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-rw-r--r--vendor/github.com/pion/rtcp/transport_layer_cc.go560
1 files changed, 560 insertions, 0 deletions
diff --git a/vendor/github.com/pion/rtcp/transport_layer_cc.go b/vendor/github.com/pion/rtcp/transport_layer_cc.go
new file mode 100644
index 0000000..9606581
--- /dev/null
+++ b/vendor/github.com/pion/rtcp/transport_layer_cc.go
@@ -0,0 +1,560 @@
+package rtcp
+
+// Author: adwpc
+
+import (
+ "encoding/binary"
+ "errors"
+ "fmt"
+ "math"
+)
+
+// https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01#page-5
+// 0 1 2 3
+// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |V=2|P| FMT=15 | PT=205 | length |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | SSRC of packet sender |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | SSRC of media source |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | base sequence number | packet status count |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | reference time | fb pkt. count |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | packet chunk | packet chunk |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// . .
+// . .
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | packet chunk | recv delta | recv delta |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// . .
+// . .
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | recv delta | recv delta | zero padding |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+// for packet status chunk
+const (
+ // type of packet status chunk
+ TypeTCCRunLengthChunk = 0
+ TypeTCCStatusVectorChunk = 1
+
+ // len of packet status chunk
+ packetStatusChunkLength = 2
+)
+
+// type of packet status symbol and recv delta
+const (
+ // https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01#section-3.1.1
+ TypeTCCPacketNotReceived = uint16(iota)
+ TypeTCCPacketReceivedSmallDelta
+ TypeTCCPacketReceivedLargeDelta
+ // https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01#page-7
+ // see Example 2: "packet received, w/o recv delta"
+ TypeTCCPacketReceivedWithoutDelta
+)
+
+// for status vector chunk
+const (
+ // https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01#section-3.1.4
+ TypeTCCSymbolSizeOneBit = 0
+ TypeTCCSymbolSizeTwoBit = 1
+
+ // Notice: RFC is wrong: "packet received" (0) and "packet not received" (1)
+ // if S == TypeTCCSymbolSizeOneBit, symbol list will be: TypeTCCPacketNotReceived TypeTCCPacketReceivedSmallDelta
+ // if S == TypeTCCSymbolSizeTwoBit, symbol list will be same as above:
+)
+
+func numOfBitsOfSymbolSize() map[uint16]uint16 {
+ return map[uint16]uint16{
+ TypeTCCSymbolSizeOneBit: 1,
+ TypeTCCSymbolSizeTwoBit: 2,
+ }
+}
+
+var _ Packet = (*TransportLayerCC)(nil) // assert is a Packet
+
+var (
+ errPacketStatusChunkLength = errors.New("packet status chunk must be 2 bytes")
+ errDeltaExceedLimit = errors.New("delta exceed limit")
+)
+
+// PacketStatusChunk has two kinds:
+// RunLengthChunk and StatusVectorChunk
+type PacketStatusChunk interface {
+ Marshal() ([]byte, error)
+ Unmarshal(rawPacket []byte) error
+}
+
+// RunLengthChunk T=TypeTCCRunLengthChunk
+// 0 1
+// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |T| S | Run Length |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+type RunLengthChunk struct {
+ PacketStatusChunk
+
+ // T = TypeTCCRunLengthChunk
+ Type uint16
+
+ // S: type of packet status
+ // kind: TypeTCCPacketNotReceived or...
+ PacketStatusSymbol uint16
+
+ // RunLength: count of S
+ RunLength uint16
+}
+
+// Marshal ..
+func (r RunLengthChunk) Marshal() ([]byte, error) {
+ chunk := make([]byte, 2)
+
+ // append 1 bit '0'
+ dst, err := setNBitsOfUint16(0, 1, 0, 0)
+ if err != nil {
+ return nil, err
+ }
+
+ // append 2 bit PacketStatusSymbol
+ dst, err = setNBitsOfUint16(dst, 2, 1, r.PacketStatusSymbol)
+ if err != nil {
+ return nil, err
+ }
+
+ // append 13 bit RunLength
+ dst, err = setNBitsOfUint16(dst, 13, 3, r.RunLength)
+ if err != nil {
+ return nil, err
+ }
+
+ binary.BigEndian.PutUint16(chunk, dst)
+ return chunk, nil
+}
+
+// Unmarshal ..
+func (r *RunLengthChunk) Unmarshal(rawPacket []byte) error {
+ if len(rawPacket) != packetStatusChunkLength {
+ return errPacketStatusChunkLength
+ }
+
+ // record type
+ r.Type = TypeTCCRunLengthChunk
+
+ // get PacketStatusSymbol
+ // r.PacketStatusSymbol = uint16(rawPacket[0] >> 5 & 0x03)
+ r.PacketStatusSymbol = getNBitsFromByte(rawPacket[0], 1, 2)
+
+ // get RunLength
+ // r.RunLength = uint16(rawPacket[0]&0x1F)*256 + uint16(rawPacket[1])
+ r.RunLength = getNBitsFromByte(rawPacket[0], 3, 5)<<8 + uint16(rawPacket[1])
+ return nil
+}
+
+// StatusVectorChunk T=typeStatusVecotrChunk
+// 0 1
+// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |T|S| symbol list |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+type StatusVectorChunk struct {
+ PacketStatusChunk
+ // T = TypeTCCRunLengthChunk
+ Type uint16
+
+ // TypeTCCSymbolSizeOneBit or TypeTCCSymbolSizeTwoBit
+ SymbolSize uint16
+
+ // when SymbolSize = TypeTCCSymbolSizeOneBit, SymbolList is 14*1bit:
+ // TypeTCCSymbolListPacketReceived or TypeTCCSymbolListPacketNotReceived
+ // when SymbolSize = TypeTCCSymbolSizeTwoBit, SymbolList is 7*2bit:
+ // TypeTCCPacketNotReceived TypeTCCPacketReceivedSmallDelta TypeTCCPacketReceivedLargeDelta or typePacketReserved
+ SymbolList []uint16
+}
+
+// Marshal ..
+func (r StatusVectorChunk) Marshal() ([]byte, error) {
+ chunk := make([]byte, 2)
+
+ // set first bit '1'
+ dst, err := setNBitsOfUint16(0, 1, 0, 1)
+ if err != nil {
+ return nil, err
+ }
+
+ // set second bit SymbolSize
+ dst, err = setNBitsOfUint16(dst, 1, 1, r.SymbolSize)
+ if err != nil {
+ return nil, err
+ }
+
+ numOfBits := numOfBitsOfSymbolSize()[r.SymbolSize]
+ // append 14 bit SymbolList
+ for i, s := range r.SymbolList {
+ index := numOfBits*uint16(i) + 2
+ dst, err = setNBitsOfUint16(dst, numOfBits, index, s)
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ binary.BigEndian.PutUint16(chunk, dst)
+ // set SymbolList(bit8-15)
+ // chunk[1] = uint8(r.SymbolList) & 0x0f
+ return chunk, nil
+}
+
+// Unmarshal ..
+func (r *StatusVectorChunk) Unmarshal(rawPacket []byte) error {
+ if len(rawPacket) != packetStatusChunkLength {
+ return errPacketStatusChunkLength
+ }
+
+ r.Type = TypeTCCStatusVectorChunk
+ r.SymbolSize = getNBitsFromByte(rawPacket[0], 1, 1)
+
+ if r.SymbolSize == TypeTCCSymbolSizeOneBit {
+ for i := uint16(0); i < 6; i++ {
+ r.SymbolList = append(r.SymbolList, getNBitsFromByte(rawPacket[0], 2+i, 1))
+ }
+ for i := uint16(0); i < 8; i++ {
+ r.SymbolList = append(r.SymbolList, getNBitsFromByte(rawPacket[1], i, 1))
+ }
+ return nil
+ }
+ if r.SymbolSize == TypeTCCSymbolSizeTwoBit {
+ for i := uint16(0); i < 3; i++ {
+ r.SymbolList = append(r.SymbolList, getNBitsFromByte(rawPacket[0], 2+i*2, 2))
+ }
+ for i := uint16(0); i < 4; i++ {
+ r.SymbolList = append(r.SymbolList, getNBitsFromByte(rawPacket[1], i*2, 2))
+ }
+ return nil
+ }
+
+ r.SymbolSize = getNBitsFromByte(rawPacket[0], 2, 6)<<8 + uint16(rawPacket[1])
+ return nil
+}
+
+const (
+ // TypeTCCDeltaScaleFactor https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01#section-3.1.5
+ TypeTCCDeltaScaleFactor = 250
+)
+
+// RecvDelta are represented as multiples of 250us
+// small delta is 1 byte: [0，63.75]ms = [0, 63750]us = [0, 255]*250us
+// big delta is 2 bytes: [-8192.0, 8191.75]ms = [-8192000, 8191750]us = [-32768, 32767]*250us
+// https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01#section-3.1.5
+type RecvDelta struct {
+ Type uint16
+ // us
+ Delta int64
+}
+
+// Marshal ..
+func (r RecvDelta) Marshal() ([]byte, error) {
+ delta := r.Delta / TypeTCCDeltaScaleFactor
+
+ // small delta
+ if r.Type == TypeTCCPacketReceivedSmallDelta && delta >= 0 && delta <= math.MaxUint8 {
+ deltaChunk := make([]byte, 1)
+ deltaChunk[0] = byte(delta)
+ return deltaChunk, nil
+ }
+
+ // big delta
+ if r.Type == TypeTCCPacketReceivedLargeDelta && delta >= math.MinInt16 && delta <= math.MaxInt16 {
+ deltaChunk := make([]byte, 2)
+ binary.BigEndian.PutUint16(deltaChunk, uint16(delta))
+ return deltaChunk, nil
+ }
+
+ // overflow
+ return nil, errDeltaExceedLimit
+}
+
+// Unmarshal ..
+func (r *RecvDelta) Unmarshal(rawPacket []byte) error {
+ chunkLen := len(rawPacket)
+
+ // must be 1 or 2 bytes
+ if chunkLen != 1 && chunkLen != 2 {
+ return errDeltaExceedLimit
+ }
+
+ if chunkLen == 1 {
+ r.Type = TypeTCCPacketReceivedSmallDelta
+ r.Delta = TypeTCCDeltaScaleFactor * int64(rawPacket[0])
+ return nil
+ }
+
+ r.Type = TypeTCCPacketReceivedLargeDelta
+ r.Delta = TypeTCCDeltaScaleFactor * int64(int16(binary.BigEndian.Uint16(rawPacket)))
+ return nil
+}
+
+const (
+ // the offset after header
+ baseSequenceNumberOffset = 8
+ packetStatusCountOffset = 10
+ referenceTimeOffset = 12
+ fbPktCountOffset = 15
+ packetChunkOffset = 16
+)
+
+// TransportLayerCC for sender-BWE
+// https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01#page-5
+type TransportLayerCC struct {
+ // header
+ Header Header
+
+ // SSRC of sender
+ SenderSSRC uint32
+
+ // SSRC of the media source
+ MediaSSRC uint32
+
+ // Transport wide sequence of rtp extension
+ BaseSequenceNumber uint16
+
+ // PacketStatusCount
+ PacketStatusCount uint16
+
+ // ReferenceTime
+ ReferenceTime uint32
+
+ // FbPktCount
+ FbPktCount uint8
+
+ // PacketChunks
+ PacketChunks []PacketStatusChunk
+
+ // RecvDeltas
+ RecvDeltas []*RecvDelta
+}
+
+// Header returns the Header associated with this packet.
+// func (t *TransportLayerCC) Header() Header {
+// return t.Header
+// return Header{
+// Padding: true,
+// Count: FormatTCC,
+// Type: TypeTCCTransportSpecificFeedback,
+// // https://tools.ietf.org/html/rfc4585#page-33
+// Length: uint16((t.len() / 4) - 1),
+// }
+// }
+
+func (t *TransportLayerCC) packetLen() uint16 {
+ n := uint16(headerLength + packetChunkOffset + len(t.PacketChunks)*2)
+ for _, d := range t.RecvDeltas {
+ delta := d.Delta / TypeTCCDeltaScaleFactor
+
+ // small delta
+ if delta >= 0 && delta <= math.MaxUint8 {
+ n++
+ } else {
+ n += 2
+ }
+ }
+ return n
+}
+
+// Len return total bytes with padding
+func (t *TransportLayerCC) Len() uint16 {
+ n := t.packetLen()
+ // has padding
+ if n%4 != 0 {
+ n = (n/4 + 1) * 4
+ }
+
+ return n
+}
+
+func (t TransportLayerCC) String() string {
+ out := fmt.Sprintf("TransportLayerCC:\n\tHeader %v\n", t.Header)
+ out += fmt.Sprintf("TransportLayerCC:\n\tSender Ssrc %d\n", t.SenderSSRC)
+ out += fmt.Sprintf("\tMedia Ssrc %d\n", t.MediaSSRC)
+ out += fmt.Sprintf("\tBase Sequence Number %d\n", t.BaseSequenceNumber)
+ out += fmt.Sprintf("\tStatus Count %d\n", t.PacketStatusCount)
+ out += fmt.Sprintf("\tReference Time %d\n", t.ReferenceTime)
+ out += fmt.Sprintf("\tFeedback Packet Count %d\n", t.FbPktCount)
+ out += "\tPacketChunks "
+ for _, chunk := range t.PacketChunks {
+ out += fmt.Sprintf("%+v ", chunk)
+ }
+ out += "\n\tRecvDeltas "
+ for _, delta := range t.RecvDeltas {
+ out += fmt.Sprintf("%+v ", delta)
+ }
+ out += "\n"
+ return out
+}
+
+// Marshal encodes the TransportLayerCC in binary
+func (t TransportLayerCC) Marshal() ([]byte, error) {
+ header, err := t.Header.Marshal()
+ if err != nil {
+ return nil, err
+ }
+
+ payload := make([]byte, t.Len()-headerLength)
+ binary.BigEndian.PutUint32(payload, t.SenderSSRC)
+ binary.BigEndian.PutUint32(payload[4:], t.MediaSSRC)
+ binary.BigEndian.PutUint16(payload[baseSequenceNumberOffset:], t.BaseSequenceNumber)
+ binary.BigEndian.PutUint16(payload[packetStatusCountOffset:], t.PacketStatusCount)
+ ReferenceTimeAndFbPktCount := appendNBitsToUint32(0, 24, t.ReferenceTime)
+ ReferenceTimeAndFbPktCount = appendNBitsToUint32(ReferenceTimeAndFbPktCount, 8, uint32(t.FbPktCount))
+ binary.BigEndian.PutUint32(payload[referenceTimeOffset:], ReferenceTimeAndFbPktCount)
+
+ for i, chunk := range t.PacketChunks {
+ b, err := chunk.Marshal()
+ if err != nil {
+ return nil, err
+ }
+ copy(payload[packetChunkOffset+i*2:], b)
+ }
+
+ recvDeltaOffset := packetChunkOffset + len(t.PacketChunks)*2
+ var i int
+ for _, delta := range t.RecvDeltas {
+ b, err := delta.Marshal()
+ if err == nil {
+ copy(payload[recvDeltaOffset+i:], b)
+ i++
+ if delta.Type == TypeTCCPacketReceivedLargeDelta {
+ i++
+ }
+ }
+ }
+
+ if t.Header.Padding {
+ payload[len(payload)-1] = uint8(t.Len() - t.packetLen())
+ }
+
+ return append(header, payload...), nil
+}
+
+// Unmarshal ..
+func (t *TransportLayerCC) Unmarshal(rawPacket []byte) error { //nolint:gocognit
+ if len(rawPacket) < (headerLength + ssrcLength) {
+ return errPacketTooShort
+ }
+
+ if err := t.Header.Unmarshal(rawPacket); err != nil {
+ return err
+ }
+
+ // https://tools.ietf.org/html/rfc4585#page-33
+ // header's length + payload's length
+ totalLength := 4 * (t.Header.Length + 1)
+
+ if totalLength <= headerLength+packetChunkOffset {
+ return errPacketTooShort
+ }
+
+ if len(rawPacket) < int(totalLength) {
+ return errPacketTooShort
+ }
+
+ if t.Header.Type != TypeTransportSpecificFeedback || t.Header.Count != FormatTCC {
+ return errWrongType
+ }
+
+ t.SenderSSRC = binary.BigEndian.Uint32(rawPacket[headerLength:])
+ t.MediaSSRC = binary.BigEndian.Uint32(rawPacket[headerLength+ssrcLength:])
+ t.BaseSequenceNumber = binary.BigEndian.Uint16(rawPacket[headerLength+baseSequenceNumberOffset:])
+ t.PacketStatusCount = binary.BigEndian.Uint16(rawPacket[headerLength+packetStatusCountOffset:])
+ t.ReferenceTime = get24BitsFromBytes(rawPacket[headerLength+referenceTimeOffset : headerLength+referenceTimeOffset+3])
+ t.FbPktCount = rawPacket[headerLength+fbPktCountOffset]
+
+ packetStatusPos := uint16(headerLength + packetChunkOffset)
+ var processedPacketNum uint16
+ for processedPacketNum < t.PacketStatusCount {
+ if packetStatusPos+packetStatusChunkLength >= totalLength {
+ return errPacketTooShort
+ }
+ typ := getNBitsFromByte(rawPacket[packetStatusPos : packetStatusPos+1][0], 0, 1)
+ var iPacketStatus PacketStatusChunk
+ switch typ {
+ case TypeTCCRunLengthChunk:
+ packetStatus := &RunLengthChunk{Type: typ}
+ iPacketStatus = packetStatus
+ err := packetStatus.Unmarshal(rawPacket[packetStatusPos : packetStatusPos+2])
+ if err != nil {
+ return err
+ }
+
+ packetNumberToProcess := min(t.PacketStatusCount-processedPacketNum, packetStatus.RunLength)
+ if packetStatus.PacketStatusSymbol == TypeTCCPacketReceivedSmallDelta ||
+ packetStatus.PacketStatusSymbol == TypeTCCPacketReceivedLargeDelta {
+ for j := uint16(0); j < packetNumberToProcess; j++ {
+ t.RecvDeltas = append(t.RecvDeltas, &RecvDelta{Type: packetStatus.PacketStatusSymbol})
+ }
+ }
+ processedPacketNum += packetNumberToProcess
+ case TypeTCCStatusVectorChunk:
+ packetStatus := &StatusVectorChunk{Type: typ}
+ iPacketStatus = packetStatus
+ err := packetStatus.Unmarshal(rawPacket[packetStatusPos : packetStatusPos+2])
+ if err != nil {
+ return err
+ }
+ if packetStatus.SymbolSize == TypeTCCSymbolSizeOneBit {
+ for j := 0; j < len(packetStatus.SymbolList); j++ {
+ if packetStatus.SymbolList[j] == TypeTCCPacketReceivedSmallDelta {
+ t.RecvDeltas = append(t.RecvDeltas, &RecvDelta{Type: TypeTCCPacketReceivedSmallDelta})
+ }
+ }
+ }
+ if packetStatus.SymbolSize == TypeTCCSymbolSizeTwoBit {
+ for j := 0; j < len(packetStatus.SymbolList); j++ {
+ if packetStatus.SymbolList[j] == TypeTCCPacketReceivedSmallDelta || packetStatus.SymbolList[j] == TypeTCCPacketReceivedLargeDelta {
+ t.RecvDeltas = append(t.RecvDeltas, &RecvDelta{Type: packetStatus.SymbolList[j]})
+ }
+ }
+ }
+ processedPacketNum += uint16(len(packetStatus.SymbolList))
+ }
+ packetStatusPos += packetStatusChunkLength
+ t.PacketChunks = append(t.PacketChunks, iPacketStatus)
+ }
+
+ recvDeltasPos := packetStatusPos
+ for _, delta := range t.RecvDeltas {
+ if recvDeltasPos >= totalLength {
+ return errPacketTooShort
+ }
+ if delta.Type == TypeTCCPacketReceivedSmallDelta {
+ err := delta.Unmarshal(rawPacket[recvDeltasPos : recvDeltasPos+1])
+ if err != nil {
+ return err
+ }
+ recvDeltasPos++
+ }
+ if delta.Type == TypeTCCPacketReceivedLargeDelta {
+ err := delta.Unmarshal(rawPacket[recvDeltasPos : recvDeltasPos+2])
+ if err != nil {
+ return err
+ }
+ recvDeltasPos += 2
+ }
+ }
+
+ return nil
+}
+
+// DestinationSSRC returns an array of SSRC values that this packet refers to.
+func (t TransportLayerCC) DestinationSSRC() []uint32 {
+ return []uint32{t.MediaSSRC}
+}
+
+func min(x, y uint16) uint16 {
+ if x < y {
+ return x
+ }
+ return y
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-17 09:48:46 +0000