From 0057a6fd47623edb1b0338fae181756457dfe120 Mon Sep 17 00:00:00 2001
From: Mark Calderbank <mark@vomp.tv>
Date: Thu, 26 Jan 2006 23:52:38 +0000
Subject: [PATCH] Add video PTS to demuxer and do some tidying

---
 demuxer.cc | 60 ++++++++++++++++++++++++++++++++++++++++++++++--------
 demuxer.h  | 17 ++++++++++------
 2 files changed, 63 insertions(+), 14 deletions(-)

diff --git a/demuxer.cc b/demuxer.cc
index afd7eec..1f553ae 100644
--- a/demuxer.cc
+++ b/demuxer.cc
@@ -69,7 +69,7 @@ void Demuxer::reset()
   video_current = audio_current = -1;
   horizontal_size = vertical_size = 0;
   aspect_ratio = (enum AspectRatio) 0;
-  cbAspectRatio = frame_rate = bit_rate = 0;
+  frame_rate = bit_rate = 0;
 }
 
 int Demuxer::shutdown()
@@ -109,18 +109,23 @@ void Demuxer::setVideoStream(int id)
   video_current = id;
 }
 
-void Demuxer::setAspectRatio()
+void Demuxer::setAspectRatio(enum AspectRatio ar)
 {
-  if (aspect_ratio != cbAspectRatio)
+  if (aspect_ratio != ar)
   {
-    cbAspectRatio = aspect_ratio;
+    aspect_ratio = ar;
     callback->call(this);
   }
 }
 
-int Demuxer::getAspectRatio()
+int Demuxer::writeAudio(int fd)
 {
-  return aspect_ratio;
+  return audiostream.drain(fd);
+}
+
+int Demuxer::writeVideo(int fd)
+{
+  return videostream.drain(fd);
 }
 
 int Demuxer::scan(UCHAR *buf, int len)
@@ -414,6 +419,16 @@ int Demuxer::parse_private1_frame(int len, int* full)
 
 void Demuxer::parse_video_details(UCHAR* buf, int len)
 {
+  // Extract video PTS if it exists
+  if ( buf[1] & 0x80 ) // PTS_DTS_flags indicate that PTS is present
+  {
+    video_pts = ( (ULLONG)(buf[3] & 0x0E) << 29 ) |
+                ( (ULLONG)(buf[4])        << 22 ) |
+                ( (ULLONG)(buf[5] & 0xFE) << 14 ) |
+                ( (ULLONG)(buf[6])        <<  7 ) |
+                ( (ULLONG)(buf[7] & 0xFE) >>  1 );
+  }
+  // Now, scan for a GOP header and extract video information
   UCHAR byte;
   int zeros = 0;
   while (len >= 8) // 8 is length of a GOP header
@@ -455,7 +470,7 @@ void Demuxer::parse_video_details(UCHAR* buf, int len)
         if (len < 7) return;
         horizontal_size = ((int)buf[0] << 4) | ((int)buf[1] >> 4);
         vertical_size = (((int)buf[1] & 0xf) << 8) | (int)buf[2];
-        aspect_ratio = (enum AspectRatio)(buf[3] >> 4);
+        setAspectRatio((enum AspectRatio)(buf[3] >> 4));
         frame_rate = buf[3] & 0x0f;
         if (frame_rate >= 1 && frame_rate <= 8)
           frame_rate = FrameRates[frame_rate];
@@ -467,7 +482,6 @@ void Demuxer::parse_video_details(UCHAR* buf, int len)
         seeking = 0;
         buf += 8; // Minimum length of sequence header
         len -= 8;
-        setAspectRatio();
         break;
       case 0xb8: // Group header
                  // We're not going to bother parsing anything.
@@ -478,3 +492,33 @@ void Demuxer::parse_video_details(UCHAR* buf, int len)
     }
   }
 }
+
+int Demuxer::findVideoPTS(UCHAR* buf, int len, ULLONG* dest)
+{
+  UINT LoPattern = 0x100 | FRAMETYPE_VID0,
+       HiPattern = 0x100 | FRAMETYPE_VIDMAX;
+
+  while (len >= 14)
+  {
+    UINT pattern = *(UINT*)buf;
+    buf++; len--;
+    if (pattern < LoPattern || pattern > HiPattern) continue;
+
+    UINT framelength = ((UINT)buf[3] << 8) | buf[4];
+    buf += 5; len -= 5;
+
+    if ( buf[1] & 0x80 ) // PTS_DTS_flags indicate that PTS is present
+    {
+      *dest = ( (ULLONG)(buf[3] & 0x0E) << 29 ) |
+              ( (ULLONG)(buf[4])        << 22 ) |
+              ( (ULLONG)(buf[5] & 0xFE) << 14 ) |
+              ( (ULLONG)(buf[6])        <<  7 ) |
+              ( (ULLONG)(buf[7] & 0xFE) >>  1 );
+      return 1;
+    }
+
+    buf += framelength; len -= framelength;
+  }
+  // No PTS found.
+  return 0;
+}
diff --git a/demuxer.h b/demuxer.h
index 96fcdac..29930b5 100644
--- a/demuxer.h
+++ b/demuxer.h
@@ -50,12 +50,18 @@ class Demuxer
     void seek();
     void setVideoStream(int id);
     void setAudioStream(int id);
-    int writeAudio(int fd) { return audiostream.drain(fd); }
-    int writeVideo(int fd) { return videostream.drain(fd); }
+    int writeAudio(int fd);
+    int writeVideo(int fd);
     int scan(UCHAR* buf, int len);
+    int findVideoPTS(UCHAR* buf, int len, ULLONG* dest);
     int put(UCHAR* buf, int len);
 
-    int getAspectRatio();
+    int getHorizontalSize() { return horizontal_size; }
+    int getVerticalSize() { return vertical_size; }
+    int getAspectRatio() { return aspect_ratio; }
+    int getFrameRate() { return frame_rate; }
+    int getBitRate() { return bit_rate; }
+    ULLONG getVideoPTS() { return video_pts; }
 
     enum AspectRatio
     {
@@ -72,7 +78,7 @@ class Demuxer
     int seeking;
     UCHAR* inbuf;
 
-    void setAspectRatio();
+    void setAspectRatio(enum AspectRatio);
     Callback* callback;
 
     int video_current, audio_current;
@@ -152,8 +158,7 @@ class Demuxer
     enum AspectRatio aspect_ratio;
     int frame_rate;
     int bit_rate;
-
-    int cbAspectRatio;
+    ULLONG video_pts;
 };
 
 #endif
-- 
2.39.5