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authorDiego Biurrun <diego@biurrun.de>2012-08-26 17:27:12 +0200
committerDiego Biurrun <diego@biurrun.de>2012-08-27 20:37:48 +0200
commit55498543354335697bf1c5616a2ba94c64fbdcf1 (patch)
tree45bdb9aa1848dbcaef84528b31f3fb4be2a3f309 /libavcodec/lsp.c
parent8f7c26e39297c8ecc8670a04936e47fbfc33439b (diff)
downloadffmpeg-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.c24
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;