install go2rtc on bob

2026-04-04 19:36:14 +02:00
parent f0b56e63d1
commit ccf88187b8
537 changed files with 69213 additions and 0 deletions
@@ -0,0 +1,122 @@
+package h264
+
+import (
+	"bytes"
+	"encoding/binary"
+)
+
+const forbiddenZeroBit = 0x80
+const nalUnitType = 0x1F
+
+// Deprecated: DecodeStream - find and return first AU in AVC format
+// useful for processing live streams with unknown separator size
+func DecodeStream(annexb []byte) ([]byte, int) {
+	startPos := -1
+
+	i := 0
+	for {
+		// search next separator
+		if i = IndexFrom(annexb, []byte{0, 0, 1}, i); i < 0 {
+			break
+		}
+
+		// move i to next AU
+		if i += 3; i >= len(annexb) {
+			break
+		}
+
+		// check if AU type valid
+		octet := annexb[i]
+		if octet&forbiddenZeroBit != 0 {
+			continue
+		}
+
+		// 0 => AUD => SPS/IF/PF => AUD
+		// 0 => SPS/PF => SPS/PF
+		nalType := octet & nalUnitType
+		if startPos >= 0 {
+			switch nalType {
+			case NALUTypeAUD, NALUTypeSPS, NALUTypePFrame:
+				if annexb[i-4] == 0 {
+					return DecodeAnnexB(annexb[startPos : i-4]), i - 4
+				} else {
+					return DecodeAnnexB(annexb[startPos : i-3]), i - 3
+				}
+			}
+		} else {
+			switch nalType {
+			case NALUTypeSPS, NALUTypePFrame:
+				if i >= 4 && annexb[i-4] == 0 {
+					startPos = i - 4
+				} else {
+					startPos = i - 3
+				}
+			}
+		}
+	}
+
+	return nil, 0
+}
+
+// DecodeAnnexB - convert AnnexB to AVC format
+// support unknown separator size
+func DecodeAnnexB(b []byte) []byte {
+	if b[2] == 1 {
+		// convert: 0 0 1 => 0 0 0 1
+		b = append([]byte{0}, b...)
+	}
+
+	startPos := 0
+
+	i := 4
+	for {
+		// search next separato
+		if i = IndexFrom(b, []byte{0, 0, 1}, i); i < 0 {
+			break
+		}
+
+		// move i to next AU
+		if i += 3; i >= len(b) {
+			break
+		}
+
+		// check if AU type valid
+		octet := b[i]
+		if octet&forbiddenZeroBit != 0 {
+			continue
+		}
+
+		switch octet & nalUnitType {
+		case NALUTypePFrame, NALUTypeIFrame, NALUTypeSPS, NALUTypePPS:
+			if b[i-4] != 0 {
+				// prefix: 0 0 1
+				binary.BigEndian.PutUint32(b[startPos:], uint32(i-startPos-7))
+				tmp := make([]byte, 0, len(b)+1)
+				tmp = append(tmp, b[:i]...)
+				tmp = append(tmp, 0)
+				b = append(tmp, b[i:]...)
+				startPos = i - 3
+			} else {
+				// prefix: 0 0 0 1
+				binary.BigEndian.PutUint32(b[startPos:], uint32(i-startPos-8))
+				startPos = i - 4
+			}
+		}
+	}
+
+	binary.BigEndian.PutUint32(b[startPos:], uint32(len(b)-startPos-4))
+	return b
+}
+
+func IndexFrom(b []byte, sep []byte, from int) int {
+	if from > 0 {
+		if from < len(b) {
+			if i := bytes.Index(b[from:], sep); i >= 0 {
+				return from + i
+			}
+		}
+		return -1
+	}
+
+	return bytes.Index(b, sep)
+}