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authorKlaus Schmidinger <vdr@tvdr.de>2001-08-03 14:18:08 +0200
committerKlaus Schmidinger <vdr@tvdr.de>2001-08-03 14:18:08 +0200
commitbff17fb1d0e39583e44ba93ea214d7434ecef2ce (patch)
treedf3c64f93c4a572feca8de742f2300bfa0f687ee /ac3dec/exponent.c
parent1962940c39c1951bd107f63d2e071df58ba0b125 (diff)
downloadvdr-bff17fb1d0e39583e44ba93ea214d7434ecef2ce.tar.gz
vdr-bff17fb1d0e39583e44ba93ea214d7434ecef2ce.tar.bz2
Added support for replaying DVDs
Diffstat (limited to 'ac3dec/exponent.c')
-rw-r--r--ac3dec/exponent.c135
1 files changed, 135 insertions, 0 deletions
diff --git a/ac3dec/exponent.c b/ac3dec/exponent.c
new file mode 100644
index 00000000..98111a5b
--- /dev/null
+++ b/ac3dec/exponent.c
@@ -0,0 +1,135 @@
+/*
+ * exponent.c
+ *
+ * Copyright (C) Aaron Holtzman - May 1999
+ *
+ * This file is part of ac3dec, a free Dolby AC-3 stream decoder.
+ *
+ * ac3dec is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * ac3dec is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Make; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include "ac3.h"
+#include "ac3_internal.h"
+
+
+#include "decode.h"
+#include "exponent.h"
+
+
+static void exp_unpack_ch(uint_16 type,uint_16 expstr,uint_16 ngrps,uint_16 initial_exp,
+ uint_16 exps[], uint_16 *dest);
+
+void
+exponent_unpack( bsi_t *bsi, audblk_t *audblk)
+{
+ uint_16 i;
+
+ for(i=0; i< bsi->nfchans; i++)
+ exp_unpack_ch(UNPACK_FBW, audblk->chexpstr[i], audblk->nchgrps[i], audblk->exps[i][0],
+ &audblk->exps[i][1], audblk->fbw_exp[i]);
+
+ if(audblk->cplinu)
+ exp_unpack_ch(UNPACK_CPL, audblk->cplexpstr, audblk->ncplgrps, audblk->cplabsexp << 1,
+ audblk->cplexps, &audblk->cpl_exp[audblk->cplstrtmant]);
+
+ if(bsi->lfeon)
+ exp_unpack_ch(UNPACK_LFE, audblk->lfeexpstr, 2, audblk->lfeexps[0],
+ &audblk->lfeexps[1], audblk->lfe_exp);
+}
+
+
+static void
+exp_unpack_ch(uint_16 type,uint_16 expstr,uint_16 ngrps,uint_16 initial_exp,
+ uint_16 exps[], uint_16 *dest)
+{
+ uint_16 i,j;
+ sint_16 exp_acc;
+ sint_16 exp_1,exp_2,exp_3;
+
+ if(expstr == EXP_REUSE)
+ return;
+
+ /* Handle the initial absolute exponent */
+ exp_acc = initial_exp;
+ j = 0;
+
+ /* In the case of a fbw channel then the initial absolute values is
+ * also an exponent */
+ if(type != UNPACK_CPL)
+ dest[j++] = exp_acc;
+
+ /* Loop through the groups and fill the dest array appropriately */
+ for(i=0; i< ngrps; i++)
+ {
+ if(exps[i] > 124)
+ goto error;
+
+ exp_1 = exps[i] / 25;
+ exp_2 = (exps[i] - (exp_1 * 25)) / 5;
+ exp_3 = exps[i] - (exp_1 * 25) - (exp_2 * 5) ;
+
+ exp_acc += (exp_1 - 2);
+
+ switch(expstr)
+ {
+ case EXP_D45:
+ dest[j++] = exp_acc;
+ dest[j++] = exp_acc;
+ case EXP_D25:
+ dest[j++] = exp_acc;
+ case EXP_D15:
+ dest[j++] = exp_acc;
+ }
+
+ exp_acc += (exp_2 - 2);
+
+ switch(expstr)
+ {
+ case EXP_D45:
+ dest[j++] = exp_acc;
+ dest[j++] = exp_acc;
+ case EXP_D25:
+ dest[j++] = exp_acc;
+ case EXP_D15:
+ dest[j++] = exp_acc;
+ }
+
+ exp_acc += (exp_3 - 2);
+
+ switch(expstr)
+ {
+ case EXP_D45:
+ dest[j++] = exp_acc;
+ dest[j++] = exp_acc;
+ case EXP_D25:
+ dest[j++] = exp_acc;
+ case EXP_D15:
+ dest[j++] = exp_acc;
+ }
+ }
+
+ return;
+
+ goto error;
+error:
+ if(!error_flag)
+ fprintf(stderr,"** Invalid exponent - skipping frame **\n");
+ error_flag = 1;
+}
+