On Thu, 16 Mar 2017 17:00:17 +0700
Muhammad Faiz <mfc...@gmail.com> wrote:
> On Thu, Mar 16, 2017 at 1:01 PM, wm4 <nfx...@googlemail.com> wrote:
> > On Thu, 16 Mar 2017 12:43:10 +0700
> > Muhammad Faiz <mfc...@gmail.com> wrote:
> >
> >> use fltp when doing s32 -> s32 resampling
> >> because s32p has no simd optimization
> >>
> >> benchmark:
> >> old 17.913s
> >> new 7.584s (use fma3)
> >>
> >> Signed-off-by: Muhammad Faiz <mfc...@gmail.com>
> >> ---
> >> libswresample/swresample.c | 2 ++
> >> 1 file changed, 2 insertions(+)
> >>
> >> diff --git a/libswresample/swresample.c b/libswresample/swresample.c
> >> index f2e6600..74c96dc 100644
> >> --- a/libswresample/swresample.c
> >> +++ b/libswresample/swresample.c
> >> @@ -223,6 +223,8 @@ av_cold int swr_init(struct SwrContext *s){
> >> }else if( av_get_planar_sample_fmt(s-> in_sample_fmt) ==
> >> AV_SAMPLE_FMT_S32P
> >> && av_get_planar_sample_fmt(s->out_sample_fmt) ==
> >> AV_SAMPLE_FMT_S32P
> >> && !s->rematrix
> >> + && s->out_sample_rate == s->in_sample_rate
> >> + && !(s->flags & SWR_FLAG_RESAMPLE)
> >> && s->engine != SWR_ENGINE_SOXR){
> >> s->int_sample_fmt= AV_SAMPLE_FMT_S32P;
> >> }else if(av_get_bytes_per_sample(s->in_sample_fmt) <= 4){
> >
> > Wouldn't going over float lose bits?
>
> Yes, of course. But when resampling with default opt, aliasing happens at
> about -90dB which is only 15 bits. Keeping 32 bits has no point at all.
>
> > I guess most times, s32 is
> > actually 24 bit padded (since we have no 24 bit format). But it could
> > be true 32 bit as well (with all bits used). Or does it use double, or
> > am I missing something else?
>
> Using double is overkill, i think.
From my naive point of view this seems ok, then.
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