libavcodec/qsvenc: Add skip_frame support to qsvenc

Add skip_frame support to qsvenc. Use per-frame metadata
"qsv_skip_frame" to control it. skip_frame option defines the behavior
of qsv_skip_frame.
no_skip: Frame skipping is disabled.
insert_dummy: Encoder inserts into bitstream frame where all macroblocks
are encoded as skipped.
insert_nothing: Similar to insert_dummy, but encoder inserts nothing.
The skipped frames are still used in brc. For example, gop still include
skipped frames, and the frames after skipped frames will be larger in
size.
brc_only: skip_frame metadata indicates the number of missed frames
before the current frame.

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

doc/encoders.texi

@@ -3564,6 +3564,24 @@ bitrate, @var{target_bitrate}, within the accuracy range @var{avbr_accuracy},
 after a @var{avbr_Convergence} period. This method does not follow HRD and the
 instant bitrate is not capped or padded.
 
+@item @var{skip_frame}
+Use per-frame metadata "qsv_skip_frame" to skip frame when encoding. This option
+defines the usage of this metadata.
+@table @samp
+@item no_skip
+Frame skipping is disabled.
+@item insert_dummy
+Encoder inserts into bitstream frame where all macroblocks are encoded as
+skipped.
+@item insert_nothing
+Similar to insert_dummy, but encoder inserts nothing into bitstream. The skipped
+frames are still used in brc. For example, gop still include skipped frames, and
+the frames after skipped frames will be larger in size.
+@item brc_only
+skip_frame metadata indicates the number of missed frames before the current
+frame.
+@end table
+
 @end table
 
 @subsection HEVC Options
@@ -3751,6 +3769,24 @@ bitrate, @var{target_bitrate}, within the accuracy range @var{avbr_accuracy},
 after a @var{avbr_Convergence} period. This method does not follow HRD and the
 instant bitrate is not capped or padded.
 
+@item @var{skip_frame}
+Use per-frame metadata "qsv_skip_frame" to skip frame when encoding. This option
+defines the usage of this metadata.
+@table @samp
+@item no_skip
+Frame skipping is disabled.
+@item insert_dummy
+Encoder inserts into bitstream frame where all macroblocks are encoded as
+skipped.
+@item insert_nothing
+Similar to insert_dummy, but encoder inserts nothing into bitstream. The skipped
+frames are still used in brc. For example, gop still include skipped frames, and
+the frames after skipped frames will be larger in size.
+@item brc_only
+skip_frame metadata indicates the number of missed frames before the current
+frame.
+@end table
+
 @end table
 
 @subsection MPEG2 Options

libavcodec/qsvenc.c

@@ -329,6 +329,22 @@ static void dump_video_param(AVCodecContext *avctx, QSVEncContext *q,
                "MinQPI: %"PRIu8"; MaxQPI: %"PRIu8"; MinQPP: %"PRIu8"; MaxQPP: %"PRIu8"; MinQPB: %"PRIu8"; MaxQPB: %"PRIu8"\n",
                co2->MinQPI, co2->MaxQPI, co2->MinQPP, co2->MaxQPP, co2->MinQPB, co2->MaxQPB);
         av_log(avctx, AV_LOG_VERBOSE, "DisableDeblockingIdc: %"PRIu32" \n", co2->DisableDeblockingIdc);
+
+        switch (co2->SkipFrame) {
+        case MFX_SKIPFRAME_NO_SKIP:
+            av_log(avctx, AV_LOG_VERBOSE, "SkipFrame: no_skip\n");
+            break;
+        case MFX_SKIPFRAME_INSERT_DUMMY:
+            av_log(avctx, AV_LOG_VERBOSE, "SkipFrame: insert_dummy\n");
+            break;
+        case MFX_SKIPFRAME_INSERT_NOTHING:
+            av_log(avctx, AV_LOG_VERBOSE, "SkipFrame: insert_nothing\n");
+            break;
+        case MFX_SKIPFRAME_BRC_ONLY:
+            av_log(avctx, AV_LOG_VERBOSE, "SkipFrame: brc_only\n");
+            break;
+        default: break;
+        }
     }
 
     if (co3) {
@@ -994,6 +1010,8 @@ static int init_video_param(AVCodecContext *avctx, QSVEncContext *q)
             q->old_max_qp_b = q->max_qp_b;
             if (q->mbbrc >= 0)
                 q->extco2.MBBRC = q->mbbrc ? MFX_CODINGOPTION_ON : MFX_CODINGOPTION_OFF;
+            if (q->skip_frame >= 0)
+                q->extco2.SkipFrame = q->skip_frame;
 
             q->extco2.Header.BufferId = MFX_EXTBUFF_CODING_OPTION2;
             q->extco2.Header.BufferSz = sizeof(q->extco2);
@@ -1914,6 +1932,19 @@ static int set_roi_encode_ctrl(AVCodecContext *avctx, const AVFrame *frame,
     return 0;
 }
 
+static void set_skip_frame_encode_ctrl(AVCodecContext *avctx, const AVFrame *frame,
+                               mfxEncodeCtrl *enc_ctrl)
+{
+    AVDictionaryEntry* skip_frame_dict = NULL;
+    if (!frame->metadata)
+        return;
+    skip_frame_dict = av_dict_get(frame->metadata, "qsv_skip_frame", NULL, 0);
+    if (!skip_frame_dict)
+        return;
+    enc_ctrl->SkipFrame = strtol(skip_frame_dict->value, NULL, 10);
+    return;
+}
+
 static int update_qp(AVCodecContext *avctx, QSVEncContext *q)
 {
     int updated = 0, new_qp = 0;
@@ -2285,6 +2316,11 @@ static int encode_frame(AVCodecContext *avctx, QSVEncContext *q,
         if (ret < 0)
             goto free;
     }
+    if ((avctx->codec_id == AV_CODEC_ID_H264 ||
+         avctx->codec_id == AV_CODEC_ID_H265) &&
+         q->skip_frame != MFX_SKIPFRAME_NO_SKIP &&
+         enc_ctrl && QSV_RUNTIME_VERSION_ATLEAST(q->ver, 1, 13))
+        set_skip_frame_encode_ctrl(avctx, frame, enc_ctrl);
 
     pkt.sync = av_mallocz(sizeof(*pkt.sync));
     if (!pkt.sync)

libavcodec/qsvenc.h

@@ -127,6 +127,18 @@
 { "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 },
 
+#define QSV_OPTION_SKIP_FRAME \
+{ "skip_frame",     "Allow frame skipping", OFFSET(qsv.skip_frame),  AV_OPT_TYPE_INT, { .i64 = MFX_SKIPFRAME_NO_SKIP }, \
+   MFX_SKIPFRAME_NO_SKIP, MFX_SKIPFRAME_BRC_ONLY, VE, "skip_frame" }, \
+{ "no_skip",        "Frame skipping is disabled", \
+    0, AV_OPT_TYPE_CONST, { .i64 = MFX_SKIPFRAME_NO_SKIP },           .flags = VE, "skip_frame" },        \
+{ "insert_dummy",   "Encoder inserts into bitstream frame where all macroblocks are encoded as skipped",  \
+    0, AV_OPT_TYPE_CONST, { .i64 = MFX_SKIPFRAME_INSERT_DUMMY },      .flags = VE, "skip_frame" },        \
+{ "insert_nothing", "Encoder inserts nothing into bitstream",                                             \
+    0, AV_OPT_TYPE_CONST, { .i64 = MFX_SKIPFRAME_INSERT_NOTHING },    .flags = VE, "skip_frame" },        \
+{ "brc_only",       "skip_frame metadata indicates the number of missed frames before the current frame", \
+    0, AV_OPT_TYPE_CONST, { .i64 = MFX_SKIPFRAME_BRC_ONLY },          .flags = VE, "skip_frame" },
+
 extern const AVCodecHWConfigInternal *const ff_qsv_enc_hw_configs[];
 
 typedef int SetEncodeCtrlCB (AVCodecContext *avctx,
@@ -286,6 +298,7 @@ typedef struct QSVEncContext {
     int old_rc_max_rate;
     // This is used for SEI Timing reset
     int old_pic_timing_sei;
+    int skip_frame;
 } QSVEncContext;
 
 int ff_qsv_enc_init(AVCodecContext *avctx, QSVEncContext *q);

libavcodec/qsvenc_h264.c

@@ -116,6 +116,7 @@ static const AVOption options[] = {
     QSV_OPTION_MAX_MIN_QP
     QSV_OPTION_SCENARIO
     QSV_OPTION_AVBR
+    QSV_OPTION_SKIP_FRAME
 
     { "cavlc",          "Enable CAVLC",                           OFFSET(qsv.cavlc),          AV_OPT_TYPE_BOOL, { .i64 = 0 },   0,          1, VE },
 #if QSV_HAVE_VCM

libavcodec/qsvenc_hevc.c

@@ -317,6 +317,7 @@ static const AVOption options[] = {
     QSV_OPTION_ADAPTIVE_B
     QSV_OPTION_SCENARIO
     QSV_OPTION_AVBR
+    QSV_OPTION_SKIP_FRAME
 
     { "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" },