latest updates from walken

CVS patchset: 93
CVS date: 2001/05/28 13:25:56

3 files changed, 234 insertions, 354 deletions

diff --git a/src/libac3/bit_allocate.c b/src/libac3/bit_allocate.c
index 407626f08..74c5ec902 100644
--- a/src/libac3/bit_allocate.c
+++ b/src/libac3/bit_allocate.c
@@ -27,360 +27,225 @@
 #include "ac3_internal.h"
 #include "bit_allocate.h"
 
-
-
-static int16_t calc_lowcomp(int16_t a,int16_t b0,int16_t b1,int16_t bin);
-static inline uint16_t min(int16_t a,int16_t b);
-static inline uint16_t max(int16_t a,int16_t b);
-
-static void ba_compute_mask(int16_t start, int16_t end, uint16_t fscod,
-			    uint16_t deltbae, uint16_t deltnseg,
-			    uint16_t deltoffst[], uint16_t deltba[],
-			    uint16_t deltlen[], int16_t excite[],
-			    int16_t mask[]);
-static void ba_compute_bap(int16_t start, int16_t end, int16_t snroffset,
-			   int8_t exp[], int16_t mask[], int16_t bap[]);
-
-/* Misc LUTs for bit allocation process */
-
-static int16_t slowdec[]  = { 0x0f,  0x11,  0x13,  0x15  };
-static int16_t fastdec[]  = { 0x3f,  0x53,  0x67,  0x7b  };
-static int16_t slowgain[] = { 0x540, 0x4d8, 0x478, 0x410 };
-static int16_t dbpbtab[]  = { 0x000, 0x700, 0x900, 0xb00 };
-
-static uint16_t floortab[] = { 0x2f0, 0x2b0, 0x270, 0x230, 0x1f0, 0x170, 0x0f0, 0xf800 };
-static int16_t fastgain[] = { 0x080, 0x100, 0x180, 0x200, 0x280, 0x300, 0x380, 0x400  };
-
-
-static int16_t bndtab[] = {  0,  1,  2,   3,   4,   5,   6,   7,   8,   9, 
-			     10, 11, 12,  13,  14,  15,  16,  17,  18,  19,
-			     20, 21, 22,  23,  24,  25,  26,  27,  28,  31,
-			     34, 37, 40,  43,  46,  49,  55,  61,  67,  73,
-			     79, 85, 97, 109, 121, 133, 157, 181, 205, 229 };
-
-static int16_t bndsz[]  = { 1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
-			    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
-			    1,  1,  1,  1,  1,  1,  1,  1,  3,  3,
-			    3,  3,  3,  3,  3,  6,  6,  6,  6,  6,
-			    6, 12, 12, 12, 12, 24, 24, 24, 24, 24 };
-
-static int16_t masktab[] = { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
-			     16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 28, 28, 29,
-			     29, 29, 30, 30, 30, 31, 31, 31, 32, 32, 32, 33, 33, 33, 34, 34,
-			     34, 35, 35, 35, 35, 35, 35, 36, 36, 36, 36, 36, 36, 37, 37, 37,
-			     37, 37, 37, 38, 38, 38, 38, 38, 38, 39, 39, 39, 39, 39, 39, 40,
-			     40, 40, 40, 40, 40, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41,
-			     41, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 43, 43, 43,
-			     43, 43, 43, 43, 43, 43, 43, 43, 43, 44, 44, 44, 44, 44, 44, 44,
-			     44, 44, 44, 44, 44, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45,
-			     45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 46, 46, 46,
-			     46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46,
-			     46, 46, 46, 46, 46, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47,
-			     47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 48, 48, 48,
-			     48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48,
-			     48, 48, 48, 48, 48, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49,
-			     49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49,  0,  0,  0 };
-
-
-static int16_t latab[] = { 0x0040, 0x003f, 0x003e, 0x003d, 0x003c, 0x003b, 0x003a, 0x0039,
-			   0x0038, 0x0037, 0x0036, 0x0035, 0x0034, 0x0034, 0x0033, 0x0032,
-			   0x0031, 0x0030, 0x002f, 0x002f, 0x002e, 0x002d, 0x002c, 0x002c,
-			   0x002b, 0x002a, 0x0029, 0x0029, 0x0028, 0x0027, 0x0026, 0x0026,
-			   0x0025, 0x0024, 0x0024, 0x0023, 0x0023, 0x0022, 0x0021, 0x0021,
-			   0x0020, 0x0020, 0x001f, 0x001e, 0x001e, 0x001d, 0x001d, 0x001c,
-			   0x001c, 0x001b, 0x001b, 0x001a, 0x001a, 0x0019, 0x0019, 0x0018,
-			   0x0018, 0x0017, 0x0017, 0x0016, 0x0016, 0x0015, 0x0015, 0x0015,
-			   0x0014, 0x0014, 0x0013, 0x0013, 0x0013, 0x0012, 0x0012, 0x0012,
-			   0x0011, 0x0011, 0x0011, 0x0010, 0x0010, 0x0010, 0x000f, 0x000f,
-			   0x000f, 0x000e, 0x000e, 0x000e, 0x000d, 0x000d, 0x000d, 0x000d,
-			   0x000c, 0x000c, 0x000c, 0x000c, 0x000b, 0x000b, 0x000b, 0x000b,
-			   0x000a, 0x000a, 0x000a, 0x000a, 0x000a, 0x0009, 0x0009, 0x0009,
-			   0x0009, 0x0009, 0x0008, 0x0008, 0x0008, 0x0008, 0x0008, 0x0008,
-			   0x0007, 0x0007, 0x0007, 0x0007, 0x0007, 0x0007, 0x0006, 0x0006,
-			   0x0006, 0x0006, 0x0006, 0x0006, 0x0006, 0x0006, 0x0005, 0x0005,
-			   0x0005, 0x0005, 0x0005, 0x0005, 0x0005, 0x0005, 0x0004, 0x0004,
-			   0x0004, 0x0004, 0x0004, 0x0004, 0x0004, 0x0004, 0x0004, 0x0004,
-			   0x0004, 0x0003, 0x0003, 0x0003, 0x0003, 0x0003, 0x0003, 0x0003,
-			   0x0003, 0x0003, 0x0003, 0x0003, 0x0003, 0x0003, 0x0003, 0x0002,
-			   0x0002, 0x0002, 0x0002, 0x0002, 0x0002, 0x0002, 0x0002, 0x0002,
-			   0x0002, 0x0002, 0x0002, 0x0002, 0x0002, 0x0002, 0x0002, 0x0002,
-			   0x0002, 0x0002, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001,
-			   0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001,
-			   0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001,
-			   0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001,
-			   0x0001, 0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-			   0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-			   0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-			   0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-			   0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-			   0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-			   0x0000, 0x0000, 0x0000, 0x0000};
-
-static int16_t hth[][50] = {{ 0x04d0, 0x04d0, 0x0440, 0x0400, 0x03e0, 0x03c0, 0x03b0, 0x03b0,  
-			      0x03a0, 0x03a0, 0x03a0, 0x03a0, 0x03a0, 0x0390, 0x0390, 0x0390,  
-			      0x0380, 0x0380, 0x0370, 0x0370, 0x0360, 0x0360, 0x0350, 0x0350,  
-			      0x0340, 0x0340, 0x0330, 0x0320, 0x0310, 0x0300, 0x02f0, 0x02f0,
-			      0x02f0, 0x02f0, 0x0300, 0x0310, 0x0340, 0x0390, 0x03e0, 0x0420,
-			      0x0460, 0x0490, 0x04a0, 0x0460, 0x0440, 0x0440, 0x0520, 0x0800,
-			      0x0840, 0x0840 },
-			    { 0x04f0, 0x04f0, 0x0460, 0x0410, 0x03e0, 0x03d0, 0x03c0, 0x03b0, 
-			      0x03b0, 0x03a0, 0x03a0, 0x03a0, 0x03a0, 0x03a0, 0x0390, 0x0390, 
-			      0x0390, 0x0380, 0x0380, 0x0380, 0x0370, 0x0370, 0x0360, 0x0360, 
-			      0x0350, 0x0350, 0x0340, 0x0340, 0x0320, 0x0310, 0x0300, 0x02f0, 
-			      0x02f0, 0x02f0, 0x02f0, 0x0300, 0x0320, 0x0350, 0x0390, 0x03e0, 
-			      0x0420, 0x0450, 0x04a0, 0x0490, 0x0460, 0x0440, 0x0480, 0x0630, 
-			      0x0840, 0x0840 },
-			    { 0x0580, 0x0580, 0x04b0, 0x0450, 0x0420, 0x03f0, 0x03e0, 0x03d0, 
-			      0x03c0, 0x03b0, 0x03b0, 0x03b0, 0x03a0, 0x03a0, 0x03a0, 0x03a0, 
-			      0x03a0, 0x03a0, 0x03a0, 0x03a0, 0x0390, 0x0390, 0x0390, 0x0390, 
-			      0x0380, 0x0380, 0x0380, 0x0370, 0x0360, 0x0350, 0x0340, 0x0330, 
-			      0x0320, 0x0310, 0x0300, 0x02f0, 0x02f0, 0x02f0, 0x0300, 0x0310, 
-			      0x0330, 0x0350, 0x03c0, 0x0410, 0x0470, 0x04a0, 0x0460, 0x0440, 
-			      0x0450, 0x04e0 }};
-
-
-static int16_t baptab[] = { 0,  1,  1,  1,  1,  1,  2,  2,  3,  3,  3,  4,  4,  5,  5,  6,
-			    6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  8,  9,  9,  9,  9, 10, 
-			    10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 14,
-			    14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15 };
-
-static int16_t sdecay;
-static int16_t fdecay;
-static int16_t sgain;
-static int16_t dbknee;
-static int16_t floor;
-static int16_t bndpsd[256];
-static int16_t excite[256];
-static int16_t mask[256];
-
-static inline uint16_t max(int16_t a,int16_t b)
-{
-    return (a > b ? a : b);
-}
-	
-static inline uint16_t min(int16_t a,int16_t b)
+static int hthtab[3][50] = {
+    {0x730, 0x730, 0x7c0, 0x800, 0x820, 0x840, 0x850, 0x850, 0x860, 0x860,
+     0x860, 0x860, 0x860, 0x870, 0x870, 0x870, 0x880, 0x880, 0x890, 0x890,
+     0x8a0, 0x8a0, 0x8b0, 0x8b0, 0x8c0, 0x8c0, 0x8d0, 0x8e0, 0x8f0, 0x900,
+     0x910, 0x910, 0x910, 0x910, 0x900, 0x8f0, 0x8c0, 0x870, 0x820, 0x7e0,
+     0x7a0, 0x770, 0x760, 0x7a0, 0x7c0, 0x7c0, 0x6e0, 0x400, 0x3c0, 0x3c0},
+    {0x710, 0x710, 0x7a0, 0x7f0, 0x820, 0x830, 0x840, 0x850, 0x850, 0x860,
+     0x860, 0x860, 0x860, 0x860, 0x870, 0x870, 0x870, 0x880, 0x880, 0x880,
+     0x890, 0x890, 0x8a0, 0x8a0, 0x8b0, 0x8b0, 0x8c0, 0x8c0, 0x8e0, 0x8f0,
+     0x900, 0x910, 0x910, 0x910, 0x910, 0x900, 0x8e0, 0x8b0, 0x870, 0x820,
+     0x7e0, 0x7b0, 0x760, 0x770, 0x7a0, 0x7c0, 0x780, 0x5d0, 0x3c0, 0x3c0},
+    {0x680, 0x680, 0x750, 0x7b0, 0x7e0, 0x810, 0x820, 0x830, 0x840, 0x850,
+     0x850, 0x850, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860,
+     0x870, 0x870, 0x870, 0x870, 0x880, 0x880, 0x880, 0x890, 0x8a0, 0x8b0,
+     0x8c0, 0x8d0, 0x8e0, 0x8f0, 0x900, 0x910, 0x910, 0x910, 0x900, 0x8f0,
+     0x8d0, 0x8b0, 0x840, 0x7f0, 0x790, 0x760, 0x7a0, 0x7c0, 0x7b0, 0x720}
+};
+
+static int8_t baptab[305] = {
+    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,	// 93 padding entries
+
+    15, 15, 15, 15, 15, 15, 15, 15, 15, 14, 14, 14, 14, 14, 14, 14,
+    14, 13, 13, 13, 13, 12, 12, 12, 12, 11, 11, 11, 11, 10, 10, 10,
+    10,  9,  9,  9,  9,  8,  8,  8,  8,  7,  7,  7,  7,  6,  6,  6,
+     6,  5,  5,  4,  4,  3,  3,  3,  2,  2,  1,  1,  1,  1,  1,  0,
+
+     0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+     0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+     0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+     0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+     0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+     0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+     0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+     0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+     0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+     0,  0,  0,  0					// 148 padding entries
+};
+
+static int bndtab[30] = {21, 22,  23,  24,  25,  26,  27,  28,  31,  34,
+			 37, 40,  43,  46,  49,  55,  61,  67,  73,  79,
+			 85, 97, 109, 121, 133, 157, 181, 205, 229, 253};
+
+static int8_t latab[256] = {
+    -64, -63, -62, -61, -60, -59, -58, -57, -56, -55, -54, -53,
+    -52, -52, -51, -50, -49, -48, -47, -47, -46, -45, -44, -44,
+    -43, -42, -41, -41, -40, -39, -38, -38, -37, -36, -36, -35,
+    -35, -34, -33, -33, -32, -32, -31, -30, -30, -29, -29, -28,
+    -28, -27, -27, -26, -26, -25, -25, -24, -24, -23, -23, -22,
+    -22, -21, -21, -21, -20, -20, -19, -19, -19, -18, -18, -18,
+    -17, -17, -17, -16, -16, -16, -15, -15, -15, -14, -14, -14,
+    -13, -13, -13, -13, -12, -12, -12, -12, -11, -11, -11, -11,
+    -10, -10, -10, -10, -10,  -9,  -9,  -9,  -9,  -9,  -8,  -8,
+     -8,  -8,  -8,  -8,  -7,  -7,  -7,  -7,  -7,  -7,  -6,  -6,
+     -6,  -6,  -6,  -6,  -6,  -6,  -5,  -5,  -5,  -5,  -5,  -5,
+     -5,  -5,  -4,  -4,  -4,  -4,  -4,  -4,  -4,  -4,  -4,  -4,
+     -4,  -3,  -3,  -3,  -3,  -3,  -3,  -3,  -3,  -3,  -3,  -3,
+     -3,  -3,  -3,  -2,  -2,  -2,  -2,  -2,  -2,  -2,  -2,  -2,
+     -2,  -2,  -2,  -2,  -2,  -2,  -2,  -2,  -2,  -2,  -1,  -1,
+     -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+     -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+     -1,  -1,  -1,  -1,  -1,  -1,   0,   0,   0,   0,   0,   0,
+      0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+      0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+      0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+      0,   0,   0,   0
+};
+
+#define UPDATE_LEAK() 		\
+do {				\
+    fastleak += fdecay;		\
+    if (fastleak > psd + fgain)	\
+	fastleak = psd + fgain;	\
+    slowleak += sdecay;		\
+    if (slowleak > psd + sgain)	\
+	slowleak = psd + sgain;	\
+} while (0)
+
+#define COMPUTE_MASK()				\
+do {						\
+    if (psd > dbknee)				\
+	mask -= (psd - dbknee) >> 2;		\
+    if (mask > hth[i])				\
+	mask = hth[i];				\
+    if (deltba != NULL)				\
+	mask -= 128 * deltba[i];		\
+    mask -= snroffset;				\
+    mask = (mask > 0) ? 0 : ((-mask) >> 5);	\
+    mask -= floor;				\
+} while (0)
+
+void bit_allocate(int fscod, audblk_t * audblk, ac3_ba_t * ba,
+		  int bndstart, int start, int end, int fastleak, int slowleak,
+		  uint8_t * exp, int8_t * bap)
 {
-    return (a < b ? a : b);
-}
+    static int slowgain[4] = {0x540, 0x4d8, 0x478, 0x410};
+    static int dbpbtab[4]  = {0xc00, 0x500, 0x300, 0x100};
+    static int floortab[8] = {0x910, 0x950, 0x990, 0x9d0,
+			      0xa10, 0xa90, 0xb10, 0x1400};
 
-void bit_allocate(int fscod, audblk_t * audblk, ac3_ba_t * ba, uint16_t start,
-		  uint16_t end, int16_t fastleak, int16_t slowleak,
-		  uint8_t * exp, uint16_t * bap, int is_lfe)
-{
-    int16_t fgain;
-    uint16_t snroffset;
     int i, j;
-    int bndstrt;
-    int lowcomp;
-
-    /* Do some setup before we do the bit alloc */
-    sdecay = slowdec[audblk->sdcycod];
-    fdecay = fastdec[audblk->fdcycod];
+    int fdecay, fgain, sdecay, sgain, dbknee, floor, snroffset;
+    int psd, mask;
+    int8_t * deltba;
+    int * hth;
+
+    fdecay = 63 + 20 * audblk->fdcycod;
+    fgain = 128 + 128 * ba->fgaincod;
+    sdecay = 15 + 2 * audblk->sdcycod;
     sgain = slowgain[audblk->sgaincod];
     dbknee = dbpbtab[audblk->dbpbcod];
+    hth = hthtab[fscod];
+    deltba = (ba->deltbae == DELTA_BIT_NONE) ? NULL : ba->deltba;
     floor = floortab[audblk->floorcod];
+    snroffset = 960 - 64 * audblk->csnroffst - 4 * ba->fsnroffst + floor;
+    floor >>= 5;
 
-    fgain = fastgain[ba->fgaincod];
-    snroffset = 64 * audblk->csnroffst + 4 * ba->fsnroffst - 960;
-
-    i = start;
-    j = bndstrt = masktab[start];
-    do {
-	int psd, lastbin;
-
-	lastbin = min (bndtab[j] + bndsz[j], end);
-	psd = 128 * exp[i++];
-	while (i < lastbin) {
-	    int next, delta;
-
-	    next = 128 * exp[i++];
-	    delta = next - psd;
-	    switch (delta >> 9) {
-	    case -6: case -5: case -4: case -3: case -2:
-		psd = next;
-		break;
-	    case -1:
-		psd = next - latab[(-delta) >> 1];
-		break;
-	    case 0:
-		psd -= latab[delta >> 1];
-		break;
-	    }
-	}
-	bndpsd[j++] = 3072 - psd;
-    } while (i < end);
-
-    // j = bndend
-    j--;
+    i = bndstart;
+    j = start;
+    if (start == 0) {	// not the coupling channel
+	int lowcomp;
 
-    i = bndstrt;
-    lowcomp = 0;
-    if (i == 0) {	// not the coupling channel
+	lowcomp = 0;
+	j = end - 1;
 	do {
 	    if (i < j) {
-		if (bndpsd[i+1] == bndpsd[i] + 256)
+		if (exp[i+1] == exp[i] - 2)
 		    lowcomp = 384;
-		else if (lowcomp && (bndpsd[i+1] < bndpsd[i]))
+		else if (lowcomp && (exp[i+1] > exp[i]))
 		    lowcomp -= 64;
 	    }
-	    excite[i++] = bndpsd[i] - fgain - lowcomp;
-	} while ((i < 3) || ((i < 7) && (bndpsd[i] < bndpsd[i-1])));
-	fastleak = bndpsd[i-1] - fgain;
-	slowleak = bndpsd[i-1] - sgain;
+	    psd = 128 * exp[i];
+	    mask = psd + fgain + lowcomp;
+	    COMPUTE_MASK ();
+	    bap[i++] = (baptab+156)[mask + 4 * exp[i]];
+	} while ((i < 3) || ((i < 7) && (exp[i] > exp[i-1])));
+	fastleak = psd + fgain;
+	slowleak = psd + sgain;
 
 	while (i < 7) {
 	    if (i < j) {
-		if (bndpsd[i+1] == bndpsd[i] + 256)
+		if (exp[i+1] == exp[i] - 2)
 		    lowcomp = 384;
-		else if (lowcomp && (bndpsd[i+1] < bndpsd[i]))
+		else if (lowcomp && (exp[i+1] > exp[i]))
 		    lowcomp -= 64;
 	    }
-	    fastleak -= fdecay;
-	    if (fastleak < bndpsd[i] - fgain)
-		fastleak = bndpsd[i] - fgain;
-	    slowleak -= sdecay;
-	    if (slowleak < bndpsd[i] - sgain)
-		slowleak = bndpsd[i] - sgain;
-	    excite[i++] = ((fastleak - lowcomp > slowleak) ?
-			   fastleak - lowcomp : slowleak);
+	    psd = 128 * exp[i];
+	    UPDATE_LEAK ();
+	    mask = ((fastleak + lowcomp < slowleak) ?
+		    fastleak + lowcomp : slowleak);
+	    COMPUTE_MASK ();
+	    bap[i++] = (baptab+156)[mask + 4 * exp[i]];
 	}
-	if (i > j)	// lfe channel
-	    goto done_excite;
+
+	if (end == 7)	// lfe channel
+	    return;
 
 	do {
-	    if (bndpsd[i+1] == bndpsd[i] + 256)
+	    if (exp[i+1] == exp[i] - 2)
 		lowcomp = 320;
-	    else if (lowcomp && (bndpsd[i+1] < bndpsd[i]))
+	    else if (lowcomp && (exp[i+1] > exp[i]))
 		lowcomp -= 64;
-	    fastleak -= fdecay;
-	    if (fastleak < bndpsd[i] - fgain)
-		fastleak = bndpsd[i] - fgain;
-	    slowleak -= sdecay;
-	    if (slowleak < bndpsd[i] - sgain)
-		slowleak = bndpsd[i] - sgain;
-	    excite[i++] = ((fastleak - lowcomp > slowleak) ?
-			   fastleak - lowcomp : slowleak);
+	    psd = 128 * exp[i];
+	    UPDATE_LEAK ();
+	    mask = ((fastleak + lowcomp < slowleak) ?
+		    fastleak + lowcomp : slowleak);
+	    COMPUTE_MASK ();
+	    bap[i++] = (baptab+156)[mask + 4 * exp[i]];
 	} while (i < 20);
 
 	while (lowcomp > 128) {		// two iterations maximum
 	    lowcomp -= 128;
-	    fastleak -= fdecay;
-	    if (fastleak < bndpsd[i] - fgain)
-		fastleak = bndpsd[i] - fgain;
-	    slowleak -= sdecay;
-	    if (slowleak < bndpsd[i] - sgain)
-		slowleak = bndpsd[i] - sgain;
-	    excite[i++] = ((fastleak - lowcomp > slowleak) ?
-			   fastleak - lowcomp : slowleak);
+	    psd = 128 * exp[i];
+	    UPDATE_LEAK ();
+	    mask = ((fastleak + lowcomp < slowleak) ?
+		    fastleak + lowcomp : slowleak);
+	    COMPUTE_MASK ();
+	    bap[i++] = (baptab+156)[mask + 4 * exp[i]];
 	}
+	j = i;
     }
 
     do {
-	fastleak -= fdecay;
-	if (fastleak < bndpsd[i] - fgain)
-	    fastleak = bndpsd[i] - fgain;
-	slowleak -= sdecay;
-	if (slowleak < bndpsd[i] - sgain)
-	    slowleak = bndpsd[i] - sgain;
-	excite[i++] = (fastleak > slowleak) ? fastleak : slowleak;
-    } while (i <= j);
-
-done_excite:
-
-    ba_compute_mask(start, end, fscod, ba->deltbae, ba->deltnseg,
-		    ba->deltoffst, ba->deltba, ba->deltlen, excite, mask);
-    ba_compute_bap(start, end, snroffset, exp, mask, bap);
-}
-
-
-static void ba_compute_mask(int16_t start, int16_t end, uint16_t fscod,
-			    uint16_t deltbae, uint16_t deltnseg,
-			    uint16_t deltoffst[], uint16_t deltba[],
-			    uint16_t deltlen[], int16_t excite[],
-			    int16_t mask[])
-{
-    int bin,k;
-    int16_t bndstrt;
-    int16_t bndend;
-    int16_t delta;
-
-    bndstrt = masktab[start]; 
-    bndend = masktab[end - 1] + 1; 
-
-    /* Compute the masking curve */
-
-    for (bin = bndstrt; bin < bndend; bin++) { 
-	if (bndpsd[bin] < dbknee) 
-	    excite[bin] += ((dbknee - bndpsd[bin]) >> 2); 
-	mask[bin] = max(excite[bin], hth[fscod][bin]);
-    }
-	
-    /* Perform delta bit modulation if necessary */
-    if ((deltbae == DELTA_BIT_REUSE) || (deltbae == DELTA_BIT_NEW)) { 
-	int16_t band = 0; 
-	int16_t seg = 0; 
-		
-	for (seg = 0; seg < deltnseg+1; seg++) { 
-	    band += deltoffst[seg]; 
-	    if (deltba[seg] >= 4) 
-		delta = (deltba[seg] - 3) << 7;
-	    else 
-		delta = (deltba[seg] - 4) << 7;
-			
-	    for (k = 0; k < deltlen[seg]; k++) { 
-		mask[band] += delta; 
-		band++; 
-	    } 
-	} 
-    }
-}
-
-static void ba_compute_bap(int16_t start, int16_t end, int16_t snroffset,
-			   int8_t exps[], int16_t mask[], int16_t bap[])
-{
-    int i,j,k;
-    int16_t lastbin = 0;
-    int16_t address = 0;
+	int startband, endband;
 
-    /* Compute the bit allocation pointer for each bin */
-    i = start; 
-    j = masktab[start]; 
-
-    do { 
-	lastbin = min(bndtab[j] + bndsz[j], end); 
-	mask[j] -= snroffset; 
-	mask[j] -= floor; 
-		
-	if (mask[j] < 0) 
-	    mask[j] = 0; 
-
-	mask[j] &= 0x1fe0;
-	mask[j] += floor; 
-	for (k = i; k < lastbin; k++) { 
-	    address = (3072 - 128 * exps[i] - mask[j]) >> 5; 
-	    address = min(63, max(0, address)); 
-	    bap[i] = baptab[address]; 
-	    i++; 
-	} 
-	j++; 
-    } while (end > lastbin);
-}
+	startband = j;
+	endband = ((bndtab-20)[i] < end) ? (bndtab-20)[i] : end;
+	psd = 128 * exp[j++];
+	while (j < endband) {
+	    int next, delta;
 
-static int16_t calc_lowcomp(int16_t a,int16_t b0,int16_t b1,int16_t bin) 
-{
-    if (bin < 7) { 
-	if ((b0 + 256) == b1)
-	    a = 384; 
-	else if (b0 > b1) 
-	    a = max(0, a - 64); 
-    } else if (bin < 20) { 
-	if ((b0 + 256) == b1) 
-	    a = 320; 
-	else if (b0 > b1) 
-	    a = max(0, a - 64) ; 
-    } else  
-	a = max(0, a - 128); 
-	
-    return(a);
+	    next = 128 * exp[j++];
+	    delta = next - psd;
+	    switch (delta >> 9) {
+	    case -6: case -5: case -4: case -3: case -2:
+		psd = next;
+		break;
+	    case -1:
+		psd = next + latab[(-delta) >> 1];
+		break;
+	    case 0:
+		psd += latab[delta >> 1];
+		break;
+	    }
+	}
+	// minpsd = -289
+	UPDATE_LEAK ();
+	mask = (fastleak < slowleak) ? fastleak : slowleak;
+	COMPUTE_MASK ();
+	i++;
+	j = startband;
+	do {
+	    // max(mask+4*exp)=147=-(minpsd+fgain-deltba-snroffset)>>5+4*exp
+	    // min(mask+4*exp)=-156=-(sgain-deltba-snroffset)>>5
+	    bap[j++] = (baptab+156)[mask + 4 * exp[j]];
+	} while (j < endband);
+    } while (j < end);
 }
-
diff --git a/src/libac3/bit_allocate.h b/src/libac3/bit_allocate.h
index cdf73414a..089acc56c 100644
--- a/src/libac3/bit_allocate.h
+++ b/src/libac3/bit_allocate.h
@@ -21,6 +21,6 @@
  *
  */
 
-void bit_allocate(int fscod, audblk_t * audblk, ac3_ba_t * ba, uint16_t start,
-		  uint16_t end, int16_t fastleak, int16_t slowleak,
-		  uint8_t * exp, uint16_t * bap, int ls_lfe);
+void bit_allocate(int fscod, audblk_t * audblk, ac3_ba_t * ba,
+		  int bndstart, int start, int end, int fastleak, int slowleak,
+		  uint8_t * exp, int8_t * bap);
diff --git a/src/libac3/parse.c b/src/libac3/parse.c
index 0596eaa49..98b8cb6ac 100644
--- a/src/libac3/parse.c
+++ b/src/libac3/parse.c
@@ -24,7 +24,6 @@
 
 #include <stdlib.h>
 #include <stdio.h>
-#include <string.h>
 #include "ac3.h"
 #include "ac3_internal.h"
 
@@ -185,6 +184,30 @@ static int parse_exponents (int expstr, int ngrps, uint8_t exponent,
     return 0;
 }
 
+static int parse_deltba (int8_t * deltba)
+{
+    int deltnseg, deltlen, delta, j;
+
+    memset (deltba, 0, 50);
+
+    deltnseg = bitstream_get (3);
+    j = 0;
+    do {
+	j += bitstream_get (5);
+	deltlen = bitstream_get (4);
+	delta = bitstream_get (3);
+	delta -= (delta >= 4) ? 3 : 4;
+	if (!deltlen)
+	    continue;
+	if (j + deltlen >= 50)
+	    return 1;
+	while (deltlen--)
+	    deltba[j++] = delta;
+    } while (deltnseg--);
+
+    return 0;
+}
+
 static inline int zero_snr_offsets (ac3_state_t * state, audblk_t * audblk)
 {
     int i;
@@ -284,7 +307,7 @@ int parse_audblk (ac3_state_t * state, audblk_t * audblk)
 		audblk->endmant[i] = audblk->cplstrtmant;
 	    else {
 		audblk->chbwcod[i] = bitstream_get (6);
-		audblk->endmant[i] = ((audblk->chbwcod[i] + 12) * 3) + 37;
+		audblk->endmant[i] = audblk->chbwcod[i] * 3 + 73;
 	    }
 	}
 
@@ -358,25 +381,13 @@ int parse_audblk (ac3_state_t * state, audblk_t * audblk)
 	    audblk->cplba.deltbae = bitstream_get (2);
 	for (i = 0; i < state->nfchans; i++)
 	    audblk->ba[i].deltbae = bitstream_get (2);
-	if (audblk->cplinu && (audblk->cplba.deltbae == DELTA_BIT_NEW)) {
-	    audblk->cplba.deltnseg = bitstream_get (3);
-	    for (i = 0; i < audblk->cplba.deltnseg + 1; i++) {
-		audblk->cplba.deltoffst[i] = bitstream_get (5);
-		audblk->cplba.deltlen[i] = bitstream_get (4);
-		audblk->cplba.deltba[i] = bitstream_get (3);
-	    }
-	}
-	for (i = 0; i < state->nfchans; i++) {
-	    if (audblk->ba[i].deltbae == DELTA_BIT_NEW) {
-		int j;
-		audblk->ba[i].deltnseg = bitstream_get (3);
-		for (j = 0; j < audblk->ba[i].deltnseg + 1; j++) {
-		    audblk->ba[i].deltoffst[j] = bitstream_get (5);
-		    audblk->ba[i].deltlen[j] = bitstream_get (4);
-		    audblk->ba[i].deltba[j] = bitstream_get (3);
-		}
-	    }
-	}
+	if (audblk->cplinu && (audblk->cplba.deltbae == DELTA_BIT_NEW) &&
+	    parse_deltba (audblk->cplba.deltba))
+	    return 1;
+	for (i = 0; i < state->nfchans; i++)
+	    if ((audblk->ba[i].deltbae == DELTA_BIT_NEW) &&
+		parse_deltba (audblk->ba[i].deltba))
+		return 1;
     }
 
     if (do_bit_alloc) {
@@ -385,20 +396,24 @@ int parse_audblk (ac3_state_t * state, audblk_t * audblk)
 	    memset (audblk->fbw_bap, 0, sizeof (audblk->fbw_bap));
 	    memset (audblk->lfe_bap, 0, sizeof (audblk->lfe_bap));
 	} else {
+	    static int bndtab[16] = {31, 35, 37, 39, 41, 42, 43, 44,
+				     45, 45, 46, 46, 47, 47, 48, 48};
+
 	    if (audblk->cplinu)
 		bit_allocate (state->fscod, audblk, &audblk->cplba,
-			      audblk->cplstrtmant, audblk->cplendmant,
-			      (audblk->cplfleak << 8) + 768,
-			      (audblk->cplsleak << 8) + 768,
-			      audblk->cpl_exp, audblk->cpl_bap, 0);
+			      bndtab[audblk->cplbegf], audblk->cplstrtmant,
+			      audblk->cplendmant,
+			      2304 - (audblk->cplfleak << 8),
+			      2304 - (audblk->cplsleak << 8),
+			      audblk->cpl_exp, audblk->cpl_bap);
 	    for (i = 0; i < state->nfchans; i++)
-		bit_allocate (state->fscod, audblk, audblk->ba + i, 0,
+		bit_allocate (state->fscod, audblk, audblk->ba + i, 0, 0,
 			      audblk->endmant[i], 0, 0,
-			      audblk->fbw_exp[i], audblk->fbw_bap[i], 0);
+			      audblk->fbw_exp[i], audblk->fbw_bap[i]);
 	    if (state->lfeon) {
 		audblk->lfeba.deltbae = DELTA_BIT_NONE;
-		bit_allocate (state->fscod, audblk, &audblk->lfeba, 0, 7, 0, 0,
-			      audblk->lfe_exp, audblk->lfe_bap, 1);
+		bit_allocate (state->fscod, audblk, &audblk->lfeba, 0, 0, 7,
+			      0, 0, audblk->lfe_exp, audblk->lfe_bap);
 	    }
 	}
     }