libavcodec: Implementation of AC3 fixedpoint decoder

Signed-off-by: Nedeljko Babic <nbabic@mips.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 46 insertions, 0 deletions

diff --git a/libavcodec/ac3.h b/libavcodec/ac3.h
index 0cc9e2c98a..ac3936d7f3 100644
--- a/libavcodec/ac3.h
+++ b/libavcodec/ac3.h
@@ -51,6 +51,52 @@
 #define EXP_D25   2
 #define EXP_D45   3
 
+#ifndef CONFIG_AC3_FIXED
+#define CONFIG_AC3_FIXED 0
+#endif
+
+#if CONFIG_AC3_FIXED
+
+#define FFT_FLOAT 0
+
+#define FIXR(a)                 ((int)((a) * 0 + 0.5))
+#define FIXR12(a)               ((int)((a) * 4096 + 0.5))
+#define FIXR15(a)               ((int)((a) * 32768 + 0.5))
+#define ROUND15(x)              ((x) + 16384) >> 15
+
+#define AC3_RENAME(x)           x ## _fixed
+#define AC3_NORM(norm)          (1<<24)/(norm)
+#define AC3_MUL(a,b)            ((((int64_t) (a)) * (b))>>12)
+#define AC3_RANGE(x)            (x)
+#define AC3_DYNAMIC_RANGE(x)    (x)
+#define AC3_SPX_BLEND(x)        (x)
+#define AC3_DYNAMIC_RANGE1      0
+
+#define INTFLOAT                int
+#define SHORTFLOAT              int16_t
+
+#else /* CONFIG_AC3_FIXED */
+
+#define FIXR(x)                 ((float)(x))
+#define FIXR12(x)               ((float)(x))
+#define FIXR15(x)               ((float)(x))
+#define ROUND15(x)              (x)
+
+#define AC3_RENAME(x)           x
+#define AC3_NORM(norm)          (1.0f/(norm))
+#define AC3_MUL(a,b)            ((a) * (b))
+#define AC3_RANGE(x)            (dynamic_range_tab[(x)])
+#define AC3_DYNAMIC_RANGE(x)    (powf(x,  s->drc_scale))
+#define AC3_SPX_BLEND(x)        (x)* (1.0f/32)
+#define AC3_DYNAMIC_RANGE1      1.0f
+
+#define INTFLOAT                float
+#define SHORTFLOAT              float
+
+#endif /* CONFIG_AC3_FIXED */
+
+#define AC3_LEVEL(x)            ROUND15((x) * FIXR15(0.7071067811865476))
+
 /* pre-defined gain values */
 #define LEVEL_PLUS_3DB          1.4142135623730950
 #define LEVEL_PLUS_1POINT5DB    1.1892071150027209