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Housekeeping for libwmapro. Define some multiple used constants, use more precise value for cos(pi/4).

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27644 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Andree Buschmann 2010-07-31 21:07:17 +00:00
parent 8be79a22fd
commit f971deed6d
1 changed files with 25 additions and 20 deletions
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35
apps/codecs/libwmapro/wmaprodec.c
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@ -124,6 +124,11 @@
#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
/* Define some multiple used constants */
#define SQRT2_FRACT24 0x016A09E6 /* 0x016A09E6 = (sqrt(2)*(1<<24)) */
#define COS_PI4_FRACT16 0x0000B505 /* 0x0000B505 = (cos(pi/4)<<16) */
#define ONE_FRACT16 0x00010000 /* 0x00010000 = (1<<16) */
/* Enable multichannel for large-memory targets only */
#if (MEMORYSIZE > 2)
#define WMAPRO_MAX_CHANNELS 8 ///< max number of handled channels
@ -646,9 +651,9 @@ static void decode_decorrelation_matrix(WMAProDecodeCtx *s,
get_bits1(&s->gb) ? 1.0 : -1.0;
if(chgroup->decorrelation_matrix[chgroup->num_channels * i + i] > 0)
chgroup->fixdecorrelation_matrix[chgroup->num_channels * i + i] = 0x10000;
chgroup->fixdecorrelation_matrix[chgroup->num_channels * i + i] = ONE_FRACT16;
else
chgroup->fixdecorrelation_matrix[chgroup->num_channels * i + i] = -0x10000;
chgroup->fixdecorrelation_matrix[chgroup->num_channels * i + i] = -ONE_FRACT16;
}
for (i = 1; i < chgroup->num_channels; i++) {
@ -754,16 +759,16 @@ static int decode_channel_transform(WMAProDecodeCtx* s)
} else {
chgroup->transform = 1;
if (s->num_channels == 2) {
chgroup->fixdecorrelation_matrix[0] = 0x10000;
chgroup->fixdecorrelation_matrix[1] = -0x10000;
chgroup->fixdecorrelation_matrix[2] = 0x10000;
chgroup->fixdecorrelation_matrix[3] = 0x10000;
chgroup->fixdecorrelation_matrix[0] = ONE_FRACT16;
chgroup->fixdecorrelation_matrix[1] = -ONE_FRACT16;
chgroup->fixdecorrelation_matrix[2] = ONE_FRACT16;
chgroup->fixdecorrelation_matrix[3] = ONE_FRACT16;
} else {
/** cos(pi/4) */
chgroup->fixdecorrelation_matrix[0] = 0xB500;
chgroup->fixdecorrelation_matrix[1] = -0xB500;
chgroup->fixdecorrelation_matrix[2] = 0xB500;
chgroup->fixdecorrelation_matrix[3] = 0xB500;
chgroup->fixdecorrelation_matrix[0] = COS_PI4_FRACT16;
chgroup->fixdecorrelation_matrix[1] = -COS_PI4_FRACT16;
chgroup->fixdecorrelation_matrix[2] = COS_PI4_FRACT16;
chgroup->fixdecorrelation_matrix[3] = COS_PI4_FRACT16;
}
}
} else if (chgroup->num_channels > 2) {
@ -867,10 +872,10 @@ static int decode_coeffs(WMAProDecodeCtx *s, int c)
}
}
} else {
vals[0] = symbol_to_vec4[idx] >> 12;
vals[0] = (symbol_to_vec4[idx] >> 12);
vals[1] = (symbol_to_vec4[idx] >> 8) & 0xF;
vals[2] = (symbol_to_vec4[idx] >> 4) & 0xF;
vals[3] = symbol_to_vec4[idx] & 0xF;
vals[3] = (symbol_to_vec4[idx] ) & 0xF;
}
/** decode sign */
@ -1042,14 +1047,14 @@ static void inverse_channel_transform(WMAProDecodeCtx *s)
}
} else if (s->num_channels == 2) {
/* Scale with sqrt(2). 0x016A09E6 = (sqrt(2)*(1<<24)) */
/* Scale with sqrt(2) */
int len = FFMIN(sfb[1], s->subframe_len) - sfb[0];
vector_fixmul_scalar(ch_data[0] + sfb[0],
ch_data[0] + sfb[0],
0x016A09E6, len);
SQRT2_FRACT24, len);
vector_fixmul_scalar(ch_data[1] + sfb[0],
ch_data[1] + sfb[0],
0x016A09E6, len);
SQRT2_FRACT24, len);
}
}