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// Copyright 2022, Chef. All rights reserved.
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// https://github.com/q191201771/lal
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//
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// Use of this source code is governed by a MIT-style license
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// that can be found in the License file.
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//
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// Author: Chef (191201771@qq.com)
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package gb28181
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import (
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"bytes"
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"encoding/hex"
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"github.com/q191201771/lal/pkg/base"
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"github.com/q191201771/lal/pkg/h2645"
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"github.com/q191201771/lal/pkg/rtprtcp"
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"github.com/q191201771/naza/pkg/bele"
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"github.com/q191201771/naza/pkg/nazabits"
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"github.com/q191201771/naza/pkg/nazabytes"
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"github.com/q191201771/naza/pkg/nazalog"
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)
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// PsUnpacker 解析ps(Program Stream)流
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//
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type PsUnpacker struct {
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list rtprtcp.RtpPacketList
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buf *nazabytes.Buffer
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audioBuf []byte
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videoBuf []byte
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audioStreamType uint8
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videoStreamType uint8
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audioPayloadType base.AvPacketPt
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videoPayloadType base.AvPacketPt
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preAudioPts int64
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preVideoPts int64
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preAudioDts int64
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preVideoDts int64
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preAudioRtpts int64
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preVideoRtpts int64
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onAvPacket base.OnAvPacketFunc
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}
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func NewPsUnpacker() *PsUnpacker {
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p := &PsUnpacker{
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buf: nazabytes.NewBuffer(psBufInitSize),
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preVideoPts: -1,
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preAudioPts: -1,
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preVideoRtpts: -1,
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preAudioRtpts: -1,
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onAvPacket: defaultOnAvPacket,
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}
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p.list.InitMaxSize(maxUnpackRtpListSize)
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return p
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}
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// WithOnAvPacket
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//
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// @param onAvPacket: 回调函数中 base.AvPacket 字段说明：
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// PayloadType AvPacketPt 见 base.AvPacketPt
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// Timestamp int64 dts，单位毫秒
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// Pts int64 pts，单位毫秒
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// Payload []byte 对于视频，h264和h265是AnnexB格式
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// 对于音频，AAC是前面携带adts的格式
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//
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func (p *PsUnpacker) WithOnAvPacket(onAvPacket base.OnAvPacketFunc) *PsUnpacker {
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p.onAvPacket = onAvPacket
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return p
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}
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// FeedRtpPacket
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//
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// 注意，内部会处理丢包、乱序等问题
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//
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// @param b: rtp包，注意，包含rtp包头部分
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//
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func (p *PsUnpacker) FeedRtpPacket(b []byte) error {
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//nazalog.Debugf("> FeedRtpPacket. len=%d", len(b))
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ipkt, err := rtprtcp.ParseRtpPacket(b)
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if err != nil {
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return err
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}
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//如果是第一帧判断一下数据是否符合
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if p.buf.Len() == 0 {
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body := ipkt.Body()
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if !(len(body) > 4 && bytes.Compare(body[0:3], []byte{0, 0, 1}) == 0) {
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return ErrGb28181
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}
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}
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//nazalog.Debugf("h=%+v", ipkt.Header)
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var isStartPositionFn = func(pkt rtprtcp.RtpPacket) bool {
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body := pkt.Body()
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return len(body) > 4 && bytes.Compare(body[0:3], []byte{0, 0, 1}) == 0
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}
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// 处理丢包、乱序、重复
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// 过期了直接丢掉
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if p.list.IsStale(ipkt.Header.Seq) {
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return ErrGb28181
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}
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// 插入队列
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p.list.Insert(ipkt)
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for {
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// 循环判断头部是否是顺序的
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if p.list.IsFirstSequential() {
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// 如果头一个是顺序的，取出来，喂入解析器
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opkt := p.list.PopFirst()
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p.list.SetUnpackedSeq(opkt.Header.Seq)
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Log.Infof("rtp sep:%d;timestamp:%d",opkt.Header.Seq,opkt.Header.Timestamp)
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p.FeedRtpBody(opkt.Body(), opkt.Header.Timestamp)
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} else {
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// 不是顺序的，如果还没达到容器阈值，就先缓存在容器中，直接退出了
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if !p.list.Full() {
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break
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}
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// 如果达到容器阈值了，就丢弃一部分
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// 丢弃哪些呢？
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// 先丢第一个，因为满了至少要丢一个了。
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//
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// 再丢弃连续的，直到下一个可解析帧位置
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// 因为不连续的话，没法判断和正在丢弃的是否同一帧的，可以给个机会看后续是否能收到
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prev := p.list.PopFirst()
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for p.list.Size > 0 {
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curr := p.list.PeekFirst()
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if rtprtcp.SubSeq(curr.Header.Seq, prev.Header.Seq) != 1 {
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break
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}
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if isStartPositionFn(curr) {
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p.list.SetUnpackedSeq(curr.Header.Seq - 1)
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break
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}
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prev = p.list.PopFirst()
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}
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// 注意，缓存的数据也需要清除
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p.buf.Reset()
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p.audioBuf = nil
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p.videoBuf = nil
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}
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}
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return nil
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}
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// FeedRtpBody 注意，传入的数据应该是连续的，属于完整帧的
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//
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func (p *PsUnpacker) FeedRtpBody(rtpBody []byte, rtpts uint32) {
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//nazalog.Debugf("> FeedRtpBody. len=%d, prev buf=%d", len(rtpBody), p.buf.Len())
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p.buf.Write(rtpBody)
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// ISO/IEC iso13818-1
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//
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// 2.5 Program Stream bitstream requirements
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//
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// TODO(chef): [fix] 有些没做有效长度判断
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for p.buf.Len() != 0 {
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rb := p.buf.Bytes()
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i := 0
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code := bele.BeUint32(rb[i:])
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i += 4
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var consumed int
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switch code {
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case psPackStartCodePackHeader:
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//nazalog.Debugf("----------pack header----------")
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consumed = parsePackHeader(rb, i)
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case psPackStartCodeSystemHeader:
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//nazalog.Debugf("----------system header----------")
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// 2.5.3.5 System header
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// Table 2-32 - Program Stream system header
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//
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consumed = parsePackStreamBody(rb, i)
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case psPackStartCodeProgramStreamMap:
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//nazalog.Debugf("----------program stream map----------")
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consumed = p.parsePsm(rb, i)
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case psPackStartCodeAudioStream:
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//nazalog.Debugf("----------audio stream----------")
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consumed = p.parseAvStream(int(code), rtpts, rb, i)
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case psPackStartCodeVideoStream:
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//nazalog.Debugf("----------video stream----------")
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consumed = p.parseAvStream(int(code), rtpts, rb, i)
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case psPackStartCodePackEnd:
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nazalog.Errorf("----------skip----------. %s", hex.Dump(nazabytes.Prefix(rb[i-4:], 32)))
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consumed = 0
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case psPackStartCodeHikStream:
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consumed = parsePackStreamBody(rb, i)
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//nazalog.Debugf("----------hik stream----------consumed=%d", consumed)
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case psPackStartCodePesPrivate2:
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fallthrough
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case psPackStartCodePesEcm:
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fallthrough
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case psPackStartCodePesEmm:
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fallthrough
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case psPackStartCodePesPadding:
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fallthrough
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case psPackStartCodePesPsd:
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fallthrough
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default:
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// TODO(chef): [opt] 所有code都处理后，不符合格式的code可以考虑重置unpacker，重新处理新喂入的数据 202207
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nazalog.Errorf("----------default----------. %s", hex.Dump(nazabytes.Prefix(rb[i-4:], 32)))
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consumed = parsePackStreamBody(rb, i)
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}
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if consumed < 0 {
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// 消费失败并不一定是数据有问题，可能是数据不完整需要等待下一个rtp包
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if code != psPackStartCodeVideoStream && code != psPackStartCodeHikStream {
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nazalog.Warnf("consumed failed. code=%d, len=(%d,%d), i=%d, buf=%s",
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code, len(rtpBody), len(rb), i, hex.Dump(nazabytes.Prefix(rb[i-4:], 128)))
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}
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return
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}
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p.buf.Skip(i + consumed)
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//nazalog.Debugf("skip. %d", i+consumed)
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}
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}
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func (p *PsUnpacker) parsePsm(rb []byte, index int) int {
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// 2.5.4 Program Stream map
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// Table 2-35 - Program Stream map
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//
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i := index
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if len(rb[i:]) < 6 {
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return -1
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}
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// skip program_stream_map_length
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// skip current_next_indicator
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// skip reserved
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// skip program_stream_map_version
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// skip reverved
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// skip marked_bit
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i += 4 // 2 + 1 + 1
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// program_stream_info_length
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l := int(bele.BeUint16(rb[i:]))
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i += 2
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if len(rb[i:]) < l+2 {
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return -1
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}
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i += l
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// elementary_stream_map_length
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esml := int(bele.BeUint16(rb[i:]))
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//nazalog.Debugf("l=%d, esml=%d", l, esml)
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i += 2
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if len(rb[i:]) < esml+4 {
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return -1
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}
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for esml > 0 {
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streamType := rb[i]
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i += 1
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streamId := rb[i]
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i += 1
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// elementary_stream_info_length
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if streamId >= 0xe0 && streamId <= 0xef {
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p.videoStreamType = streamType
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switch p.videoStreamType {
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case StreamTypeH264:
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p.videoPayloadType = base.AvPacketPtAvc
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case StreamTypeH265:
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p.videoPayloadType = base.AvPacketPtHevc
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default:
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p.videoPayloadType = base.AvPacketPtUnknown
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}
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} else if streamId >= 0xc0 && streamId <= 0xdf {
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p.audioStreamType = streamType
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switch p.audioStreamType {
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case StreamTypeAAC:
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p.audioPayloadType = base.AvPacketPtAac
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default:
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p.audioPayloadType = base.AvPacketPtUnknown
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}
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}
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esil := int(bele.BeUint16(rb[i:]))
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//nazalog.Debugf("streamType=%d, streamId=%d, esil=%d", streamType, streamId, esil)
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i += 2 + esil
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esml = esml - 4 - esil
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}
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// skip
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i += 4
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return i - index
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}
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func (p *PsUnpacker) parseAvStream(code int, rtpts uint32, rb []byte, index int) int {
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i := index
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// 注意，由于length是两字节，所以存在一个帧分成多个pes包的情况
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length := int(bele.BeUint16(rb[i:]))
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if length == 65535 {
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nazalog.Warnf("CHEFGREPME length=%d", length)
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}
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i += 2
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//nazalog.Debugf("parseAvStream. code=%d, expected=%d, actual=%d", code, length, len(rb)-i)
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if len(rb)-i < length {
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return -1
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}
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ptsDtsFlag := rb[i+1] >> 6
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phdl := int(rb[i+2]) // pes header data length
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i += 3
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var pts int64 = -1
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var dts int64 = -1
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j := 0
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if ptsDtsFlag&0x2 != 0 {
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_, pts = readPts(rb[i:])
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j += 5
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}
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if ptsDtsFlag&0x1 != 0 {
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_, dts = readPts(rb[i+j:])
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} else {
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dts = pts
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}
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i += phdl
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//nazalog.Debugf("parseAvStream. code=%d, length=%d, pts=%d, dts=%d", code, length, pts, dts)
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if code == psPackStartCodeAudioStream {
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// 注意，处理音频的逻辑和处理视频的类似，参考处理视频的注释
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if p.audioStreamType == StreamTypeAAC {
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//nazalog.Debugf("audio code=%d, length=%d, ptsDtsFlag=%d, phdl=%d, pts=%d, dts=%d,type=%d", code, length, ptsDtsFlag, phdl, pts, dts, p.audioStreamType)
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if pts == -1 {
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if p.preAudioPts == -1 {
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if p.preAudioRtpts == -1 {
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// noop
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} else {
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if p.preAudioRtpts != int64(rtpts) {
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p.onAvPacket(&base.AvPacket{
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PayloadType: p.audioPayloadType,
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Timestamp: p.preAudioDts / 90,
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Pts: p.preAudioPts / 90,
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Payload: p.audioBuf,
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})
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p.audioBuf = nil
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} else {
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// noop
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}
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}
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} else {
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pts = p.preAudioPts
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}
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} else {
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if pts != p.preAudioPts && p.preAudioPts >= 0 {
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p.onAvPacket(&base.AvPacket{
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PayloadType: p.audioPayloadType,
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Timestamp: p.preAudioDts / 90,
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Pts: p.preAudioPts / 90,
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Payload: p.audioBuf,
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})
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p.audioBuf = nil
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} else {
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// noop
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}
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}
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p.audioBuf = append(p.audioBuf, rb[i:i+length-3-phdl]...)
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p.preAudioRtpts = int64(rtpts)
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p.preAudioPts = pts
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p.preAudioDts = dts
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} else {
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nazalog.Errorf("unknown audio stream type. ast=%d", p.audioStreamType)
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}
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} else if code == psPackStartCodeVideoStream {
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// 判断出当前pes是否是新的帧，然后将缓存中的帧回调给上层
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if pts == -1 {
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// 当前pes包没有pts
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if p.preVideoPts == -1 {
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if p.preVideoRtpts == -1 {
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// 整个流的第一帧，啥也不干
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} else {
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// 整个流没有pts字段，退化成使用rtpts
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if p.preVideoRtpts != int64(rtpts) {
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// 使用rtp的时间戳回调，但是，并不用rtp的时间戳更新pts
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p.iterateNaluByStartCode(code, p.preVideoRtpts, p.preVideoRtpts)
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p.videoBuf = nil
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} else {
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// 同一帧，啥也不干
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}
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}
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} else {
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// 当前pes包没有pts，而前一个有
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// 这种情况我们认为是同一帧，啥也不干
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pts = p.preVideoPts
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}
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} else {
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// 当前pes包有pts
|
|
|
|
|
|
if pts != p.preVideoPts && p.preVideoPts >= 0 {
|
|
|
// 当前pes包是新的帧，将缓存中的帧回调给上层
|
|
|
|
|
|
p.iterateNaluByStartCode(code, p.preVideoPts, p.preVideoPts)
|
|
|
p.videoBuf = nil
|
|
|
} else {
|
|
|
// 两种情况：
|
|
|
// 1. pts != prev && prev == -1 也即第一帧
|
|
|
// 2. pts == prev && prev != -1 也即同一帧（前后两个pes包的时间戳相同）
|
|
|
// 这两种情况，都啥也不干
|
|
|
}
|
|
|
}
|
|
|
|
|
|
// 注意，是处理完之前的数据后，再将当前pes包存入缓存中
|
|
|
p.videoBuf = append(p.videoBuf, rb[i:i+length-3-phdl]...)
|
|
|
p.preVideoRtpts = int64(rtpts)
|
|
|
p.preVideoPts = pts
|
|
|
p.preVideoDts = dts
|
|
|
}
|
|
|
|
|
|
return 2 + length
|
|
|
}
|
|
|
|
|
|
// parsePackHeader 注意，`rb[index:]`为待解析的内存块
|
|
|
//
|
|
|
func parsePackHeader(rb []byte, index int) int {
|
|
|
// 2.5.3.3 Pack layer of Program Stream
|
|
|
// Table 2-33 - Program Stream pack header
|
|
|
|
|
|
i := index
|
|
|
// TODO(chef): 这里按MPEG-2处理，还需要处理MPEG-1 202206
|
|
|
|
|
|
// skip system clock reference(SCR)
|
|
|
// skip PES program mux rate
|
|
|
i += 6 + 3
|
|
|
if len(rb) <= i {
|
|
|
nazalog.Warnf("[p] expected=%d, actual=%d", i, len(rb))
|
|
|
return -1
|
|
|
}
|
|
|
|
|
|
// skip stuffing
|
|
|
l := int(rb[i] & 0x7)
|
|
|
i += 1 + l
|
|
|
|
|
|
return i - index
|
|
|
}
|
|
|
|
|
|
func parsePackStreamBody(rb []byte, index int) int {
|
|
|
i := index
|
|
|
|
|
|
if len(rb) < i+2 {
|
|
|
nazalog.Warnf("needed=%d, actual=%d", i+2, len(rb))
|
|
|
return -1
|
|
|
}
|
|
|
l := int(bele.BeUint16(rb[i:]))
|
|
|
i += 2 + l
|
|
|
if len(rb) < i {
|
|
|
nazalog.Warnf("needed=%d, actual=%d", i, len(rb))
|
|
|
return -1
|
|
|
}
|
|
|
|
|
|
return i - index
|
|
|
}
|
|
|
|
|
|
// iterateNaluByStartCode 通过nal start code分隔缓存数据，将nal回调给上层
|
|
|
//
|
|
|
func (p *PsUnpacker) iterateNaluByStartCode(code int, pts, dts int64) {
|
|
|
leading, preLeading, startPos := 0, 0, 0
|
|
|
startPos, preLeading = h2645.IterateNaluStartCode(p.videoBuf, 0)
|
|
|
if startPos < 0 {
|
|
|
nazalog.Errorf("CHEFNOTICEME %s", hex.Dump(nazabytes.Prefix(p.videoBuf, 32)))
|
|
|
return
|
|
|
}
|
|
|
|
|
|
nextPos := startPos
|
|
|
nalu := p.videoBuf[:0]
|
|
|
for startPos >= 0 {
|
|
|
nextPos, leading = h2645.IterateNaluStartCode(p.videoBuf, startPos+preLeading)
|
|
|
// 找到下一个，则取两个start code之间的内容
|
|
|
// 找不到下一个，则取startcode到末尾的内容
|
|
|
// 不管是否找到下一个，都回调
|
|
|
if nextPos >= 0 {
|
|
|
nalu = p.videoBuf[startPos:nextPos]
|
|
|
} else {
|
|
|
nalu = p.videoBuf[startPos:]
|
|
|
}
|
|
|
startPos = nextPos
|
|
|
|
|
|
p.onAvPacket(&base.AvPacket{
|
|
|
PayloadType: p.videoPayloadType,
|
|
|
Timestamp: dts / 90,
|
|
|
Pts: pts / 90,
|
|
|
Payload: nalu,
|
|
|
})
|
|
|
|
|
|
if nextPos >= 0 {
|
|
|
preLeading = leading
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
// ---------------------------------------------------------------------------------------------------------------------
|
|
|
|
|
|
// TODO(chef): [refactor] 以下代码拷贝来自package mpegts，重复了
|
|
|
|
|
|
// Pes -----------------------------------------------------------
|
|
|
// <iso13818-1.pdf>
|
|
|
// <2.4.3.6 PES packet> <page 49/174>
|
|
|
// <Table E.1 - PES packet header example> <page 142/174>
|
|
|
// <F.0.2 PES packet> <page 144/174>
|
|
|
// packet_start_code_prefix [24b] *** always 0x00, 0x00, 0x01
|
|
|
// stream_id [8b] *
|
|
|
// PES_packet_length [16b] **
|
|
|
// '10' [2b]
|
|
|
// PES_scrambling_control [2b]
|
|
|
// PES_priority [1b]
|
|
|
// data_alignment_indicator [1b]
|
|
|
// copyright [1b]
|
|
|
// original_or_copy [1b] *
|
|
|
// PTS_DTS_flags [2b]
|
|
|
// ESCR_flag [1b]
|
|
|
// ES_rate_flag [1b]
|
|
|
// DSM_trick_mode_flag [1b]
|
|
|
// additional_copy_info_flag [1b]
|
|
|
// PES_CRC_flag [1b]
|
|
|
// PES_extension_flag [1b] *
|
|
|
// PES_header_data_length [8b] *
|
|
|
// -----------------------------------------------------------
|
|
|
type Pes struct {
|
|
|
pscp uint32
|
|
|
sid uint8
|
|
|
ppl uint16
|
|
|
pad1 uint8
|
|
|
ptsDtsFlag uint8
|
|
|
pad2 uint8
|
|
|
phdl uint8
|
|
|
pts int64
|
|
|
dts int64
|
|
|
}
|
|
|
|
|
|
func ParsePes(b []byte) (pes Pes, length int) {
|
|
|
br := nazabits.NewBitReader(b)
|
|
|
//pes.pscp, _ = br.ReadBits32(24)
|
|
|
//pes.sid, _ = br.ReadBits8(8)
|
|
|
//pes.ppl, _ = br.ReadBits16(16)
|
|
|
|
|
|
pes.pad1, _ = br.ReadBits8(8)
|
|
|
pes.ptsDtsFlag, _ = br.ReadBits8(2)
|
|
|
pes.pad2, _ = br.ReadBits8(6)
|
|
|
pes.phdl, _ = br.ReadBits8(8)
|
|
|
|
|
|
_, _ = br.ReadBytes(uint(pes.phdl))
|
|
|
length = 9 + int(pes.phdl)
|
|
|
|
|
|
// 处理得不是特别标准
|
|
|
if pes.ptsDtsFlag&0x2 != 0 {
|
|
|
_, pes.pts = readPts(b[9:])
|
|
|
}
|
|
|
if pes.ptsDtsFlag&0x1 != 0 {
|
|
|
_, pes.dts = readPts(b[14:])
|
|
|
} else {
|
|
|
pes.dts = pes.pts
|
|
|
}
|
|
|
//pes.pts = (pes.pts - delay) / 90
|
|
|
//pes.dts = (pes.dts - delay) / 90
|
|
|
|
|
|
return
|
|
|
}
|
|
|
|
|
|
// read pts or dts
|
|
|
func readPts(b []byte) (fb uint8, pts int64) {
|
|
|
fb = b[0] >> 4
|
|
|
pts |= int64((b[0]>>1)&0x07) << 30
|
|
|
pts |= (int64(b[1])<<8 | int64(b[2])) >> 1 << 15
|
|
|
pts |= (int64(b[3])<<8 | int64(b[4])) >> 1
|
|
|
return
|
|
|
}
|
|
|
|
|
|
func defaultOnAvPacket(packet *base.AvPacket) {
|
|
|
// noop
|
|
|
}
|