From d375f3ea3ead88dcc4f41c6e5c551370cd305755 Mon Sep 17 00:00:00 2001
From: Felix Domke <tmbinc@elitedvb.net>
Date: Sun, 14 Aug 2005 16:25:44 +0000
Subject: [PATCH]  - add tstools to evaluate PTS values from TS files for
 playback

---
 lib/dvb/tstools.cpp | 151 ++++++++++++++++++++++++++++++++++++++++++++
 lib/dvb/tstools.h   |  42 ++++++++++++
 2 files changed, 193 insertions(+)
 create mode 100644 lib/dvb/tstools.cpp
 create mode 100644 lib/dvb/tstools.h

diff --git a/lib/dvb/tstools.cpp b/lib/dvb/tstools.cpp
new file mode 100644
index 00000000..5d1c7e35
--- /dev/null
+++ b/lib/dvb/tstools.cpp
@@ -0,0 +1,151 @@
+#include <lib/dvb/tstools.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <stdio.h>
+
+eDVBTSTools::eDVBTSTools()
+{
+	m_fd = -1;
+	m_pid = -1;
+	m_maxrange = 1*1024*1024;
+	
+	m_begin_valid = 0;
+	m_end_valid = 0;
+}
+
+eDVBTSTools::~eDVBTSTools()
+{
+	closeFile();
+}
+
+int eDVBTSTools::openFile(const char *filename)
+{
+	closeFile();
+	m_fd = ::open(filename, O_RDONLY);
+	if (m_fd < 0)
+		return -1;
+	return 0;
+}
+
+void eDVBTSTools::closeFile()
+{
+	if (m_fd >= 0)
+		::close(m_fd);
+}
+
+void eDVBTSTools::setSyncPID(int pid)
+{
+	m_pid = pid;
+}
+
+void eDVBTSTools::setSearchRange(int maxrange)
+{
+	m_maxrange = maxrange;
+}
+
+int eDVBTSTools::getPTS(off_t &offset, pts_t &pts)
+{
+	if (m_fd < 0)
+		return -1;
+	if (m_pid < 0)
+		return -1;
+
+	offset -= offset % 188;
+	
+		// TODO: multiple files!	
+	if (lseek(m_fd, offset, SEEK_SET) < 0)
+		return -1;
+
+	int left = m_maxrange;
+	
+	while (left >= 188)
+	{
+		unsigned char block[188];
+		if (read(m_fd, block, 188) != 188)
+			break;
+		left -= 188;
+		offset += 188;
+		
+		if (block[0] != 0x47)
+		{
+			int i = 0;
+			while (i < 188)
+				if (block[i] == 0x47)
+					break;
+			offset = lseek(m_fd, i - 188, SEEK_CUR);
+			continue;
+		}
+		
+		int pid = ((block[1] << 8) | block[2]) & 0x1FFF;
+		int pusi = !!(block[1] & 0x40);
+		
+//		printf("PID %04x, PUSI %d\n", pid, pusi);
+		
+		if (pid != m_pid)
+			continue;
+		if (!pusi)
+			continue;
+		
+			/* ok, now we have a PES header */
+		unsigned char *pes;
+		
+			/* check for adaption field */
+		if (block[3] & 0x10)
+			pes = block + block[4] + 4 + 1;
+		else
+			pes = block + 4;
+		
+			/* somehow not a startcode. (this is invalid, since pusi was set.) ignore it. */
+		if (pes[0] || pes[1] || (pes[2] != 1))
+			continue;
+		
+		if (pes[7] & 0x80) /* PTS */
+		{
+			pts  = ((unsigned long long)(pes[ 9]&0xE))  << 29;
+			pts |= ((unsigned long long)(pes[10]&0xFF)) << 22;
+			pts |= ((unsigned long long)(pes[11]&0xFE)) << 14;
+			pts |= ((unsigned long long)(pes[12]&0xFF)) << 7;
+			pts |= ((unsigned long long)(pes[13]&0xFE)) >> 1;
+			offset -= 188;
+			return 0;
+		}
+	}
+
+	return -1;
+}
+
+void eDVBTSTools::calcBegin()
+{
+	if (m_fd < 0)	
+		return;
+	if (!m_begin_valid)
+	{
+		m_offset_begin = 0;
+		if (!getPTS(m_offset_begin, m_pts_begin))
+			m_begin_valid = 1;
+	}
+}
+
+void eDVBTSTools::calcEnd()
+{
+	if (m_fd < 0)	
+		return;
+	
+	if (!m_end_valid)
+	{
+		m_offset_end = lseek(m_fd, 0, SEEK_END) - m_maxrange;
+		if (!getPTS(m_offset_end, m_pts_end))
+			m_end_valid = 1;
+	}
+}
+
+int eDVBTSTools::calcLen(pts_t &len)
+{
+	calcBegin(); calcEnd();
+	if (!(m_begin_valid && m_end_valid))
+		return -1;
+	len = m_pts_end - m_pts_begin;
+	return 0;
+}
+
diff --git a/lib/dvb/tstools.h b/lib/dvb/tstools.h
new file mode 100644
index 00000000..c6f2cbbc
--- /dev/null
+++ b/lib/dvb/tstools.h
@@ -0,0 +1,42 @@
+#ifndef __lib_dvb_tstools_h
+#define __lib_dvb_tstools_h
+
+#include <sys/types.h>
+
+/*
+ * Note: we're interested in PTS values, not STC values.
+ * thus we're not evaluating PES headers, not adaption fields.
+ */
+
+class eDVBTSTools
+{
+public:
+	typedef unsigned long long pts_t;
+	eDVBTSTools();
+	~eDVBTSTools();
+
+	int openFile(const char *filename);
+	void closeFile();
+	
+	void setSyncPID(int pid);
+	void setSearchRange(int maxrange);
+	
+		/* get first PTS *after* the given offset. */
+	int getPTS(off_t &offset, pts_t &pts);
+	
+	void calcBegin();
+	void calcEnd();
+	
+	int calcLen(pts_t &len);
+	
+private:
+	int m_fd, m_pid;
+	int m_maxrange;
+	
+	int m_begin_valid, m_end_valid;
+	pts_t m_pts_begin, m_pts_end;
+	off_t m_offset_begin, m_offset_end;
+};
+
+
+#endif
-- 
2.30.2