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Fix H265Payloader #350

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Merged
Juliapixel merged 1 commit into from
Jan 4, 2026
+21 −207
Merged

Fix H265Payloader #350

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222 changes: 18 additions & 204 deletions codecs/h265_packet.go
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Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,6 @@ import (
"encoding/binary"
"errors"
"fmt"
"math"
)

//
Expand Down Expand Up @@ -1721,10 +1720,20 @@ func (p *H265Packet) Packet() isH265Packet {
return p.packet
}

// h265Packetizer converts an Annex-B H265 stream into RFC7798 RTP packet payloads.
type h265Packetizer struct{}
// H265Payloader payloads H265 packets.
type H265Payloader struct {
// Deprecated: Has no effect.
AddDONL bool
SkipAggregation bool
}

// Payload fragments a H265 packet across one or more byte arrays.
func (p *H265Payloader) Payload(mtu uint16, payload []byte) [][]byte { // nolint:cyclop
// SampleBuilder reuses the payload buffer so this is required
tmp := make([]byte, len(payload))
copy(tmp, payload)
payload = tmp

func (p *h265Packetizer) Payload(mtu uint16, payload []byte) [][]byte { // nolint:cyclop
var payloads [][]byte
naluBuffer := make([]h265SingleNALUnitPacket, 0)

Expand Down Expand Up @@ -1776,6 +1785,11 @@ func (p *h265Packetizer) Payload(mtu uint16, payload []byte) [][]byte { // nolin
payloads = append(payloads, fragment.serialize(make([]byte, 0)))
}
} else {
if p.SkipAggregation {
payloads = append(payloads, nalu)

return
}
if len(naluBuffer) == 0 {
if canAggregateH265(mtu, &packet) {
naluBuffer = append(naluBuffer, packet)
Expand All @@ -1796,203 +1810,3 @@ func (p *h265Packetizer) Payload(mtu uint16, payload []byte) [][]byte { // nolin

return payloads
}

// H265Payloader payloads H265 packets.
type H265Payloader struct {
AddDONL bool
SkipAggregation bool
donl uint16
}

// Payload fragments a H265 packet across one or more byte arrays.
func (p *H265Payloader) Payload(mtu uint16, payload []byte) [][]byte { //nolint:gocognit,cyclop
var payloads [][]byte
if len(payload) == 0 || mtu == 0 {
return payloads
}

bufferedNALUs := make([][]byte, 0)
aggregationBufferSize := 0

flushBufferedNals := func() {
if len(bufferedNALUs) == 0 {
return
}
if len(bufferedNALUs) == 1 { //nolint:nestif
// emit this as a single NALU packet
nalu := bufferedNALUs[0]

if p.AddDONL {
buf := make([]byte, len(nalu)+2)

// copy the NALU header to the payload header
copy(buf[0:h265NaluHeaderSize], nalu[0:h265NaluHeaderSize])

// copy the DONL into the header
binary.BigEndian.PutUint16(buf[h265NaluHeaderSize:h265NaluHeaderSize+2], p.donl)

// write the payload
copy(buf[h265NaluHeaderSize+2:], nalu[h265NaluHeaderSize:])

p.donl++

payloads = append(payloads, buf)
} else {
// write the nalu directly to the payload
payloads = append(payloads, nalu)
}
} else {
// construct an aggregation packet
aggregationPacketSize := aggregationBufferSize
buf := make([]byte, aggregationPacketSize)

layerID := uint8(math.MaxUint8)
tid := uint8(math.MaxUint8)
for _, nalu := range bufferedNALUs {
header := newH265NALUHeader(nalu[0], nalu[1])
headerLayerID := header.LayerID()
headerTID := header.TID()
if headerLayerID < layerID {
layerID = headerLayerID
}
if headerTID < tid {
tid = headerTID
}
}

binary.BigEndian.PutUint16(buf[0:2], (uint16(h265NaluAggregationPacketType)<<9)|(uint16(layerID)<<3)|uint16(tid))

index := 2
for i, nalu := range bufferedNALUs {
if p.AddDONL {
if i == 0 {
binary.BigEndian.PutUint16(buf[index:index+2], p.donl)
index += 2
} else {
buf[index] = byte(i - 1)
index++
}
}

// Since the type of mtu is uint16, len(nalu) fits in as well, so it is safe.
// #nosec
binary.BigEndian.PutUint16(buf[index:index+2], uint16(len(nalu)))
index += 2
index += copy(buf[index:], nalu)
}
payloads = append(payloads, buf)
}
// clear the buffered NALUs
bufferedNALUs = make([][]byte, 0)
aggregationBufferSize = 0
}

calcMarginalAggregationSize := func(nalu []byte) int {
marginalAggregationSize := len(nalu) + 2 // +2 is NALU size Field size
if len(bufferedNALUs) == 1 {
marginalAggregationSize = len(nalu) + 4 // +4 are Aggregation header + NALU size Field size
}
if p.AddDONL {
if len(bufferedNALUs) == 0 {
marginalAggregationSize += 2
} else {
marginalAggregationSize++
}
}

return marginalAggregationSize
}

emitNalus(payload, func(nalu []byte) {
if len(nalu) < 2 {
// NALU header is 2 bytes
return
}

naluLen := len(nalu) + 2
if p.AddDONL {
naluLen += 2
}
if naluLen <= int(mtu) { //nolint:nestif
// this nalu fits into a single packet, either it can be emitted as
// a single nalu or appended to the previous aggregation packet
marginalAggregationSize := calcMarginalAggregationSize(nalu)

if aggregationBufferSize+marginalAggregationSize > int(mtu) {
flushBufferedNals()
marginalAggregationSize = calcMarginalAggregationSize(nalu)
}
bufferedNALUs = append(bufferedNALUs, nalu)
aggregationBufferSize += marginalAggregationSize
if p.SkipAggregation {
// emit this immediately.
flushBufferedNals()
}
} else {
// if this nalu doesn't fit in the current mtu, it needs to be fragmented
fuPacketHeaderSize := h265FragmentationUnitHeaderSize + 2 /* payload header size */
if p.AddDONL {
fuPacketHeaderSize += 2
}

// then, fragment the nalu
maxFUPayloadSize := int(mtu) - fuPacketHeaderSize

naluHeader := newH265NALUHeader(nalu[0], nalu[1])

// the nalu header is omitted from the fragmentation packet payload
nalu = nalu[h265NaluHeaderSize:]

if maxFUPayloadSize <= 0 || len(nalu) == 0 {
return
}

// flush any buffered aggregation packets.
flushBufferedNals()

fullNALUSize := len(nalu)
for len(nalu) > 0 {
curentFUPayloadSize := min(len(nalu), maxFUPayloadSize)

out := make([]byte, fuPacketHeaderSize+curentFUPayloadSize)

// write the payload header
binary.BigEndian.PutUint16(out[0:2], uint16(naluHeader))
out[0] = (out[0] & 0b10000001) | h265NaluFragmentationUnitType<<1

// write the fragment header
out[2] = byte(H265FragmentationUnitHeader(naluHeader.Type()))
if len(nalu) == fullNALUSize {
// Set start bit
out[2] |= 1 << 7
} else if len(nalu)-curentFUPayloadSize == 0 {
// Set end bit
out[2] |= 1 << 6
}

if p.AddDONL {
// write the DONL header
binary.BigEndian.PutUint16(out[3:5], p.donl)

p.donl++

// copy the fragment payload
copy(out[5:], nalu[0:curentFUPayloadSize])
} else {
// copy the fragment payload
copy(out[3:], nalu[0:curentFUPayloadSize])
}

// append the fragment to the payload
payloads = append(payloads, out)

// advance the nalu data pointer
nalu = nalu[curentFUPayloadSize:]
}
}
})

flushBufferedNals()

return payloads
}
6 changes: 3 additions & 3 deletions codecs/h265_packet_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -622,7 +622,7 @@ func TestH265_SingleRoundtrip(t *testing.T) {
}

func TestH265Packetizer_Single(t *testing.T) {
packetizer := h265Packetizer{}
packetizer := H265Payloader{}

// type 1, 8 payload length NALU
basicPacket := make([]byte, 0)
Expand All @@ -639,7 +639,7 @@ func TestH265Packetizer_Single(t *testing.T) {
}

func TestH265Packetizer_Aggregated(t *testing.T) {
packetizer := h265Packetizer{}
packetizer := H265Payloader{}
// type 0, 8 payload length
basicPacket := make([]byte, 0)
basicPacket = append(basicPacket, annexbNALUStartCode...)
Expand Down Expand Up @@ -682,7 +682,7 @@ func TestH265Packetizer_Aggregated(t *testing.T) {
func TestH265Packetizer_Fragmented(t *testing.T) {
initSequence := []byte{0x00, 0x00, 0x00, 0x01, 0x00}

packetizer := h265Packetizer{}
packetizer := H265Payloader{}
// type 0, 50 payload length
bigPacket := make([]byte, 0)
bigPacket = append(bigPacket, initSequence...)
Expand Down
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