From 65e33d8e23277bb96809842656482e0e3fe8746f Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 10 Dec 2016 02:03:43 +0100 Subject: [PATCH] swresample/resample_template: Add filter values in parallel This is faster 2871 -> 2189 cycles for int16 matrixbench -> 23456hz Fixes a integer overflow in a artificial corner case Fixes part of 668007-media Found-by: Matt Wolenetz Signed-off-by: Michael Niedermayer --- libswresample/resample_template.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/libswresample/resample_template.c b/libswresample/resample_template.c index 31cf3500ab..4c227b9940 100644 --- a/libswresample/resample_template.c +++ b/libswresample/resample_template.c @@ -104,12 +104,20 @@ static int RENAME(resample_common)(ResampleContext *c, for (dst_index = 0; dst_index < n; dst_index++) { FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index; - FELEM2 val= FOFFSET; + FELEM2 val = FOFFSET; + FELEM2 val2= 0; int i; - for (i = 0; i < c->filter_length; i++) { - val += src[sample_index + i] * (FELEM2)filter[i]; + for (i = 0; i + 1 < c->filter_length; i+=2) { + val += src[sample_index + i ] * (FELEM2)filter[i ]; + val2 += src[sample_index + i + 1] * (FELEM2)filter[i + 1]; } - OUT(dst[dst_index], val); + if (i < c->filter_length) + val += src[sample_index + i ] * (FELEM2)filter[i ]; +#ifdef FELEML + OUT(dst[dst_index], val + (FELEML)val2); +#else + OUT(dst[dst_index], val + val2); +#endif frac += c->dst_incr_mod; index += c->dst_incr_div;