/qsvenc_hevc.c
+++ b/libavcodec/qsvenc_hevc.c
@@ -236,6 +236,7 @@ static const AVOption options[] = {
     QSV_OPTION_ADAPTIVE_I
     QSV_OPTION_ADAPTIVE_B
     QSV_OPTION_SCENARIO
+    QSV_OPTION_AVBR
 
     { "idr_interval", "Distance (in I-frames) between IDR frames", OFFSET(qsv.idr_interval), AV_OPT_TYPE_INT, { .i64 = 0 }, -1, INT_MAX, VE, "idr_interval" },
     { "begin_only", "Output an IDR-frame only at the beginning of the stream", 0, AV_OPT_TYPE_CONST, { .i64 = -1 }, 0, 0, VE, "idr_interval" },