path: root/remux.c

/*
 * remux.c: A streaming MPEG2 remultiplexer
 *
 * See the main source file 'vdr.c' for copyright information and
 * how to reach the author.
 *
 * The parts of this code that implement cTS2PES have been taken from
 * the Linux DVB driver's 'tuxplayer' example and were rewritten to suit
 * VDR's needs.
 *
 * The cDolbyRepacker code was originally written by Reinhard Nissl <rnissl@gmx.de>,
 * and adapted to the VDR coding style by Klaus.Schmidinger@cadsoft.de.
 *
 * $Id: remux.c 1.33 2005/03/20 13:18:15 kls Exp $
 */

#include "remux.h"
#include <stdlib.h>
#include "channels.h"
#include "thread.h"
#include "tools.h"

// --- cRepacker -------------------------------------------------------------

class cRepacker {
protected:
  int maxPacketSize;
  uint8_t subStreamId;
public:
  cRepacker(void) { maxPacketSize = 6 + 65535; subStreamId = 0; }
  virtual ~cRepacker() {}
  virtual void Reset(void) {}
  virtual int Put(cRingBufferLinear *ResultBuffer, const uchar *Data, int Count) = 0;
  virtual int BreakAt(const uchar *Data, int Count) = 0;
  void SetMaxPacketSize(int MaxPacketSize) { maxPacketSize = MaxPacketSize; }
  void SetSubStreamId(uint8_t SubStreamId) { subStreamId = SubStreamId; }
  };

// --- cDolbyRepacker --------------------------------------------------------

class cDolbyRepacker : public cRepacker {
private:
  static int frameSizes[];
  uchar fragmentData[6 + 65535];
  int fragmentLen;
  int fragmentTodo;
  uchar pesHeader[6 + 3 + 255 + 4 + 4];
  int pesHeaderLen;
  uchar pesHeaderBackup[6 + 3 + 255];
  int pesHeaderBackupLen;
  uchar chk1;
  uchar chk2;
  int ac3todo;
  enum {
    find_0b,
    find_77,
    store_chk1,
    store_chk2,
    get_length,
    output_packet
    } state;
  void ResetPesHeader(bool ContinuationFrame = false);
  void AppendSubStreamID(bool ContinuationFrame = false);
  bool FinishRemainder(cRingBufferLinear *ResultBuffer, const uchar *const Data, const int Todo, int &Done, int &Bite);
  bool StartNewPacket(cRingBufferLinear *ResultBuffer, const uchar *const Data, const int Todo, int &Done, int &Bite);
public:
  cDolbyRepacker(void);
  virtual void Reset(void);
  virtual int Put(cRingBufferLinear *ResultBuffer, const uchar *Data, int Count);
  virtual int BreakAt(const uchar *Data, int Count);
  };

// frameSizes are in words, i. e. multiply them by 2 to get bytes
int cDolbyRepacker::frameSizes[] = {
  // fs = 48 kHz
    64,   64,   80,   80,   96,   96,  112,  112,  128,  128,  160,  160,  192,  192,  224,  224,
   256,  256,  320,  320,  384,  384,  448,  448,  512,  512,  640,  640,  768,  768,  896,  896,
  1024, 1024, 1152, 1152, 1280, 1280,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
     0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
  // fs = 44.1 kHz
    69,   70,   87,   88,  104,  105,  121,  122,  139,  140,  174,  175,  208,  209,  243,  244,
   278,  279,  348,  349,  417,  418,  487,  488,  557,  558,  696,  697,  835,  836,  975,  976,
  1114, 1115, 1253, 1254, 1393, 1394,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
     0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
  // fs = 32 kHz
    96,   96,  120,  120,  144,  144,  168,  168,  192,  192,  240,  240,  288,  288,  336,  336,
   384,  384,  480,  480,  576,  576,  672,  672,  768,  768,  960,  960, 1152, 1152, 1344, 1344,
  1536, 1536, 1728, 1728, 1920, 1920,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
     0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
  //
     0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
     0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
     0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
     0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
  };

cDolbyRepacker::cDolbyRepacker(void)
{
  pesHeader[0] = 0x00;
  pesHeader[1] = 0x00;
  pesHeader[2] = 0x01;
  pesHeader[3] = 0xBD;
  pesHeader[4] = 0x00;
  pesHeader[5] = 0x00;
  Reset();
}

void cDolbyRepacker::AppendSubStreamID(bool ContinuationFrame)
{
  if (subStreamId) {
     pesHeader[pesHeaderLen++] = subStreamId;
     // number of ac3 frames "starting" in this packet (1 by design).
     pesHeader[pesHeaderLen++] = 0x01;
     // offset to start of first ac3 frame (0 means "no ac3 frame starting"
     // so 1 (by design) addresses the first byte after the next two bytes).
     pesHeader[pesHeaderLen++] = 0x00;
     pesHeader[pesHeaderLen++] = (ContinuationFrame ? 0x00 : 0x01);
     }
}

void cDolbyRepacker::ResetPesHeader(bool ContinuationFrame)
{
  pesHeader[6] = 0x80;
  pesHeader[7] = 0x00;
  pesHeader[8] = 0x00;
  pesHeaderLen = 9;
  AppendSubStreamID(ContinuationFrame);
}

void cDolbyRepacker::Reset(void)
{
  ResetPesHeader();
  state = find_0b;
  ac3todo = 0;
  chk1 = 0;
  chk2 = 0;
  fragmentLen = 0;
  fragmentTodo = 0;
  pesHeaderBackupLen = 0;
}

bool cDolbyRepacker::FinishRemainder(cRingBufferLinear *ResultBuffer, const uchar *const Data, const int Todo, int &Done, int &Bite)
{
  // enough data available to put PES packet into buffer?
  if (fragmentTodo <= Todo) {
     // output a previous fragment first
     if (fragmentLen > 0) {
        Bite = fragmentLen;
        int n = ResultBuffer->Put(fragmentData, Bite);
        if (Bite != n) {
           Reset();
           return false;
           }
        fragmentLen = 0;
        }
     Bite = fragmentTodo;
     int n = ResultBuffer->Put(Data, Bite);
     if (Bite != n) {
        Reset();
        Done += n;
        return false;
        }
     fragmentTodo = 0;
     // ac3 frame completely processed?
     if (Bite >= ac3todo)
        state = find_0b; // go on with finding start of next packet
     }
  else {
     // copy the fragment into separate buffer for later processing
     Bite = Todo;
     if (fragmentLen + Bite > (int)sizeof(fragmentData)) {
        Reset();
        return false;
        }
     memcpy(fragmentData + fragmentLen, Data, Bite);
     fragmentLen += Bite;
     fragmentTodo -= Bite;
     }
  return true;
}

bool cDolbyRepacker::StartNewPacket(cRingBufferLinear *ResultBuffer, const uchar *const Data, const int Todo, int &Done, int &Bite)
{
  int packetLen = pesHeaderLen + ac3todo;
  // limit packet to maximum size
  if (packetLen > maxPacketSize)
     packetLen = maxPacketSize;
  pesHeader[4] = (packetLen - 6) >> 8;
  pesHeader[5] = (packetLen - 6) & 0xFF;
  Bite = pesHeaderLen;
  // enough data available to put PES packet into buffer?
  if (packetLen - pesHeaderLen <= Todo) {
     int n = ResultBuffer->Put(pesHeader, Bite);
     if (Bite != n) {
        Reset();
        return false;
        }
     Bite = packetLen - pesHeaderLen;
     n = ResultBuffer->Put(Data, Bite);
     if (Bite != n) {
        Reset();
        Done += n;
        return false;
        }
     // ac3 frame completely processed?
     if (Bite >= ac3todo)
        state = find_0b; // go on with finding start of next packet
     }
  else {
     fragmentTodo = packetLen;
     // copy the pesheader into separate buffer for later processing
     if (fragmentLen + Bite > (int)sizeof(fragmentData)) {
        Reset();
        return false;
        }
     memcpy(fragmentData + fragmentLen, pesHeader, Bite);
     fragmentLen += Bite;
     fragmentTodo -= Bite;
     // copy the fragment into separate buffer for later processing
     Bite = Todo;
     if (fragmentLen + Bite > (int)sizeof(fragmentData)) {
        Reset();
        return false;
        }
     memcpy(fragmentData + fragmentLen, Data, Bite);
     fragmentLen += Bite;
     fragmentTodo -= Bite;
     }
  return true;
}

int cDolbyRepacker::Put(cRingBufferLinear *ResultBuffer, const uchar *Data, int Count)
{
  // check for MPEG 2
  if ((Data[6] & 0xC0) != 0x80)
     return 0;

  // backup PES header
  if (Data[6] != 0x80 || Data[7] != 0x00 || Data[8] != 0x00) {
     pesHeaderBackupLen = 6 + 3 + Data[8];
     memcpy(pesHeaderBackup, Data, pesHeaderBackupLen);
     }

  // skip PES header
  int done = 6 + 3 + Data[8];
  int todo = Count - done;
  const uchar *data = Data + done;

  // look for 0x0B 0x77 <chk1> <chk2> <frameSize>
  while (todo > 0) {
        switch (state) {
          case find_0b:
               if (*data == 0x0B) {
                  ++(int &)state;
                  // copy header information once for later use
                  if (pesHeaderBackupLen > 0) {
                     pesHeaderLen = pesHeaderBackupLen;
                     pesHeaderBackupLen = 0;
                     memcpy(pesHeader, pesHeaderBackup, pesHeaderLen);
                     AppendSubStreamID();
                     }
                  }
               data++;
               done++;
               todo--;
               continue;
          case find_77:
               if (*data != 0x77) {
                  state = find_0b;
                  continue;
                  }
               data++;
               done++;
               todo--;
               ++(int &)state;
               continue;
          case store_chk1:
               chk1 = *data++;
               done++;
               todo--;
               ++(int &)state;
               continue;
          case store_chk2:
               chk2 = *data++;
               done++;
               todo--;
               ++(int &)state;
               continue;
          case get_length:
               ac3todo = 2 * frameSizes[*data];
               // frameSizeCode was invalid => restart searching
               if (ac3todo <= 0) {
                  // reset PES header instead of using a wrong one
                  ResetPesHeader();
                  if (chk1 == 0x0B) {
                     if (chk2 == 0x77) {
                        state = store_chk1;
                        continue;
                        }
                     if (chk2 == 0x0B) {
                        state = find_77;
                        continue;
                        }
                     state = find_0b;
                     continue;
                     }
                  if (chk2 == 0x0B) {
                     state = find_77;
                     continue;
                     }
                  state = find_0b;
                  continue;
                  }
               // append read data to header for common output processing
               pesHeader[pesHeaderLen++] = 0x0B;
               pesHeader[pesHeaderLen++] = 0x77;
               pesHeader[pesHeaderLen++] = chk1;
               pesHeader[pesHeaderLen++] = chk2;
               ac3todo -= 4;
               ++(int &)state;
               // fall through to output
          case output_packet: {
               int bite = 0;
               // finish remainder of ac3 frame?
               if (fragmentTodo > 0) {
                  if (!FinishRemainder(ResultBuffer, data, todo, done, bite))
                     return done;
                  }
               else {
                  // start a new packet
                  if (!StartNewPacket(ResultBuffer, data, todo, done, bite))
                     return done;
                  // prepare for next (continuation) packet
                  ResetPesHeader(state == output_packet);
                  }
               data += bite;
               done += bite;
               todo -= bite;
               ac3todo -= bite;
               }
          }
        }
  return Count;
}

int cDolbyRepacker::BreakAt(const uchar *Data, int Count)
{
  // enough data for test?
  if (Count < 6 + 3)
     return -1;
  // check for MPEG 2
  if ((Data[6] & 0xC0) != 0x80)
     return -1;
  int headerLen = Data[8] + 6 + 3;
  // break after fragment tail?
  if (ac3todo > 0)
     return headerLen + ac3todo;
  // enough data for test?
  if (Count < headerLen + 5)
     return -1;
  const uchar *data = Data + headerLen;
  // break after ac3 frame?
  if (data[0] == 0x0B && data[1] == 0x77 && frameSizes[data[4]] > 0)
     return headerLen + 2 * frameSizes[data[4]];
  return -1;
}

// --- cTS2PES ---------------------------------------------------------------

#include <netinet/in.h>

//XXX TODO: these should really be available in some driver header file!
#define PROG_STREAM_MAP  0xBC
#ifndef PRIVATE_STREAM1
#define PRIVATE_STREAM1  0xBD
#endif
#define PADDING_STREAM   0xBE
#ifndef PRIVATE_STREAM2
#define PRIVATE_STREAM2  0xBF
#endif
#define AUDIO_STREAM_S   0xC0
#define AUDIO_STREAM_E   0xDF
#define VIDEO_STREAM_S   0xE0
#define VIDEO_STREAM_E   0xEF
#define ECM_STREAM       0xF0
#define EMM_STREAM       0xF1
#define DSM_CC_STREAM    0xF2
#define ISO13522_STREAM  0xF3
#define PROG_STREAM_DIR  0xFF

//pts_dts flags
#define PTS_ONLY         0x80

#define TS_SIZE        188
#define PID_MASK_HI    0x1F
#define CONT_CNT_MASK  0x0F

// Flags:
#define PAY_START      0x40
#define TS_ERROR       0x80
#define ADAPT_FIELD    0x20

#define MAX_PLENGTH  0xFFFF          // the maximum PES packet length (theoretically)
#define MMAX_PLENGTH (64*MAX_PLENGTH) // some stations send PES packets that are extremely large, e.g. DVB-T in Finland or HDTV 1920x1080

#define IPACKS 2048

// Start codes:
#define SC_PICTURE 0x00  // "picture header"

#define MAXNONUSEFULDATA (10*1024*1024)
#define MAXNUMUPTERRORS  10

class cTS2PES {
private:
  int pid;
  int size;
  int found;
  int count;
  uint8_t *buf;
  uint8_t cid;
  uint8_t audioCid;
  uint8_t subStreamId;
  int plength;
  uint8_t plen[2];
  uint8_t flag1;
  uint8_t flag2;
  uint8_t hlength;
  int mpeg;
  uint8_t check;
  int which;
  bool done;
  cRingBufferLinear *resultBuffer;
  int tsErrors;
  int ccErrors;
  int ccCounter;
  cRepacker *repacker;
  static uint8_t headr[];
  void store(uint8_t *Data, int Count);
  void reset_ipack(void);
  void send_ipack(void);
  void write_ipack(const uint8_t *Data, int Count);
  void instant_repack(const uint8_t *Buf, int Count);
public:
  cTS2PES(int Pid, cRingBufferLinear *ResultBuffer, int Size, uint8_t AudioCid = 0x00, uint8_t SubStreamId = 0x00, cRepacker *Repacker = NULL);
  ~cTS2PES();
  int Pid(void) { return pid; }
  void ts_to_pes(const uint8_t *Buf); // don't need count (=188)
  void Clear(void);
  };

uint8_t cTS2PES::headr[] = { 0x00, 0x00, 0x01 };

cTS2PES::cTS2PES(int Pid, cRingBufferLinear *ResultBuffer, int Size, uint8_t AudioCid, uint8_t SubStreamId, cRepacker *Repacker)
{
  pid = Pid;
  resultBuffer = ResultBuffer;
  size = Size;
  audioCid = AudioCid;
  subStreamId = SubStreamId;
  repacker = Repacker;
  if (repacker) {
     repacker->SetMaxPacketSize(size);
     repacker->SetSubStreamId(subStreamId);
     }

  tsErrors = 0;
  ccErrors = 0;
  ccCounter = -1;

  if (!(buf = MALLOC(uint8_t, size)))
     esyslog("Not enough memory for ts_transform");

  reset_ipack();
}

cTS2PES::~cTS2PES()
{
  if (tsErrors || ccErrors)
     dsyslog("cTS2PES got %d TS errors, %d TS continuity errors", tsErrors, ccErrors);
  free(buf);
  delete repacker;
}

void cTS2PES::Clear(void)
{
  reset_ipack();
  if (repacker)
     repacker->Reset();
}

void cTS2PES::store(uint8_t *Data, int Count)
{
  int n = repacker ? repacker->Put(resultBuffer, Data, Count) : resultBuffer->Put(Data, Count);
  if (n != Count)
     esyslog("ERROR: result buffer overflow, dropped %d out of %d byte", Count - n, Count);
}

void cTS2PES::reset_ipack(void)
{
  found = 0;
  cid = 0;
  plength = 0;
  flag1 = 0;
  flag2 = 0;
  hlength = 0;
  mpeg = 0;
  check = 0;
  which = 0;
  done = false;
  count = 0;
}

void cTS2PES::send_ipack(void)
{
  if (count < 10)
     return;
  buf[3] = (AUDIO_STREAM_S <= cid && cid <= AUDIO_STREAM_E && audioCid) ? audioCid : cid;
  buf[4] = (uint8_t)(((count - 6) & 0xFF00) >> 8);
  buf[5] = (uint8_t)((count - 6) & 0x00FF);
  store(buf, count);

  switch (mpeg) {
    case 2:
            buf[6] = 0x80;
            buf[7] = 0x00;
            buf[8] = 0x00;
            count = 9;
            break;
    case 1:
            buf[6] = 0x0F;
            count = 7;
            break;
    }
}

void cTS2PES::write_ipack(const uint8_t *Data, int Count)
{
  if (count < 6) {
     memcpy(buf, headr, 3);
     count = 6;
     }

  // determine amount of data to process
  int bite = Count;
  if (count + bite > size)
     bite = size - count;
  if (repacker) {
     int breakAt = repacker->BreakAt(buf, count);
     // avoid memcpy of data after break location
     if (0 <= breakAt && breakAt < count + bite) {
        bite = breakAt - count;
        if (bite < 0) // should never happen
           bite = 0;
        }
     }

  memcpy(buf + count, Data, bite);
  count += bite;

  if (repacker) {
     // determine break location
     int breakAt = repacker->BreakAt(buf, count);
     if (breakAt > size) // won't fit into packet?
        breakAt = -1;
     if (breakAt > count) // not enough data?
        breakAt = -1;
     // push out data before break location
     if (breakAt > 0) {
        // adjust bite if above memcpy was to large
        bite -= count - breakAt;
        count = breakAt;
        send_ipack();
        // recurse for data after break location
        if (Count - bite > 0)
           write_ipack(Data + bite, Count - bite);
        }
     }

  // push out data when buffer is full
  if (count >= size) {
     send_ipack();
     // recurse for remaining data
     if (Count - bite > 0)
        write_ipack(Data + bite, Count - bite);
     }
}

void cTS2PES::instant_repack(const uint8_t *Buf, int Count)
{
  int c = 0;

  while (c < Count && (mpeg == 0 || (mpeg == 1 && found < 7) || (mpeg == 2 && found < 9)) && (found < 5 || !done)) {
        switch (found ) {
          case 0:
          case 1:
                  if (Buf[c] == 0x00)
                     found++;
                  else
                     found = 0;
                  c++;
                  break;
          case 2:
                  if (Buf[c] == 0x01)
                     found++;
                  else if (Buf[c] != 0)
                     found = 0;
                  c++;
                  break;
          case 3:
                  cid = 0;
                  switch (Buf[c]) {
                    case PROG_STREAM_MAP:
                    case PRIVATE_STREAM2:
                    case PROG_STREAM_DIR:
                    case ECM_STREAM     :
                    case EMM_STREAM     :
                    case PADDING_STREAM :
                    case DSM_CC_STREAM  :
                    case ISO13522_STREAM:
                         done = true;
                    case PRIVATE_STREAM1:
                    case VIDEO_STREAM_S ... VIDEO_STREAM_E:
                    case AUDIO_STREAM_S ... AUDIO_STREAM_E:
                         found++;
                         cid = Buf[c++];
                         break;
                    default:
                         found = 0;
                         break;
                    }
                  break;
          case 4:
                  if (Count - c > 1) {
                     unsigned short *pl = (unsigned short *)(Buf + c);
                     plength = ntohs(*pl);
                     c += 2;
                     found += 2;
                     }
                  else {
                     plen[0] = Buf[c];
                     found++;
                     return;
                     }
                  break;
          case 5: {
                    plen[1] = Buf[c++];
                    unsigned short *pl = (unsigned short *)plen;
                    plength = ntohs(*pl);
                    found++;
                  }
                  break;
          case 6:
                  if (!done) {
                     flag1 = Buf[c++];
                     found++;
                     if ((flag1 & 0xC0) == 0x80 )
                        mpeg = 2;
                     else {
                        hlength = 0;
                        which = 0;
                        mpeg = 1;
                        flag2 = 0;
                        }
                     }
                  break;
          case 7:
                  if (!done && mpeg == 2) {
                     flag2 = Buf[c++];
                     found++;
                     }
                  break;
          case 8:
                  if (!done && mpeg == 2) {
                     hlength = Buf[c++];
                     found++;
                     }
                  break;
          default:
                  break;
          }
        }

  if (!plength)
     plength = MMAX_PLENGTH - 6;

  if (done || ((mpeg == 2 && found >= 9) || (mpeg == 1 && found >= 7))) {
     switch (cid) {
       case AUDIO_STREAM_S ... AUDIO_STREAM_E:
       case VIDEO_STREAM_S ... VIDEO_STREAM_E:
       case PRIVATE_STREAM1:

            if (mpeg == 2 && found == 9) {
               write_ipack(&flag1, 1);
               write_ipack(&flag2, 1);
               write_ipack(&hlength, 1);
               }

            if (mpeg == 1 && found == 7)
               write_ipack(&flag1, 1);

            if (mpeg == 2 && (flag2 & PTS_ONLY) && found < 14) {
               while (c < Count && found < 14) {
                     write_ipack(Buf + c, 1);
                     c++;
                     found++;
                     }
               if (c == Count)
                  return;
               }

            while (c < Count && found < plength + 6) {
                  int l = Count - c;
                  if (l + found > plength + 6)
                     l = plength + 6 - found;
                  write_ipack(Buf + c, l);
                  found += l;
                  c += l;
                  }

            break;
       }

     if (done) {
        if (found + Count - c < plength + 6) {
           found += Count - c;
           c = Count;
           }
        else {
           c += plength + 6 - found;
           found = plength + 6;
           }
        }

     if (plength && found == plength + 6) {
        if (plength == MMAX_PLENGTH - 6)
           esyslog("ERROR: PES packet length overflow in remuxer (stream corruption)");
        send_ipack();
        reset_ipack();
        if (c < Count)
           instant_repack(Buf + c, Count - c);
        }
     }
  return;
}

void cTS2PES::ts_to_pes(const uint8_t *Buf) // don't need count (=188)
{
  if (!Buf)
     return;

  if (Buf[1] & TS_ERROR)
     tsErrors++;
  if ((Buf[3] ^ ccCounter) & CONT_CNT_MASK) {
     // This should check duplicates and packets which do not increase the counter.
     // But as the errors usually come in bursts this should be enough to
     // show you there is something wrong with signal quality.
     if (ccCounter != -1 && ((Buf[3] ^ (ccCounter + 1)) & CONT_CNT_MASK)) {
        ccErrors++;
        // Enable this if you are having problems with signal quality.
        // These are the errors I used to get with Nova-T when antenna
        // was not positioned correcly (not transport errors). //tvr
        //dsyslog("TS continuity error (%d)", ccCounter);
        }
     ccCounter = Buf[3] & CONT_CNT_MASK;
     }

  if (Buf[1] & PAY_START) {
     if (plength == MMAX_PLENGTH - 6 && found > 6) {
        plength = found - 6;
        found = 0;
        send_ipack();
        reset_ipack();
        }
     }

  uint8_t off = 0;

  if (Buf[3] & ADAPT_FIELD) {  // adaptation field?
     off = Buf[4] + 1;
     if (off + 4 > 187)
        return;
     }

  instant_repack(Buf + 4 + off, TS_SIZE - 4 - off);
}

// --- cRemux ----------------------------------------------------------------

#define RESULTBUFFERSIZE KILOBYTE(256)

cRemux::cRemux(int VPid, const int *APids, const int *DPids, const int *SPids, bool ExitOnFailure)
{
  exitOnFailure = ExitOnFailure;
  isRadio = VPid == 0 || VPid == 1 || VPid == 0x1FFF;
  numUPTerrors = 0;
  synced = false;
  skipped = 0;
  numTracks = 0;
  resultSkipped = 0;
  resultBuffer = new cRingBufferLinear(RESULTBUFFERSIZE, IPACKS, false, "Result");
  resultBuffer->SetTimeouts(0, 100);
  if (VPid)
     ts2pes[numTracks++] = new cTS2PES(VPid, resultBuffer, IPACKS);
  if (APids) {
     int n = 0;
     while (*APids && numTracks < MAXTRACKS && n < MAXAPIDS)
           ts2pes[numTracks++] = new cTS2PES(*APids++, resultBuffer, IPACKS, 0xC0 + n++);
     }
  if (DPids) {
     int n = 0;
     while (*DPids && numTracks < MAXTRACKS && n < MAXDPIDS)
           ts2pes[numTracks++] = new cTS2PES(*DPids++, resultBuffer, IPACKS, 0x00, 0x80 + n++, new cDolbyRepacker);
     }
  /* future...
  if (SPids) {
     int n = 0;
     while (*SPids && numTracks < MAXTRACKS && n < MAXSPIDS)
           ts2pes[numTracks++] = new cTS2PES(*SPids++, resultBuffer, IPACKS, 0x00, 0x28 + n++);
     }
  */
}

cRemux::~cRemux()
{
  for (int t = 0; t < numTracks; t++)
      delete ts2pes[t];
  delete resultBuffer;
}

int cRemux::GetPid(const uchar *Data)
{
  return (((uint16_t)Data[0] & PID_MASK_HI) << 8) | (Data[1] & 0xFF);
}

int cRemux::GetPacketLength(const uchar *Data, int Count, int Offset)
{
  // Returns the length of the packet starting at Offset, or -1 if Count is
  // too small to contain the entire packet.
  int Length = (Offset + 5 < Count) ? (Data[Offset + 4] << 8) + Data[Offset + 5] + 6 : -1;
  if (Length > 0 && Offset + Length <= Count)
     return Length;
  return -1;
}

int cRemux::ScanVideoPacket(const uchar *Data, int Count, int Offset, uchar &PictureType)
{
  // Scans the video packet starting at Offset and returns its length.
  // If the return value is -1 the packet was not completely in the buffer.
  int Length = GetPacketLength(Data, Count, Offset);
  if (Length > 0) {
     if (Length >= 8) {
        int i = Offset + 8; // the minimum length of the video packet header
        i += Data[i] + 1;   // possible additional header bytes
        for (; i < Offset + Length - 5; i++) {
            if (Data[i] == 0 && Data[i + 1] == 0 && Data[i + 2] == 1) {
               switch (Data[i + 3]) {
                 case SC_PICTURE: PictureType = (Data[i + 5] >> 3) & 0x07;
                                  return Length;
                 }
               }
            }
        }
     PictureType = NO_PICTURE;
     return Length;
     }
  return -1;
}

#define TS_SYNC_BYTE 0x47

int cRemux::Put(const uchar *Data, int Count)
{
  int used = 0;

  // Make sure we are looking at a TS packet:

  while (Count > TS_SIZE) {
        if (Data[0] == TS_SYNC_BYTE && Data[TS_SIZE] == TS_SYNC_BYTE)
           break;
        Data++;
        Count--;
        used++;
        }
  if (used)
     esyslog("ERROR: skipped %d byte to sync on TS packet", used);

  // Convert incoming TS data into multiplexed PES:

  for (int i = 0; i < Count; i += TS_SIZE) {
      if (Count - i < TS_SIZE)
         break;
      if (Data[i] != TS_SYNC_BYTE)
         break;
      if (resultBuffer->Free() < 2 * IPACKS)
         break; // A cTS2PES might write one full packet and also a small rest
      int pid = GetPid(Data + i + 1);
      if (Data[i + 3] & 0x10) { // got payload
         for (int t = 0; t < numTracks; t++) {
             if (ts2pes[t]->Pid() == pid) {
                ts2pes[t]->ts_to_pes(Data + i);
                break;
                }
             }
         }
      used += TS_SIZE;
      }

  // Check if we're getting anywhere here:
  if (!synced && skipped >= 0) {
     if (skipped > MAXNONUSEFULDATA) {
        esyslog("ERROR: no useful data seen within %d byte of video stream", skipped);
        skipped = -1;
        if (exitOnFailure)
           cThread::EmergencyExit(true);
        }
     else
        skipped += used;
     }

  return used;
}

uchar *cRemux::Get(int &Count, uchar *PictureType)
{
  // Remove any previously skipped data from the result buffer:

  if (resultSkipped > 0) {
     resultBuffer->Del(resultSkipped);
     resultSkipped = 0;
     }

#if 0
  // Test recording without determining the real frame borders:
  if (PictureType)
     *PictureType = I_FRAME;
  return resultBuffer->Get(Count);
#endif

  // Special VPID case to enable recording radio channels:

  if (isRadio) {
     // XXX actually '0' should be enough, but '1' must be used with encrypted channels (driver bug?)
     // XXX also allowing 0x1FFF to not break Michael Paar's original patch,
     // XXX but it would probably be best to only use '0'
     // Force syncing of radio channels to avoid "no useful data" error
     synced = true;
     if (PictureType)
        *PictureType = I_FRAME;
     return resultBuffer->Get(Count);
     }

  // Check for frame borders:

  if (PictureType)
     *PictureType = NO_PICTURE;

  Count = 0;
  uchar *resultData = NULL;
  int resultCount = 0;
  uchar *data = resultBuffer->Get(resultCount);
  if (data) {
     for (int i = 0; i < resultCount - 3; i++) {
         if (data[i] == 0 && data[i + 1] == 0 && data[i + 2] == 1) {
            int l = 0;
            uchar StreamType = data[i + 3];
            if (VIDEO_STREAM_S <= StreamType && StreamType <= VIDEO_STREAM_E) {
               uchar pt = NO_PICTURE;
               l = ScanVideoPacket(data, resultCount, i, pt);
               if (l < 0)
                  return resultData;
               if (pt != NO_PICTURE) {
                  if (pt < I_FRAME || B_FRAME < pt) {
                     esyslog("ERROR: unknown picture type '%d'", pt);
                     if (++numUPTerrors > MAXNUMUPTERRORS && exitOnFailure)
                        cThread::EmergencyExit(true);
                     }
                  else if (!synced) {
                     if (pt == I_FRAME) {
                        if (PictureType)
                           *PictureType = pt;
                        resultSkipped = i; // will drop everything before this position
                        SetBrokenLink(data + i, l);
                        synced = true;
                        }
                     }
                  else if (Count)
                     return resultData;
                  else if (PictureType)
                     *PictureType = pt;
                  }
               }
            else { //if (AUDIO_STREAM_S <= StreamType && StreamType <= AUDIO_STREAM_E || StreamType == PRIVATE_STREAM1) {
               l = GetPacketLength(data, resultCount, i);
               if (l < 0)
                  return resultData;
               }
            if (synced) {
               if (!Count)
                  resultData = data + i;
               Count += l;
               }
            else
               resultSkipped = i + l;
            if (l > 0)
               i += l - 1; // the loop increments, too
            }
         }
     }
  return resultData;
}

void cRemux::Del(int Count)
{
  resultBuffer->Del(Count);
}

void cRemux::Clear(void)
{
  for (int t = 0; t < numTracks; t++)
      ts2pes[t]->Clear();
  resultBuffer->Clear();
  synced = false;
  skipped = 0;
  resultSkipped = 0;
}

void cRemux::SetBrokenLink(uchar *Data, int Length)
{
  if (Length > 9 && Data[0] == 0 && Data[1] == 0 && Data[2] == 1 && (Data[3] & 0xF0) == VIDEO_STREAM_S) {
     for (int i = Data[8] + 9; i < Length - 7; i++) { // +9 to skip video packet header
         if (Data[i] == 0 && Data[i + 1] == 0 && Data[i + 2] == 1 && Data[i + 3] == 0xB8) {
            if (!(Data[i + 7] & 0x40)) // set flag only if GOP is not closed
               Data[i + 7] |= 0x20;
            return;
            }
         }
     dsyslog("SetBrokenLink: no GOP header found in video packet");
     }
  else
     dsyslog("SetBrokenLink: no video packet in frame");
}