From a1785d95c28c81c5443695100b6016bf68da3025 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andreas=20=C3=96man?= <andreas@lonelycoder.com>
Date: Mon, 28 Jan 2008 21:53:49 +0000
Subject: [PATCH] Implement the TS packet demuxer as a startcode parser instead
 of relying on the payload-unit-start-indicator bit. This delivers packets
 faster thru the system for sources that only sets the
 payload-unit-start-indicator bits on I-frames

---
 pes.c     | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 pes.h     |  3 +++
 tsdemux.c | 57 +---------------------------------------------------
 3 files changed, 64 insertions(+), 56 deletions(-)

diff --git a/pes.c b/pes.c
index dace71ce..4a487655 100644
--- a/pes.c
+++ b/pes.c
@@ -62,6 +62,66 @@ static void pes_compute_pts(th_transport_t *t, th_stream_t *st, th_pkt_t *pkt);
   _pts;							\
 })
 
+/**
+ * pes_reassembly()
+ *
+ * 
+ */
+
+void
+pes_reassembly(th_transport_t *t, th_stream_t *st, uint8_t *data, 
+	       int len, int start, int err)
+{
+  uint32_t sc;
+  int i;
+
+  if(LIST_FIRST(&t->tht_muxers) == NULL)
+    return; /* No muxers will take packet, so drop here */
+
+  sc = st->st_startcond;
+
+  if(st->st_buffer == NULL) {
+    st->st_buffer_size = 4000;
+    st->st_buffer = malloc(st->st_buffer_size);
+  }
+
+  if(st->st_buffer_ptr + len >= st->st_buffer_size) {
+    st->st_buffer_size += len * 4;
+    st->st_buffer = realloc(st->st_buffer, st->st_buffer_size);
+  }
+
+  for(i = 0; i < len; i++) {
+    st->st_buffer[st->st_buffer_ptr++] = data[i];
+    sc = sc << 8 | data[i];
+
+    if((sc & 0xffffff00) == 0x00000100) {
+      /* Startcode condition */
+      switch(sc) {
+      case 0x000001e0 ... 0x000001ef:
+      case 0x000001c0 ... 0x000001cf:
+      case 0x000001bd:
+	st->st_buffer_ptr -= 4;
+	if(st->st_buffer_ptr < 0) {
+	  /* Fake startcode, can be seen during stream start */
+	  st->st_buffer_ptr = 0;
+	  break;
+	}
+
+	if(st->st_startcode != 0) {
+	  /* It would be nice to embed much of what's done in
+	   *  pes_packet_input() here to avoid a bunch of memcpy()s 
+	   */
+	  pes_packet_input(t, st, st->st_buffer + 2, st->st_buffer_ptr - 2);
+	  st->st_buffer_ptr = 0;
+	}
+	st->st_startcode = sc;
+	break;
+      }
+    }
+  }
+  st->st_startcond = sc;
+}
+
 
 
 
diff --git a/pes.h b/pes.h
index ff95cf0f..8a9cbce5 100644
--- a/pes.h
+++ b/pes.h
@@ -24,4 +24,7 @@ int pes_packet_input(th_transport_t *th, th_stream_t *st, uint8_t *data,
 
 void pes_compute_duration(th_transport_t *t, th_stream_t *st, th_pkt_t *pkt);
 
+void pes_reassembly(th_transport_t *t, th_stream_t *st, uint8_t *data, 
+		    int len, int start, int err);
+
 #endif /* PES_H */
diff --git a/tsdemux.c b/tsdemux.c
index 2f20c519..672f50e8 100644
--- a/tsdemux.c
+++ b/tsdemux.c
@@ -49,61 +49,6 @@
 #include "buffer.h"
 #include "tsdemux.h"
 
-static int 
-ts_reassembly_pes(th_transport_t *t, th_stream_t *st, uint8_t *data, int len)
-{
-  int l2;
-
-  if(len < 9) 
-    return -1;
-
-  if(data[0] != 0 || data[1] != 0 || data[2] != 1)
-    return -1;
-
-  l2 = (data[4] << 8) | data[5];
-  
-  len  -= 6;
-  data += 6;
- 
-  return pes_packet_input(t, st, data, len);
-}
-
-/*
- * TS packet reassembly
- */
-static void
-ts_reassembly(th_transport_t *t, th_stream_t *st, uint8_t *data, int len, 
-	      int pusi, int err)
-{
-  if(pusi) {
-    if(ts_reassembly_pes(t, st, st->st_buffer, st->st_buffer_ptr) == 0)
-      st->st_buffer = NULL; /* Memory was consumed by pes_packet_input() */
-
-    st->st_buffer_ptr = 0;
-    st->st_buffer_errors = 0;
-
-    if(st->st_buffer == NULL) {
-
-      if(st->st_buffer_size < 1000)
-	st->st_buffer_size = 4000;
-
-      st->st_buffer = malloc(st->st_buffer_size);
-    }
-  }
-
-  if(st->st_buffer == NULL)
-    return;
-
-  st->st_buffer_errors += err;
-
-  if(st->st_buffer_ptr + len >= st->st_buffer_size) {
-    st->st_buffer_size += len * 4;
-    st->st_buffer = realloc(st->st_buffer, st->st_buffer_size);
-  }
-  
-  memcpy(st->st_buffer + st->st_buffer_ptr, data, len);
-  st->st_buffer_ptr += len;
-}
 
 /**
  * Code for dealing with a complete section
@@ -216,7 +161,7 @@ ts_recv_packet(th_transport_t *t, int pid, uint8_t *tsb, int dodescramble)
     if(afl > 188)
       break;
 
-    ts_reassembly(t, st, tsb + afl, 188 - afl, pusi, err);
+    pes_reassembly(t, st, tsb + afl, 188 - afl, pusi, err);
     break;
   }
 }