av/codec/h264/h264dec/rbsp.go

package h264dec

import (
	"fmt"

	"github.com/ausocean/h264decode/h264/bits"
)

const (
	profileBaseline          = 66
	profileMain              = 77
	profileExtended          = 88
	profileHigh              = 100
	profileHigh10            = 110
	profileHigh422           = 122
	profileHigh444Predictive = 244
)

var (
	ProfileIDC = map[int]string{
		profileBaseline:          "Baseline",
		profileMain:              "Main",
		profileExtended:          "Extended",
		profileHigh:              "High",
		profileHigh10:            "High 10",
		profileHigh422:           "High 4:2:2",
		profileHigh444Predictive: "High 4:4:4",
	}
)

// 7.3.2.11
func rbspTrailingBits(br *bits.BitReader) {
	_, err := br.ReadBits(1)
	if err != nil {
		fmt.Printf("error reading StopOneBit: %v\n", err)
	}
	// 7.2
	for !br.ByteAligned() {
		// RBSPAlignmentZeroBit
		_, err := br.ReadBits(1)
		if err != nil {
			fmt.Printf("error reading AligntmentZeroBit: %v\n", err)
			break
		}
	}
}
func NewRBSP(frame []byte) []byte {
	// TODO: NALUType 14,20,21 add padding to 3rd or 4th byte
	return frame[5:]
}

// TODO: Should be base-ten big endian bit arrays, not bytes
// ITU A.2.1.1 - Bit 9 is 1
func isConstrainedBaselineProfile(profile int, b []byte) bool {
	if profile != profileBaseline {
		return false
	}
	if len(b) > 8 && b[8] == 1 {
		return true
	}
	return false
}

// ITU A2.4.2 - Bit 12 and 13 are 1
func isConstrainedHighProfile(profile int, b []byte) bool {
	if profile != profileHigh {
		return false
	}
	if len(b) > 13 {
		if b[12] == 1 && b[13] == 1 {
			return true
		}
	}
	return false
}

// ITU A2.8 - Bit 11 is 1
func isHigh10IntraProfile(profile int, b []byte) bool {
	if profile != profileHigh10 {
		return false
	}
	if len(b) > 11 && b[11] == 1 {
		return true
	}
	return false
}