More enhancements:

- added getopt_long to parse the command line options
  - added -D (--device) option
  - added -q (--quiet) option
  - added -I (--iec958) option
  - added AC3 to IEC958 encapsulation code (not tested)
  - addec xrun detection and restart

ac3dec/ac3spdif.c

@@ -0,0 +1,137 @@
+/***************************************************************************/
+/*  This code has been fully inspired from various place                   */
+/*  I will give their name later. May they be bless .... It works   	   */
+/*                                                                         */
+/*	For the moment test it.                                            */   
+/*									   */
+/* 27-08-00 -- Ze'ev Maor -- fixed recovery from flase syncword detection  */
+/* 								           */
+/* 24-08-00 -- Ze'ev Maor -- Modified for integrtion with DXR3-OMS-plugin  */  
+/***************************************************************************/
+									   
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include <libac3/ac3.h>
+#include <libac3/ac3_internal.h>
+#include <libac3/parse.h>
+#include <libac3/crc.h>
+
+#include "output.h"
+
+void swab(const void*, void*, size_t);
+
+#define BLOCK_SIZE 6144
+
+static char buf[BLOCK_SIZE];
+static uint32_t sbuffer_size;
+static syncinfo_t syncinfo;
+static char *sbuffer;
+static int done_banner;
+
+static uint32_t
+buffer_syncframe(syncinfo_t *syncinfo, uint8_t **start, uint8_t *end)
+{
+  uint8_t *cur = *start;
+  uint16_t syncword = syncinfo->syncword;
+  uint32_t ret = 0;
+ 
+  //
+  // Find an ac3 sync frame.
+  //
+  while(syncword != 0x0b77)
+    {
+      if(cur >= end)
+	goto done;
+      syncword = (syncword << 8) + *cur++;
+    }
+ 
+  //need the next 3 bytes to decide how big the frame is
+  while(sbuffer_size < 3)
+    {
+      if(cur >= end)
+	goto done;
+ 
+      sbuffer[sbuffer_size++] = *cur++;
+    }
+                                                                                    
+  parse_syncinfo_data(syncinfo,sbuffer);
+ 
+  while(sbuffer_size < syncinfo->frame_size * 2 - 2)
+    {
+      if(cur >= end)
+	goto done;
+ 
+      sbuffer[sbuffer_size++] = *cur++;
+    }
+ 
+  crc_init();
+  crc_process_frame(sbuffer,syncinfo->frame_size * 2 - 2);
+	
+  if(!crc_validate())
+    {
+      //error_flag = 1;
+      fprintf(stderr,"** CRC failed - skipping frame **\n");
+      syncword = 0xffff;
+      sbuffer_size = 0;
+      bzero(buf,BLOCK_SIZE);
+
+      goto done;
+    }                                                                           
+  //
+  //if we got to this point, we found a valid ac3 frame to decode
+  //
+ 
+  //reset the syncword for next time
+  syncword = 0xffff;
+  sbuffer_size = 0;
+  ret = 1;
+ 
+ done:
+  syncinfo->syncword = syncword;
+  *start = cur;
+  return ret;
+}                                                                                  
+
+void
+init_spdif(void)
+{
+  sbuffer_size = 0;
+  sbuffer = &buf[10];
+  done_banner = 0;
+}
+
+int
+output_spdif(uint8_t *data_start, uint8_t *data_end, int quiet)
+{
+  unsigned short *sbuf = (unsigned short *)buf;
+  int ret = 0, res;
+  
+  while(buffer_syncframe(&syncinfo, &data_start, data_end))
+    {
+      sbuf[0] = 0xf872;  //spdif syncword
+      sbuf[1] = 0x4e1f;  // .............
+      sbuf[2] = 0x0001;  // AC3 data
+      sbuf[3] = syncinfo.frame_size * 16;
+      sbuf[4] = 0x0b77;  // AC3 syncwork
+
+      if (!done_banner) {
+        fprintf(stdout,"AC3 Stream ");
+	fprintf(stdout,"%2.1f KHz",syncinfo.sampling_rate * 1e-3);
+        fprintf(stdout,"%4d kbps",syncinfo.bit_rate);
+        fprintf(stdout,"\n");
+        done_banner = 1;
+      }
+      
+      // extract_ac3 seems to write swabbed data
+      swab(&buf[10], &buf[10], syncinfo.frame_size * 2 - 2);
+      res = output_play(sbuf, BLOCK_SIZE / 2 / 2);	/* 2 channels, 16-bit samples */
+      ret = ret < 0 ? ret : res;
+      bzero(buf,BLOCK_SIZE);
+    }
+  return ret;
+}