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author | Justin Ruggles <justin.ruggles@gmail.com> | 2011-02-13 22:49:50 +0300 |
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committer | Michael Niedermayer <michaelni@gmx.at> | 2011-02-15 01:58:20 +0300 |
commit | 7539a1fee2c4935eb3318d625f881df85f2c9c04 (patch) | |
tree | 79b531353a0c98dc0268ac0bc985284042f7236d /libavcodec/ac3dsp.h | |
parent | e590448c65b7f9cd1a9bcf39ee6874882034edc9 (diff) |
ac3enc: Add x86-optimized function to speed up log2_tab().
AC3DSPContext.ac3_max_msb_abs_int16() finds the maximum MSB of the absolute
value of each element in an array of int16_t.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
(cherry picked from commit fbb6b49dabc3398440c6dfa838aa090a7a6ebc0d)
Diffstat (limited to 'libavcodec/ac3dsp.h')
-rw-r--r-- | libavcodec/ac3dsp.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/libavcodec/ac3dsp.h b/libavcodec/ac3dsp.h index 7f13b11f3b..a4f141f2f5 100644 --- a/libavcodec/ac3dsp.h +++ b/libavcodec/ac3dsp.h @@ -35,6 +35,17 @@ typedef struct AC3DSPContext { * @param nb_coefs number of frequency coefficients. */ void (*ac3_exponent_min)(uint8_t *exp, int num_reuse_blocks, int nb_coefs); + + /** + * Calculate the maximum MSB of the absolute value of each element in an + * array of int16_t. + * @param src input array + * constraints: align 16. values must be in range [-32767,32767] + * @param len number of values in the array + * constraints: multiple of 16 greater than 0 + * @return a value with the same MSB as max(abs(src[])) + */ + int (*ac3_max_msb_abs_int16)(const int16_t *src, int len); } AC3DSPContext; void ff_ac3dsp_init (AC3DSPContext *c); |