804 lines
23 KiB
Go
804 lines
23 KiB
Go
package codecs
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import (
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"errors"
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"fmt"
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)
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//
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// Errors
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//
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var (
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errH265CorruptedPacket = errors.New("corrupted h265 packet")
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errInvalidH265PacketType = errors.New("invalid h265 packet type")
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)
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//
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// Network Abstraction Unit Header implementation
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//
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const (
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// sizeof(uint16)
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h265NaluHeaderSize = 2
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// https://datatracker.ietf.org/doc/html/rfc7798#section-4.4.2
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h265NaluAggregationPacketType = 48
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// https://datatracker.ietf.org/doc/html/rfc7798#section-4.4.3
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h265NaluFragmentationUnitType = 49
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// https://datatracker.ietf.org/doc/html/rfc7798#section-4.4.4
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h265NaluPACIPacketType = 50
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)
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// H265NALUHeader is a H265 NAL Unit Header
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// https://datatracker.ietf.org/doc/html/rfc7798#section-1.1.4
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// +---------------+---------------+
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// |0|1|2|3|4|5|6|7|0|1|2|3|4|5|6|7|
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// |F| Type | LayerID | TID |
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// +-------------+-----------------+
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type H265NALUHeader uint16
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func newH265NALUHeader(highByte, lowByte uint8) H265NALUHeader {
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return H265NALUHeader((uint16(highByte) << 8) | uint16(lowByte))
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}
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// F is the forbidden bit, should always be 0.
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func (h H265NALUHeader) F() bool {
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return (uint16(h) >> 15) != 0
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}
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// Type of NAL Unit.
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func (h H265NALUHeader) Type() uint8 {
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// 01111110 00000000
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const mask = 0b01111110 << 8
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return uint8((uint16(h) & mask) >> (8 + 1))
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}
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// IsTypeVCLUnit returns whether or not the NAL Unit type is a VCL NAL unit.
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func (h H265NALUHeader) IsTypeVCLUnit() bool {
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// Type is coded on 6 bits
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const msbMask = 0b00100000
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return (h.Type() & msbMask) == 0
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}
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// LayerID should always be 0 in non-3D HEVC context.
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func (h H265NALUHeader) LayerID() uint8 {
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// 00000001 11111000
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const mask = (0b00000001 << 8) | 0b11111000
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return uint8((uint16(h) & mask) >> 3)
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}
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// TID is the temporal identifier of the NAL unit +1.
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func (h H265NALUHeader) TID() uint8 {
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const mask = 0b00000111
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return uint8(uint16(h) & mask)
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}
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// IsAggregationPacket returns whether or not the packet is an Aggregation packet.
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func (h H265NALUHeader) IsAggregationPacket() bool {
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return h.Type() == h265NaluAggregationPacketType
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}
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// IsFragmentationUnit returns whether or not the packet is a Fragmentation Unit packet.
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func (h H265NALUHeader) IsFragmentationUnit() bool {
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return h.Type() == h265NaluFragmentationUnitType
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}
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// IsPACIPacket returns whether or not the packet is a PACI packet.
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func (h H265NALUHeader) IsPACIPacket() bool {
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return h.Type() == h265NaluPACIPacketType
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}
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//
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// Single NAL Unit Packet implementation
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//
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// H265SingleNALUnitPacket represents a NALU packet, containing exactly one NAL unit.
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// 0 1 2 3
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// 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
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | PayloadHdr | DONL (conditional) |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | |
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// | NAL unit payload data |
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// | |
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// | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | :...OPTIONAL RTP padding |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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//
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// Reference: https://datatracker.ietf.org/doc/html/rfc7798#section-4.4.1
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type H265SingleNALUnitPacket struct {
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// payloadHeader is the header of the H265 packet.
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payloadHeader H265NALUHeader
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// donl is a 16-bit field, that may or may not be present.
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donl *uint16
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// payload of the fragmentation unit.
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payload []byte
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mightNeedDONL bool
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}
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// WithDONL can be called to specify whether or not DONL might be parsed.
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// DONL may need to be parsed if `sprop-max-don-diff` is greater than 0 on the RTP stream.
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func (p *H265SingleNALUnitPacket) WithDONL(value bool) {
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p.mightNeedDONL = value
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}
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// Unmarshal parses the passed byte slice and stores the result in the H265SingleNALUnitPacket this method is called upon.
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func (p *H265SingleNALUnitPacket) Unmarshal(payload []byte) ([]byte, error) {
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// sizeof(headers)
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const totalHeaderSize = h265NaluHeaderSize
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if payload == nil {
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return nil, errNilPacket
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} else if len(payload) <= totalHeaderSize {
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return nil, fmt.Errorf("%w: %d <= %v", errShortPacket, len(payload), totalHeaderSize)
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}
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payloadHeader := newH265NALUHeader(payload[0], payload[1])
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if payloadHeader.F() {
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return nil, errH265CorruptedPacket
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}
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if payloadHeader.IsFragmentationUnit() || payloadHeader.IsPACIPacket() || payloadHeader.IsAggregationPacket() {
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return nil, errInvalidH265PacketType
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}
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payload = payload[2:]
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if p.mightNeedDONL {
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// sizeof(uint16)
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if len(payload) <= 2 {
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return nil, errShortPacket
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}
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donl := (uint16(payload[0]) << 8) | uint16(payload[1])
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p.donl = &donl
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payload = payload[2:]
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}
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p.payloadHeader = payloadHeader
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p.payload = payload
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return nil, nil
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}
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// PayloadHeader returns the NALU header of the packet.
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func (p *H265SingleNALUnitPacket) PayloadHeader() H265NALUHeader {
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return p.payloadHeader
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}
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// DONL returns the DONL of the packet.
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func (p *H265SingleNALUnitPacket) DONL() *uint16 {
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return p.donl
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}
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// Payload returns the Fragmentation Unit packet payload.
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func (p *H265SingleNALUnitPacket) Payload() []byte {
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return p.payload
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}
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func (p *H265SingleNALUnitPacket) isH265Packet() {}
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//
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// Aggregation Packets implementation
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//
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// H265AggregationUnitFirst represent the First Aggregation Unit in an AP.
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//
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// 0 1 2 3
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// 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
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// : DONL (conditional) | NALU size |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | NALU size | |
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// +-+-+-+-+-+-+-+-+ NAL unit |
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// | |
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// | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | :
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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//
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// Reference: https://datatracker.ietf.org/doc/html/rfc7798#section-4.4.2
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type H265AggregationUnitFirst struct {
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donl *uint16
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nalUnitSize uint16
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nalUnit []byte
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}
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// DONL field, when present, specifies the value of the 16 least
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// significant bits of the decoding order number of the aggregated NAL
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// unit.
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func (u H265AggregationUnitFirst) DONL() *uint16 {
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return u.donl
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}
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// NALUSize represents the size, in bytes, of the NalUnit.
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func (u H265AggregationUnitFirst) NALUSize() uint16 {
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return u.nalUnitSize
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}
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// NalUnit payload.
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func (u H265AggregationUnitFirst) NalUnit() []byte {
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return u.nalUnit
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}
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// H265AggregationUnit represent the an Aggregation Unit in an AP, which is not the first one.
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//
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// 0 1 2 3
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// 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
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// : DOND (cond) | NALU size |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | |
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// | NAL unit |
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// | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | :
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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//
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// Reference: https://datatracker.ietf.org/doc/html/rfc7798#section-4.4.2
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type H265AggregationUnit struct {
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dond *uint8
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nalUnitSize uint16
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nalUnit []byte
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}
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// DOND field plus 1 specifies the difference between
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// the decoding order number values of the current aggregated NAL unit
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// and the preceding aggregated NAL unit in the same AP.
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func (u H265AggregationUnit) DOND() *uint8 {
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return u.dond
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}
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// NALUSize represents the size, in bytes, of the NalUnit.
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func (u H265AggregationUnit) NALUSize() uint16 {
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return u.nalUnitSize
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}
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// NalUnit payload.
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func (u H265AggregationUnit) NalUnit() []byte {
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return u.nalUnit
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}
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// H265AggregationPacket represents an Aggregation packet.
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// 0 1 2 3
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// 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
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | PayloadHdr (Type=48) | |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
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// | |
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// | two or more aggregation units |
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// | |
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// | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | :...OPTIONAL RTP padding |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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//
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// Reference: https://datatracker.ietf.org/doc/html/rfc7798#section-4.4.2
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type H265AggregationPacket struct {
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firstUnit *H265AggregationUnitFirst
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otherUnits []H265AggregationUnit
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mightNeedDONL bool
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}
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// WithDONL can be called to specify whether or not DONL might be parsed.
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// DONL may need to be parsed if `sprop-max-don-diff` is greater than 0 on the RTP stream.
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func (p *H265AggregationPacket) WithDONL(value bool) {
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p.mightNeedDONL = value
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}
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// Unmarshal parses the passed byte slice and stores the result in the H265AggregationPacket this method is called upon.
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func (p *H265AggregationPacket) Unmarshal(payload []byte) ([]byte, error) {
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// sizeof(headers)
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const totalHeaderSize = h265NaluHeaderSize
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if payload == nil {
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return nil, errNilPacket
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} else if len(payload) <= totalHeaderSize {
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return nil, fmt.Errorf("%w: %d <= %v", errShortPacket, len(payload), totalHeaderSize)
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}
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payloadHeader := newH265NALUHeader(payload[0], payload[1])
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if payloadHeader.F() {
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return nil, errH265CorruptedPacket
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}
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if !payloadHeader.IsAggregationPacket() {
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return nil, errInvalidH265PacketType
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}
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// First parse the first aggregation unit
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payload = payload[2:]
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firstUnit := &H265AggregationUnitFirst{}
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if p.mightNeedDONL {
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if len(payload) < 2 {
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return nil, errShortPacket
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}
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donl := (uint16(payload[0]) << 8) | uint16(payload[1])
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firstUnit.donl = &donl
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payload = payload[2:]
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}
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if len(payload) < 2 {
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return nil, errShortPacket
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}
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firstUnit.nalUnitSize = (uint16(payload[0]) << 8) | uint16(payload[1])
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payload = payload[2:]
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if len(payload) < int(firstUnit.nalUnitSize) {
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return nil, errShortPacket
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}
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firstUnit.nalUnit = payload[:firstUnit.nalUnitSize]
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payload = payload[firstUnit.nalUnitSize:]
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// Parse remaining Aggregation Units
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var units []H265AggregationUnit
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for {
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unit := H265AggregationUnit{}
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if p.mightNeedDONL {
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if len(payload) < 1 {
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break
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}
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dond := payload[0]
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unit.dond = &dond
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payload = payload[1:]
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}
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if len(payload) < 2 {
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break
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}
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unit.nalUnitSize = (uint16(payload[0]) << 8) | uint16(payload[1])
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payload = payload[2:]
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if len(payload) < int(unit.nalUnitSize) {
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break
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}
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unit.nalUnit = payload[:unit.nalUnitSize]
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payload = payload[unit.nalUnitSize:]
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units = append(units, unit)
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}
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// There need to be **at least** two Aggregation Units (first + another one)
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if len(units) == 0 {
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return nil, errShortPacket
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}
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p.firstUnit = firstUnit
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p.otherUnits = units
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return nil, nil
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}
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// FirstUnit returns the first Aggregated Unit of the packet.
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func (p *H265AggregationPacket) FirstUnit() *H265AggregationUnitFirst {
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return p.firstUnit
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}
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// OtherUnits returns the all the other Aggregated Unit of the packet (excluding the first one).
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func (p *H265AggregationPacket) OtherUnits() []H265AggregationUnit {
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return p.otherUnits
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}
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func (p *H265AggregationPacket) isH265Packet() {}
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//
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// Fragmentation Unit implementation
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//
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const (
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// sizeof(uint8)
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h265FragmentationUnitHeaderSize = 1
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)
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// H265FragmentationUnitHeader is a H265 FU Header
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// +---------------+
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// |0|1|2|3|4|5|6|7|
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// +-+-+-+-+-+-+-+-+
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// |S|E| FuType |
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// +---------------+
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type H265FragmentationUnitHeader uint8
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// S represents the start of a fragmented NAL unit.
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func (h H265FragmentationUnitHeader) S() bool {
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const mask = 0b10000000
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return ((h & mask) >> 7) != 0
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}
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// E represents the end of a fragmented NAL unit.
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func (h H265FragmentationUnitHeader) E() bool {
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const mask = 0b01000000
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return ((h & mask) >> 6) != 0
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}
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// FuType MUST be equal to the field Type of the fragmented NAL unit.
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func (h H265FragmentationUnitHeader) FuType() uint8 {
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const mask = 0b00111111
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return uint8(h) & mask
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}
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// H265FragmentationUnitPacket represents a single Fragmentation Unit packet.
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//
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// 0 1 2 3
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// 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
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | PayloadHdr (Type=49) | FU header | DONL (cond) |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-|
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// | DONL (cond) | |
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// |-+-+-+-+-+-+-+-+ |
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// | FU payload |
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// | |
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// | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | :...OPTIONAL RTP padding |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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//
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// Reference: https://datatracker.ietf.org/doc/html/rfc7798#section-4.4.3
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type H265FragmentationUnitPacket struct {
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// payloadHeader is the header of the H265 packet.
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payloadHeader H265NALUHeader
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// fuHeader is the header of the fragmentation unit
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fuHeader H265FragmentationUnitHeader
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// donl is a 16-bit field, that may or may not be present.
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donl *uint16
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// payload of the fragmentation unit.
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payload []byte
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mightNeedDONL bool
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}
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// WithDONL can be called to specify whether or not DONL might be parsed.
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// DONL may need to be parsed if `sprop-max-don-diff` is greater than 0 on the RTP stream.
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func (p *H265FragmentationUnitPacket) WithDONL(value bool) {
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p.mightNeedDONL = value
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}
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// Unmarshal parses the passed byte slice and stores the result in the H265FragmentationUnitPacket this method is called upon.
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func (p *H265FragmentationUnitPacket) Unmarshal(payload []byte) ([]byte, error) {
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// sizeof(headers)
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const totalHeaderSize = h265NaluHeaderSize + h265FragmentationUnitHeaderSize
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if payload == nil {
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return nil, errNilPacket
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} else if len(payload) <= totalHeaderSize {
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return nil, fmt.Errorf("%w: %d <= %v", errShortPacket, len(payload), totalHeaderSize)
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}
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payloadHeader := newH265NALUHeader(payload[0], payload[1])
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if payloadHeader.F() {
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return nil, errH265CorruptedPacket
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}
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if !payloadHeader.IsFragmentationUnit() {
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return nil, errInvalidH265PacketType
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}
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fuHeader := H265FragmentationUnitHeader(payload[2])
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payload = payload[3:]
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if fuHeader.S() && p.mightNeedDONL {
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// sizeof(uint16)
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if len(payload) <= 2 {
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return nil, errShortPacket
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}
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donl := (uint16(payload[0]) << 8) | uint16(payload[1])
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p.donl = &donl
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payload = payload[2:]
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}
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p.payloadHeader = payloadHeader
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p.fuHeader = fuHeader
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p.payload = payload
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return nil, nil
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}
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// PayloadHeader returns the NALU header of the packet.
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func (p *H265FragmentationUnitPacket) PayloadHeader() H265NALUHeader {
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return p.payloadHeader
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}
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// FuHeader returns the Fragmentation Unit Header of the packet.
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func (p *H265FragmentationUnitPacket) FuHeader() H265FragmentationUnitHeader {
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return p.fuHeader
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}
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// DONL returns the DONL of the packet.
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func (p *H265FragmentationUnitPacket) DONL() *uint16 {
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return p.donl
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}
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// Payload returns the Fragmentation Unit packet payload.
|
|
func (p *H265FragmentationUnitPacket) Payload() []byte {
|
|
return p.payload
|
|
}
|
|
|
|
func (p *H265FragmentationUnitPacket) isH265Packet() {}
|
|
|
|
//
|
|
// PACI implementation
|
|
//
|
|
|
|
// H265PACIPacket represents a single H265 PACI packet.
|
|
//
|
|
// 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
|
|
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
// | PayloadHdr (Type=50) |A| cType | PHSsize |F0..2|Y|
|
|
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
// | Payload Header Extension Structure (PHES) |
|
|
// |=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=|
|
|
// | |
|
|
// | PACI payload: NAL unit |
|
|
// | . . . |
|
|
// | |
|
|
// | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
// | :...OPTIONAL RTP padding |
|
|
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
//
|
|
// Reference: https://datatracker.ietf.org/doc/html/rfc7798#section-4.4.4
|
|
type H265PACIPacket struct {
|
|
// payloadHeader is the header of the H265 packet.
|
|
payloadHeader H265NALUHeader
|
|
|
|
// Field which holds value for `A`, `cType`, `PHSsize`, `F0`, `F1`, `F2` and `Y` fields.
|
|
paciHeaderFields uint16
|
|
|
|
// phes is a header extension, of byte length `PHSsize`
|
|
phes []byte
|
|
|
|
// Payload contains NAL units & optional padding
|
|
payload []byte
|
|
}
|
|
|
|
// PayloadHeader returns the NAL Unit Header.
|
|
func (p *H265PACIPacket) PayloadHeader() H265NALUHeader {
|
|
return p.payloadHeader
|
|
}
|
|
|
|
// A copies the F bit of the PACI payload NALU.
|
|
func (p *H265PACIPacket) A() bool {
|
|
const mask = 0b10000000 << 8
|
|
return (p.paciHeaderFields & mask) != 0
|
|
}
|
|
|
|
// CType copies the Type field of the PACI payload NALU.
|
|
func (p *H265PACIPacket) CType() uint8 {
|
|
const mask = 0b01111110 << 8
|
|
return uint8((p.paciHeaderFields & mask) >> (8 + 1))
|
|
}
|
|
|
|
// PHSsize indicates the size of the PHES field.
|
|
func (p *H265PACIPacket) PHSsize() uint8 {
|
|
const mask = (0b00000001 << 8) | 0b11110000
|
|
return uint8((p.paciHeaderFields & mask) >> 4)
|
|
}
|
|
|
|
// F0 indicates the presence of a Temporal Scalability support extension in the PHES.
|
|
func (p *H265PACIPacket) F0() bool {
|
|
const mask = 0b00001000
|
|
return (p.paciHeaderFields & mask) != 0
|
|
}
|
|
|
|
// F1 must be zero, reserved for future extensions.
|
|
func (p *H265PACIPacket) F1() bool {
|
|
const mask = 0b00000100
|
|
return (p.paciHeaderFields & mask) != 0
|
|
}
|
|
|
|
// F2 must be zero, reserved for future extensions.
|
|
func (p *H265PACIPacket) F2() bool {
|
|
const mask = 0b00000010
|
|
return (p.paciHeaderFields & mask) != 0
|
|
}
|
|
|
|
// Y must be zero, reserved for future extensions.
|
|
func (p *H265PACIPacket) Y() bool {
|
|
const mask = 0b00000001
|
|
return (p.paciHeaderFields & mask) != 0
|
|
}
|
|
|
|
// PHES contains header extensions. Its size is indicated by PHSsize.
|
|
func (p *H265PACIPacket) PHES() []byte {
|
|
return p.phes
|
|
}
|
|
|
|
// Payload is a single NALU or NALU-like struct, not including the first two octets (header).
|
|
func (p *H265PACIPacket) Payload() []byte {
|
|
return p.payload
|
|
}
|
|
|
|
// TSCI returns the Temporal Scalability Control Information extension, if present.
|
|
func (p *H265PACIPacket) TSCI() *H265TSCI {
|
|
if !p.F0() || p.PHSsize() < 3 {
|
|
return nil
|
|
}
|
|
|
|
tsci := H265TSCI((uint32(p.phes[0]) << 16) | (uint32(p.phes[1]) << 8) | uint32(p.phes[0]))
|
|
return &tsci
|
|
}
|
|
|
|
// Unmarshal parses the passed byte slice and stores the result in the H265PACIPacket this method is called upon.
|
|
func (p *H265PACIPacket) Unmarshal(payload []byte) ([]byte, error) {
|
|
// sizeof(headers)
|
|
const totalHeaderSize = h265NaluHeaderSize + 2
|
|
if payload == nil {
|
|
return nil, errNilPacket
|
|
} else if len(payload) <= totalHeaderSize {
|
|
return nil, fmt.Errorf("%w: %d <= %v", errShortPacket, len(payload), totalHeaderSize)
|
|
}
|
|
|
|
payloadHeader := newH265NALUHeader(payload[0], payload[1])
|
|
if payloadHeader.F() {
|
|
return nil, errH265CorruptedPacket
|
|
}
|
|
if !payloadHeader.IsPACIPacket() {
|
|
return nil, errInvalidH265PacketType
|
|
}
|
|
|
|
paciHeaderFields := (uint16(payload[2]) << 8) | uint16(payload[3])
|
|
payload = payload[4:]
|
|
|
|
p.paciHeaderFields = paciHeaderFields
|
|
headerExtensionSize := p.PHSsize()
|
|
|
|
if len(payload) < int(headerExtensionSize)+1 {
|
|
p.paciHeaderFields = 0
|
|
return nil, errShortPacket
|
|
}
|
|
|
|
p.payloadHeader = payloadHeader
|
|
|
|
if headerExtensionSize > 0 {
|
|
p.phes = payload[:headerExtensionSize]
|
|
}
|
|
|
|
payload = payload[headerExtensionSize:]
|
|
p.payload = payload
|
|
|
|
return nil, nil
|
|
}
|
|
|
|
func (p *H265PACIPacket) isH265Packet() {}
|
|
|
|
//
|
|
// Temporal Scalability Control Information
|
|
//
|
|
|
|
// H265TSCI is a Temporal Scalability Control Information header extension.
|
|
// Reference: https://datatracker.ietf.org/doc/html/rfc7798#section-4.5
|
|
type H265TSCI uint32
|
|
|
|
// TL0PICIDX see RFC7798 for more details.
|
|
func (h H265TSCI) TL0PICIDX() uint8 {
|
|
const m1 = 0xFFFF0000
|
|
const m2 = 0xFF00
|
|
return uint8((((h & m1) >> 16) & m2) >> 8)
|
|
}
|
|
|
|
// IrapPicID see RFC7798 for more details.
|
|
func (h H265TSCI) IrapPicID() uint8 {
|
|
const m1 = 0xFFFF0000
|
|
const m2 = 0x00FF
|
|
return uint8(((h & m1) >> 16) & m2)
|
|
}
|
|
|
|
// S see RFC7798 for more details.
|
|
func (h H265TSCI) S() bool {
|
|
const m1 = 0xFF00
|
|
const m2 = 0b10000000
|
|
return (uint8((h&m1)>>8) & m2) != 0
|
|
}
|
|
|
|
// E see RFC7798 for more details.
|
|
func (h H265TSCI) E() bool {
|
|
const m1 = 0xFF00
|
|
const m2 = 0b01000000
|
|
return (uint8((h&m1)>>8) & m2) != 0
|
|
}
|
|
|
|
// RES see RFC7798 for more details.
|
|
func (h H265TSCI) RES() uint8 {
|
|
const m1 = 0xFF00
|
|
const m2 = 0b00111111
|
|
return uint8((h&m1)>>8) & m2
|
|
}
|
|
|
|
//
|
|
// H265 Packet interface
|
|
//
|
|
|
|
type isH265Packet interface {
|
|
isH265Packet()
|
|
}
|
|
|
|
var (
|
|
_ isH265Packet = (*H265FragmentationUnitPacket)(nil)
|
|
_ isH265Packet = (*H265PACIPacket)(nil)
|
|
_ isH265Packet = (*H265SingleNALUnitPacket)(nil)
|
|
_ isH265Packet = (*H265AggregationPacket)(nil)
|
|
)
|
|
|
|
//
|
|
// Packet implementation
|
|
//
|
|
|
|
// H265Packet represents a H265 packet, stored in the payload of an RTP packet.
|
|
type H265Packet struct {
|
|
packet isH265Packet
|
|
mightNeedDONL bool
|
|
}
|
|
|
|
// WithDONL can be called to specify whether or not DONL might be parsed.
|
|
// DONL may need to be parsed if `sprop-max-don-diff` is greater than 0 on the RTP stream.
|
|
func (p *H265Packet) WithDONL(value bool) {
|
|
p.mightNeedDONL = value
|
|
}
|
|
|
|
// Unmarshal parses the passed byte slice and stores the result in the H265Packet this method is called upon
|
|
func (p *H265Packet) Unmarshal(payload []byte) ([]byte, error) {
|
|
if payload == nil {
|
|
return nil, errNilPacket
|
|
} else if len(payload) <= h265NaluHeaderSize {
|
|
return nil, fmt.Errorf("%w: %d <= %v", errShortPacket, len(payload), h265NaluHeaderSize)
|
|
}
|
|
|
|
payloadHeader := newH265NALUHeader(payload[0], payload[1])
|
|
if payloadHeader.F() {
|
|
return nil, errH265CorruptedPacket
|
|
}
|
|
|
|
switch {
|
|
case payloadHeader.IsPACIPacket():
|
|
decoded := &H265PACIPacket{}
|
|
if _, err := decoded.Unmarshal(payload); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
p.packet = decoded
|
|
|
|
case payloadHeader.IsFragmentationUnit():
|
|
decoded := &H265FragmentationUnitPacket{}
|
|
decoded.WithDONL(p.mightNeedDONL)
|
|
|
|
if _, err := decoded.Unmarshal(payload); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
p.packet = decoded
|
|
|
|
case payloadHeader.IsAggregationPacket():
|
|
decoded := &H265AggregationPacket{}
|
|
decoded.WithDONL(p.mightNeedDONL)
|
|
|
|
if _, err := decoded.Unmarshal(payload); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
p.packet = decoded
|
|
|
|
default:
|
|
decoded := &H265SingleNALUnitPacket{}
|
|
decoded.WithDONL(p.mightNeedDONL)
|
|
|
|
if _, err := decoded.Unmarshal(payload); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
p.packet = decoded
|
|
}
|
|
|
|
return nil, nil
|
|
}
|
|
|
|
// Packet returns the populated packet.
|
|
// Must be casted to one of:
|
|
// - *H265SingleNALUnitPacket
|
|
// - *H265FragmentationUnitPacket
|
|
// - *H265AggregationPacket
|
|
// - *H265PACIPacket
|
|
// nolint:golint
|
|
func (p *H265Packet) Packet() isH265Packet {
|
|
return p.packet
|
|
}
|