From eb768a75f8a0b347ab0f84c2c68959f5dbde6d4b Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 23 Apr 2023 23:51:38 +0200 Subject: [PATCH] avcodec/apedec: Move pointer instead of copying each element in delay in long_filter_high_3800() ~1000 -> 930 cycles Signed-off-by: Michael Niedermayer --- libavcodec/apedec.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c index c08d13d6c2..40cd78a991 100644 --- a/libavcodec/apedec.c +++ b/libavcodec/apedec.c @@ -944,7 +944,7 @@ static void long_filter_high_3800(int32_t *buffer, int order, int shift, int len { int i, j; int32_t dotprod, sign; - int32_t coeffs[256], delay[256]; + int32_t coeffs[256], delay[256+256], *delayp = delay; if (order >= length) return; @@ -956,13 +956,16 @@ static void long_filter_high_3800(int32_t *buffer, int order, int shift, int len dotprod = 0; sign = APESIGN(buffer[i]); for (j = 0; j < order; j++) { - dotprod += delay[j] * (unsigned)coeffs[j]; - coeffs[j] += ((delay[j] >> 31) | 1) * sign; + dotprod += delayp[j] * (unsigned)coeffs[j]; + coeffs[j] += ((delayp[j] >> 31) | 1) * sign; } buffer[i] -= (unsigned)(dotprod >> shift); - for (j = 0; j < order - 1; j++) - delay[j] = delay[j + 1]; - delay[order - 1] = buffer[i]; + delayp ++; + delayp[order - 1] = buffer[i]; + if (delayp - delay == 256) { + memcpy(delay, delayp, sizeof(*delay)*256); + delayp = delay; + } } }