1 files changed, 113 insertions, 0 deletions
diff --git a/libtoolame-dab/crc.c b/libtoolame-dab/crc.c
new file mode 100644
index 0000000..b83ac03
--- /dev/null
+++ b/libtoolame-dab/crc.c
@@ -0,0 +1,113 @@
+#include <stdio.h>
+#include <string.h>
+#include "common.h"
+#include "crc.h"
+
+/*****************************************************************************
+*
+*  CRC error protection package
+*
+*****************************************************************************/
+
+void CRC_calc (frame_info * frame, unsigned int bit_alloc[2][SBLIMIT],
+	       unsigned int scfsi[2][SBLIMIT], unsigned int *crc)
+{
+  int i, k;
+  frame_header *header = frame->header;
+  int nch = frame->nch;
+  int sblimit = frame->sblimit;
+  int jsbound = frame->jsbound;
+  al_table *alloc = frame->alloc;
+
+  *crc = 0xffff;		/* changed from '0' 92-08-11 shn */
+  update_CRC (header->bitrate_index, 4, crc);
+  update_CRC (header->sampling_frequency, 2, crc);
+  update_CRC (header->padding, 1, crc);
+  update_CRC (header->extension, 1, crc);
+  update_CRC (header->mode, 2, crc);
+  update_CRC (header->mode_ext, 2, crc);
+  update_CRC (header->copyright, 1, crc);
+  update_CRC (header->original, 1, crc);
+  update_CRC (header->emphasis, 2, crc);
+
+  for (i = 0; i < sblimit; i++)
+    for (k = 0; k < ((i < jsbound) ? nch : 1); k++)
+      update_CRC (bit_alloc[k][i], (*alloc)[i][0].bits, crc);
+
+  for (i = 0; i < sblimit; i++)
+    for (k = 0; k < nch; k++)
+      if (bit_alloc[k][i])
+	update_CRC (scfsi[k][i], 2, crc);
+}
+
+void update_CRC (unsigned int data, unsigned int length, unsigned int *crc)
+{
+  unsigned int masking, carry;
+
+  masking = 1 << length;
+
+  while ((masking >>= 1)) {
+    carry = *crc & 0x8000;
+    *crc <<= 1;
+    if (!carry ^ !(data & masking))
+      *crc ^= CRC16_POLYNOMIAL;
+  }
+  *crc &= 0xffff;
+}
+
+void
+CRC_calcDAB (frame_info * frame,
+	     unsigned int bit_alloc[2][SBLIMIT],
+	     unsigned int scfsi[2][SBLIMIT],
+	     unsigned int scalar[2][3][SBLIMIT], unsigned int *crc,
+	     int packed)
+{
+  int i, j, k;
+  int nch = frame->nch;
+  int nb_scalar;
+  int f[5] = { 0, 4, 8, 16, 30 };
+  int first, last;
+
+  first = f[packed];
+  last = f[packed + 1];
+  if (last > frame->sblimit)
+    last = frame->sblimit;
+
+  nb_scalar = 0;
+  *crc = 0x0;
+  for (i = first; i < last; i++)
+    for (k = 0; k < nch; k++)
+      if (bit_alloc[k][i])	/* above jsbound, bit_alloc[0][i] == ba[1][i] */
+	switch (scfsi[k][i]) {
+	case 0:
+	  for (j = 0; j < 3; j++) {
+	    nb_scalar++;
+	    update_CRCDAB (scalar[k][j][i] >> 3, 3, crc);
+	  }
+	  break;
+	case 1:
+	case 3:
+	  nb_scalar += 2;
+	  update_CRCDAB (scalar[k][0][i] >> 3, 3, crc);
+	  update_CRCDAB (scalar[k][2][i] >> 3, 3, crc);
+	  break;
+	case 2:
+	  nb_scalar++;
+	  update_CRCDAB (scalar[k][0][i] >> 3, 3, crc);
+	}
+}
+
+void update_CRCDAB (unsigned int data, unsigned int length, unsigned int *crc)
+{
+  unsigned int masking, carry;
+
+  masking = 1 << length;
+
+  while ((masking >>= 1)) {
+    carry = *crc & 0x80;
+    *crc <<= 1;
+    if (!carry ^ !(data & masking))
+      *crc ^= CRC8_POLYNOMIAL;
+  }
+  *crc &= 0xff;
+}