libavcodec/qsvenc: enable LowDelayBRC and MaxFrameSizeI/MaxFrameSizeP for more accurate bitrate control

Feature introduction of LowDelayBRC, MaxFrameSizeI and MaxFrameSizeP could be found here:
https://github.com/Intel-Media-SDK/MediaSDK/blob/master/doc/mediasdk-man.md

Signed-off-by: Dmitry Ermilov <dmitry.ermilov@intel.com>
Signed-off-by: Fan F He <fan.f.he@intel.com>

doc/encoders.texi

@@ -3266,6 +3266,14 @@ Enable rate distortion optimization.
 @item @var{max_frame_size}
 Maximum encoded frame size in bytes.
 
+@item @var{max_frame_size_i}
+Maximum encoded frame size for I frames in bytes. If this value is set as larger
+than zero, then for I frames the value set by max_frame_size is ignored.
+
+@item @var{max_frame_size_p}
+Maximum encoded frame size for P frames in bytes. If this value is set as larger
+than zero, then for P frames the value set by max_frame_size is ignored.
+
 @item @var{max_slice_size}
 Maximum encoded slice size in bytes.
 
@@ -3282,6 +3290,11 @@ Setting this flag enables macroblock level bitrate control that generally
 improves subjective visual quality. Enabling this flag may have negative impact
 on performance and objective visual quality metric.
 
+@item @var{low_delay_brc}
+Setting this flag turns on or off LowDelayBRC feautre in qsv plugin, which provides
+more accurate bitrate control to minimize the variance of bitstream size frame
+by frame. Value: -1-default 0-off 1-on
+
 @item @var{adaptive_i}
 This flag controls insertion of I frames by the QSV encoder. Turn ON this flag
 to allow changing of frame type from P and B to I.
@@ -3394,6 +3407,14 @@ Enable rate distortion optimization.
 @item @var{max_frame_size}
 Maximum encoded frame size in bytes.
 
+@item @var{max_frame_size_i}
+Maximum encoded frame size for I frames in bytes. If this value is set as larger
+than zero, then for I frames the value set by max_frame_size is ignored.
+
+@item @var{max_frame_size_p}
+Maximum encoded frame size for P frames in bytes. If this value is set as larger
+than zero, then for P frames the value set by max_frame_size is ignored.
+
 @item @var{max_slice_size}
 Maximum encoded slice size in bytes.
 
@@ -3402,6 +3423,11 @@ Setting this flag enables macroblock level bitrate control that generally
 improves subjective visual quality. Enabling this flag may have negative impact
 on performance and objective visual quality metric.
 
+@item @var{low_delay_brc}
+Setting this flag turns on or off LowDelayBRC feautre in qsv plugin, which provides
+more accurate bitrate control to minimize the variance of bitstream size frame
+by frame. Value: -1-default 0-off 1-on
+
 @item @var{p_strategy}
 Enable P-pyramid: 0-default 1-simple 2-pyramid(bf need to be set to 0).
 

libavcodec/qsvenc.c

@@ -376,6 +376,13 @@ static void dump_video_param(AVCodecContext *avctx, QSVEncContext *q,
 #if QSV_VERSION_ATLEAST(1, 16)
     av_log(avctx, AV_LOG_VERBOSE, "IntRefCycleDist: %"PRId16"\n", co3->IntRefCycleDist);
 #endif
+#if QSV_VERSION_ATLEAST(1, 23)
+    av_log(avctx, AV_LOG_VERBOSE, "LowDelayBRC: %s\n", print_threestate(co3->LowDelayBRC));
+#endif
+#if QSV_VERSION_ATLEAST(1, 19)
+    av_log(avctx, AV_LOG_VERBOSE, "MaxFrameSizeI: %d; ", co3->MaxFrameSizeI);
+    av_log(avctx, AV_LOG_VERBOSE, "MaxFrameSizeP: %d\n", co3->MaxFrameSizeP);
+#endif
 }
 
 static void dump_video_vp9_param(AVCodecContext *avctx, QSVEncContext *q,
@@ -990,6 +997,16 @@ static int init_video_param(AVCodecContext *avctx, QSVEncContext *q)
 #if QSV_VERSION_ATLEAST(1, 16)
             if (q->int_ref_cycle_dist >= 0)
                 q->extco3.IntRefCycleDist = q->int_ref_cycle_dist;
+#endif
+#if QSV_VERSION_ATLEAST(1, 23)
+            if (q->low_delay_brc >= 0)
+                q->extco3.LowDelayBRC = q->low_delay_brc ? MFX_CODINGOPTION_ON : MFX_CODINGOPTION_OFF;
+#endif
+#if QSV_VERSION_ATLEAST(1, 19)
+            if (q->max_frame_size_p >= 0)
+                q->extco3.MaxFrameSizeI = q->max_frame_size_i;
+            if (q->max_frame_size_p >= 0)
+                q->extco3.MaxFrameSizeP = q->max_frame_size_p;
 #endif
         }
 

libavcodec/qsvenc.h

@@ -90,8 +90,10 @@
 { "slower",      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = MFX_TARGETUSAGE_2  },            INT_MIN, INT_MAX, VE, "preset" },                                                \
 { "veryslow",    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = MFX_TARGETUSAGE_BEST_QUALITY  }, INT_MIN, INT_MAX, VE, "preset" },                                                \
 { "rdo",            "Enable rate distortion optimization",    OFFSET(qsv.rdo),            AV_OPT_TYPE_INT, { .i64 = -1 }, -1,          1, VE },                         \
-{ "max_frame_size", "Maximum encoded frame size in bytes",    OFFSET(qsv.max_frame_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, UINT16_MAX, VE },                         \
+{ "max_frame_size", "Maximum encoded frame size in bytes",    OFFSET(qsv.max_frame_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1,    INT_MAX, VE },                         \
-{ "max_slice_size", "Maximum encoded slice size in bytes",    OFFSET(qsv.max_slice_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, UINT16_MAX, VE },                         \
+{ "max_frame_size_i", "Maximum encoded I frame size in bytes",OFFSET(qsv.max_frame_size_i), AV_OPT_TYPE_INT, { .i64 = -1 }, -1,  INT_MAX, VE },                         \
+{ "max_frame_size_p", "Maximum encoded P frame size in bytes",OFFSET(qsv.max_frame_size_p), AV_OPT_TYPE_INT, { .i64 = -1 }, -1,  INT_MAX, VE },                         \
+{ "max_slice_size", "Maximum encoded slice size in bytes",    OFFSET(qsv.max_slice_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1,    INT_MAX, VE },                         \
 { "bitrate_limit",  "Toggle bitrate limitations",             OFFSET(qsv.bitrate_limit),  AV_OPT_TYPE_INT, { .i64 = -1 }, -1,          1, VE },                         \
 { "mbbrc",          "MB level bitrate control",               OFFSET(qsv.mbbrc),          AV_OPT_TYPE_INT, { .i64 = -1 }, -1,          1, VE },                         \
 { "extbrc",         "Extended bitrate control",               OFFSET(qsv.extbrc),         AV_OPT_TYPE_INT, { .i64 = -1 }, -1,          1, VE },                         \
@@ -102,6 +104,7 @@
 { "forced_idr",     "Forcing I frames as IDR frames",         OFFSET(qsv.forced_idr),     AV_OPT_TYPE_BOOL,{ .i64 = 0  },  0,          1, VE },                         \
 { "low_power", "enable low power mode(experimental: many limitations by mfx version, BRC modes, etc.)", OFFSET(qsv.low_power), AV_OPT_TYPE_BOOL, { .i64 = -1}, -1, 1, VE},\
 { "dblk_idc", "This option disable deblocking. It has value in range 0~2.",   OFFSET(qsv.dblk_idc),   AV_OPT_TYPE_INT,    { .i64 = 0 },   0,  2,  VE},    \
+{ "low_delay_brc",   "Allow to strictly obey avg frame size", OFFSET(qsv.low_delay_brc),  AV_OPT_TYPE_BOOL,{ .i64 = -1 }, -1,          1, VE },                         \
 
 extern const AVCodecHWConfigInternal *const ff_qsv_enc_hw_configs[];
 
@@ -173,6 +176,8 @@ typedef struct QSVEncContext {
     int vcm;
     int rdo;
     int max_frame_size;
+    int max_frame_size_i;
+    int max_frame_size_p;
     int max_slice_size;
     int dblk_idc;
 
@@ -212,6 +217,7 @@ typedef struct QSVEncContext {
     char *load_plugins;
     SetEncodeCtrlCB *set_encode_ctrl_cb;
     int forced_idr;
+    int low_delay_brc;
 } QSVEncContext;
 
 int ff_qsv_enc_init(AVCodecContext *avctx, QSVEncContext *q);