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 +1,148 @@
+package aac
+
+import (
+	"encoding/hex"
+
+	"github.com/AlexxIT/go2rtc/pkg/bits"
+	"github.com/AlexxIT/go2rtc/pkg/core"
+	"github.com/pion/rtp"
+)
+
+const ADTSHeaderSize = 7
+
+func ADTSHeaderLen(b []byte) int {
+	if HasCRC(b) {
+		return 9 // 7 bytes header + 2 bytes CRC
+	}
+	return ADTSHeaderSize
+}
+
+func IsADTS(b []byte) bool {
+	// AAAAAAAA AAAABCCD EEFFFFGH HHIJKLMM MMMMMMMM MMMOOOOO OOOOOOPP (QQQQQQQQ QQQQQQQQ)
+	// A	12	Syncword, all bits must be set to 1.
+	// C	2	Layer, always set to 0.
+	return len(b) >= ADTSHeaderSize && b[0] == 0xFF && b[1]&0b1111_0110 == 0xF0
+}
+
+func HasCRC(b []byte) bool {
+	// AAAAAAAA AAAABCCD EEFFFFGH HHIJKLMM MMMMMMMM MMMOOOOO OOOOOOPP (QQQQQQQQ QQQQQQQQ)
+	// D	1	Protection absence, set to 1 if there is no CRC and 0 if there is CRC.
+	return b[1]&0b1 == 0
+}
+
+func ADTSToCodec(b []byte) *core.Codec {
+	// 1. Check ADTS header
+	if !IsADTS(b) {
+		return nil
+	}
+
+	// 2. Decode ADTS params
+	// https://wiki.multimedia.cx/index.php/ADTS
+	rd := bits.NewReader(b)
+	_ = rd.ReadBits(12)              // Syncword, all bits must be set to 1
+	_ = rd.ReadBit()                 // MPEG Version, set to 0 for MPEG-4 and 1 for MPEG-2
+	_ = rd.ReadBits(2)               // Layer, always set to 0
+	_ = rd.ReadBit()                 // Protection absence, set to 1 if there is no CRC and 0 if there is CRC
+	objType := rd.ReadBits8(2) + 1   // Profile, the MPEG-4 Audio Object Type minus 1
+	sampleRateIdx := rd.ReadBits8(4) // MPEG-4 Sampling Frequency Index
+	_ = rd.ReadBit()                 // Private bit, guaranteed never to be used by MPEG, set to 0 when encoding, ignore when decoding
+	channels := rd.ReadBits8(3)      // MPEG-4 Channel Configuration
+
+	//_ = rd.ReadBit()    // Originality, set to 1 to signal originality of the audio and 0 otherwise
+	//_ = rd.ReadBit()    // Home, set to 1 to signal home usage of the audio and 0 otherwise
+	//_ = rd.ReadBit()    // Copyright ID bit
+	//_ = rd.ReadBit()    // Copyright ID start
+	//_ = rd.ReadBits(13) // Frame length
+	//_ = rd.ReadBits(11) // Buffer fullness
+	//_ = rd.ReadBits(2)  // Number of AAC frames (Raw Data Blocks) in ADTS frame minus 1
+	//_ = rd.ReadBits(16) // CRC check
+
+	// 3. Encode RTP config
+	wr := bits.NewWriter(nil)
+	wr.WriteBits8(objType, 5)
+	wr.WriteBits8(sampleRateIdx, 4)
+	wr.WriteBits8(channels, 4)
+	conf := wr.Bytes()
+
+	codec := &core.Codec{
+		Name:      core.CodecAAC,
+		ClockRate: sampleRates[sampleRateIdx],
+		Channels:  channels,
+		FmtpLine:  FMTP + hex.EncodeToString(conf),
+	}
+	return codec
+}
+
+func ReadADTSSize(b []byte) uint16 {
+	// AAAAAAAA AAAABCCD EEFFFFGH HHIJKLMM MMMMMMMM MMMOOOOO OOOOOOPP (QQQQQQQQ QQQQQQQQ)
+	_ = b[5] // bounds
+	return uint16(b[3]&0b11)<<11 | uint16(b[4])<<3 | uint16(b[5]>>5)
+}
+
+func WriteADTSSize(b []byte, size uint16) {
+	// AAAAAAAA AAAABCCD EEFFFFGH HHIJKLMM MMMMMMMM MMMOOOOO OOOOOOPP (QQQQQQQQ QQQQQQQQ)
+	_ = b[5] // bounds
+	b[3] |= byte(size >> (8 + 3))
+	b[4] = byte(size >> 3)
+	b[5] |= byte(size << 5)
+	return
+}
+
+func ADTSTimeSize(b []byte) uint32 {
+	var units uint32
+	for len(b) > ADTSHeaderSize {
+		auSize := ReadADTSSize(b)
+		b = b[auSize:]
+		units++
+	}
+	return units * AUTime
+}
+
+func CodecToADTS(codec *core.Codec) []byte {
+	s := core.Between(codec.FmtpLine, "config=", ";")
+	conf, err := hex.DecodeString(s)
+	if err != nil {
+		return nil
+	}
+
+	objType, sampleFreqIdx, channels, _ := DecodeConfig(conf)
+	profile := objType - 1
+
+	wr := bits.NewWriter(nil)
+	wr.WriteAllBits(1, 12)          // Syncword, all bits must be set to 1
+	wr.WriteBit(0)                  // MPEG Version, set to 0 for MPEG-4 and 1 for MPEG-2
+	wr.WriteBits8(0, 2)             // Layer, always set to 0
+	wr.WriteBit(1)                  // Protection absence, set to 1 if there is no CRC and 0 if there is CRC
+	wr.WriteBits8(profile, 2)       // Profile, the MPEG-4 Audio Object Type minus 1
+	wr.WriteBits8(sampleFreqIdx, 4) // MPEG-4 Sampling Frequency Index
+	wr.WriteBit(0)                  // Private bit, guaranteed never to be used by MPEG, set to 0 when encoding, ignore when decoding
+	wr.WriteBits8(channels, 3)      // MPEG-4 Channel Configuration
+	wr.WriteBit(0)                  // Originality, set to 1 to signal originality of the audio and 0 otherwise
+	wr.WriteBit(0)                  // Home, set to 1 to signal home usage of the audio and 0 otherwise
+	wr.WriteBit(0)                  // Copyright ID bit
+	wr.WriteBit(0)                  // Copyright ID start
+	wr.WriteBits16(0, 13)           // Frame length
+	wr.WriteAllBits(1, 11)          // Buffer fullness (variable bitrate)
+	wr.WriteBits8(0, 2)             // Number of AAC frames (Raw Data Blocks) in ADTS frame minus 1
+
+	return wr.Bytes()
+}
+
+func EncodeToADTS(codec *core.Codec, handler core.HandlerFunc) core.HandlerFunc {
+	adts := CodecToADTS(codec)
+
+	return func(packet *rtp.Packet) {
+		if !IsADTS(packet.Payload) {
+			b := make([]byte, ADTSHeaderSize+len(packet.Payload))
+			copy(b, adts)
+			copy(b[ADTSHeaderSize:], packet.Payload)
+			WriteADTSSize(b, uint16(len(b)))
+
+			clone := *packet
+			clone.Payload = b
+			handler(&clone)
+		} else {
+			handler(packet)
+		}
+	}
+}