Redesigned the ring buffer; prepared for remultiplexing

HISTORY

@@ -414,7 +414,7 @@ Video Disk Recorder Revision History
   given number of seconds. This is mainly useful in combination with the new
   'runvdr' script that restarts VDR in case is has exited.
 
-2001-03-02: Version 0.72
+2001-04-01: Version 0.72
 
 - Fixed SVDRP commands LSTC and LSTT to make them return an error message if
   no channels or timers are defined.
@@ -427,3 +427,8 @@ Video Disk Recorder Revision History
 - Fixed internationalization of some Main menu texts.
 - Updated 'channels.conf' after the recent changes of Premiere World (thanks
   to Axel Gruber).
+- Redesigned the ring buffer to make it work with two separate threads for
+  input and output (also prepared for using a remultiplexer).
+- Fixed setting system time from transponders.
+- Fixed a segfault in the Schedule menu in case there is no EPG information.
+- The 'runvdr' script now kills any leftover vdr threads before restarting it.

Makefile

@@ -4,13 +4,14 @@
 # See the main source file 'vdr.c' for copyright information and
 # how to reach the author.
 #
-# $Id: Makefile 1.20 2001/02/24 15:52:58 kls Exp $
+# $Id: Makefile 1.21 2001/03/18 16:47:00 kls Exp $
 
 DVBDIR   = ../DVB
 
 INCLUDES = -I$(DVBDIR)/driver
 OBJS = config.o dvbapi.o dvbosd.o eit.o font.o i18n.o interface.o menu.o osd.o\
-       recording.o remote.o svdrp.o thread.o tools.o vdr.o videodir.o
+       recording.o remote.o remux.o ringbuffer.o svdrp.o thread.o tools.o vdr.o\
+       videodir.o
 
 OSDFONT = -adobe-helvetica-medium-r-normal--23-*-100-100-p-*-iso8859-1
 FIXFONT = -adobe-courier-bold-r-normal--25-*-100-100-m-*-iso8859-1
@@ -37,21 +38,23 @@ font: genfontfile fontfix.c fontosd.c
 # Implicit rules:
 
 %.o: %.c
-	g++ -g -O2 -Wall -m486 -c $(DEFINES) $(INCLUDES) $<
+	g++ -g -O2 -Wall -Woverloaded-virtual -m486 -c $(DEFINES) $(INCLUDES) $<
 
 # Dependencies:
 
 config.o    : config.c config.h dvbapi.h dvbosd.h eit.h font.h i18n.h interface.h remote.h svdrp.h thread.h tools.h
-dvbapi.o   : dvbapi.c config.h dvbapi.h dvbosd.h eit.h font.h interface.h recording.h remote.h svdrp.h thread.h tools.h videodir.h
+dvbapi.o    : dvbapi.c config.h dvbapi.h dvbosd.h eit.h font.h interface.h recording.h remote.h remux.h ringbuffer.h svdrp.h thread.h tools.h videodir.h
 dvbosd.o    : dvbosd.c dvbosd.h font.h tools.h
 eit.o       : eit.c config.h dvbapi.h dvbosd.h eit.h font.h thread.h tools.h videodir.h
 font.o      : font.c font.h fontfix.c fontosd.c tools.h
 i18n.o      : i18n.c config.h dvbapi.h dvbosd.h eit.h font.h i18n.h thread.h tools.h
-interface.o: interface.c config.h dvbapi.h dvbosd.h eit.h font.h i18n.h interface.h remote.h svdrp.h thread.h tools.h
+interface.o : interface.c config.h dvbapi.h dvbosd.h eit.h font.h i18n.h interface.h remote.h svdrp.h thread.h tools.h
 menu.o      : menu.c config.h dvbapi.h dvbosd.h eit.h font.h i18n.h interface.h menu.h osd.h recording.h remote.h svdrp.h thread.h tools.h
 osd.o       : osd.c config.h dvbapi.h dvbosd.h eit.h font.h i18n.h interface.h osd.h remote.h svdrp.h thread.h tools.h
-recording.o: recording.c config.h dvbapi.h dvbosd.h eit.h font.h interface.h recording.h remote.h svdrp.h thread.h tools.h videodir.h
+recording.o : recording.c config.h dvbapi.h dvbosd.h eit.h font.h interface.h recording.h remote.h svdrp.h thread.h tools.h videodir.h
 remote.o    : remote.c config.h dvbapi.h dvbosd.h eit.h font.h remote.h thread.h tools.h
+remux.o     : remux.c remux.h tools.h
+ringbuffer.o: ringbuffer.c ringbuffer.h thread.h tools.h
 svdrp.o     : svdrp.c config.h dvbapi.h dvbosd.h eit.h font.h interface.h remote.h svdrp.h thread.h tools.h
 thread.o    : thread.c thread.h tools.h
 tools.o     : tools.c tools.h

config.h

@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: config.h 1.42 2001/02/24 13:19:39 kls Exp $
+ * $Id: config.h 1.43 2001/03/18 16:47:00 kls Exp $
  */
 
 #ifndef __CONFIG_H
@@ -19,7 +19,7 @@
 #include "eit.h"
 #include "tools.h"
 
-#define VDRVERSION "0.71"
+#define VDRVERSION "0.72"
 
 #define MaxBuffer 10000
 

dvbapi.c

@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: dvbapi.c 1.63 2001/03/14 18:39:53 kls Exp $
+ * $Id: dvbapi.c 1.64 2001/03/18 16:47:16 kls Exp $
  */
 
 #include "dvbapi.h"
@@ -22,6 +22,8 @@ extern "C" {
 #include "config.h"
 #include "interface.h"
 #include "recording.h"
+#include "remux.h"
+#include "ringbuffer.h"
 #include "tools.h"
 #include "videodir.h"
 
@@ -29,29 +31,9 @@ extern "C" {
 #define VBIDEVICE   "/dev/vbi"
 
 // The size of the array used to buffer video data:
+// (must be larger than MINVIDEODATA - see remux.h)
 #define VIDEOBUFSIZE (1024*1024)
 
-// The minimum amount of video data necessary to identify frames
-// (must be smaller than VIDEOBUFSIZE!):
-#define MINVIDEODATA (256*1024) // just a safe guess (max. size of any frame block, plus some safety)
-
-// The maximum time the buffer is allowed to write data to disk when recording:
-#define MAXRECORDWRITETIME 50 // ms
-
-// Picture types:
-#define NO_PICTURE 0
-#define I_FRAME    1
-#define P_FRAME    2
-#define B_FRAME    3
-
-// Start codes:
-#define SC_PICTURE 0x00  // "picture header"
-#define SC_SEQU    0xB3  // "sequence header"
-#define SC_PHEAD   0xBA  // "pack header"
-#define SC_SHEAD   0xBB  // "system header"
-#define SC_AUDIO   0xC0
-#define SC_VIDEO   0xE0
-
 #define FRAMESPERSEC 25
 
 // The maximum file size is limited by the range that can be covered
@@ -333,7 +315,7 @@ int cIndexFile::Get(uchar FileNumber, int FileOffset)
   return -1;
 }
 
-// --- cRingBuffer -----------------------------------------------------------
+// --- cRingBuffer_ -----------------------------------------------------------
 
 /* cRingBuffer reads data from an input file, stores it in a buffer and writes
    it to an output file upon request. The Read() and Write() functions should
@@ -344,7 +326,7 @@ int cIndexFile::Get(uchar FileNumber, int FileOffset)
    will be made.
 */
 
-class cRingBuffer {
+class cRingBuffer_ {
 private:
   uchar *buffer;
   int size, head, tail, freeLimit, availLimit;
@@ -367,8 +349,8 @@ protected:
   int FindStartCode(uchar Code, int Offset = 0);
   int GetPacketLength(int Offset = 0);
 public:
-  cRingBuffer(int *InFile, int *OutFile, int Size, int FreeLimit = 0, int AvailLimit = 0);
+  cRingBuffer_(int *InFile, int *OutFile, int Size, int FreeLimit = 0, int AvailLimit = 0);
-  virtual ~cRingBuffer();
+  virtual ~cRingBuffer_();
   virtual int Read(int Max = -1);
   virtual int Write(int Max = -1);
   bool EndOfFile(void) { return eof; }
@@ -377,7 +359,7 @@ public:
   void Skip(int n);
   };
 
-cRingBuffer::cRingBuffer(int *InFile, int *OutFile, int Size, int FreeLimit, int AvailLimit)
+cRingBuffer_::cRingBuffer_(int *InFile, int *OutFile, int Size, int FreeLimit, int AvailLimit)
 {
   inFile = InFile;
   outFile = OutFile;
@@ -393,13 +375,13 @@ cRingBuffer::cRingBuffer(int *InFile, int *OutFile, int Size, int FreeLimit, int
      esyslog(LOG_ERR, "ERROR: can't allocate ring buffer (size=%d)", size);
 }
 
-cRingBuffer::~cRingBuffer()
+cRingBuffer_::~cRingBuffer_()
 {
   dsyslog(LOG_INFO, "buffer stats: %d free, %d overflows, limit exceeded %d times", minFree, countOverflow, countLimit);
   delete buffer;
 }
 
-int cRingBuffer::Byte(int Offset)
+int cRingBuffer_::Byte(int Offset)
 {
   if (buffer && Offset < Available()) {
      Offset += head;
@@ -410,7 +392,7 @@ int cRingBuffer::Byte(int Offset)
   return -1;
 }
 
-bool cRingBuffer::Set(int Offset, int Length, int Value)
+bool cRingBuffer_::Set(int Offset, int Length, int Value)
 {
   if (buffer && Offset + Length <= Available() ) {
      Offset += head;
@@ -425,7 +407,7 @@ bool cRingBuffer::Set(int Offset, int Length, int Value)
   return false;
 }
 
-void cRingBuffer::Skip(int n)
+void cRingBuffer_::Skip(int n)
 {
   if (n > 0) {
      if (head < tail) {
@@ -443,7 +425,7 @@ void cRingBuffer::Skip(int n)
      }
 }
 
-int cRingBuffer::Read(int Max)
+int cRingBuffer_::Read(int Max)
 {
   if (buffer) {
      eof = false;
@@ -501,7 +483,7 @@ int cRingBuffer::Read(int Max)
   return -1;
 }
 
-int cRingBuffer::Write(int Max)
+int cRingBuffer_::Write(int Max)
 {
   if (buffer) {
      int avail = Available();
@@ -540,7 +522,7 @@ int cRingBuffer::Write(int Max)
   return -1;
 }
 
-int cRingBuffer::FindStartCode(uchar Code, int Offset)
+int cRingBuffer_::FindStartCode(uchar Code, int Offset)
 {
   // Searches for a start code (beginning at Offset) and returns the number
   // of bytes from Offset to the start code.
@@ -557,7 +539,7 @@ int cRingBuffer::FindStartCode(uchar Code, int Offset)
   return -1;
 }
 
-int cRingBuffer::GetPacketLength(int Offset)
+int cRingBuffer_::GetPacketLength(int Offset)
 {
   // Returns the entire length of the packet starting at offset.
   return (Byte(Offset + 4) << 8) + Byte(Offset + 5) + 6;
@@ -671,31 +653,29 @@ int cFileName::NextFile(void)
 
 // --- cRecordBuffer ---------------------------------------------------------
 
-class cRecordBuffer : public cRingBuffer, public cThread {
+class cRecordBuffer : public cRingBuffer {
 private:
   cFileName fileName;
   cIndexFile *index;
+  cRemux remux;
   uchar pictureType;
   int fileSize;
   int videoDev;
   int recordFile;
-  bool ok, synced, stop;
+  bool recording;
   time_t lastDiskSpaceCheck;
   bool RunningLowOnDiskSpace(void);
-  int ScanVideoPacket(int *PictureType, int Offset);
-  int Synchronize(void);
   bool NextFile(void);
-  virtual int Write(int Max = -1);
-  bool WriteWithTimeout(void);
 protected:
-  virtual void Action(void);
+  virtual void Input(void);
+  virtual void Output(void);
 public:
   cRecordBuffer(int *InFile, const char *FileName);
   virtual ~cRecordBuffer();
   };
 
 cRecordBuffer::cRecordBuffer(int *InFile, const char *FileName)
-:cRingBuffer(InFile, &recordFile, VIDEOBUFSIZE, VIDEOBUFSIZE / 10, 0)
+:cRingBuffer(VIDEOBUFSIZE)
 ,fileName(FileName, true)
 {
   index = NULL;
@@ -703,7 +683,7 @@ cRecordBuffer::cRecordBuffer(int *InFile, const char *FileName)
   fileSize = 0;
   videoDev = *InFile;
   recordFile = fileName.Open();
-  ok = synced = stop = false;
+  recording = false;
   lastDiskSpaceCheck = time(NULL);
   if (!fileName.Name())
      return;
@@ -712,44 +692,15 @@ cRecordBuffer::cRecordBuffer(int *InFile, const char *FileName)
   if (!index)
      esyslog(LOG_ERR, "ERROR: can't allocate index");
      // let's continue without index, so we'll at least have the recording
-  ok = true;
   Start();
 }
 
 cRecordBuffer::~cRecordBuffer()
 {
-  stop = true;
+  Stop();
-  Cancel(3);
   delete index;
 }
 
-void cRecordBuffer::Action(void)
-{
-  dsyslog(LOG_INFO, "recording thread started (pid=%d)", getpid());
-
-  time_t t = time(NULL);
-  for (;;) {
-      usleep(1); // this keeps the CPU load low
-
-      LOCK_THREAD;
-
-      int r = Read();
-      if (r >= 0) {
-         if (r > 0)
-            t = time(NULL);
-         if (!WriteWithTimeout())
-            break;
-         }
-      if (r < 0 || (r == 0 && time(NULL) - t > 5)) {
-         esyslog(LOG_ERR, "ERROR: video data stream broken");
-         t = time(NULL);
-         }
-      }
-  SetPlayMode(videoDev, VID_PLAY_RESET);
-
-  dsyslog(LOG_INFO, "end recording thread");
-}
-
 bool cRecordBuffer::RunningLowOnDiskSpace(void)
 {
   if (time(NULL) > lastDiskSpaceCheck + DISKCHECKINTERVAL) {
@@ -763,88 +714,6 @@ bool cRecordBuffer::RunningLowOnDiskSpace(void)
   return false;
 }
 
-int cRecordBuffer::ScanVideoPacket(int *PictureType, int Offset)
-{
-  // 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(Offset);
-  if (Length <= Available()) {
-     int i = Offset + 8; // the minimum length of the video packet header
-     i += Byte(i) + 1;   // possible additional header bytes
-     for (; i < Offset + Length; i++) {
-         if (Byte(i) == 0 && Byte(i + 1) == 0 && Byte(i + 2) == 1) {
-            switch (Byte(i + 3)) {
-              case SC_PICTURE: *PictureType = GetPictureType(i);
-                               return Length;
-              }
-            }
-         }
-     *PictureType = NO_PICTURE;
-     return Length;
-     }
-  return -1;
-}
-
-int cRecordBuffer::Synchronize(void)
-{
-  // Positions to the start of a data block (skipping everything up to
-  // an I-frame if not synced) and returns the block length.
-
-  pictureType = NO_PICTURE;
-
-  //XXX remove this once the buffer is handled with two separate threads:
-  if (!synced && Free() < 100000) {
-     dsyslog(LOG_INFO, "unable to synchronize, dropped %d bytes", Available());
-     Clear();
-     return 0;
-     }
-  for (int i = 0; Available() > MINVIDEODATA && i < MINVIDEODATA; i++) {
-      if (Byte(i) == 0 && Byte(i + 1) == 0 && Byte(i + 2) == 1) {
-         switch (Byte(i + 3)) {
-           case SC_VIDEO:   {
-                              int pt = NO_PICTURE;
-                              int l = ScanVideoPacket(&pt, i);
-                              if (l < 0)
-                                 return 0; // no useful data found, wait for more
-                              if (pt != NO_PICTURE) {
-                                 if (pt < I_FRAME || B_FRAME < pt) {
-                                    esyslog(LOG_ERR, "ERROR: unknown picture type '%d'", pt);
-                                    }
-                                 else if (pictureType == NO_PICTURE) {
-                                    if (!synced) {
-                                       if (pt == I_FRAME) {
-                                          Skip(i);
-                                          synced = true;
-                                          }
-                                       else {
-                                          Skip(i + l);
-                                          i = 0;
-                                          break;
-                                          }
-                                       }
-                                    if (synced)
-                                       pictureType = pt;
-                                    }
-                                 else
-                                    return i;
-                                 }
-                              else if (!synced) {
-                                 Skip(i + l);
-                                 i = 0;
-                                 break;
-                                 }
-                              i += l - 1; // -1 to compensate for i++ in the loop!
-                            }
-                            break;
-           case SC_AUDIO:   i += GetPacketLength(i) - 1; // -1 to compensate for i++ in the loop!
-                            break;
-           }
-         }
-      }
-  return 0; // no useful data found, wait for more
-}
-
 bool cRecordBuffer::NextFile(void)
 {
   if (recordFile >= 0 && pictureType == I_FRAME) { // every file shall start with an I_FRAME
@@ -856,56 +725,93 @@ bool cRecordBuffer::NextFile(void)
   return recordFile >= 0;
 }
 
-int cRecordBuffer::Write(int Max)
+void cRecordBuffer::Input(void)
 {
-  // This function ignores the incoming 'Max'!
+  dsyslog(LOG_INFO, "input thread started (pid=%d)", getpid());
-  // It tries to write out exactly *one* frame block.
+
-  if (!ok)
+  uchar b[MINVIDEODATA];
-     return -1;
+  time_t t = time(NULL);
-  int n = Synchronize();
+  recording = true;
-  if (n) {
+  for (;;) {
-     if (stop && pictureType == I_FRAME) {
+      int r = read(videoDev, b, sizeof(b));
-        ok = false;
+      if (r > 0) {
-        return -1; // finish the recording before the next 'I' frame
+         uchar *p = b;
+         while (r > 0) {
+               int w = Put(p, r);
+               p += w;
+               r -= w;
                }
+         t = time(NULL);
+         }
+      else if (r < 0) {
+         if (errno != EAGAIN) {
+            LOG_ERROR;
+            break;
+            }
+         }
+      else if (time(NULL) - t > 5) {
+         esyslog(LOG_ERR, "ERROR: video data stream broken");
+         t = time(NULL);
+         }
+      cFile::FileReady(videoDev, 100);
+      if (!recording)
+         break;
+      }
+  SetPlayMode(videoDev, VID_PLAY_RESET);
+
+  dsyslog(LOG_INFO, "input thread ended (pid=%d)", getpid());
+}
+
+void cRecordBuffer::Output(void)
+{
+  dsyslog(LOG_INFO, "output thread started (pid=%d)", getpid());
+
+  uchar b[MINVIDEODATA * 2];
+  int r = 0;
+  for (;;) {
+      usleep(1); // this keeps the CPU load low
+      r += Get(b + r, sizeof(b) - r);
+      if (r > 0) {
+         //XXX buffer full???
+         int Count = r, Result;
+         const uchar *p = remux.Process(b, Count, Result, pictureType);
+         if (p) {
+            if (!Busy() && pictureType == I_FRAME) // finish the recording before the next 'I' frame
+               break;
             if (NextFile()) {
                if (index && pictureType != NO_PICTURE)
                   index->Write(pictureType, fileName.Number(), fileSize);
-        int written = 0;
+               while (Result > 0) {
-        for (;;) {
+                     int w = write(recordFile, p, Result);
-            int w = cRingBuffer::Write(n);
+                     if (w < 0) {
-            if (w >= 0) {
+                        LOG_ERROR_STR(fileName.Name());
+                        recording = false;
+                        return;
+                        }
+                     p += w;
+                     Result -= w;
                      fileSize += w;
-               written += w;
+                     }
-               n -= w;
-               if (n == 0)
-                  return written;
                }
             else
-               return w;
-            }
-        }
-     return -1;
-     }
-  return 0;
-}
-
-bool cRecordBuffer::WriteWithTimeout(void)
-{
-  int t0 = time_ms();
-  do {
-     int w = Write();
-     if (w < 0)
-        return false;
-     if (w == 0)
                break;
-     } while (time_ms() - t0 < MAXRECORDWRITETIME);
+            }
-  return true;
+         if (Count > 0) {
+            r -= Count;
+            memmove(b, b + Count, r);
+            }
+         if (!recording)
+            break;
+         }
+      }
+  recording = false;
+
+  dsyslog(LOG_INFO, "output thread ended (pid=%d)", getpid());
 }
 
 // --- cReplayBuffer ---------------------------------------------------------
 
-class cReplayBuffer : public cRingBuffer, public cThread {
+class cReplayBuffer : public cRingBuffer_, public cThread {
 private:
   enum eReplayCmd { rcNone, rcStill, rcPause, rcPlay, rcForward, rcBackward };
   enum eReplayMode { rmStill, rmPlay, rmFastForward, rmFastRewind, rmSlowRewind };
@@ -944,7 +850,7 @@ public:
   };
 
 cReplayBuffer::cReplayBuffer(int *OutFile, const char *FileName)
-:cRingBuffer(&replayFile, OutFile, VIDEOBUFSIZE, 0, VIDEOBUFSIZE / 10)
+:cRingBuffer_(&replayFile, OutFile, VIDEOBUFSIZE, 0, VIDEOBUFSIZE / 10)
 ,fileName(FileName, false)
 {
   index = NULL;
@@ -1271,7 +1177,7 @@ int cReplayBuffer::Read(int Max = -1)
      int readin = 0;
      do {
         // If Max is > 0 here we need to make sure we read in the entire block!
-        int r = cRingBuffer::Read(Max);
+        int r = cRingBuffer_::Read(Max);
         if (r >= 0)
            readin += r;
         else
@@ -1300,7 +1206,7 @@ int cReplayBuffer::Write(int Max)
   if (Max) {
      int w;
      do {
-        w = cRingBuffer::Write(Max);
+        w = cRingBuffer_::Write(Max);
         if (w >= 0) {
            fileOffset += w;
            Written += w;
@@ -1348,7 +1254,7 @@ void cTransferBuffer::Action(void)
 {
   dsyslog(LOG_INFO, "data transfer thread started (pid=%d)", getpid());
 
-  cRingBuffer Buffer(&fromDevice, &toDevice, VIDEOBUFSIZE, 0, 0);
+  cRingBuffer_ Buffer(&fromDevice, &toDevice, VIDEOBUFSIZE, 0, 0);
   active = true;
   while (active && Buffer.Available() < 100000) { // need to give the read buffer a head start
         Buffer.Read(); // initializes fromDevice for reading
@@ -1364,7 +1270,7 @@ void cTransferBuffer::Action(void)
 
 // --- cCuttingBuffer --------------------------------------------------------
 
-class cCuttingBuffer : public cRingBuffer, public cThread {
+class cCuttingBuffer : public cRingBuffer_, public cThread {
 private:
   bool active;
   int fromFile, toFile;
@@ -1379,7 +1285,7 @@ public:
   };
 
 cCuttingBuffer::cCuttingBuffer(const char *FromFileName, const char *ToFileName)
-:cRingBuffer(&fromFile, &toFile, VIDEOBUFSIZE, 0, VIDEOBUFSIZE / 10)
+:cRingBuffer_(&fromFile, &toFile, VIDEOBUFSIZE, 0, VIDEOBUFSIZE / 10)
 {
   active = false;
   fromFile = toFile = -1;
@@ -1438,7 +1344,7 @@ void cCuttingBuffer::Action(void)
                  CurrentFileNumber = FileNumber;
                  }
               if (fromFile >= 0)
-                 Length = cRingBuffer::Read(Length);
+                 Length = cRingBuffer_::Read(Length);
               else
                  break;
               }
@@ -1456,7 +1362,7 @@ void cCuttingBuffer::Action(void)
                  }
               LastIFrame = 0;
               }
-           cRingBuffer::Write(Length);
+           cRingBuffer_::Write(Length);
            toIndex->Write(PictureType, toFileName->Number(), FileSize);
            FileSize += Length;
            if (!LastIFrame)

remux.c

@@ -0,0 +1,173 @@
+/*
+ * remux.c: A streaming MPEG2 remultiplexer
+ *
+ * See the main source file 'vdr.c' for copyright information and
+ * how to reach the author.
+ *
+ * $Id: remux.c 1.1 2001/03/31 08:42:17 kls Exp $
+ */
+
+/* The calling interface of the 'cRemux::Process()' function is defined
+   as follows:
+
+   'Data' points to a chunk of data that consists of 'Count' bytes.
+   The 'Process' function shall try to remultiplex as much of the
+   data as possible and return a pointer to the resulting buffer.
+   That buffer typically is different from the incoming 'Data',
+   but in the simplest case (when 'Process' does nothing) might
+   as well point to the original 'Data'. When returning, 'Count'
+   shall be set to the number of bytes that have been processed
+   (i.e. have been taken from 'Data'), while 'Result' indicates
+   how many bytes the returned buffer contains. 'PictureType' shall
+   be set to NO_PICTURE if the returned data does not start a new
+   picture, or one of I_FRAME, P_FRAME or B_FRAME if a new picture
+   starting point has been found. This also means that the returned
+   data buffer may contain at most one entire video frame, because
+   the next frame must be returned with its own value for 'PictureType'.
+
+   'Process' shall do it's best to keep the latency time as short
+   as possible in order to allow a quick start of VDR's "Transfer
+   mode" (displaying the signal of one DVB card on another card).
+   In order to do that, this function may decide to first pass
+   through the incoming data (almost) unprocessed, and make
+   actual processing kick in after a few seconds (if that is at
+   all possible for the algorithm). This may result in a non-
+   optimal stream at the beginning, which won't matter for normal
+   recordings but may make switching through encrypted channels
+   in "Transfer mode" faster.
+
+   In the resulting data stream, a new packet shall always be started
+   when a frame border is encountered. VDR needs this in order to
+   be able to detect and store the frame indexes, and to easily
+   display single frames in fast forward/back mode. The very first
+   data block returned shall be the starting point of an I_FRAME.
+   Everything before that shall be silently dropped.
+
+   If the incoming data is not enough to do remultiplexing, a value
+   of NULL shall be returned ('Result' has no meaning then). This
+   will tell the caller to wait for more data to be presented in
+   the next call. If NULL is returned and 'Count' is not 0, the
+   caller shall remove 'Count' bytes from the beginning of 'Data'
+   before the next call. This is the way 'Process' indicates that
+   it must skip that data.
+
+   Any data that is not used during this call will appear at the
+   beginning of the incoming 'Data' buffer at the next call, plus
+   any new data that has become available.
+
+   It is guaranteed that the caller will completely process any
+   returned data before the next call to 'Process'. That way, 'Process'
+   can dynamically allocate its return buffer and be sure the caller
+   doesn't keep any pointers into that buffer.
+*/
+
+#include "remux.h"
+#include "tools.h"
+
+#if defined(REMUX_NONE)
+
+cRemux::cRemux(void)
+{
+  synced = false;
+}
+
+cRemux::~cRemux()
+{
+}
+
+int cRemux::GetPacketLength(const uchar *Data, int Count, int Offset)
+{
+  // Returns the entire length of the packet starting at offset, or -1 in case of error.
+  return (Offset + 5 < Count) ? (Data[Offset + 4] << 8) + Data[Offset + 5] + 6 : -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 && Offset + Length <= Count) {
+     int i = Offset + 8; // the minimum length of the video packet header
+     i += Data[i] + 1;   // possible additional header bytes
+     for (; i < Offset + Length; 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;
+}
+
+const uchar *cRemux::Process(const uchar *Data, int &Count, int &Result, uchar &PictureType)
+{
+  int Skip = 0;
+
+  PictureType = NO_PICTURE;
+
+  if (Count >= MINVIDEODATA) {
+     for (int i = 0; i < Count; i++) {
+         if (Data[i] == 0 && Data[i + 1] == 0 && Data[i + 2] == 1) {
+            switch (Data[i + 3]) {
+              case SC_VIDEO:
+                   {
+                     uchar pt = NO_PICTURE;
+                     int l = ScanVideoPacket(Data, Count, i, pt);
+                     if (l < 0) {
+                        if (Skip < Count)
+                           Count = Skip;
+                        return NULL; // no useful data found, wait for more
+                        }
+                     if (pt != NO_PICTURE) {
+                        if (pt < I_FRAME || B_FRAME < pt) {
+                           esyslog(LOG_ERR, "ERROR: unknown picture type '%d'", pt);
+                           }
+                        else if (PictureType == NO_PICTURE) {
+                           if (!synced) {
+                              if (pt == I_FRAME) {
+                                 Skip = i;
+                                 synced = true;
+                                 }
+                              else {
+                                 i += l;
+                                 Skip = i;
+                                 break;
+                                 }
+                              }
+                           if (synced)
+                              PictureType = pt;
+                           }
+                        else {
+                           Count = i;
+                           Result = i - Skip;
+                           return Data + Skip;
+                           }
+                        }
+                     else if (!synced) {
+                        i += l;
+                        Skip = i;
+                        break;
+                        }
+                     i += l - 1; // -1 to compensate for i++ in the loop!
+                   }
+                   break;
+              case SC_AUDIO:
+                   i += GetPacketLength(Data, Count, i) - 1; // -1 to compensate for i++ in the loop!
+                   break;
+              }
+            }
+         }
+     }
+  if (Skip < Count)
+     Count = Skip;
+  return NULL; // no useful data found, wait for more
+}
+
+#elif defined(REMUX_TEST)
+#endif
+

remux.h

@@ -0,0 +1,51 @@
+/*
+ * remux.h: A streaming MPEG2 remultiplexer
+ *
+ * See the main source file 'vdr.c' for copyright information and
+ * how to reach the author.
+ *
+ * $Id: remux.h 1.1 2001/03/31 08:42:27 kls Exp $
+ */
+
+#ifndef __REMUX_H
+#define __REMUX_H
+
+// There are various experiments with different types of remultiplexers
+// going on at the moment. Select the remultiplexer here:
+#define REMUX_NONE 1
+//#define REMUX_TEST 1
+
+// Picture types:
+#define NO_PICTURE 0
+#define I_FRAME    1
+#define P_FRAME    2
+#define B_FRAME    3
+
+// Start codes:
+#define SC_PICTURE 0x00  // "picture header"
+#define SC_SEQU    0xB3  // "sequence header"
+#define SC_PHEAD   0xBA  // "pack header"
+#define SC_SHEAD   0xBB  // "system header"
+#define SC_AUDIO   0xC0
+#define SC_VIDEO   0xE0
+
+// The minimum amount of video data necessary to identify frames:
+#define MINVIDEODATA (256*1024) // just a safe guess (max. size of any frame block, plus some safety)
+
+typedef unsigned char uchar;
+
+class cRemux {
+private:
+#if defined(REMUX_NONE)
+  bool synced;
+  int GetPacketLength(const uchar *Data, int Count, int Offset);
+  int ScanVideoPacket(const uchar *Data, int Count, int Offset, uchar &PictureType);
+#elif defined(REMUX_TEST)
+#endif
+public:
+  cRemux(void);
+  ~cRemux();
+  const uchar *Process(const uchar *Data, int &Count, int &Result, uchar &PictureType);
+  };
+
+#endif // __REMUX_H

ringbuffer.c

@@ -0,0 +1,170 @@
+/*
+ * ringbuffer.c: A threaded ring buffer
+ *
+ * See the main source file 'vdr.c' for copyright information and
+ * how to reach the author.
+ *
+ * Parts of this file were inspired by the 'ringbuffy.c' from the
+ * LinuxDVB driver (see linuxtv.org).
+ *
+ * $Id: ringbuffer.c 1.1 2001/03/18 16:47:00 kls Exp $
+ */
+
+#include "ringbuffer.h"
+#include "tools.h"
+
+// --- cRingBufferInputThread -------------------------------------------------
+
+class cRingBufferInputThread : public cThread {
+private:
+  cRingBuffer *ringBuffer;
+protected:
+  virtual void Action(void) { ringBuffer->Input(); }
+public:
+  cRingBufferInputThread(cRingBuffer *RingBuffer) { ringBuffer = RingBuffer; }
+  };
+
+// --- cRingBufferOutputThread ------------------------------------------------
+
+class cRingBufferOutputThread : public cThread {
+private:
+  cRingBuffer *ringBuffer;
+protected:
+  virtual void Action(void) { ringBuffer->Output(); }
+public:
+  cRingBufferOutputThread(cRingBuffer *RingBuffer) { ringBuffer = RingBuffer; }
+  };
+
+// --- cRingBuffer ------------------------------------------------------------
+
+cRingBuffer::cRingBuffer(int Size)
+{
+  size = Size;
+  buffer = NULL;
+  inputThread = NULL;
+  outputThread = NULL;
+  maxFill = 0;
+  busy = false;
+  if (size > 1) { // 'size - 1' must not be 0!
+     buffer = new uchar[size];
+     if (!buffer)
+        esyslog(LOG_ERR, "ERROR: can't allocate ring buffer (size=%d)", size);
+     Clear();
+     }
+  else
+     esyslog(LOG_ERR, "ERROR: illegal size for ring buffer (%d)", size);
+}
+
+cRingBuffer::~cRingBuffer()
+{
+  delete inputThread;
+  delete outputThread;
+  delete buffer;
+  dsyslog(LOG_INFO, "buffer stats: %d (%d%%) used", maxFill, maxFill * 100 / (size - 1));
+}
+
+void cRingBuffer::Clear(void)
+{
+  mutex.Lock();
+  head = tail = 0;
+  mutex.Unlock();
+}
+
+int cRingBuffer::Put(const uchar *Data, int Count)
+{
+  if (Count > 0) {
+     mutex.Lock();
+     int rest = size - head;
+     int diff = tail - head;
+     mutex.Unlock();
+     int free = (diff > 0) ? diff - 1 : size + diff - 1;
+     // Statistics:
+     int fill = size - free - 1 + Count;
+     if (fill >= size)
+        fill = size - 1;
+     if (fill > maxFill) {
+        maxFill = fill;
+        int percent = maxFill * 100 / (size - 1);
+        if (percent > 75)
+           dsyslog(LOG_INFO, "buffer usage: %d%%", percent);
+        }
+     //
+     if (free <= 0)
+        return 0;
+     if (free < Count)
+        Count = free;
+     if (Count > maxFill)
+        maxFill = Count;
+     if (Count >= rest) {
+        memcpy(buffer + head, Data, rest);
+        if (Count - rest)
+           memcpy(buffer, Data + rest, Count - rest);
+        head = Count - rest;
+        }
+     else {
+        memcpy(buffer + head, Data, Count);
+        head += Count;
+        }
+     }
+  return Count;
+}
+
+int cRingBuffer::Get(uchar *Data, int Count)
+{
+  if (Count > 0) {
+     mutex.Lock();
+     int rest = size - tail;
+     int diff = head - tail;
+     mutex.Unlock();
+     int cont = (diff >= 0) ? diff : size + diff;
+     if (rest <= 0)
+        return 0;
+     if (cont < Count)
+        Count = cont;
+     if (Count >= rest) {
+        memcpy(Data, buffer + tail, rest);
+        if (Count - rest)
+           memcpy(Data + rest, buffer, Count - rest);
+        tail = Count - rest;
+        }
+     else {
+        memcpy(Data, buffer + tail, Count);
+        tail += Count;
+        }
+     }
+  return Count;
+}
+
+bool cRingBuffer::Start(void)
+{
+  if (!busy) {
+     busy = true;
+     outputThread = new cRingBufferOutputThread(this);
+     if (!outputThread->Start())
+        DELETENULL(outputThread);
+     inputThread = new cRingBufferInputThread(this);
+     if (!inputThread->Start()) {
+        DELETENULL(inputThread);
+        DELETENULL(outputThread);
+        }
+     busy = outputThread && inputThread;
+     }
+  return busy;
+}
+
+bool cRingBuffer::Active(void)
+{
+  return outputThread && outputThread->Active() && inputThread && inputThread->Active();
+}
+
+void cRingBuffer::Stop(void)
+{
+  busy = false;
+  for (time_t t0 = time(NULL) + 3; time(NULL) < t0; ) {
+      if (!((outputThread && outputThread->Active()) || (inputThread && inputThread->Active())))
+         break;
+      }
+  DELETENULL(inputThread);
+  DELETENULL(outputThread);
+}
+

ringbuffer.h

@@ -0,0 +1,55 @@
+/*
+ * ringbuffer.h: A threaded ring buffer
+ *
+ * See the main source file 'vdr.c' for copyright information and
+ * how to reach the author.
+ *
+ * $Id: ringbuffer.h 1.1 2001/03/18 16:47:00 kls Exp $
+ */
+
+#ifndef __RINGBUFFER_H
+#define __RINGBUFFER_H
+
+#include "thread.h"
+
+typedef unsigned char uchar;
+
+class cRingBufferInputThread;
+class cRingBufferOutputThread;
+
+class cRingBuffer {
+  friend class cRingBufferInputThread;
+  friend class cRingBufferOutputThread;
+private:
+  cRingBufferInputThread *inputThread;
+  cRingBufferOutputThread *outputThread;
+  cMutex mutex;
+  int size, head, tail;
+  uchar *buffer;
+  int maxFill;
+  bool busy;
+protected:
+  bool Busy(void) { return busy; }
+  void Clear(void);
+    // Immediately clears the ring buffer.
+  int Put(const uchar *Data, int Count);
+    // Puts at most Count bytes of Data into the ring buffer.
+    // Returns the number of bytes actually stored.
+  int Get(uchar *Data, int Count);
+    // Gets at most Count bytes of Data from the ring buffer.
+    // Returns the number of bytes actually retrieved.
+  virtual void Input(void) = 0;
+    // Runs as a separate thread and shall continuously read data from
+    // a source and call Put() to store the data in the ring buffer.
+  virtual void Output(void) = 0;
+    // Runs as a separate thread and shall continuously call Get() to
+    // retrieve data from the ring buffer and write it to a destination.
+public:
+  cRingBuffer(int Size);
+  virtual ~cRingBuffer();
+  bool Start(void);
+  bool Active(void);
+  void Stop(void);
+  };
+
+#endif // __RINGBUFFER_H