codec/vaapi: calculate max bit-rate from BaseParam

examples/codecparam/main.go

@@ -67,7 +67,7 @@ func main() {
 			// This example is using libva's hardware accelerated codec.
 			// Set encoder parameters to prohibit bitrate overshoot as possible.
 			cp.RateControlMode = vaapi.RateControlVBR
-			cp.RateControl.BitsPerSecond = 400000
+			cp.BitRate = 400000
 			cp.RateControl.TargetPercentage = 95
 			c.VideoEncoderBuilders = []codec.VideoEncoderBuilder{&cp}
 		},

pkg/codec/vaapi/params.go

@@ -27,13 +27,16 @@ type SequenceParamVP8 struct {
 // NewVP8Param returns default parameters of VP8 codec.
 func NewVP8Param() (ParamVP8, error) {
 	return ParamVP8{
+		BaseParams: codec.BaseParams{
+			BitRate:          320000,
+			KeyFrameInterval: 30,
+		},
 		Sequence: SequenceParamVP8{
 			ClampQindexLow:  9,
 			ClampQindexHigh: 127,
 		},
 		RateControlMode: RateControlVBR,
 		RateControl: RateControlParam{
-			BitsPerSecond:    400000,
 			TargetPercentage: 80,
 			WindowSize:       1500,
 			InitialQP:        60,
@@ -62,10 +65,11 @@ type ParamVP9 struct {
 
 // RateControlParam represents VAEncMiscParameterRateControl.
 type RateControlParam struct {
-	// BitsPerSecond is a maximum bit-rate.
+	// bitsPerSecond is a maximum bit-rate.
-	// This parameter overwrites prop.Codec.BitRate.
+	// This parameter is calculated from BaseParams.BitRate.
-	BitsPerSecond uint
+	bitsPerSecond uint
-	// TargetPercentage is a target bit-rate relative to BitsPerSecond.
+	// TargetPercentage is a target bit-rate relative to the maximum bit-rate.
+	// BaseParams.BitRate / (TargetPercentage * 0.01) will be the maximum bit-rate.
 	TargetPercentage uint
 	// WindowSize is a rate control window size in milliseconds.
 	WindowSize uint
@@ -96,9 +100,12 @@ const (
 // NewVP9Param returns default parameters of VP9 codec.
 func NewVP9Param() (ParamVP9, error) {
 	return ParamVP9{
+		BaseParams: codec.BaseParams{
+			BitRate:          320000,
+			KeyFrameInterval: 30,
+		},
 		RateControlMode: RateControlVBR,
 		RateControl: RateControlParam{
-			BitsPerSecond:    400000,
 			TargetPercentage: 80,
 			WindowSize:       1500,
 			InitialQP:        60,

pkg/codec/vaapi/vp8.go

@@ -106,9 +106,8 @@ func newVP8Encoder(r video.Reader, p prop.Media, params ParamVP8) (io.ReadCloser
 		p.FrameRate = 30
 	}
 
-	if params.RateControl.BitsPerSecond == 0 {
+	params.RateControl.bitsPerSecond =
-		params.RateControl.BitsPerSecond = uint(float32(params.BitRate) * 1.5)
+		uint(float32(params.BitRate) / (0.01 * float32(params.RateControl.TargetPercentage)))
-	}
 
 	// Parameters are from https://github.com/intel/libva-utils/blob/master/encode/vp8enc.c
 	e := &encoderVP8{
@@ -119,7 +118,7 @@ func newVP8Encoder(r video.Reader, p prop.Media, params ParamVP8) (io.ReadCloser
 		seqParam: C.VAEncSequenceParameterBufferVP8{
 			frame_width:     C.uint(p.Width),
 			frame_height:    C.uint(p.Height),
-			bits_per_second: C.uint(params.RateControl.BitsPerSecond),
+			bits_per_second: C.uint(params.RateControl.bitsPerSecond),
 			intra_period:    C.uint(params.KeyFrameInterval),
 			kf_max_dist:     C.uint(params.KeyFrameInterval),
 			reference_frames: [4]C.VASurfaceID{
@@ -153,9 +152,9 @@ func newVP8Encoder(r video.Reader, p prop.Media, params ParamVP8) (io.ReadCloser
 				_type: C.VAEncMiscParameterTypeHRD,
 			},
 			data: C.VAEncMiscParameterHRD{
-				initial_buffer_fullness: C.uint(params.RateControl.BitsPerSecond *
+				initial_buffer_fullness: C.uint(params.RateControl.bitsPerSecond *
 					params.RateControl.WindowSize / 2000),
-				buffer_size: C.uint(params.RateControl.BitsPerSecond *
+				buffer_size: C.uint(params.RateControl.bitsPerSecond *
 					params.RateControl.WindowSize / 1000),
 			},
 		},
@@ -176,7 +175,7 @@ func newVP8Encoder(r video.Reader, p prop.Media, params ParamVP8) (io.ReadCloser
 				initial_qp:        C.uint(params.RateControl.InitialQP),
 				min_qp:            C.uint(params.RateControl.MinQP),
 				max_qp:            C.uint(params.RateControl.MaxQP),
-				bits_per_second:   C.uint(params.RateControl.BitsPerSecond),
+				bits_per_second:   C.uint(params.RateControl.bitsPerSecond),
 				target_percentage: C.uint(params.RateControl.TargetPercentage),
 			},
 		},

pkg/codec/vaapi/vp9.go

@@ -110,9 +110,8 @@ func newVP9Encoder(r video.Reader, p prop.Media, params ParamVP9) (io.ReadCloser
 		p.FrameRate = 30
 	}
 
-	if params.RateControl.BitsPerSecond == 0 {
+	params.RateControl.bitsPerSecond =
-		params.RateControl.BitsPerSecond = uint(float32(params.BitRate) * 1.5)
+		uint(float32(params.BitRate) / (0.01 * float32(params.RateControl.TargetPercentage)))
-	}
 
 	// Parameters are from https://github.com/intel/libva-utils/blob/master/encode/vp9enc.c
 	e := &encoderVP9{
@@ -123,7 +122,7 @@ func newVP9Encoder(r video.Reader, p prop.Media, params ParamVP9) (io.ReadCloser
 		seqParam: C.VAEncSequenceParameterBufferVP9{
 			max_frame_width:  8192,
 			max_frame_height: 8192,
-			bits_per_second:  C.uint(params.RateControl.BitsPerSecond),
+			bits_per_second:  C.uint(params.RateControl.bitsPerSecond),
 			intra_period:     C.uint(params.KeyFrameInterval),
 			kf_min_dist:      1,
 			kf_max_dist:      C.uint(params.KeyFrameInterval),
@@ -161,9 +160,9 @@ func newVP9Encoder(r video.Reader, p prop.Media, params ParamVP9) (io.ReadCloser
 				_type: C.VAEncMiscParameterTypeHRD,
 			},
 			data: C.VAEncMiscParameterHRD{
-				initial_buffer_fullness: C.uint(params.RateControl.BitsPerSecond *
+				initial_buffer_fullness: C.uint(params.RateControl.bitsPerSecond *
 					params.RateControl.WindowSize / 2000),
-				buffer_size: C.uint(params.RateControl.BitsPerSecond *
+				buffer_size: C.uint(params.RateControl.bitsPerSecond *
 					params.RateControl.WindowSize / 1000),
 			},
 		},
@@ -184,7 +183,7 @@ func newVP9Encoder(r video.Reader, p prop.Media, params ParamVP9) (io.ReadCloser
 				initial_qp:        C.uint(params.RateControl.InitialQP),
 				min_qp:            C.uint(params.RateControl.MinQP),
 				max_qp:            C.uint(params.RateControl.MaxQP),
-				bits_per_second:   C.uint(params.RateControl.BitsPerSecond),
+				bits_per_second:   C.uint(params.RateControl.bitsPerSecond),
 				target_percentage: C.uint(params.RateControl.TargetPercentage),
 			},
 		},