diff options
Diffstat (limited to 'media/libstagefright/codecs/amrwbenc/src/math_op.c')
-rw-r--r-- | media/libstagefright/codecs/amrwbenc/src/math_op.c | 438 |
1 files changed, 219 insertions, 219 deletions
diff --git a/media/libstagefright/codecs/amrwbenc/src/math_op.c b/media/libstagefright/codecs/amrwbenc/src/math_op.c index 1c95ed0..1a7b513 100644 --- a/media/libstagefright/codecs/amrwbenc/src/math_op.c +++ b/media/libstagefright/codecs/amrwbenc/src/math_op.c @@ -1,219 +1,219 @@ -/*
- ** Copyright 2003-2010, VisualOn, Inc.
- **
- ** Licensed under the Apache License, Version 2.0 (the "License");
- ** you may not use this file except in compliance with the License.
- ** You may obtain a copy of the License at
- **
- ** http://www.apache.org/licenses/LICENSE-2.0
- **
- ** Unless required by applicable law or agreed to in writing, software
- ** distributed under the License is distributed on an "AS IS" BASIS,
- ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- ** See the License for the specific language governing permissions and
- ** limitations under the License.
- */
-
-/*___________________________________________________________________________
-| |
-| This file contains mathematic operations in fixed point. |
-| |
-| Isqrt() : inverse square root (16 bits precision). |
-| Pow2() : 2^x (16 bits precision). |
-| Log2() : log2 (16 bits precision). |
-| Dot_product() : scalar product of <x[],y[]> |
-| |
-| These operations are not standard double precision operations. |
-| They are used where low complexity is important and the full 32 bits |
-| precision is not necessary. For example, the function Div_32() has a |
-| 24 bits precision which is enough for our purposes. |
-| |
-| In this file, the values use theses representations: |
-| |
-| Word32 L_32 : standard signed 32 bits format |
-| Word16 hi, lo : L_32 = hi<<16 + lo<<1 (DPF - Double Precision Format) |
-| Word32 frac, Word16 exp : L_32 = frac << exp-31 (normalised format) |
-| Word16 int, frac : L_32 = int.frac (fractional format) |
-|___________________________________________________________________________|
-*/
-#include "typedef.h"
-#include "basic_op.h"
-#include "math_op.h"
-
-/*___________________________________________________________________________
-| |
-| Function Name : Isqrt |
-| |
-| Compute 1/sqrt(L_x). |
-| if L_x is negative or zero, result is 1 (7fffffff). |
-|---------------------------------------------------------------------------|
-| Algorithm: |
-| |
-| 1- Normalization of L_x. |
-| 2- call Isqrt_n(L_x, exponant) |
-| 3- L_y = L_x << exponant |
-|___________________________________________________________________________|
-*/
-Word32 Isqrt( /* (o) Q31 : output value (range: 0<=val<1) */
- Word32 L_x /* (i) Q0 : input value (range: 0<=val<=7fffffff) */
- )
-{
- Word16 exp;
- Word32 L_y;
- exp = norm_l(L_x);
- L_x = (L_x << exp); /* L_x is normalized */
- exp = (31 - exp);
- Isqrt_n(&L_x, &exp);
- L_y = (L_x << exp); /* denormalization */
- return (L_y);
-}
-
-/*___________________________________________________________________________
-| |
-| Function Name : Isqrt_n |
-| |
-| Compute 1/sqrt(value). |
-| if value is negative or zero, result is 1 (frac=7fffffff, exp=0). |
-|---------------------------------------------------------------------------|
-| Algorithm: |
-| |
-| The function 1/sqrt(value) is approximated by a table and linear |
-| interpolation. |
-| |
-| 1- If exponant is odd then shift fraction right once. |
-| 2- exponant = -((exponant-1)>>1) |
-| 3- i = bit25-b30 of fraction, 16 <= i <= 63 ->because of normalization. |
-| 4- a = bit10-b24 |
-| 5- i -=16 |
-| 6- fraction = table[i]<<16 - (table[i] - table[i+1]) * a * 2 |
-|___________________________________________________________________________|
-*/
-static Word16 table_isqrt[49] =
-{
- 32767, 31790, 30894, 30070, 29309, 28602, 27945, 27330, 26755, 26214,
- 25705, 25225, 24770, 24339, 23930, 23541, 23170, 22817, 22479, 22155,
- 21845, 21548, 21263, 20988, 20724, 20470, 20225, 19988, 19760, 19539,
- 19326, 19119, 18919, 18725, 18536, 18354, 18176, 18004, 17837, 17674,
- 17515, 17361, 17211, 17064, 16921, 16782, 16646, 16514, 16384
-};
-
-void Isqrt_n(
- Word32 * frac, /* (i/o) Q31: normalized value (1.0 < frac <= 0.5) */
- Word16 * exp /* (i/o) : exponent (value = frac x 2^exponent) */
- )
-{
- Word16 i, a, tmp;
-
- if (*frac <= (Word32) 0)
- {
- *exp = 0;
- *frac = 0x7fffffffL;
- return;
- }
-
- if((*exp & 1) == 1) /*If exponant odd -> shift right */
- *frac = (*frac) >> 1;
-
- *exp = negate((*exp - 1) >> 1);
-
- *frac = (*frac >> 9);
- i = extract_h(*frac); /* Extract b25-b31 */
- *frac = (*frac >> 1);
- a = (Word16)(*frac); /* Extract b10-b24 */
- a = (Word16) (a & (Word16) 0x7fff);
- i -= 16;
- *frac = L_deposit_h(table_isqrt[i]); /* table[i] << 16 */
- tmp = vo_sub(table_isqrt[i], table_isqrt[i + 1]); /* table[i] - table[i+1]) */
- *frac = vo_L_msu(*frac, tmp, a); /* frac -= tmp*a*2 */
-
- return;
-}
-
-/*___________________________________________________________________________
-| |
-| Function Name : Pow2() |
-| |
-| L_x = pow(2.0, exponant.fraction) (exponant = interger part) |
-| = pow(2.0, 0.fraction) << exponant |
-|---------------------------------------------------------------------------|
-| Algorithm: |
-| |
-| The function Pow2(L_x) is approximated by a table and linear |
-| interpolation. |
-| |
-| 1- i = bit10-b15 of fraction, 0 <= i <= 31 |
-| 2- a = bit0-b9 of fraction |
-| 3- L_x = table[i]<<16 - (table[i] - table[i+1]) * a * 2 |
-| 4- L_x = L_x >> (30-exponant) (with rounding) |
-|___________________________________________________________________________|
-*/
-static Word16 table_pow2[33] =
-{
- 16384, 16743, 17109, 17484, 17867, 18258, 18658, 19066, 19484, 19911,
- 20347, 20792, 21247, 21713, 22188, 22674, 23170, 23678, 24196, 24726,
- 25268, 25821, 26386, 26964, 27554, 28158, 28774, 29405, 30048, 30706,
- 31379, 32066, 32767
-};
-
-Word32 Pow2( /* (o) Q0 : result (range: 0<=val<=0x7fffffff) */
- Word16 exponant, /* (i) Q0 : Integer part. (range: 0<=val<=30) */
- Word16 fraction /* (i) Q15 : Fractionnal part. (range: 0.0<=val<1.0) */
- )
-{
- Word16 exp, i, a, tmp;
- Word32 L_x;
-
- L_x = vo_L_mult(fraction, 32); /* L_x = fraction<<6 */
- i = extract_h(L_x); /* Extract b10-b16 of fraction */
- L_x =L_x >> 1;
- a = (Word16)(L_x); /* Extract b0-b9 of fraction */
- a = (Word16) (a & (Word16) 0x7fff);
-
- L_x = L_deposit_h(table_pow2[i]); /* table[i] << 16 */
- tmp = vo_sub(table_pow2[i], table_pow2[i + 1]); /* table[i] - table[i+1] */
- L_x -= (tmp * a)<<1; /* L_x -= tmp*a*2 */
-
- exp = vo_sub(30, exponant);
- L_x = vo_L_shr_r(L_x, exp);
-
- return (L_x);
-}
-
-/*___________________________________________________________________________
-| |
-| Function Name : Dot_product12() |
-| |
-| Compute scalar product of <x[],y[]> using accumulator. |
-| |
-| The result is normalized (in Q31) with exponent (0..30). |
-|---------------------------------------------------------------------------|
-| Algorithm: |
-| |
-| dot_product = sum(x[i]*y[i]) i=0..N-1 |
-|___________________________________________________________________________|
-*/
-
-Word32 Dot_product12( /* (o) Q31: normalized result (1 < val <= -1) */
- Word16 x[], /* (i) 12bits: x vector */
- Word16 y[], /* (i) 12bits: y vector */
- Word16 lg, /* (i) : vector length */
- Word16 * exp /* (o) : exponent of result (0..+30) */
- )
-{
- Word16 sft;
- Word32 i, L_sum;
- L_sum = 0;
- for (i = 0; i < lg; i++)
- {
- L_sum += x[i] * y[i];
- }
- L_sum = (L_sum << 1) + 1;
- /* Normalize acc in Q31 */
- sft = norm_l(L_sum);
- L_sum = L_sum << sft;
- *exp = 30 - sft; /* exponent = 0..30 */
- return (L_sum);
-
-}
-
-
+/* + ** Copyright 2003-2010, VisualOn, Inc. + ** + ** Licensed under the Apache License, Version 2.0 (the "License"); + ** you may not use this file except in compliance with the License. + ** You may obtain a copy of the License at + ** + ** http://www.apache.org/licenses/LICENSE-2.0 + ** + ** Unless required by applicable law or agreed to in writing, software + ** distributed under the License is distributed on an "AS IS" BASIS, + ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + ** See the License for the specific language governing permissions and + ** limitations under the License. + */ + +/*___________________________________________________________________________ +| | +| This file contains mathematic operations in fixed point. | +| | +| Isqrt() : inverse square root (16 bits precision). | +| Pow2() : 2^x (16 bits precision). | +| Log2() : log2 (16 bits precision). | +| Dot_product() : scalar product of <x[],y[]> | +| | +| These operations are not standard double precision operations. | +| They are used where low complexity is important and the full 32 bits | +| precision is not necessary. For example, the function Div_32() has a | +| 24 bits precision which is enough for our purposes. | +| | +| In this file, the values use theses representations: | +| | +| Word32 L_32 : standard signed 32 bits format | +| Word16 hi, lo : L_32 = hi<<16 + lo<<1 (DPF - Double Precision Format) | +| Word32 frac, Word16 exp : L_32 = frac << exp-31 (normalised format) | +| Word16 int, frac : L_32 = int.frac (fractional format) | +|___________________________________________________________________________| +*/ +#include "typedef.h" +#include "basic_op.h" +#include "math_op.h" + +/*___________________________________________________________________________ +| | +| Function Name : Isqrt | +| | +| Compute 1/sqrt(L_x). | +| if L_x is negative or zero, result is 1 (7fffffff). | +|---------------------------------------------------------------------------| +| Algorithm: | +| | +| 1- Normalization of L_x. | +| 2- call Isqrt_n(L_x, exponant) | +| 3- L_y = L_x << exponant | +|___________________________________________________________________________| +*/ +Word32 Isqrt( /* (o) Q31 : output value (range: 0<=val<1) */ + Word32 L_x /* (i) Q0 : input value (range: 0<=val<=7fffffff) */ + ) +{ + Word16 exp; + Word32 L_y; + exp = norm_l(L_x); + L_x = (L_x << exp); /* L_x is normalized */ + exp = (31 - exp); + Isqrt_n(&L_x, &exp); + L_y = (L_x << exp); /* denormalization */ + return (L_y); +} + +/*___________________________________________________________________________ +| | +| Function Name : Isqrt_n | +| | +| Compute 1/sqrt(value). | +| if value is negative or zero, result is 1 (frac=7fffffff, exp=0). | +|---------------------------------------------------------------------------| +| Algorithm: | +| | +| The function 1/sqrt(value) is approximated by a table and linear | +| interpolation. | +| | +| 1- If exponant is odd then shift fraction right once. | +| 2- exponant = -((exponant-1)>>1) | +| 3- i = bit25-b30 of fraction, 16 <= i <= 63 ->because of normalization. | +| 4- a = bit10-b24 | +| 5- i -=16 | +| 6- fraction = table[i]<<16 - (table[i] - table[i+1]) * a * 2 | +|___________________________________________________________________________| +*/ +static Word16 table_isqrt[49] = +{ + 32767, 31790, 30894, 30070, 29309, 28602, 27945, 27330, 26755, 26214, + 25705, 25225, 24770, 24339, 23930, 23541, 23170, 22817, 22479, 22155, + 21845, 21548, 21263, 20988, 20724, 20470, 20225, 19988, 19760, 19539, + 19326, 19119, 18919, 18725, 18536, 18354, 18176, 18004, 17837, 17674, + 17515, 17361, 17211, 17064, 16921, 16782, 16646, 16514, 16384 +}; + +void Isqrt_n( + Word32 * frac, /* (i/o) Q31: normalized value (1.0 < frac <= 0.5) */ + Word16 * exp /* (i/o) : exponent (value = frac x 2^exponent) */ + ) +{ + Word16 i, a, tmp; + + if (*frac <= (Word32) 0) + { + *exp = 0; + *frac = 0x7fffffffL; + return; + } + + if((*exp & 1) == 1) /*If exponant odd -> shift right */ + *frac = (*frac) >> 1; + + *exp = negate((*exp - 1) >> 1); + + *frac = (*frac >> 9); + i = extract_h(*frac); /* Extract b25-b31 */ + *frac = (*frac >> 1); + a = (Word16)(*frac); /* Extract b10-b24 */ + a = (Word16) (a & (Word16) 0x7fff); + i -= 16; + *frac = L_deposit_h(table_isqrt[i]); /* table[i] << 16 */ + tmp = vo_sub(table_isqrt[i], table_isqrt[i + 1]); /* table[i] - table[i+1]) */ + *frac = vo_L_msu(*frac, tmp, a); /* frac -= tmp*a*2 */ + + return; +} + +/*___________________________________________________________________________ +| | +| Function Name : Pow2() | +| | +| L_x = pow(2.0, exponant.fraction) (exponant = interger part) | +| = pow(2.0, 0.fraction) << exponant | +|---------------------------------------------------------------------------| +| Algorithm: | +| | +| The function Pow2(L_x) is approximated by a table and linear | +| interpolation. | +| | +| 1- i = bit10-b15 of fraction, 0 <= i <= 31 | +| 2- a = bit0-b9 of fraction | +| 3- L_x = table[i]<<16 - (table[i] - table[i+1]) * a * 2 | +| 4- L_x = L_x >> (30-exponant) (with rounding) | +|___________________________________________________________________________| +*/ +static Word16 table_pow2[33] = +{ + 16384, 16743, 17109, 17484, 17867, 18258, 18658, 19066, 19484, 19911, + 20347, 20792, 21247, 21713, 22188, 22674, 23170, 23678, 24196, 24726, + 25268, 25821, 26386, 26964, 27554, 28158, 28774, 29405, 30048, 30706, + 31379, 32066, 32767 +}; + +Word32 Pow2( /* (o) Q0 : result (range: 0<=val<=0x7fffffff) */ + Word16 exponant, /* (i) Q0 : Integer part. (range: 0<=val<=30) */ + Word16 fraction /* (i) Q15 : Fractionnal part. (range: 0.0<=val<1.0) */ + ) +{ + Word16 exp, i, a, tmp; + Word32 L_x; + + L_x = vo_L_mult(fraction, 32); /* L_x = fraction<<6 */ + i = extract_h(L_x); /* Extract b10-b16 of fraction */ + L_x =L_x >> 1; + a = (Word16)(L_x); /* Extract b0-b9 of fraction */ + a = (Word16) (a & (Word16) 0x7fff); + + L_x = L_deposit_h(table_pow2[i]); /* table[i] << 16 */ + tmp = vo_sub(table_pow2[i], table_pow2[i + 1]); /* table[i] - table[i+1] */ + L_x -= (tmp * a)<<1; /* L_x -= tmp*a*2 */ + + exp = vo_sub(30, exponant); + L_x = vo_L_shr_r(L_x, exp); + + return (L_x); +} + +/*___________________________________________________________________________ +| | +| Function Name : Dot_product12() | +| | +| Compute scalar product of <x[],y[]> using accumulator. | +| | +| The result is normalized (in Q31) with exponent (0..30). | +|---------------------------------------------------------------------------| +| Algorithm: | +| | +| dot_product = sum(x[i]*y[i]) i=0..N-1 | +|___________________________________________________________________________| +*/ + +Word32 Dot_product12( /* (o) Q31: normalized result (1 < val <= -1) */ + Word16 x[], /* (i) 12bits: x vector */ + Word16 y[], /* (i) 12bits: y vector */ + Word16 lg, /* (i) : vector length */ + Word16 * exp /* (o) : exponent of result (0..+30) */ + ) +{ + Word16 sft; + Word32 i, L_sum; + L_sum = 0; + for (i = 0; i < lg; i++) + { + L_sum += x[i] * y[i]; + } + L_sum = (L_sum << 1) + 1; + /* Normalize acc in Q31 */ + sft = norm_l(L_sum); + L_sum = L_sum << sft; + *exp = 30 - sft; /* exponent = 0..30 */ + return (L_sum); + +} + + |