swresample/resample_template: try to consider src_size more exactly

This should avoid slight differences in the output causes by input
size alignment differences between archs

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libswresample/resample_template.c

@@ -106,7 +106,9 @@ int RENAME(swri_resample)(ResampleContext *c, DELEM *dst, const DELEM *src, int
     if(compensation_distance == 0 && c->filter_length == 1 && c->phase_shift==0){
         int64_t index2= (1LL<<32)*c->frac/c->src_incr + (1LL<<32)*index;
         int64_t incr= (1LL<<32) * c->dst_incr / c->src_incr;
-        dst_size= FFMIN(dst_size, (src_size-1-index) * (int64_t)c->src_incr / c->dst_incr);
+        int new_size = (src_size * (int64_t)c->src_incr - frac + c->dst_incr - 1) / c->dst_incr;
+
+        dst_size= FFMIN(dst_size, new_size);
 
         for(dst_index=0; dst_index < dst_size; dst_index++){
             dst[dst_index] = src[index2>>32];

tests/fate/libswresample.mak

@@ -326,13 +326,13 @@ fate-swr-resample_nn-$(3)-$(1)-$(2): REF = tests/data/asynth-$(1)-1.wav
 fate-swr-resample_nn-fltp-44100-8000: CMP_TARGET = 590.98
 fate-swr-resample_nn-fltp-44100-8000: SIZE_TOLERANCE = 529200 - 20486
 
-fate-swr-resample_nn-fltp-8000-44100: CMP_TARGET = 3163.03
+fate-swr-resample_nn-fltp-8000-44100: CMP_TARGET = 3163.32
 fate-swr-resample_nn-fltp-8000-44100: SIZE_TOLERANCE = 96000 - 20480
 
 fate-swr-resample_nn-s16p-44100-8000: CMP_TARGET = 590.97
 fate-swr-resample_nn-s16p-44100-8000: SIZE_TOLERANCE = 529200 - 20486
 
-fate-swr-resample_nn-s16p-8000-44100: CMP_TARGET = 3163.10
+fate-swr-resample_nn-s16p-8000-44100: CMP_TARGET = 3163.39
 fate-swr-resample_nn-s16p-8000-44100: SIZE_TOLERANCE = 96000 - 20480
 endef