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tdemultimedia/mpeglib/lib/mpegplay/mpegSystemStream.cpp

236 lines
5.8 KiB

/*
reads paket input data
Copyright (C) 2000 Martin Vogt
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as published by
the Free Software Foundation.
For more information look at the file COPYRIGHT in this package
*/
#include "mpegSystemStream.h"
#define _RESYNC_STATE_INIT 0
#define _RESYNC_STATE_NEED_PACKET 1
#define _RESYNC_STATE_NEED_START 2
#include <iostream>
using namespace std;
MpegSystemStream::MpegSystemStream(InputStream* input) {
this->input=input;
syncCode=0xff; // invalid
lState=_RESYNC_STATE_INIT;
tsSystemStream=new TSSystemStream(input);
psSystemStream=new PSSystemStream(input);
pesSystemStream=new PESSystemStream(input);
}
MpegSystemStream::~MpegSystemStream() {
delete tsSystemStream;
delete psSystemStream;
delete pesSystemStream;
}
int MpegSystemStream::getByteDirect() {
unsigned char byte;
if (input->read((char*)&byte,1) != 1) {
return -1;
}
return (int)byte;
}
int MpegSystemStream::readSyncCode() {
int byte;
byte=getByteDirect();
if (byte==-1) {
return false;
}
syncCode<<=8;
syncCode|=byte;
syncCode&=0xffffffff;
return true;
}
int MpegSystemStream::firstInitialize(MpegSystemHeader* mpegHeader) {
if (readSyncCode() == false) {
return false;
}
mpegHeader->setHeader(syncCode);
// SEQ_START_CODE: 1b3
if (mpegHeader->hasRAWHeader()) {
// If we found a seq_heade_start code we assume
// that we are a video only stream
// we must directly insert it.
// here we set for all future calls fixed
// parameter
mpegHeader->setLayer(_PACKET_NO_SYSLAYER); // no syslayer
mpegHeader->setPacketID(_PAKET_ID_VIDEO);
mpegHeader->setPacketLen(8192);
mpegHeader->resetAvailableLayers();
return true;
}
// no 1bb
if (syncCode == _SYSTEM_HEADER_START_CODE) return false;
// TS 1ba
if (processSystemHeader(mpegHeader) == true) {
// have init. we are a syslayer
mpegHeader->setLayer(_PACKET_SYSLAYER); // syslayer
lState=_RESYNC_STATE_NEED_START;
return true;
}
return false;
}
void MpegSystemStream::reset() {
lState=_RESYNC_STATE_NEED_PACKET;
}
int MpegSystemStream::nextPacket(MpegSystemHeader* mpegHeader) {
int layer=mpegHeader->getLayer();
if (layer == _PACKET_NO_SYSLAYER) {
return true;
}
// seek to packet
if (readSyncCode() == false) {
return false;
}
// default to "HLT" operation
mpegHeader->setPacketID(_PAKET_ID_NUKE);
mpegHeader->setPacketLen(0);
// here we know that we are a SYSLAYER (TS or 1ba)
if (lState == _RESYNC_STATE_NEED_PACKET) {
// no 1bb codes in resync state
if (syncCode == _SYSTEM_HEADER_START_CODE) return false;
}
// is this a syslayer _STARTCODE_ ?
if (MpegSystemHeader::isSystemHeader(syncCode)==true) {
// set startcode & process it
mpegHeader->setHeader(syncCode);
// TS 1ba 1bb
if (processSystemHeader(mpegHeader) == true) {
lState=_RESYNC_STATE_NEED_START;
return true;
}
reset();
return false;
}
if (lState != _RESYNC_STATE_NEED_START) return false;
// no syslayer startcode. PES processing
if ((syncCode & 0xFFFFFF00) == 0x00000100) {
int bytes=pesSystemStream->processStartCode(syncCode,mpegHeader);
if (bytes == 0) {
reset();
return false;
}
// if we are a TS layer we cannot read getPESPacketLength byte
// but only the bytes given by getTSPacketLength
// additionally we must store the mapping between pid and real packetID.
if (mpegHeader->hasTSHeader()) {
unsigned int pid=mpegHeader->getPid();
unsigned int id =mpegHeader->getPacketID();
printf("current PID:%x current PacketID:%x\n",pid,id);
MapPidStream* mapPidStream=mpegHeader->lookup(pid);
mapPidStream->psType=id;
mapPidStream->pesPacketSize=mpegHeader->getPESPacketLen();
int ts=mpegHeader->getTSPacketLen();
if (bytes > ts) {
cout << "ERROR PES READ MORE than TS HAS"<<endl;
return false;
}
mpegHeader->setTSPacketLen(ts-bytes);
return demux_ts_pes_buffer(mpegHeader);
}
// 1ba stream
mpegHeader->setPacketLen(mpegHeader->getPESPacketLen());
return true;
}
// something unknown/else went wrong
return false;
}
int MpegSystemStream::demux_ts_pes_buffer(MpegSystemHeader* mpegHeader) {
if (lState == _RESYNC_STATE_NEED_PACKET) {
cout << "NO ts_pes because of resync"<<endl;
return false;
}
MapPidStream* mapPidStream=mpegHeader->lookup(mpegHeader->getPid());
int pes=mapPidStream->pesPacketSize;
int ts=mpegHeader->getTSPacketLen();
int wantRead=pes;
// bug workaround for PES packetlength == 0
if (pes > 0) {
if (ts < wantRead) {
cout << "TS is less setting wantRead:"<<ts<<endl;
mapPidStream->pesPacketSize=pes-ts;
wantRead=ts;
} else {
// pes < ts
mpegHeader->setTSPacketLen(ts-pes);
wantRead=pes;
}
} else {
// in case of bug, always put the whole packet for pid in
wantRead=ts;
}
mpegHeader->setPacketID(mapPidStream->psType);
mpegHeader->setPacketLen(wantRead);
return true;
}
int MpegSystemStream::processSystemHeader(MpegSystemHeader* mpegHeader) {
if (mpegHeader->hasTSHeader()) {
if (tsSystemStream->processStartCode(mpegHeader) == true) {
if (mpegHeader->getPacketID() == _PAKET_ID_NUKE) {
// nuke the data by signalling how much bytes to nuke
mpegHeader->setPacketLen(mpegHeader->getTSPacketLen());
return true;
}
unsigned int pus=mpegHeader->getPayload_unit_start_indicator();
if (pus == false) {
// we need to append data
return demux_ts_pes_buffer(mpegHeader);
}
return true;
}
return false;
}
if (mpegHeader->hasPSHeader()) {
return (psSystemStream->processStartCode(mpegHeader));
}
return false;
}