Initial community commit

Src/f263/Header.cpp

@@ -0,0 +1,92 @@
+#include "Decoder.h"
+
+
+/*
+ * decode headers from one input stream
+ * until an End of Sequence or picture start code
+ * is found
+ */
+int Decoder::getheader()
+{
+  unsigned int sorenson_version;
+
+  /* look for startcode */
+  startcode();
+  buffer.getbits(PSC_LENGTH);
+  sorenson_version = buffer.getbits(5);
+  if (sorenson_version <= 1) 
+	{
+		escapemode=sorenson_version;
+    getpicturehdr();
+  }
+	else
+		return 0;
+
+  return 1;
+}
+
+/* align to start of next startcode */
+
+void Decoder::startcode()
+{
+  /* search for new picture start code */
+  while (buffer.showbits(PSC_LENGTH)!=1l) 
+         buffer.flushbits(1);
+}
+
+/* decode picture header */
+
+void Decoder::getpicturehdr()
+{
+  int pei, tmp;
+
+  buffer.getbits(8);
+
+  tmp = buffer.getbits(3);	
+	switch(tmp)
+	{
+		    case 0:
+        horizontal_size = buffer.getbits(8);
+        vertical_size = buffer.getbits(8);
+        break;
+    case 1:
+        horizontal_size = buffer.getbits(16);
+        vertical_size = buffer.getbits(16);
+        break;
+    case 2:
+        horizontal_size = 352;
+        vertical_size = 288;
+        break;
+    case 3:
+        horizontal_size = 176;
+        vertical_size = 144;
+        break;
+    case 4:
+        horizontal_size = 128;
+        vertical_size = 96;
+        break;
+    case 5:
+        horizontal_size = 320;
+        vertical_size = 240;
+        break;
+    case 6:
+        horizontal_size = 160;
+        vertical_size = 120;
+        break;
+
+	}
+	pict_type = buffer.getbits(2);
+	deblock=buffer.getbits(1); // deblocking flag
+  quant = buffer.getbits(5);	
+
+  pei = buffer.getbits(1);
+pspare:
+  if (pei) {
+     /* extra info for possible future backward compatible additions */
+    buffer.getbits(8);  /* not used */
+    pei = buffer.getbits(1);
+    if (pei) goto pspare; /* keep on reading pspare until pei=0 */
+  }
+
+}
+