preparing integration of new AC3 decoder

Originally committed as revision 1089 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 56 insertions, 0 deletions

diff --git a/libavcodec/ac3.h b/libavcodec/ac3.h
new file mode 100644
index 0000000000..d62c3c168b
--- /dev/null
+++ b/libavcodec/ac3.h
@@ -0,0 +1,56 @@
+/*
+ * Common code between AC3 encoder and decoder
+ * Copyright (c) 2000, 2001, 2002 Fabrice Bellard.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#define AC3_MAX_CODED_FRAME_SIZE 3840 /* in bytes */
+#define AC3_MAX_CHANNELS 6 /* including LFE channel */
+
+#define NB_BLOCKS 6 /* number of PCM blocks inside an AC3 frame */
+#define AC3_FRAME_SIZE (NB_BLOCKS * 256)
+
+/* exponent encoding strategy */
+#define EXP_REUSE 0
+#define EXP_NEW   1
+
+#define EXP_D15   1
+#define EXP_D25   2
+#define EXP_D45   3
+
+typedef struct AC3BitAllocParameters {
+    int fscod; /* frequency */
+    int halfratecod;
+    int sgain, sdecay, fdecay, dbknee, floor;
+    int cplfleak, cplsleak;
+} AC3BitAllocParameters;
+
+extern const UINT16 ac3_freqs[3];
+extern const UINT16 ac3_bitratetab[19];
+extern const INT16 ac3_window[256];
+extern const UINT8 sdecaytab[4];
+extern const UINT8 fdecaytab[4];
+extern const UINT16 sgaintab[4];
+extern const UINT16 dbkneetab[4];
+extern const UINT16 floortab[8];
+extern const UINT16 fgaintab[8];
+
+void ac3_common_init(void);
+void ac3_parametric_bit_allocation(AC3BitAllocParameters *s, UINT8 *bap,
+                                   INT8 *exp, int start, int end,
+                                   int snroffset, int fgain, int is_lfe,
+                                   int deltbae,int deltnseg, 
+                                   UINT8 *deltoffst, UINT8 *deltlen, UINT8 *deltba);