use samples for more accurate jumps when .ap files are not available

diff --git a/lib/dvb/tstools.cpp b/lib/dvb/tstools.cpp
index 5c99ea60c50027d03244d0d6c91b9516bc3d77a3..73ceb7e36f493c8037e05270719747f4d8a2329a 100644 (file)
--- a/lib/dvb/tstools.cpp
+++ b/lib/dvb/tstools.cpp
@@ -14,6 +14,7 @@ eDVBTSTools::eDVBTSTools()
        m_end_valid = 0;
        
        m_use_streaminfo = 0;
+       m_samples_taken = 0;
 }
 
 eDVBTSTools::~eDVBTSTools()
@@ -34,6 +35,8 @@ int eDVBTSTools::openFile(const char *filename)
                eDebug("no recorded stream information available");
                m_use_streaminfo = 0;
        }
+       
+       m_samples_taken = 0;
 
        if (m_file.open(filename) < 0)
                return -1;
@@ -128,6 +131,8 @@ int eDVBTSTools::getPTS(off_t &offset, pts_t &pts, int fixed)
                        pts |= ((unsigned long long)(pes[13]&0xFE)) >> 1;
                        offset -= 188;
                        
+//                     eDebug("found pts %08llx at %08llx", pts, offset);
+                       
                                /* convert to zero-based */
                        if (fixed)
                                fixupPTS(offset, pts);
@@ -176,11 +181,40 @@ int eDVBTSTools::getOffset(off_t &offset, pts_t &pts)
                return 0;
        } else
        {
+//             eDebug("get offset");
+               if (!m_samples_taken)
+                       takeSamples();
+               
+               if (m_samples.empty())
+                       return -1;
+               
+//             eDebug("ok, samples ok");
+                       /* search entry before and after */
+               std::map<pts_t, off_t>::const_iterator l = m_samples.lower_bound(pts);
+               std::map<pts_t, off_t>::const_iterator u = l;
+
+               if (l != m_samples.begin())
+                       --l;
+               
+               int birate;
+               if ((u == m_samples.end()) || (l == m_samples.end()))
+                       return -1;
+
+               pts_t pts_diff = u->first - l->first;
+               off_t offset_diff = u->second - l->second;
+//             eDebug("using: %llx:%llx -> %llx:%llx", l->first, u->first, l->second, u->second);
+       
+               if (!pts_diff)
+                       return -1;
+
                int bitrate = calcBitrate(); /* in bits/s */
+               bitrate = offset_diff * 90000 * 8 / pts_diff;
+
                if (bitrate <= 0)
                        return -1;
                
-               offset = (pts * (pts_t)bitrate) / 8ULL / 90000ULL;
+               offset = l->second;
+               offset += ((pts - l->first) * (pts_t)bitrate) / 8ULL / 90000ULL;
                offset -= offset % 188;
 
                return 0;
@@ -275,4 +309,35 @@ int eDVBTSTools::calcBitrate()
                return -1;
        
        return bitrate;
+}
+
+       /* pts, off */
+void eDVBTSTools::takeSamples()
+{
+       m_samples_taken = 1;
+       m_samples.clear();
+       pts_t dummy;
+       if (calcLen(dummy) == -1)
+               return;
+       
+       int nr_samples = 30;
+       off_t bytes_per_sample = (m_offset_end - m_offset_begin) / (long long)nr_samples;
+       if (bytes_per_sample < 1*1024*1024)
+               bytes_per_sample = 1*1024*1024;
+       
+       bytes_per_sample -= bytes_per_sample % 188;
+       
+       for (off_t offset = m_offset_begin; offset < m_offset_end; offset += bytes_per_sample)
+       {
+               off_t o = offset;
+               pts_t p;
+               if (!eDVBTSTools::getPTS(o, p, 1))
+               {
+//                     eDebug("sample: %llx, %llx", o, p);
+                       m_samples[p] = o;
+               }
+       }
+       m_samples[m_pts_begin] = m_offset_begin;
+       m_samples[m_pts_end] = m_offset_end;
+//     eDebug("begin, end: %llx %llx", m_offset_begin, m_offset_end); 
 }

diff --git a/lib/dvb/tstools.h b/lib/dvb/tstools.h
index b6a275dcce108798800b4b960fb183b8bed7874b..1aa10c70e6fa52398880a0f2bedc1cef8c67fc4c 100644 (file)
--- a/lib/dvb/tstools.h
+++ b/lib/dvb/tstools.h
@@ -51,6 +51,8 @@ public:
        
        int calcBitrate(); /* in bits/sec */
        
+       void takeSamples();
+       
 private:
        int m_pid;
        int m_maxrange;
@@ -61,6 +63,10 @@ private:
        pts_t m_pts_begin, m_pts_end;
        off_t m_offset_begin, m_offset_end;
        
+               /* for simple linear interpolation */
+       std::map<pts_t, off_t> m_samples;
+       int m_samples_taken;
+       
        eMPEGStreamInformation m_streaminfo;
        int m_use_streaminfo;
 };