media: venus: venc: Add support for frame-skip mode v4l2 control

This adds support for frame-skip-mode standard v4l2 control in
encoder driver. The control is implemented based on the
combination of client selected bitrate-mode and frame-skip-mode.
Once The client selected bitrate-mode (constant or variable) and
the frame-skip-mode is not disabled we set variable framerate for
rate controller.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/qcom/venus/core.h

@@ -207,6 +207,7 @@ struct venc_controls {
 	u32 bitrate_peak;
 	u32 rc_enable;
 	u32 const_quality;
+	u32 frame_skip_mode;
 
 	u32 h264_i_period;
 	u32 h264_entropy_mode;

drivers/media/platform/qcom/venus/venc.c

@@ -745,9 +745,11 @@ static int venc_set_properties(struct venus_inst *inst)
 	if (!ctr->rc_enable)
 		rate_control = HFI_RATE_CONTROL_OFF;
 	else if (ctr->bitrate_mode == V4L2_MPEG_VIDEO_BITRATE_MODE_VBR)
-		rate_control = HFI_RATE_CONTROL_VBR_CFR;
+		rate_control = ctr->frame_skip_mode ? HFI_RATE_CONTROL_VBR_VFR :
+						      HFI_RATE_CONTROL_VBR_CFR;
 	else if (ctr->bitrate_mode == V4L2_MPEG_VIDEO_BITRATE_MODE_CBR)
-		rate_control = HFI_RATE_CONTROL_CBR_CFR;
+		rate_control = ctr->frame_skip_mode ? HFI_RATE_CONTROL_CBR_VFR :
+						      HFI_RATE_CONTROL_CBR_CFR;
 	else if (ctr->bitrate_mode == V4L2_MPEG_VIDEO_BITRATE_MODE_CQ)
 		rate_control = HFI_RATE_CONTROL_CQ;
 

drivers/media/platform/qcom/venus/venc_ctrls.c

@@ -205,6 +205,9 @@ static int venc_op_s_ctrl(struct v4l2_ctrl *ctrl)
 	case V4L2_CID_MPEG_VIDEO_CONSTANT_QUALITY:
 		ctr->const_quality = ctrl->val;
 		break;
+	case V4L2_CID_MPEG_VIDEO_FRAME_SKIP_MODE:
+		ctr->frame_skip_mode = ctrl->val;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -220,7 +223,7 @@ int venc_ctrl_init(struct venus_inst *inst)
 {
 	int ret;
 
-	ret = v4l2_ctrl_handler_init(&inst->ctrl_handler, 32);
+	ret = v4l2_ctrl_handler_init(&inst->ctrl_handler, 33);
 	if (ret)
 		return ret;
 
@@ -364,6 +367,13 @@ int venc_ctrl_init(struct venus_inst *inst)
 	v4l2_ctrl_new_std(&inst->ctrl_handler, &venc_ctrl_ops,
 			  V4L2_CID_MPEG_VIDEO_CONSTANT_QUALITY, 0, 100, 1, 0);
 
+	v4l2_ctrl_new_std_menu(&inst->ctrl_handler, &venc_ctrl_ops,
+			       V4L2_CID_MPEG_VIDEO_FRAME_SKIP_MODE,
+			       V4L2_MPEG_VIDEO_FRAME_SKIP_MODE_BUF_LIMIT,
+			       ~((1 << V4L2_MPEG_VIDEO_FRAME_SKIP_MODE_DISABLED) |
+			       (1 << V4L2_MPEG_VIDEO_FRAME_SKIP_MODE_BUF_LIMIT)),
+			       V4L2_MPEG_VIDEO_FRAME_SKIP_MODE_DISABLED);
+
 	ret = inst->ctrl_handler.error;
 	if (ret)
 		goto err;