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author | Diego Biurrun <diego@biurrun.de> | 2012-08-26 17:27:12 +0200 |
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committer | Diego Biurrun <diego@biurrun.de> | 2012-08-27 20:37:48 +0200 |
commit | 55498543354335697bf1c5616a2ba94c64fbdcf1 (patch) | |
tree | 45bdb9aa1848dbcaef84528b31f3fb4be2a3f309 /libavcodec/lsp.c | |
parent | 8f7c26e39297c8ecc8670a04936e47fbfc33439b (diff) | |
download | ffmpeg-55498543354335697bf1c5616a2ba94c64fbdcf1.tar.gz |
celp_math: Move ff_cos() to the only place it is used
Diffstat (limited to 'libavcodec/lsp.c')
-rw-r--r-- | libavcodec/lsp.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/libavcodec/lsp.c b/libavcodec/lsp.c index 2adc9cfa39..b501bfb7b8 100644 --- a/libavcodec/lsp.c +++ b/libavcodec/lsp.c @@ -55,6 +55,30 @@ void ff_set_min_dist_lsf(float *lsf, double min_spacing, int size) prev = lsf[i] = FFMAX(lsf[i], prev + min_spacing); } + +/* Cosine table: base_cos[i] = (1 << 15) * cos(i * PI / 64) */ +static const int16_t tab_cos[65] = +{ + 32767, 32738, 32617, 32421, 32145, 31793, 31364, 30860, + 30280, 29629, 28905, 28113, 27252, 26326, 25336, 24285, + 23176, 22011, 20793, 19525, 18210, 16851, 15451, 14014, + 12543, 11043, 9515, 7965, 6395, 4810, 3214, 1609, + 1, -1607, -3211, -4808, -6393, -7962, -9513, -11040, + -12541, -14012, -15449, -16848, -18207, -19523, -20791, -22009, + -23174, -24283, -25334, -26324, -27250, -28111, -28904, -29627, + -30279, -30858, -31363, -31792, -32144, -32419, -32616, -32736, -32768, +}; + +static int16_t ff_cos(uint16_t arg) +{ + uint8_t offset= arg; + uint8_t ind = arg >> 8; + + assert(arg <= 0x3fff); + + return tab_cos[ind] + (offset * (tab_cos[ind+1] - tab_cos[ind]) >> 8); +} + void ff_acelp_lsf2lsp(int16_t *lsp, const int16_t *lsf, int lp_order) { int i; |